Re: [Emc-users] [Off] Ballscrew Support?
Since we are a wood shop, and don't have any real metal working capabilities I didn't really consider it a viable option. I believe that the manufacturer has redesigned the drive train since these were built, due in part to our input. We plan to retrofit, at our next rebuild. Todd Zuercher P. Graham Dunn Inc. 630 Henry Street Dalton, Ohio 44618 Phone: (330)828-2105ext. 2031 -- P. Graham Dunn Phone: 330-828-2105 E-mail: to...@pgrahamdunn.com 630 Henry St. Dalton, OH 44618 www.pgrahamdunn.com -Original Message- From: Viesturs Lācis [mailto:viesturs.la...@gmail.com] Sent: Monday, July 23, 2012 4:07 PM To: Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] [Off] Ballscrew Support? 2012/7/23 Todd Zuercher to...@pgrahamdunn.com: Our first of these two machines actually had the racks and pinions replaced while still under factory warranty. We are only cutting MDF with them (just lots of it). The flaws I see with the machines are, spring loaded engagement of the pinion to rack, (lets pinion pull out of rack under heavy loads (like rapid accel), support bearings for the pinions and transmission shafts are to close together and overloaded. I don't want to start dissing the Manufacturer they have stood behind the product, the machine design just isn't well suited for us and our application. Just out of curiousity: have You considered rebuilding it, making that shaft longer and increasing distance between bearings and even put stronger bearings there? I am sure that in longer term it would provide cost savings - less downtime, less parts to replace etc. -- Viesturs If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
Greetings, So I just got a response from my ballscrew vendor. They can supply a 40mm diameter with 40mm pitch (3048 mm long) for a reasonable cost. Less than $1k including shipping and machining. Looks like that could safely rotate at 977 RPM which would move the ballnut at 1538 IPM (with both ends supported with double bearings spaced apart). Even though it will cost me additional money, it may cost less (not to mention significant time/experimentation/etc) compared to machining the required hardware to drive the ballnut with my current ballscrews. Also, seems like rotating the ballscrew can be problematic - I read at sufficient RPM's the lubrication can driven away from the ballscew from centrifugal force. I was planning on having a ballscrew for each rail, but if I go this route I think I will only have a single ballscrew in the middle of both rails. The main reason (besides cost) is the significant inertia the ballscrew will have rotating at speed. Cheers, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Sun, Jul 22, 2012 at 6:25 PM, Jeshua Lacock jes...@3dtopo.com wrote: Dunno why they said that, I've been running the rack and pinion for a few years now, as have quite a few others on their machines, and the rack and pinion works just fine. No resonance, though that's usually a factor of the stepper motor and drive, and there are ways to dampen the resonance so that it's a non-factor. I like the very minimal amount of backlash, and very positive gear engagement in my setup. Thanks Mark, good to know! Cheers, Jeshua Lacock Jeshua, Yeah, don't know why they said that, unless they had a poorly designed rack and pinion system. I got mine from CNC Router parts and Boston Gear for the rack. Not terribly expensive either, and Boston Gear doesn't mind working with the little guys like us. I'll have to dig up my contact point at Boston Gear. She was very knowledgeable and very good at taking care of customer service. I think I have her name and email address at home somewhere. Can't seem to find it here at work. Mark -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
It may depend a lot on how well the machine is designed around the rack. We have two moving gantry 5x10ft routers that have been no end of a maintenance nightmare for me, because of their rack and pinion design. Since 2005 I have had to replace 2 sets of racks 4 sets of pinions, and countless bearings, and transmission shafts in the drive train for the rack and pinion on each machine. And the quality of the cut at federates above 200ipm leaves much to be desired compared to our similarly sized and specked ball screw driven machines. To give them credit we are using them much harder than they were designed for, we run'em 24hr 5 days a week, and have more than twice as many machining hours on them than any other machine the manufacturer knows of. Todd Zuercher P. Graham Dunn Inc. 630 Henry Street Dalton, Ohio 44618 Phone: (330)828-2105ext. 2031 -- P. Graham Dunn Phone: 330-828-2105 E-mail: to...@pgrahamdunn.com 630 Henry St. Dalton, OH 44618 www.pgrahamdunn.com -Original Message- From: Mark Wendt [mailto:wendt.m...@gmail.com] Sent: Sunday, July 22, 2012 7:46 AM To: Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] [Off] Ballscrew Support? On Sat, Jul 21, 2012 at 8:38 PM, Jeshua Lacock jes...@3dtopo.com wrote: snippage Of course, you could also just go the rack-and-pinion route. The rack teeth should point down to shed dirt and chips. I don't recall the specifics, but I read somewhere that rack-and-pinon was not a good solution. Maybe it had something to do with resonance? Cheers, Jeshua Lacock Dunno why they said that, I've been running the rack and pinion for a few years now, as have quite a few others on their machines, and the rack and pinion works just fine. No resonance, though that's usually a factor of the stepper motor and drive, and there are ways to dampen the resonance so that it's a non-factor. I like the very minimal amount of backlash, and very positive gear engagement in my setup. Mark -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
2012/7/23 Todd Zuercher to...@pgrahamdunn.com: And the quality of the cut at federates above 200ipm leaves much to be desired compared to our similarly sized and specked ball screw driven machines. To give them credit we are using them much harder than they were designed for, we run'em 24hr 5 days a week, and have more than twice as many machining hours on them than any other machine the manufacturer knows of. Well, the last sentence explains it all. Machine is 7 years old, so it means - life of racks is about 2-3 years. IMHO that is not bad, especially, when You mention the conditions of their use. And I am sure, that You know - running ballscrews over their rated load would lead to the same result. Just that ballscrews could have higher rated load... I have racks and pinions in waterjet machine, they work very nice. I like them, because their maintenance is something I can do myself. I would not like to start changing balls in ballscrew or something like that... -- Viesturs If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On 07/23/2012 03:05 AM, Jeshua Lacock wrote: So I just got a response from my ballscrew vendor. They can supply a 40mm diameter with 40mm pitch (3048 mm long) for a reasonable cost. Less than $1k including shipping and machining. Looks like that could safely rotate at 977 RPM which would move the ballnut at 1538 IPM (with both ends supported with double bearings spaced apart). I have been impressed by the white paper for the PCNC1100, and since you're aiming for very high rapids, and since this white paper has some very good information, I recommend reading it, and all their white papers. Some of the folks on this list could probably vouch for their veracity, I just didn't find any clear errors in their analysis. http://www.tormach.com/engineering_pcnc1100.html I think I'd like to own one of these some day. -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On 22 July 2012 23:32, Jeshua Lacock jes...@3dtopo.com wrote: Has anyone successfully machined the parts required? A variant, yes: https://picasaweb.google.com/lh/photo/9gDwFeKRO-e7uH17gD0ru9MTjNZETYmyPJy0liipFm0?feat=directlink https://picasaweb.google.com/lh/photo/codwX5WaHkHyyW76-J-GxtMTjNZETYmyPJy0liipFm0?feat=directlink -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
Our first of these two machines actually had the racks and pinions replaced while still under factory warranty. We are only cutting MDF with them (just lots of it). The flaws I see with the machines are, spring loaded engagement of the pinion to rack, (lets pinion pull out of rack under heavy loads (like rapid accel), support bearings for the pinions and transmission shafts are to close together and overloaded. I don't want to start dissing the Manufacturer they have stood behind the product, the machine design just isn't well suited for us and our application. Todd Zuercher P. Graham Dunn Inc. 630 Henry Street Dalton, Ohio 44618 Phone: (330)828-2105ext. 2031 -- P. Graham Dunn Phone: 330-828-2105 E-mail: to...@pgrahamdunn.com 630 Henry St. Dalton, OH 44618 www.pgrahamdunn.com -Original Message- From: Viesturs Lācis [mailto:viesturs.la...@gmail.com] Sent: Monday, July 23, 2012 9:28 AM To: Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] [Off] Ballscrew Support? 2012/7/23 Todd Zuercher to...@pgrahamdunn.com: And the quality of the cut at federates above 200ipm leaves much to be desired compared to our similarly sized and specked ball screw driven machines. To give them credit we are using them much harder than they were designed for, we run'em 24hr 5 days a week, and have more than twice as many machining hours on them than any other machine the manufacturer knows of. Well, the last sentence explains it all. Machine is 7 years old, so it means - life of racks is about 2-3 years. IMHO that is not bad, especially, when You mention the conditions of their use. And I am sure, that You know - running ballscrews over their rated load would lead to the same result. Just that ballscrews could have higher rated load... I have racks and pinions in waterjet machine, they work very nice. I like them, because their maintenance is something I can do myself. I would not like to start changing balls in ballscrew or something like that... -- Viesturs If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
2012/7/23 Todd Zuercher to...@pgrahamdunn.com: Our first of these two machines actually had the racks and pinions replaced while still under factory warranty. We are only cutting MDF with them (just lots of it). The flaws I see with the machines are, spring loaded engagement of the pinion to rack, (lets pinion pull out of rack under heavy loads (like rapid accel), support bearings for the pinions and transmission shafts are to close together and overloaded. I don't want to start dissing the Manufacturer they have stood behind the product, the machine design just isn't well suited for us and our application. Just out of curiousity: have You considered rebuilding it, making that shaft longer and increasing distance between bearings and even put stronger bearings there? I am sure that in longer term it would provide cost savings - less downtime, less parts to replace etc. -- Viesturs If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On 22 July 2012 03:16, John Kasunich jmkasun...@fastmail.fm wrote: The main problem is that force is transferred between belts by only one or two teeth - the ones directly under the idler pulleys. Making the idler pulleys as large as possible would improve that a bit. The Bell-Everman version has two rollers on each side so there are several teeth in mesh. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
I'm using their kit on my bamboo CNC saw beveler, with the rack purchased from Boston Gears. The setup was pretty easy, and the rack and pinion is working great on the machine. Mark On Sat, Jul 21, 2012 at 8:34 PM, Greg Bernard yankeelena2...@yahoo.comwrote: Have you considered rack and pinion for your machine. CNCrouterparts has a very affordable solution: http://www.cncrouterparts.com/rack-and-pinion-drive-nema-34-p-80.htmlI'venot used them but they have gotten good reviews from users at CNCzone and I've been happy with other components of theirs I've used on my machine. +++ We are like tenant farmers chopping down the fence around our house for fuel when we should be using Nature's inexhaustible sources of energy -- sun, wind and tide. ... I'd put my money on the sun and solar energy. What a source of power! I hope we don't have to wait until oil and coal run out before we tackle that. -Thomas Edison, inventor (1847-1931) -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
Neither, of our 5x10 routers have any support on the long table screws (12 ft long). But they are large diameter screws, secured, fixed and stretched in position with a rotating nut moving the table. I think rotating the nut rather than the screw helps a lot with wip. Todd Zuercher P. Graham Dunn Inc. 630 Henry Street Dalton, Ohio 44618 Phone: (330)828-2105ext. 2031 -- P. Graham Dunn Phone: 330-828-2105 E-mail: to...@pgrahamdunn.com 630 Henry St. Dalton, OH 44618 www.pgrahamdunn.com -Original Message- From: Jeshua Lacock [mailto:jes...@3dtopo.com] Sent: Friday, July 20, 2012 6:19 PM To: Enhanced Machine Controller (EMC) Subject: [Emc-users] [Off] Ballscrew Support? Greetings, I am upgrading my machine to handle a full 4x8 foot board of material (and 5 feet of Z!). The new table is 5x9 feet. I just received my 3-meter 25mm supported rails and 25mm C7 ballscrews. I am sure with a 10-foot span that the horizontal ballscrews will sag a little from gravity. Is this much of a concern? Does anyone know of a trick to put some kind of support in the middle of the span? I can't think of any practical way. Thanks! Best, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
Todd Zuercher wrote: Neither, of our 5x10 routers have any support on the long table screws (12 ft long). But they are large diameter screws, secured, fixed and stretched in position with a rotating nut moving the table. I think rotating the nut rather than the screw helps a lot with wip. Well, it completely removes it, in fact! If the nut is not perfectly centered, the screw may vibrate slightly, but it won't do anything terrible. When the screw is spinning fast, the vibration can build to very large amplitude very quickly and permanently bend the screw. Jon -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Jul 22, 2012, at 5:45 AM, Mark Wendt wrote: Of course, you could also just go the rack-and-pinion route. The rack teeth should point down to shed dirt and chips. I don't recall the specifics, but I read somewhere that rack-and-pinon was not a good solution. Maybe it had something to do with resonance? Dunno why they said that, I've been running the rack and pinion for a few years now, as have quite a few others on their machines, and the rack and pinion works just fine. No resonance, though that's usually a factor of the stepper motor and drive, and there are ways to dampen the resonance so that it's a non-factor. I like the very minimal amount of backlash, and very positive gear engagement in my setup. Thanks Mark, good to know! Cheers, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Jul 22, 2012, at 11:04 AM, Jon Elson wrote: Todd Zuercher wrote: Neither, of our 5x10 routers have any support on the long table screws (12 ft long). But they are large diameter screws, secured, fixed and stretched in position with a rotating nut moving the table. I think rotating the nut rather than the screw helps a lot with wip. Well, it completely removes it, in fact! If the nut is not perfectly centered, the screw may vibrate slightly, but it won't do anything terrible. When the screw is spinning fast, the vibration can build to very large amplitude very quickly and permanently bend the screw. The more I think about it, I really think this is the best solution despite the challenges involved. If it fails miserably, then I guess I will go with rack pinion as a backup plan. Has anyone successfully machined the parts required? I would be willing to commission to have couple mounts to be manufactured. Looking on the web I did find some people who reported success building their own. Here is one mount: http://www.cnczone.com/forums/showthread.php?p=798791#post798791 And another: http://www.mycncuk.com/forums/showthread.php/3340-Rotating-Ballnut-design-ideas WIth a video of it running at 590 IPM here: http://www.youtube.com/watch?v=mSNFD9zx7fE Cheers, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Fri, 20 Jul 2012 20:00:10 -0400, you wrote: Sag is only the start of the problem. The whip is going to be the real problem. The ballnut is no holp holding it up at the limits of travel. Not strictly true - the size needs to be CAREFULLY calculated for the job in hand and the mounting method needs to be considered. Good ballscrew manufacturers have tables that define limits for their screws, but the examples I've looked at require both ends to be fixed and max rotational speed of around 1000 rpm for a 3m long 25mm ballscrew with loads kept below 2000 Kg. As long as you follow manufacturers specs it isn't going to whip or destroy the ballnut. That said, for a 10ft long screw I'd go bigger than 25mm :) A Google search for ballscrew length versus diameter gives lots of data. www.techno-isel.com/Tic/H834/PDF/H834P011.pd gives some good info. Steve Blackmore -- -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On 20.07.12 16:18, Jeshua Lacock wrote: I am sure with a 10-foot span that the horizontal ballscrews will sag a little from gravity. Is this much of a concern? Does anyone know of a trick to put some kind of support in the middle of the span? I can't think of any practical way. One method which has been used on very long lathes is one or more pivoting supports holding up the leadscrew. Imagine a cross-drilled rod with a weight on one end. It will hang vertically on a bolt through the hole. Now a segment of an arc (imagine a slim pie-slice of a V-belt pulley) welded on the other end will support the leadscrew in the V, but be pushed aside by the passing leadscrew nut housing, and slide under it, to bob up again when it has passed. While that has been used in industry on older long lathes, it doesn't seem ideal, since a cnc machine is likely to whack into it at speed, or reverse at that one tiny point where the shape of the ballscrew nut housing hasn't quite let it bob up, but sliding back under could be at least high friction, if not an outright jam. Those left/right alternating support legs, where striking the left one from the right causes it to fold down, and pull up the right one behind the leadscrew nut housing, by means of a link, are perhaps also not at their best when struck at speed. I'd be tempted to go for a horizontally retracting flat support, reaching out under the ballscrew from the adjacent frame. Imagine a bit of flat in a long slot, with the corners of the exposed edge cut well back, forming a ramp nearly to the middle of the edge. When the (also heavily chamfered) ballscrew nut housing whizzes by, it progressively pushes the support strip back into the slot in the frame, and progressively re-emerges as it passes. If the slot is deep, smooth, and well lubricated, then the support ought to retract much like that angled spring-loaded brass catch on domestic external doors. (The one which locks you out without your keys, even if only once in life.) If even that is too noisy when hit at speed, then the support could be automatically retracted when the carriage is near (reed switch or optical sensor), either pneumatically or by means of a small motor. In any event, I'd fix a long slender ballscrew, to avoid whipping, and rotate the nut. It is hard to image how vibration of a very long slender ballscrew can be avoided if it is spun at speed. Erik -- Re: Graphics: A picture is worth 10K words -- but only those to describe the picture. Hardly any sets of 10K words can be adequately described with pictures. -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
2012/7/21 Erik Christiansen dva...@internode.on.net: In any event, I'd fix a long slender ballscrew, to avoid whipping, and rotate the nut. I did this on the last machine I built with this exact intention in my mind. The overall result - failure. I seriously doubt I will ever do that again. Longest screw was 2800 mm long (other 2 were 1800 mm long), all of them - 16 mm diameter, 10 mm pitch. My main conclusion - the nut housing requires pretty precise machining to match the central axis of the nut itself with the axis around which that nut rotates in bearings. I had some deviations there, so the rotation of the nut caused the screw to vibrate, so the max speed ended up to be 5x smaller than initially planned just to avoid excessive vibrations. -- Viesturs If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On 21 July 2012 05:09, Jeshua Lacock jes...@3dtopo.com wrote: 550 RPMs does not exactly strike me as spinning at high speed. Besides, wouldn't the gyroscopic force help stabilized oscillations? No, centrifugal force acts as a positive feedback on any off-centre movement. As Steve has said, there are specs for this in the ballscrew catalogues, and he seems to be suggesting that 25mm is fine for 10' according to them. As a warning, whipping can be a deadly problem with long bars out the back of a lathe headstock. They need to be restrained quite strongly. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On 21.07.12 14:41, Viesturs Lācis wrote: 2012/7/21 Erik Christiansen dva...@internode.on.net: In any event, I'd fix a long slender ballscrew, to avoid whipping, and rotate the nut. I did this on the last machine I built with this exact intention in my mind. The overall result - failure. I seriously doubt I will ever do that again. Longest screw was 2800 mm long (other 2 were 1800 mm long), all of them - 16 mm diameter, 10 mm pitch. My main conclusion - the nut housing requires pretty precise machining to match the central axis of the nut itself with the axis around which that nut rotates in bearings. I had some deviations there, so the rotation of the nut caused the screw to vibrate, so the max speed ended up to be 5x smaller than initially planned just to avoid excessive vibrations. Viesturs, Of the other machines that you've built, do any have a horizontal ballscrew as long and slender as this one, spun at similar speeds? There is nothing quite like a direct physical comparison, to sort out which is better. It is a pity that you are do far away. It would be very interesting to see the effect first hand, just to learn. Are you game to mention how badly eccentric the nut housing was machined, in order to create the problem? Is there room to machine a little off the outside of the bearing mount, and slip on an eccentric outer, locktited in place with the equal eccentricities opposed, to cancel them? (Or some other rectification.) Admittedly, an 80% reduction in maximum rapid speed doesn't mean an 80% reduction in production rate, but it still seems a big loss. If the eccentricity is very small, is there possibly a resonance in the frame exacerbating the vibration? A significant mass tightly clamped in several different places might help check for that? Erik -- Theory is grey, but the golden tree of life is green. - Goethe -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
For long machines where the cutting forces are not hugely significant (such as a wood router) could one not used a aircraft cable setup? The cable could then be run over a motorized pulley. Something I always thought of but haven't fleshed it out further. Brian -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
I am not sure what yo mean by preload/stretch though. After installing the ballscrew you then put an indicator on the end of the ball screw with the mag base on the machine base. You then tighten the bearing preload until you see .007 to .009 stretch of the end of the ballscrew. I don't know which is really moving - the screw stretching for the machine base compressing. I am sure both is happening but to what extent I don't know. -- dos centavos -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
Hi Jeshua I am sure with a 10-foot span that the horizontal ballscrews will sag a little from gravity. Is this much of a concern? I think for long screws it generally a good idea not to drive the ball-screws, but the nut. While this will not reduce the sag you mentioned, it will greatly improve stability and reduce vibrations. There are special servo with hollow axis that you can directly attach to the carriage frame and the ball nut, the result is nice in-line direct ball-nut drive. But using a belt drive an a standard motor you could most probably build nice drive, too. No as rigid and dynamic and precise, but still much better than to drive a long screw. cu Flo -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On 7/21/2012 8:42 AM, andy pugh wrote: On 21 July 2012 05:09, Jeshua Lacock jes...@3dtopo.com wrote: 550 RPMs does not exactly strike me as spinning at high speed. Besides, wouldn't the gyroscopic force help stabilized oscillations? No, centrifugal force acts as a positive feedback on any off-centre movement. As Steve has said, there are specs for this in the ballscrew catalogues, and he seems to be suggesting that 25mm is fine for 10' according to them. As a warning, whipping can be a deadly problem with long bars out the back of a lathe headstock. They need to be restrained quite strongly. For example, see the Types of end fixity and Critical speed entries in http://www.roton.com/application_engineering.aspx From Figure 28, I infer that the critical speed for a 25mm (1in) drive screw 10ft long and supported at both ends is about 1000rpm. From Table 40 I infer that this speed drops to about 320rpm if one end is free and rises to about 1550rpm if one end is fixed and the other supported. See Table 40 for a definition of free, supported, and fixed. I once saw a student start up a lathe with about 3 feet of slender rod extending out the back of the headstock. In less time than it took the hapless student to hit the kill switch, that free end was tracing out a cone shaped path at speed. Hate to think what would have happened to anybody unfortunate enough to be within its range. The shop supervisor went white as a sheet. Given enough students (and I was one too!) everything that can happen, will happen. Regards, Kent -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
2012/7/21 Erik Christiansen dva...@internode.on.net: Of the other machines that you've built, do any have a horizontal ballscrew as long and slender as this one, spun at similar speeds? That was the first time I used ballscrews, so I have no other experiece to compare with. For the next machines I am designing ballscrews only for Z axes, where the travel is relatively short. For X and Y, where travel is larger (for one of them it is up to 6 m) I will stick with rack and pinion. Are you game to mention how badly eccentric the nut housing was machined, in order to create the problem? Is there room to machine a little off the outside of the bearing mount, and slip on an eccentric outer, locktited in place with the equal eccentricities opposed, to cancel them? (Or some other rectification.) I have no idea, how to measure it precisely. Anyway, I think that manufacturing new, more precise housings is the only way to go. Admittedly, an 80% reduction in maximum rapid speed doesn't mean an 80% reduction in production rate, but it still seems a big loss. Yes of course, feedrates for milling certainly would not reach even close to max speeds. It is big loss in all the rapids. If the eccentricity is very small, is there possibly a resonance in the frame exacerbating the vibration? A significant mass tightly clamped in several different places might help check for that? It is not eccentric. The thing is that center line of the ballscrew nut does not match the line it actually rotates around - there is some angle between them. So it pushes the ballscrew in one side of the nut in one direction and on the other side - in opposite direction. -- Viesturs If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
Jeshua Lacock wrote: On Jul 20, 2012, at 6:00 PM, Stephen Dubovsky wrote: Sag is only the start of the problem. The whip is going to be the real problem. Hi Stephen, I am not sure I understand what you mean by whip? Long, thin shafts tend to whip when spun at high speeds. Look up first critical speed. When the rotation speed matches the first vibrational moment's natural frequency, the vibration can build to enormous magnitude very quickly, permanently bending the shaft. Above the first critical speed, the shaft will rotate about its center of mass. Below that speed, it will rotate around the axis of its support bearings. Most ballscrew manufacturers have charts of critical speed, and you'd be amazed at how low these are for the longer ones, even at 25mm diameter. Also remember that a ballscrew is a lot less stiff than a solid shaft, and so the natural frequency is a lot lower. Jon -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Saturday 21 July 2012 11:45:42 andy pugh did opine: On 21 July 2012 05:09, Jeshua Lacock jes...@3dtopo.com wrote: 550 RPMs does not exactly strike me as spinning at high speed. Besides, wouldn't the gyroscopic force help stabilized oscillations? No, centrifugal force acts as a positive feedback on any off-centre movement. As Steve has said, there are specs for this in the ballscrew catalogues, and he seems to be suggesting that 25mm is fine for 10' according to them. As a warning, whipping can be a deadly problem with long bars out the back of a lathe headstock. They need to be restrained quite strongly. Yeah, I've had to make s miniature gun barrel spider for my mini-lathe and dial that in pretty closely if I want to turn more than 3 or 4 hundred revs. I once had a 3 foot piece of hot roll making a 4 circle on the far end, scary. It was only off maybe 1/16 turning the chuck by hand! Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene is up! Oppernockity tunes but once. -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
Jeshua Lacock wrote: It looks like over a 10 foot span I have about 24mm (0.96 inches) of sag in the middle. 10 foot span? 25 mm diameter? Oh, my, that sounds WAY past the safe range. See http://www.nookindustries.com/ball/BallCalculators.cfm#CriticalSpeed for a critical speed calculator. With the stiffest fixing of the ends, you might be able to get 500 RPM safely. That would be 100 IPM with a 5 TPI screw. With a coarser leadscrew pitch, you don't ned as high an RPM, so maybe this will be OK. Jon -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
Jeshua Lacock wrote: On Jul 20, 2012, at 9:13 PM, Stuart Stevenson wrote: Andy's solution is the correct solution. A string will fold under compression. This will allow the supports to collapse together when the nut moves their direction on the screw. The string will pull the supports along with the nut and allow the supports to space themselves along the screw with the spacing equivalent to the length of the string sections. The 5 axis Cincinnati machines in my shop have .007 to .009 in preload/stretch. Hi Stuart, Thanks for the clarification! I am not sure what yo mean by preload/stretch though. Bearings at each end of the leadscrew STRETCH it across the frame of the machine, literally making the screw a few thousandths of an inch longer. This raises the natural vibration frequency moving the critical speed up, as well as prevents the screw from buckling under compressive loads. As long as the forces applied at the ballnut are less than the tension, then the screw remains under some tension. -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
This web page has a chart for calculating the critical speed for ball screws: http://www.roton.com/application_engineering.aspx +++ We are like tenant farmers chopping down the fence around our house for fuel when we should be using Nature's inexhaustible sources of energy -- sun, wind and tide. ... I'd put my money on the sun and solar energy. What a source of power! I hope we don't have to wait until oil and coal run out before we tackle that. -Thomas Edison, inventor (1847-1931) From: Jeshua Lacock jes...@3dtopo.com To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Sent: Friday, July 20, 2012 5:18 PM Subject: [Emc-users] [Off] Ballscrew Support? Greetings, I am upgrading my machine to handle a full 4x8 foot board of material (and 5 feet of Z!). The new table is 5x9 feet. I just received my 3-meter 25mm supported rails and 25mm C7 ballscrews. I am sure with a 10-foot span that the horizontal ballscrews will sag a little from gravity. Is this much of a concern? Does anyone know of a trick to put some kind of support in the middle of the span? I can't think of any practical way. Thanks! Best, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Jul 21, 2012, at 9:50 AM, Jon Elson wrote: Jeshua Lacock wrote: It looks like over a 10 foot span I have about 24mm (0.96 inches) of sag in the middle. 10 foot span? 25 mm diameter? Oh, my, that sounds WAY past the safe range. See http://www.nookindustries.com/ball/BallCalculators.cfm#CriticalSpeed for a critical speed calculator. With the stiffest fixing of the ends, you might be able to get 500 RPM safely. That would be 100 IPM with a 5 TPI screw. With a coarser leadscrew pitch, you don't ned as high an RPM, so maybe this will be OK. Thanks everyone for all the very useful information!!! Most of the information I had no idea about! And thanks for the calculator Jon. Using End Fixity B (one end double bearing the other single bearing) for 117 inch span I get a safe RPM of 278. At 5cm/rev that is 547 IPM. I think I could happily live with that. More important than top end speed to me is how fast the table can accelerate. And for a 250+ pound table 547 IPM rapids seems pretty decent to me. This axis is also going to be the slowest, so for raster scanning I can move more rapidly on the Y axis. If I had double bearing on both sides (End Fixity C), I would get to 805 IPM and with End Fixity D I would get to 1220 IPM. Unfortunately, I think that would require taking the ballscrews to a machine shop. I guess if I ever want faster top end speed that is an option. Thanks again, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Sat, 21 Jul 2012 14:41:01 +0300, you wrote: 2012/7/21 Erik Christiansen dva...@internode.on.net: In any event, I'd fix a long slender ballscrew, to avoid whipping, and rotate the nut. I did this on the last machine I built with this exact intention in my mind. The overall result - failure. I seriously doubt I will ever do that again. Longest screw was 2800 mm long (other 2 were 1800 mm long), all of them - 16 mm diameter, 10 mm pitch. Yea - too small a diameter screw for decent performance at that length. I have a 2.5m ballscrew here that came off a laser cutter. Now bear in mind there are no cutting forces involved, it was off the Y axis and only moving the head across the gantry. It's 32mm diameter and has large bearing blocks and preload adjustment on both ends. Also has two ball nuts for backlash adjustment :) I also have another 32mm one that was an unused spare off a Denford CNC lathe - it's only got about 300 mm of travel but was designed to be fixed at one end only - hence the diameter. They were destined for a slant bed lathe I designed but I never got around to building it G. Steve Blackmore -- -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On 21 July 2012 23:04, Jeshua Lacock jes...@3dtopo.com wrote: At 5cm/rev that is 547 IPM. I think I could happily live with that. That's a very high-lead ballscrew. I haven't seen any balls crews with a pitch twice the diameter. Are you sure you are not a factor of 10 out? -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Jul 21, 2012, at 5:49 PM, andy pugh wrote: On 21 July 2012 23:04, Jeshua Lacock jes...@3dtopo.com wrote: At 5cm/rev that is 547 IPM. I think I could happily live with that. That's a very high-lead ballscrew. I haven't seen any balls crews with a pitch twice the diameter. Are you sure you are not a factor of 10 out? That is funny - at the same time you must have been thinking of this, I was double checking it! The specs said the lead was 5. I had assumed 5cm - in fact it is only 5mm! Doh! So you are correct - off by a factor of 10! To make matters worse, I thought they were 25mm, but they are 20mm. So that drops the safe speed down to a miserable 43.89 IPM. :'( Damn. Anyone want to buy two brand new ballscrews? :D Maybe I will use them on a laser cutter instead. High speed is not as important to me on a laser cutter as it is on a 3D milling machine. Path lengths are *much* longer doing 3D stuff versus 2D cutting…. Maybe I will use timing belts for this machine. Just seems like they will have a lot of flex over a 10 foot span. Chain drive? Cheers, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Sat, Jul 21, 2012, at 06:04 PM, Jeshua Lacock wrote: Damn. Anyone want to buy two brand new ballscrews? :D Maybe I will use them on a laser cutter instead. High speed is not as important to me on a laser cutter as it is on a 3D milling machine. Path lengths are *much* longer doing 3D stuff versus 2D cutting…. Maybe I will use timing belts for this machine. Just seems like they will have a lot of flex over a 10 foot span. Chain drive? I saw an idea once that attempted to solve the problem of timing belt stretch by attaching one belt along its full length to the machine frame, then meshing another belt to that one to drive the axis. A picture is worth a thousand words, see this posting: http://www.mycncuk.com/forums/showthread.php/1599-Planning-and-build-of-my-8020-aluminium-CNC-Router?p=10463viewfull=1#post10463 It essentially becomes a rack-and-pinion of sorts. I didn't read that full thread to see if he actually built the machine, and how it worked out. I think I also saw the same idea discussed on CNCzone. Of course, you could also just go the rack-and-pinion route. The rack teeth should point down to shed dirt and chips. -- John Kasunich jmkasun...@fastmail.fm -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
Have you considered rack and pinion for your machine. CNCrouterparts has a very affordable solution: http://www.cncrouterparts.com/rack-and-pinion-drive-nema-34-p-80.htmlI've not used them but they have gotten good reviews from users at CNCzone and I've been happy with other components of theirs I've used on my machine. +++ We are like tenant farmers chopping down the fence around our house for fuel when we should be using Nature's inexhaustible sources of energy -- sun, wind and tide. ... I'd put my money on the sun and solar energy. What a source of power! I hope we don't have to wait until oil and coal run out before we tackle that. -Thomas Edison, inventor (1847-1931) From: Jeshua Lacock jes...@3dtopo.com To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Sent: Saturday, July 21, 2012 7:04 PM Subject: Re: [Emc-users] [Off] Ballscrew Support? On Jul 21, 2012, at 5:49 PM, andy pugh wrote: On 21 July 2012 23:04, Jeshua Lacock jes...@3dtopo.com wrote: At 5cm/rev that is 547 IPM. I think I could happily live with that. That's a very high-lead ballscrew. I haven't seen any balls crews with a pitch twice the diameter. Are you sure you are not a factor of 10 out? That is funny - at the same time you must have been thinking of this, I was double checking it! The specs said the lead was 5. I had assumed 5cm - in fact it is only 5mm! Doh! So you are correct - off by a factor of 10! To make matters worse, I thought they were 25mm, but they are 20mm. So that drops the safe speed down to a miserable 43.89 IPM. :'( Damn. Anyone want to buy two brand new ballscrews? :D Maybe I will use them on a laser cutter instead. High speed is not as important to me on a laser cutter as it is on a 3D milling machine. Path lengths are *much* longer doing 3D stuff versus 2D cutting…. Maybe I will use timing belts for this machine. Just seems like they will have a lot of flex over a 10 foot span. Chain drive? Cheers, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Jul 21, 2012, at 5:49 PM, andy pugh wrote: On 21 July 2012 23:04, Jeshua Lacock jes...@3dtopo.com wrote: At 5cm/rev that is 547 IPM. I think I could happily live with that. That's a very high-lead ballscrew. I haven't seen any balls crews with a pitch twice the diameter. Are you sure you are not a factor of 10 out? Hm... It looks like if have a sliding support like you suggested trailing on either side of the ball screw by 38 inches that would allow me to get up to 1113 RPM which would give me a pretty respectable 388 IPM…. Best, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Jul 21, 2012, at 6:24 PM, John Kasunich wrote: n Sat, Jul 21, 2012, at 06:04 PM, Jeshua Lacock wrote: Damn. Anyone want to buy two brand new ballscrews? :D Maybe I will use them on a laser cutter instead. High speed is not as important to me on a laser cutter as it is on a 3D milling machine. Path lengths are *much* longer doing 3D stuff versus 2D cutting…. Maybe I will use timing belts for this machine. Just seems like they will have a lot of flex over a 10 foot span. Chain drive? I saw an idea once that attempted to solve the problem of timing belt stretch by attaching one belt along its full length to the machine frame, then meshing another belt to that one to drive the axis. A picture is worth a thousand words, see this posting: http://www.mycncuk.com/forums/showthread.php/1599-Planning-and-build-of-my-8020-aluminium-CNC-Router?p=10463viewfull=1#post10463 It essentially becomes a rack-and-pinion of sorts. I didn't read that full thread to see if he actually built the machine, and how it worked out. I think I also saw the same idea discussed on CNCzone. Interesting. Yeah, looks like he never built it - or at least reported back. Of course, you could also just go the rack-and-pinion route. The rack teeth should point down to shed dirt and chips. I don't recall the specifics, but I read somewhere that rack-and-pinon was not a good solution. Maybe it had something to do with resonance? Cheers, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Sat, 21 Jul 2012, John Kasunich wrote: Date: Sat, 21 Jul 2012 20:24:22 -0400 From: John Kasunich jmkasun...@fastmail.fm Reply-To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Subject: Re: [Emc-users] [Off] Ballscrew Support? On Sat, Jul 21, 2012, at 06:04 PM, Jeshua Lacock wrote: Damn. Anyone want to buy two brand new ballscrews? :D Maybe I will use them on a laser cutter instead. High speed is not as important to me on a laser cutter as it is on a 3D milling machine. Path lengths are *much* longer doing 3D stuff versus 2D cutting??. Maybe I will use timing belts for this machine. Just seems like they will have a lot of flex over a 10 foot span. Chain drive? I saw an idea once that attempted to solve the problem of timing belt stretch by attaching one belt along its full length to the machine frame, then meshing another belt to that one to drive the axis. A picture is worth a thousand words, see this posting: http://www.mycncuk.com/forums/showthread.php/1599-Planning-and-build-of-my-8020-aluminium-CNC-Router?p=10463viewfull=1#post10463 It essentially becomes a rack-and-pinion of sorts. I didn't read that full thread to see if he actually built the machine, and how it worked out. I think I also saw the same idea discussed on CNCzone. Of course, you could also just go the rack-and-pinion route. The rack teeth should point down to shed dirt and chips. -- John Kasunich jmkasun...@fastmail.fm Theres a commercial version of this or something very close (with I think special belts) but my google foo is failing me now Peter Wallace Mesa Electronics -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
Theres a commercial version of this or something very close (with I think special belts) but my google foo is failing me now Peter Wallace Mesa Electronics Ahh here it is: http://bell-everman.com/products/linear-positioning/servobelt-linear-sbl Peter Wallace Mesa Electronics -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
I also remembered seeing a more commercial version of that somewhere, but like you I couldn't find it. When I found that forum post I stopped looking :) On Sat, Jul 21, 2012, at 05:47 PM, Peter C. Wallace wrote: Theres a commercial version of this or something very close (with I think special belts) but my google foo is failing me now Peter Wallace Mesa Electronics Ahh here it is: http://bell-everman.com/products/linear-positioning/servobelt-linear-sbl Peter Wallace Mesa Electronics -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Jul 21, 2012, at 6:47 PM, Peter C. Wallace wrote: Ahh here it is: http://bell-everman.com/products/linear-positioning/servobelt-linear-sbl Thats pretty cool. I wonder what keeps the belts together? Gravity? Cheers, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
The idler pulleys push them together on either side of the pinion, which is where the force is transferred from the upper belt to the lower one. The lower one is glued to the machine frame along its entire length, so the force is then transferred to the frame. Neither belt has any significant tension outside the area of the idlers, so there isn't much needed to keep them together - gravity does it. I don't think it would work with regular trapezoidal timing belts (like the MXK, XL, L, etc series), because the teeth are smaller than the spaces between the teeth. So they belts wouldn't mesh tightly. A GT or HTD belt might do better, I haven't looked up those belt profiles to see if they would provide a positive mesh. Thinking about it a bit, maybe even trapezoid belts would work. The teeth on the upper belt don't need to be centered in the spaces on the lower belt. On the left side of the drive unit, the right flank of the upper belt tooth could be in contact with the left flank of the lower belt tooth, so it could transfer tension to the lower belt. On the right side of the drive unit things are reversed, with the left flank of the upper tooth in contact with the right flank of the lower tooth. Again, it can transfer tension to the lower belt. The main problem is that force is transferred between belts by only one or two teeth - the ones directly under the idler pulleys. Making the idler pulleys as large as possible would improve that a bit. It all comes down to how much force is needed, and how expensive is strong, wide belting compared to alternative ways of doing the same thing (like rack and pinion). By comparison, if you used only the upper belt, and stretched it tight enough that both sides were under tension loading even with maximum force on the carriage, it would be stronger (load limited by the teeth in mesh over 180 degrees of pinion) but springier (tension members of the belt are long and thin, and even if steel they are elastic). But you have to buy half as much belting, so the belting could be bigger. It would be an interesting design exercise. Econobelt and SDP-SI are both belt suppliers with a good bit of technical info on their sites. The ultimate choice depends on your requirements. If you have lots of cutting force, rack and pinion would probably be better. If you need speed and low noise and not so much stiffness, a single timing belt with two idlers and a pinion would be better. The interlocking belt thing is weaker than both, I think, but much stiffer than the single belt. On Sat, Jul 21, 2012, at 07:38 PM, Jeshua Lacock wrote: On Jul 21, 2012, at 6:47 PM, Peter C. Wallace wrote: Ahh here it is: http://bell-everman.com/products/linear-positioning/servobelt-linear-sbl Thats pretty cool. I wonder what keeps the belts together? Gravity? Cheers, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- John Kasunich jmkasun...@fastmail.fm -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
andy pugh wrote: On 21 July 2012 23:04, Jeshua Lacock jes...@3dtopo.com wrote: At 5cm/rev that is 547 IPM. I think I could happily live with that. That's a very high-lead ballscrew. I haven't seen any balls crews with a pitch twice the diameter. Are you sure you are not a factor of 10 out? You can get high-lead ballscrews, but they are usually special-order items. I have some fairly small ballscrews with something like 20mm lead on my pick place machine (Yamaha/Philips). They are over a meter long, so they were fighting this exact problem. This machine runs over a m/sec so they definitely run into the danger region without a high-lead screw. Jon -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] [Off] Ballscrew Support?
Greetings, I am upgrading my machine to handle a full 4x8 foot board of material (and 5 feet of Z!). The new table is 5x9 feet. I just received my 3-meter 25mm supported rails and 25mm C7 ballscrews. I am sure with a 10-foot span that the horizontal ballscrews will sag a little from gravity. Is this much of a concern? Does anyone know of a trick to put some kind of support in the middle of the span? I can't think of any practical way. Thanks! Best, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On 20 July 2012 23:18, Jeshua Lacock jes...@3dtopo.com wrote: I am sure with a 10-foot span that the horizontal ballscrews will sag a little from gravity. Is this much of a concern? Does anyone know of a trick to put some kind of support in the middle of the span? I can't think of any practical way. I can think of impractical ways. For example, something rather like a gear with ballscrew-sized tooth-gaps that the balls crews can pass through. However, typically the screw won't be able to sag, as it will be held up by the ballnut. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
Sag is only the start of the problem. The whip is going to be the real problem. The ballnut is no holp holding it up at the limits of travel. Stephen However, typically the screw won't be able to sag, as it will be held up by the ballnut. -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
Back in 1885 they fixed the problem with two U shaped supports on levers http://www.collection.archivist.info/archive/DJCPD/PD/2001/2001_05_08_Claymills/P1010003.JPG on the lower left you see a shaft beside the rail the crane is on you can see a catch lever that operates the mechanism below the floor which brings up the other U support behind the crane. While it is changing over the trolley supports the shaft. Almost visible at http://ccgi.archivist.plus.com/php/showresult.php?searchv4page=1srcdata=titledir=fgmfile=ph423subject=488 A box of pictures is awol at the moment when I find it I will scan a better picture I think I have Dave Caroline -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On 21 July 2012 01:43, Dave Caroline dave.thearchiv...@gmail.com wrote: Back in 1885 they fixed the problem with two U shaped supports on levers http://www.collection.archivist.info/archive/DJCPD/PD/2001/2001_05_08_Claymills/P1010003.JPG That is conceptually similar to what I suggested. I also suspect that that crane lives in the top of a pumping station beam-engine shed? -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Sat, Jul 21, 2012 at 2:08 AM, andy pugh bodge...@gmail.com wrote: On 21 July 2012 01:43, Dave Caroline dave.thearchiv...@gmail.com wrote: Back in 1885 they fixed the problem with two U shaped supports on levers http://www.collection.archivist.info/archive/DJCPD/PD/2001/2001_05_08_Claymills/P1010003.JPG That is conceptually similar to what I suggested. I also suspect that that crane lives in the top of a pumping station beam-engine shed? yes it is The engine houses have two engines each (sewage pumping engines) Dave Caroline -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
Jeshua Lacock wrote: Greetings, I am upgrading my machine to handle a full 4x8 foot board of material (and 5 feet of Z!). The new table is 5x9 feet. I just received my 3-meter 25mm supported rails and 25mm C7 ballscrews. I am sure with a 10-foot span that the horizontal ballscrews will sag a little from gravity. Is this much of a concern? Does anyone know of a trick to put some kind of support in the middle of the span? I can't think of any practical way. Apply tension to the screws through the frame of the machine? Jon -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On 21 July 2012 02:32, Jon Elson el...@pico-systems.com wrote: Apply tension to the screws through the frame of the machine? A linear rail and several supports tied to the carriage and each other with string, utilising the pathetic performance of string in compression to advantage. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Jul 20, 2012, at 6:00 PM, Stephen Dubovsky wrote: Sag is only the start of the problem. The whip is going to be the real problem. Hi Stephen, I am not sure I understand what you mean by whip? The ballnut is no holp holding it up at the limits of travel. My thoughts too. Cheers, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Jul 20, 2012, at 6:43 PM, Dave Caroline wrote: A box of pictures is awol at the moment when I find it I will scan a better picture I think I have Hi Dave, Sounds interesting, but I am afraid I don't quite grasp the concept. I am a visual learner and the concept is quite clear from those images. Thanks, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Jul 20, 2012, at 7:32 PM, Jon Elson wrote: Apply tension to the screws through the frame of the machine? Hi Jon, Interesting! I wonder how much tension it would need - seems like a quite a lot. Seems like the shaft would slide off or damage the bearings before adequate tension was achieved. Do you know if this is done in practice by any large machines? Best, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Jul 20, 2012, at 7:40 PM, andy pugh wrote: On 21 July 2012 02:32, Jon Elson el...@pico-systems.com wrote: Apply tension to the screws through the frame of the machine? A linear rail and several supports tied to the carriage and each other with string, utilising the pathetic performance of string in compression to advantage. Hi Andy, OK; I am afraid you guys totally lost me! Cheers, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
whipping around. You have a long thin rod that will be spun at high speed. Its going to act like a jump rope ;) Im told long machines hold the screw stationary and spin the nut to solve that problem. I am not sure I understand what you mean by whip? -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Friday 20 July 2012 22:45:54 Jeshua Lacock did opine: On Jul 20, 2012, at 7:40 PM, andy pugh wrote: On 21 July 2012 02:32, Jon Elson el...@pico-systems.com wrote: Apply tension to the screws through the frame of the machine? A linear rail and several supports tied to the carriage and each other with string, utilising the pathetic performance of string in compression to advantage. Hi Andy, OK; I am afraid you guys totally lost me! Cheers, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 I have this mental picture of Andy, with the equivalent of a whole can of Skoal in his cheek, but its not Skoal, its his tongue. ;-) Cheers, Gene -- There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) My web page: http://coyoteden.dyndns-free.com:85/gene is up! Air pollution is really making us pay through the nose. -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On 21 July 2012 03:47, Gene Heskett ghesk...@wdtv.com wrote: A linear rail and several supports tied to the carriage and each other with string, utilising the pathetic performance of string in compression to advantage. I have this mental picture of Andy, with the equivalent of a whole can of Skoal in his cheek, but its not Skoal, its his tongue. ;-) It was actually a serious suggestion, but described in a jocular way. If you had a set of plain bushes to suit the OD of the screw held in brackets sliding on a linear rail adjacent to the screw, then they could be pushed out of the way by the ballnut/carriage and others could be dragged behind the carriage on chains/strings. Rather like the cable loops follow a travelling crane. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
Andy's solution is the correct solution. A string will fold under compression. This will allow the supports to collapse together when the nut moves their direction on the screw. The string will pull the supports along with the nut and allow the supports to space themselves along the screw with the spacing equivalent to the length of the string sections. The 5 axis Cincinnati machines in my shop have .007 to .009 in preload/stretch. -- dos centavos -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Jul 20, 2012, at 8:47 PM, Gene Heskett wrote: I have this mental picture of Andy, with the equivalent of a whole can of Skoal in his cheek, but its not Skoal, its his tongue. ;-) Hi Gene, I sensed sarcasm, but I was too dim to make full sense of what Andy was saying! ;) Best, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Jul 20, 2012, at 8:27 PM, Stephen Dubovsky wrote: whipping around. You have a long thin rod that will be spun at high speed. Its going to act like a jump rope ;) Im told long machines hold the screw stationary and spin the nut to solve that problem. Hi Stephen, It is easy for me to imagine it bouncing up and down a little, but apparently I am lacking the brain power to imagine what would actually make it whip. It seems either end would have to be rapidly moved up and down (or side to side) for a whip to occur and the ends will be planted quite stationary. The table will move 2 inches per revolution, so even at 550 RPM, it would move the whole length of the rails (10 feet) in 10 seconds which seems really fast to me. The table weighs about 250 pounds, so I can't imagine moving it faster than that. 550 RPMs does not exactly strike me as spinning at high speed. Besides, wouldn't the gyroscopic force help stabilized oscillations? Thanks, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] [Off] Ballscrew Support?
On Jul 20, 2012, at 9:13 PM, Stuart Stevenson wrote: Andy's solution is the correct solution. A string will fold under compression. This will allow the supports to collapse together when the nut moves their direction on the screw. The string will pull the supports along with the nut and allow the supports to space themselves along the screw with the spacing equivalent to the length of the string sections. The 5 axis Cincinnati machines in my shop have .007 to .009 in preload/stretch. Hi Stuart, Thanks for the clarification! I am not sure what yo mean by preload/stretch though. Cheers, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
