What I envision, after watching 'The Little Hobber' on youtube about 100 times. Doing hobbing with a mechanical connection between the Hobbing arbor and the work arbor is painful, all those gears, can guarantee that I won't have the set I need. I found on Ebay, tool suppliers, in China, selling DP20 or Module 1.25 hobs for about US$50. Using what I can see in the little hobber, I need to accurately twist the hob axis, and then synchronize, the hob to the work, and feed the hob once every revolution of the work. For adjusting the twist, I was figuring on accurately placing two drill bushings that would hold two dowel pins against which I would place my sine bar, and just use a set of gage blocks to get the angle right. For powering this thing, I am considering some of Jon's servo motors, running in the 1500 to 2000 rpm range, with appropriate gear reduction to the hob and the work spindles. If I can use the encoder A channel or B channel as the locking frequency from the hob spindle, coming up with a divider for the work spindle should not be hard. Basic construction would entail use of 5200 series double row ball bearings for the spindles, and those very nice, and oh so cheap ER collet spindles. ----- Original Message -----
From: [email protected] To: [email protected] Sent: Thursday, July 30, 2015 4:03:38 AM Subject: Emc-users Digest, Vol 111, Issue 59 Send Emc-users mailing list submissions to [email protected] To subscribe or unsubscribe via the World Wide Web, visit https://lists.sourceforge.net/lists/listinfo/emc-users or, via email, send a message with subject or body 'help' to [email protected] You can reach the person managing the list at [email protected] When replying, please edit your Subject line so it is more specific than "Re: Contents of Emc-users digest..." Today's Topics: 1. Re: Gear hobbing machine (Karlsson & Wang) 2. Re: Switches for home, limits (andy pugh) 3. Re: Before i go bonkers: M98, M99 (Mark Wendt) 4. Re: Before i go bonkers: M98, M99 (Mark Wendt) 5. Re: Before i go bonkers: M98, M99 (Mark Wendt) 6. Re: Switches for home, limits (Gene Heskett) 7. Re: Switches for home, limits (John Alexander Stewart) ---------------------------------------------------------------------- Message: 1 Date: Thu, 30 Jul 2015 11:19:14 +0200 From: Karlsson & Wang <[email protected]> Subject: Re: [Emc-users] Gear hobbing machine To: "Enhanced Machine Controller \(EMC\)" <[email protected]> Message-ID: <[email protected]> Content-Type: text/plain; charset=US-ASCII Sounds great. I bough a few hundred kilos of material probably intented for gears from bankcrupt company which i intend to use for testing machine. Nicklas Karlsson On Thu, 30 Jul 2015 10:09:51 +0100 andy pugh <[email protected]> wrote: > On 30 July 2015 at 07:16, Dave Caroline <[email protected]> wrote: > > Andy has implemented it on a mill > > http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Hobbing > > I have now created a dedicated hobbing GladeVCP panel which performs > basic gear calculations (including span across teeth for size > checking) as well as running the hobbing process. > > I will try to remember to add it to the Wiki page. > > > -- > atp > If you can't fix it, you don't own it. > http://www.ifixit.com/Manifesto > > ------------------------------------------------------------------------------ > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------ Message: 2 Date: Thu, 30 Jul 2015 10:30:21 +0100 From: andy pugh <[email protected]> Subject: Re: [Emc-users] Switches for home, limits To: "Enhanced Machine Controller (EMC)" <[email protected]> Message-ID: <can1+yzvwuwhqkscll7ou9od-mithruhwsflbzxuwq3wansw...@mail.gmail.com> Content-Type: text/plain; charset=UTF-8 On 30 July 2015 at 08:02, Marcus Bowman <[email protected]> wrote: > it would be useful if folks could put the pictures somewhere we could all see > them. I have been tending to embed inductive proxes in the machine somewhere with a drilled hole as the target. https://picasaweb.google.com/108164504656404380542/HarrisonMill#5989135693933177186 The Y-axis prox is embedded in the gib block, and uses a drilled hole target. The Z-axis is actually also on the gib block and the target is a metal block screwed to the main column casting. The X (not visible) is in a bolted-on block under the edge of the saddle with another drilled hole in the underdide of the table slide as the target. They can all get wet but X and Y are completely protected from swarf and the Z is out of the way of swarf. I bought 5 of the 8mm proximity sensors from eBay for less than ?15. You want the ones where the outer threaded boy extends right to the end as the others won't work buried in metal. http://www.ebay.co.uk/itm/190836819378 For example. There may be arguments for buying more expensive ones for better reliability. Not immediately obvious is that they have an LED inside them to indicate status. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto ------------------------------ Message: 3 Date: Thu, 30 Jul 2015 06:36:53 -0400 From: Mark Wendt <[email protected]> Subject: Re: [Emc-users] Before i go bonkers: M98, M99 To: "Enhanced Machine Controller (EMC)" <[email protected]> Message-ID: <CABWWDmqW7=5vG+PF7pgKDoj==d8l4abwa2ajojowu9mzgtc...@mail.gmail.com> Content-Type: text/plain; charset=UTF-8 On Wed, Jul 29, 2015 at 6:16 PM, Robert Ellenberg <[email protected]> wrote: > Sorry folks, it looks like I managed to butt-dial an email during my > commute this morning. Crisis averted :) > > Rob > Uh huh. Suuuuuurrrrrre. ;-) Mark -- One Man, One Machine, One Computer! <VBSEG> ------------------------------ Message: 4 Date: Thu, 30 Jul 2015 06:37:45 -0400 From: Mark Wendt <[email protected]> Subject: Re: [Emc-users] Before i go bonkers: M98, M99 To: "Enhanced Machine Controller (EMC)" <[email protected]> Message-ID: <cabwwdmrqtnku5+penkdwyv_90x5r7xbyd_gpvm+rebmnbnx...@mail.gmail.com> Content-Type: text/plain; charset=UTF-8 Brilliant! Mark On Wed, Jul 29, 2015 at 6:19 PM, Sebastian Kuzminsky <[email protected]> wrote: > I propose we make "I Kill Kokomo" the official code name of the next > release. > > > On 7/29/15 4:16 PM, Robert Ellenberg wrote: > > Sorry folks, it looks like I managed to butt-dial an email during my > > commute this morning. Crisis averted :) > > > > Rob > -- One Man, One Machine, One Computer! <VBSEG> ------------------------------ Message: 5 Date: Thu, 30 Jul 2015 06:39:45 -0400 From: Mark Wendt <[email protected]> Subject: Re: [Emc-users] Before i go bonkers: M98, M99 To: "Enhanced Machine Controller (EMC)" <[email protected]> Message-ID: <CABWWDmoa1+=1N4eWhZ4PsMh7vr7kF+f7=6k0pdqejuelfpe...@mail.gmail.com> Content-Type: text/plain; charset=UTF-8 On Thu, Jul 30, 2015 at 2:10 AM, George Ramsower <[email protected]> wrote: > This is interesting. I've seen this sort of thing on other email lists > and thought it was some sort of spam or some type of malware. Now I > understand it's just a mistake. I never thought of this possibility! > Very interesting what we can do with our butts. > > George R. > Thanks George. That image will be stuck in my mind for the rest of the day. TMI. ;-) Mark -- One Man, One Machine, One Computer! <VBSEG> ------------------------------ Message: 6 Date: Thu, 30 Jul 2015 07:02:15 -0400 From: Gene Heskett <[email protected]> Subject: Re: [Emc-users] Switches for home, limits To: [email protected] Message-ID: <[email protected]> Content-Type: Text/Plain; charset="iso-8859-1" On Thursday 30 July 2015 03:02:45 Marcus Bowman wrote: > On 30 Jul 2015, at 03:51, Gene Heskett wrote: > > I bought a bag of small, roller tipped microswitches, and have a > > couple mounts laid out but not carved yet. > > > > Going thru searches on ebay just now, for both inductive, > > capacitative, and IR proximity switches, It sees like the majority > > of them are needing 6 volts or more, and around 300 ma each to > > function. Having seen some micropower capacitative switches in the > > textbooks of yore, it seems like the ball has been dropped in terms > > of being useful in a 5 volt logic circuit. > > > > Both the microswitch, and the inductive versions would seem to be > > sensitive to collecting swarf, particularly if its a rare earth > > magnet running a reed switch. > > > > My lathe seems to be relatively happy with a microswitch located > > under the back edge of the bed for Z homing where swarf tends to > > fall on past it, but x has to be kept swept clean because its > > actually on top of the carriage. > > > > I see a whole passel of stuff drilled onto GO704's in the hits I can > > get from google, but all of them preclude retaining the rubber swarf > > shields, which I'd say was not worth the tradeoff. There has to be > > a better way. > > > > So what sort of switches, and what swarf shielding to keep them > > relatively clean & accurate are others using? > > > > PM's with pix appreciated if you have the time. > > Actually, this is a really interesting question. Having spent ages > thinking about shielded locations for the mill, and about to do the > same for the lathe, it would be useful if folks could put the pictures > somewhere we could all see them. If anyone has any recommendations > about makes and models of switches/sensors which provide better > accuracy and repeatability than others, or useful ways of providing > adjustment on mounting arrangements, that would also be very useful. > > Marcus > My thoughts exactly Marcus. In my googling, something like 3/4ths of the sites that may have had helpful pictures, were behind a login requester. Since I am not a member of any of those Mach oriented groups, thats less than helpful. For X, I have considered removing the pointer which is also a mechanical limit stop, and likely demolishable to an out of control move as there are a couple OEM stoppers that would hit it. Once removed, then move one of the stopper knobs (they are in a 'T' slot in the front edge of the table) to someplace near the center of the table, and mount a switch that it would close on the way by which would function as the home switch. A similar setup is now on my lathe, with the switch under the back rail of what passes for a bed, located to be activated when no tool holder is mounted, and only 3/4" or so from the chuck face. X has already been homed and parked about 1mm from its outside limit. Having both switches well off center moderately well precludes its looking for the switch in the wrong direction as its z is normally parked well away from the work for gauge etc checking access to whats in the chuck. So this has worked well for a year for me. But I see no way to make certain that it looks in the right direction to find home on a mill without physically locating the switch well away from the center of the table. eg the switches trip point will need to be toward the end of the travel, and a HOME_OFFSET then used to put zero back at the center. From there, soft limits + & - would be used in place of the existing knobs hitting the heavy centrally located pointer. There are not currently available, any such Y stops, so all of that will have to be imagined and built. Again, off center far enough that from any usual powerup location that it will search in the correct direction to find the switch, then a HOME-OFFSET that establishes a zero on the dro's at the center of travel, and again setting software limits from this arbitrary home rather than actual limit switches. Z homing will either be completely arbitrary because of uncalibrated tool lengths in an R8 spindle, or some sort of a pcb pad laying on the table and a G38.2 move to find the top, sensitive side of the pcb. In that case, how do I guarantee that I will remember to place the contact pad? It needs to be automatic, and that gets complex. I often do that on my toy mill, jogging down slowly till I get the probe tripped message, and then home it after rising even slower to open the contact so I can home it there, typically about .064" above the table. This would be more accurately done IF I could home with the probe tripped, but LCNC won't allow that. And I'm too lazy to put a switch in the probe lead. ;-) Or just sense someplace on the column & call it home. That doesn't seem to be foolproof either, and I am absolutely the fool that will prove it. :) Thats why I ask for ideas & pix. If you PM me pix, include perms to post them on my web page, and they will then be available for others till I fall over. > > Thanks. > > > > Cheers, Gene Heskett > > -- > > "There are four boxes to be used in defense of liberty: > > soap, ballot, jury, and ammo. Please use in that order." > > -Ed Howdershelt (Author) > > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > > -------------------------------------------------------------------- > >---------- _______________________________________________ > > Emc-users mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-users > > ---------------------------------------------------------------------- >-------- _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------ Message: 7 Date: Thu, 30 Jul 2015 07:03:29 -0400 From: John Alexander Stewart <[email protected]> Subject: Re: [Emc-users] Switches for home, limits To: "Enhanced Machine Controller (EMC)" <[email protected]> Message-ID: <cak8hy3jdncexbl5azsx9n5uvdqmtmsdvtoonafh5tzwgtka...@mail.gmail.com> Content-Type: text/plain; charset=UTF-8 Gene: I used (for better or worse) microswitches. X axis - you can see it to the left of one of the pics. Uses the original table stop and some of the screws that were in the table (for locking handles? can't remember off hand) http://cnc-for-model-engineers.blogspot.ca/2015/04/g0704-and-cnc-conversion-kit-last.html The Z and Y axis: http://cnc-for-model-engineers.blogspot.ca/2014/09/the-new-cnc-mill-kc20vsbf20g0704-part-3.html John. ------------------------------ ------------------------------------------------------------------------------ ------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users End of Emc-users Digest, Vol 111, Issue 59 ****************************************** ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
