Re: [Emc-users] [off] Lost PLA Casting
On 9/23/2012 11:12 PM, Kent A. Reed wrote: On 9/23/2012 10:25 PM, Jeshua Lacock wrote: Greetings, This web page describes the process I used going from OpenSCAD to casted aluminum parts in a day: http://3dtopo.com/lostPLA/ The casted parts are ultimately going to be controlled by LinuxCNC. Congratulations, Jeshua. Your project made Hackaday today. I hope your website is ready for the inevitable bump in traffic. 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
[Emc-users] Helical interpolation not quite round, WTF?
I have a routine that lets me mill a deep circle in several passes, typically to cutout circles from plates. Something strange is going on and the resulting shape is not exactly round. It can be best described as a circle with humps. The routine is below. It is basically a while loop, milling progressively deeper until Z reaches the required depth. Every loop consists of two half circles milled helically, with the end mill going down along a spiral. Any idea why the shape may not end up being circular? Thanks Routine attached. (Copyright - Igor Chudov, released under GNU Public License V3) Ocirculargroove sub (circular groove, good for milling through holes too) #xc = #1 (X center) #yc = #2 (Y center) #safez = #3 (safe height) #depth = #4 (depth of milling) #radius = #5 (outside radius) #milld = #6 (end mill diameter) #frate = #7 (feed rate) #zstep = #8 (z step, per circle, optional) Oif if [ #frate NE 0 ] F#frate Oif endif Oif if [ #zstep EQ 0 ] #zstep = [#milld/3] Oif endif #z = #safez #r = [#radius - #milld/2] G0 Z#safez G4 P0 G0 X[#xc + #r] Y#yc Oloop while [ 1 ] Oif if [ #z - #zstep LT #depth] #zstep = [#z - #depth] Oif endif G2 X[#xc - #r] Y#yc Z[#z - #zstep/2] R#r G2 X[#xc + #r] Y#yc Z[#z - #zstep] R#r #z = [#z - #zstep] Oif if [ #z LE #depth ] Oloop break Oif endif Oloop endwhile G2 X[#xc - #r] Y#yc R#r G2 X[#xc + #r] Y#yc R#r G0 Z#safez Ocirculargroove endsub M2 -- 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] Helical interpolation not quite round, WTF?
On 25 September 2012 19:20, Igor Chudov ichu...@gmail.com wrote: I have a routine that lets me mill a deep circle in several passes, typically to cutout circles from plates. You ought to be able to do this with one line of G-code? G2 I[diameter/2] Z 10 P10 ? Lumps at the 4 quadrants would normally be due to backlash problems. -- 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] Helical interpolation not quite round, WTF?
On Tue, 2012-09-25 at 13:20 -0500, Igor Chudov wrote: I have a routine that lets me mill a deep circle in several passes, typically to cutout circles from plates. Something strange is going on and the resulting shape is not exactly round. It can be best described as a circle with humps. The routine is below. It is basically a while loop, milling progressively deeper until Z reaches the required depth. Every loop consists of two half circles milled helically, with the end mill going down along a spiral. Any idea why the shape may not end up being circular? Thanks Routine attached. (Copyright - Igor Chudov, released under GNU Public License V3) Ocirculargroove sub (circular groove, good for milling through holes too) #xc = #1 (X center) #yc = #2 (Y center) #safez = #3 (safe height) #depth = #4 (depth of milling) #radius = #5 (outside radius) #milld = #6 (end mill diameter) #frate = #7 (feed rate) #zstep = #8 (z step, per circle, optional) Oif if [ #frate NE 0 ] F#frate Oif endif Oif if [ #zstep EQ 0 ] #zstep = [#milld/3] Oif endif #z = #safez #r = [#radius - #milld/2] G0 Z#safez G4 P0 G0 X[#xc + #r] Y#yc Oloop while [ 1 ] Oif if [ #z - #zstep LT #depth] #zstep = [#z - #depth] Oif endif G2 X[#xc - #r] Y#yc Z[#z - #zstep/2] R#r G2 X[#xc + #r] Y#yc Z[#z - #zstep] R#r #z = [#z - #zstep] Oif if [ #z LE #depth ] Oloop break Oif endif Oloop endwhile G2 X[#xc - #r] Y#yc R#r G2 X[#xc + #r] Y#yc R#r G0 Z#safez Ocirculargroove endsub M2 Hi Igor, Just off the top of my head I suspect that your program is fine; but the machine is well used and has measurable backlash. In a perfect machine you get real axis reversal ( X | Y ) every 90 degrees. If your ballscrews (lead screw) have backlash then you have to catch up with that before the axis actually changes direction. Since the slope is small around the inflection points not much happens until you take up the slack and then you see the actual reversal. Might be as much as 10 degrees off the ideal. Multiple passes may make it look better but will not necessarily improve the precision. Backlash comp does not fix this; only throwing $$$ at the machine. :-( I hope it turns out to be something fixable without the injection of many $. Dave -- 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] Helical interpolation not quite round, WTF?
Igor, I don't have an answer for you, other than to check on how you've defined you trajectory planning accuracy outside of this routine. Why are you using two half circles? You could just send the cutter back to the starting xy location in a single G2 instruction. N. Christopher Perry On Sep 25, 2012, at 14:20, Igor Chudov ichu...@gmail.com wrote: I have a routine that lets me mill a deep circle in several passes, typically to cutout circles from plates. Something strange is going on and the resulting shape is not exactly round. It can be best described as a circle with humps. The routine is below. It is basically a while loop, milling progressively deeper until Z reaches the required depth. Every loop consists of two half circles milled helically, with the end mill going down along a spiral. Any idea why the shape may not end up being circular? Thanks Routine attached. (Copyright - Igor Chudov, released under GNU Public License V3) Ocirculargroove sub (circular groove, good for milling through holes too) #xc = #1 (X center) #yc = #2 (Y center) #safez = #3 (safe height) #depth = #4 (depth of milling) #radius = #5 (outside radius) #milld = #6 (end mill diameter) #frate = #7 (feed rate) #zstep = #8 (z step, per circle, optional) Oif if [ #frate NE 0 ] F#frate Oif endif Oif if [ #zstep EQ 0 ] #zstep = [#milld/3] Oif endif #z = #safez #r = [#radius - #milld/2] G0 Z#safez G4 P0 G0 X[#xc + #r] Y#yc Oloop while [ 1 ] Oif if [ #z - #zstep LT #depth] #zstep = [#z - #depth] Oif endif G2 X[#xc - #r] Y#yc Z[#z - #zstep/2] R#r G2 X[#xc + #r] Y#yc Z[#z - #zstep] R#r #z = [#z - #zstep] Oif if [ #z LE #depth ] Oloop break Oif endif Oloop endwhile G2 X[#xc - #r] Y#yc R#r G2 X[#xc + #r] Y#yc R#r G0 Z#safez Ocirculargroove endsub M2 -- 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] Helical interpolation not quite round, WTF?
Andy, thanks, what is P? Number of passes? The problem is that the lumps do not look like caused by backlash. There is one place where there is a lump, caused by all passes except the first one. I am very puzzled. i On Tue, Sep 25, 2012 at 1:40 PM, andy pugh bodge...@gmail.com wrote: On 25 September 2012 19:20, Igor Chudov ichu...@gmail.com wrote: I have a routine that lets me mill a deep circle in several passes, typically to cutout circles from plates. You ought to be able to do this with one line of G-code? G2 I[diameter/2] Z 10 P10 ? Lumps at the 4 quadrants would normally be due to backlash problems. -- 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 -- 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] 100 watt 3 phase AC servo amplifier?
On Sep 22, 2012 10:39 PM, Jon Elson el...@pico-systems.com wrote: Viesturs La-cis wrote: 2012/9/22 Jason Burton lathebuil...@gmail.com: Does Mesa or Pico (or another vendor) make a small, inexpensive amp for this size 3 phase servo? Mesa has small BLDC servo amps, but their rated voltage is much lower - 7i39HV is 50 VDC. I do not know about Pico Systems products. Our PWM servo amp has been tested to 122 V, and is good to 20 A. It can be used with either Mesa or Pico Systems controller boards. It needs the Hall signals from the motor for commutation. Jon Hall effect sensors assuming straight contact closures here, not active signals, right? I am at a decision fork. 1) Spend money and time on this hardware, get better performance. Or 2) Sell this and build my own repstrap like version run by with steppers and linuxcnc. I intend to put a flame cutting head on it for small format steel sheet and plate. With a head swap and sitting on top of a Z stage I want to experiment with liquid binder based 3D powder prints. I already have steppers, several drivers, acme leadscrews. It just seemed tantalizing having the complete xy built already minus the control. Don't really want to put $300+ into an experimentation platform that ends up slower than what i could build from my junk box. All thoughts/comments welcome! Best, Jason -- 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] Helical interpolation not quite round, WTF?
On Tue, Sep 25, 2012 at 2:13 PM, Stephen Dubovsky smdubov...@gmail.comwrote: How big are the humps? How many are there? There is one big hump on an about 4 inch circle. This hump is about 1mm tall and 20mm wide. It appears consistently on all passes, except the first one. There is also a much smaller hump in another quadrant, visible, but smaller. I am not` in exact stop mode. i Are you in exact stop mode? If motion stops at the beginning/end of each semicircle then you will get a little hump from springback during the pause. Lead-in out are typ used when cutting IDs to prevent that. Stephen -- 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] Helical interpolation not quite round, WTF?
On Tue, 2012-09-25 at 15:13 -0400, Stephen Dubovsky wrote: How big are the humps? How many are there? Are you in exact stop mode? If motion stops at the beginning/end of each semicircle then you will get a little hump from springback during the pause. Lead-in out are typ used when cutting IDs to prevent that. Stephen Ah! Both good questions I should have been smart enough to ask. Since my mill is not as stiff as would be ideal I tend to take small Z increments/360 degrees and work my way down taking at least an extra pass or two at the max depth as spring passes. To extend Stephen's question: where are the humps, exactly at 0, 90, 180 270 or offset some. Are they deep enough to not be backlash anomalies? Dave -- 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] Helical interpolation not quite round, WTF?
Humps are 1) Northwest corner, biggest hump, 1mm tall by 20mm wide 2) Northeast corner, 0.5mm by 15mm wide On Tue, Sep 25, 2012 at 3:08 PM, dave dengv...@charter.net wrote: On Tue, 2012-09-25 at 15:13 -0400, Stephen Dubovsky wrote: How big are the humps? How many are there? Are you in exact stop mode? If motion stops at the beginning/end of each semicircle then you will get a little hump from springback during the pause. Lead-in out are typ used when cutting IDs to prevent that. Stephen Ah! Both good questions I should have been smart enough to ask. Since my mill is not as stiff as would be ideal I tend to take small Z increments/360 degrees and work my way down taking at least an extra pass or two at the max depth as spring passes. To extend Stephen's question: where are the humps, exactly at 0, 90, 180 270 or offset some. Are they deep enough to not be backlash anomalies? Dave -- 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 -- 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] Helical interpolation not quite round, WTF?
It's pretty unlikely, but with the first pass being free of humps I'd be tempted to look at tool deflection. If your first pass is milling in from fresh air it'll take a lighter cut, the heavier (and more consistent) cut on each subsequent pass could then be deflecting slightly. If this is the case, and you don't find a better solution - you can always do the cut in two passes, cut it 1-3 mm undersize then do a quick finish pass to cleanup. Not ideal, but I tend to have to do this with smaller diameter cutters on my non-rigid router. Your sub looks OK, but I'd also be tempted to use G2 I J Z P directly to rule out any... odd motion planning. Ben -Original Message- From: Igor Chudov [mailto:ichu...@gmail.com] Sent: 25 September 2012 21:31 To: dengv...@charter.net; Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] Helical interpolation not quite round, WTF? Humps are 1) Northwest corner, biggest hump, 1mm tall by 20mm wide 2) Northeast corner, 0.5mm by 15mm wide On Tue, Sep 25, 2012 at 3:08 PM, dave dengv...@charter.net wrote: On Tue, 2012-09-25 at 15:13 -0400, Stephen Dubovsky wrote: How big are the humps? How many are there? Are you in exact stop mode? If motion stops at the beginning/end of each semicircle then you will get a little hump from springback during the pause. Lead-in out are typ used when cutting IDs to prevent that. Stephen Ah! Both good questions I should have been smart enough to ask. Since my mill is not as stiff as would be ideal I tend to take small Z increments/360 degrees and work my way down taking at least an extra pass or two at the max depth as spring passes. To extend Stephen's question: where are the humps, exactly at 0, 90, 180 270 or offset some. Are they deep enough to not be backlash anomalies? Dave -- 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 -- 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] Lost PLA Casting
On Sep 24, 2012, at 6:33 AM, Steve Stallings wrote: It looks like he used a crucible lifter to do the pour. Guilty as charged! 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] Lost PLA Casting
On Sep 25, 2012, at 9:54 AM, Kent A. Reed wrote: Congratulations, Jeshua. Your project made Hackaday today. I hope your website is ready for the inevitable bump in traffic. Thanks Kent! Ready, willing and able!!! 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] Helical interpolation not quite round, WTF?
Sometimes milling in the opposite direction will help.Rough one direction then put in a finish pass in the other. Looking at your code I see you have a G2.Unless this is plastic or something really gummy you should be using G3 for ID work.Or you are using left handed mills. Climb milling is the way to do most everything. Terry - Original Message - From: dave dengv...@charter.net To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Cc: Sent: Tuesday, September 25, 2012 3:08 PM Subject: Re: [Emc-users] Helical interpolation not quite round, WTF? On Tue, 2012-09-25 at 15:13 -0400, Stephen Dubovsky wrote: How big are the humps? How many are there? Are you in exact stop mode? If motion stops at the beginning/end of each semicircle then you will get a little hump from springback during the pause. Lead-in out are typ used when cutting IDs to prevent that. Stephen Ah! Both good questions I should have been smart enough to ask. Since my mill is not as stiff as would be ideal I tend to take small Z increments/360 degrees and work my way down taking at least an extra pass or two at the max depth as spring passes. To extend Stephen's question: where are the humps, exactly at 0, 90, 180 270 or offset some. Are they deep enough to not be backlash anomalies? Dave -- 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 -- 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] Helical interpolation not quite round, WTF?
Igor Chudov wrote: Andy, thanks, what is P? Number of passes? The problem is that the lumps do not look like caused by backlash. There is one place where there is a lump, caused by all passes except the first one. I am very puzzled. Can you blow up the Axis plot window and see the lump? You can also plot velocity in Halscope and look for non-sinusoidal bumps there. You might try makebore.c or makering.c from my web page http://pico-systems.com/gcode.html and see if you get different results. makering.c makes a slightly undersize circular pass in 4 quadrants X the number of depth steps, then spirals out and makes 4 more quadrants at the finish diameter. It definitely does not give bumps with a 2.4.x LinuxCNC on an older Linux kernel. I have not done any precision work with 2.5 (my production system runs a bit behind on updates). 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] 100 watt 3 phase AC servo amplifier?
Jason Burton wrote: Hall effect sensors assuming straight contact closures here, not active signals, right? Well, the typical real Hall sensor in the motor needs +5 V, but is often like a contact closure to ground. So, the Hall sensor package has 5 wires, +5, Ground and 3 signal wires. I am at a decision fork. 1) Spend money and time on this hardware, get better performance. Or 2) Sell this and build my own repstrap like version run by with steppers and linuxcnc. Well, brushless servos have WAY more performance than steppers. Although, in the repstrap size machine, it may not make a whole lot of difference. I intend to put a flame cutting head on it for small format steel sheet and plate. Hmm, I can't imagine a repstrap with a torch on it. With a head swap and sitting on top of a Z stage I want to experiment with liquid binder based 3D powder prints. I already have steppers, several drivers, acme leadscrews. It just seemed tantalizing having the complete xy built already minus the control. Don't really want to put $300+ into an experimentation platform that ends up slower than what i could build from my junk box. Well, probably won't be slower. I think your motors were rated to 3000 RPM at ~200 V, so I'm guessing you'd get about 1800 RPM with my servo amps. 1800 RPM with a 20 TPI leadscrew would give 90 IPM, but if the leadscrew had slower pitch, you could get 360 IPM at 5 TPI, for instance. Not sure you can actually spin a thin leadscrew at 1800 RPM without bending it, so the motor may not be the limiting factor. You certainly cannot get 1800 RPM with most stepper motors, they will severely overheat at sustained speeds over 1000 RPM. 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] Helical interpolation not quite round, WTF?
Igor Chudov wrote: Humps are 1) Northwest corner, biggest hump, 1mm tall by 20mm wide 2) Northeast corner, 0.5mm by 15mm wide This has to be a program error. And, you should be able to EASILY see this on the Axis 3D display. Load the program, and then use the mouse buttons to tilt the display until you are looking flat at the XY plane. Zoom in and pan around the circle. The deviation on successive depth passes should show up very easily if it is a mm deep into the wall of the hole. If it shows up on the preview, that gets backlash and the entire motion system off the hook. 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] Helical interpolation not quite round, WTF?
On Tuesday 25 September 2012 23:23:36 Igor Chudov did opine: I have a routine that lets me mill a deep circle in several passes, typically to cutout circles from plates. Something strange is going on and the resulting shape is not exactly round. It can be best described as a circle with humps. The routine is below. It is basically a while loop, milling progressively deeper until Z reaches the required depth. Every loop consists of two half circles milled helically, with the end mill going down along a spiral. Any idea why the shape may not end up being circular? Thanks Routine attached. (Copyright - Igor Chudov, released under GNU Public License V3) Ocirculargroove sub (circular groove, good for milling through holes too) #xc = #1 (X center) #yc = #2 (Y center) #safez = #3 (safe height) #depth = #4 (depth of milling) #radius = #5 (outside radius) #milld = #6 (end mill diameter) #frate = #7 (feed rate) #zstep = #8 (z step, per circle, optional) Oif if [ #frate NE 0 ] F#frate Oif endif Oif if [ #zstep EQ 0 ] #zstep = [#milld/3] Oif endif #z = #safez #r = [#radius - #milld/2] G0 Z#safez G4 P0 G0 X[#xc + #r] Y#yc Oloop while [ 1 ] Oif if [ #z - #zstep LT #depth] #zstep = [#z - #depth] Oif endif G2 X[#xc - #r] Y#yc Z[#z - #zstep/2] R#r G2 X[#xc + #r] Y#yc Z[#z - #zstep] R#r #z = [#z - #zstep] Oif if [ #z LE #depth ] Oloop break Oif endif Oloop endwhile G2 X[#xc - #r] Y#yc R#r G2 X[#xc + #r] Y#yc R#r G0 Z#safez Ocirculargroove endsub M2 The first thing I'd check would be uncompensated backlash. Then it would go to damaged screws, like a highly used area wobbled out. Third would be scaling error on one axis, but thats fairly easy to check. 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! A penny saved has not been spent. -- 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
