Re: [Emc-users] Stepper speed
Kirk, Yes, I have used the dampers and they work well. My motors at home don't have the dual shafts. I made due with some old motors. Things are working well for me right now without them. I could run faster if I had them on the motors. Here are work, I have seen the results and it's not pretty. Steppers do have a lot of oscillations during stepping. There is always a resonant speed where torque falls way off. With the electronic gearing of EMC, there is no way to avoid this condition. One just has to make sure there is still enough torque to continue the motion without breaking the phase. Jim C Kirk Wallace [EMAIL PROTECTED] company.com To Sent by: Enhanced Machine Controller (EMC) emc-users-bounces emc-users@lists.sourceforge.net @lists.sourceforg cc e.net Subject Re: [Emc-users] Stepper speed 03/07/2008 03:13 PM Please respond to Enhanced Machine Controller (EMC) [EMAIL PROTECTED] sourceforge.net On Fri, 2008-03-07 at 14:19 -0500, [EMAIL PROTECTED] wrote: Ian, I am using the basic output from HAL via a 1284 parallel printer port, (mode 2). The stepper motor drivers are just doing the chopping to limit current. I didn't change HAL in any way. The one thing you might try is to limit the acceleration. I was surprised when I raised the motor voltage and started missing steps. That was not at all what I expected. I am driving a 2.5mm pitch lead screw with 1.8 degree steppers (NEMA 14) Jim Combs Lexington, Ky Others on this list have used mass and/or fluid dampers to deal with stepper resonance problems. I wonder if a high resolution encoder and Halscope could be used to study inter-step movement at speed? Maybe running on another EMC PC? -- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC lathe, Bridgeport mill conversion, doing XY now, Zubal lathe conversion pending) - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Stepper speed
Please, I did not in any way mean to be unfair to EMC. I did not mean it in that way at all. EMC is a fantastic program. What I mean is that by doing the electronic gearing there is no way to avoid a condition where a stepper motor is operating at a step rate where resonance is present. It will happen and there is not anything EMC can do to prevent it. Its just a condition of steppers that cannot be avoided. It's hard to read E-mail and not have the writing be taken in the wrong way. Don't take my comments to be bashing EMC in any way. It has been everything I have been looking for in CNC control. I have no issues with EMC at all. It's a fantastic package and there has been a ton of work put into it. Jim C Gene Heskett [EMAIL PROTECTED] izon.net To Sent by: Enhanced Machine Controller (EMC) emc-users-bounces emc-users@lists.sourceforge.net @lists.sourceforg cc e.net Subject Re: [Emc-users] Stepper speed 03/10/2008 09:38 AM Please respond to Enhanced Machine Controller (EMC) [EMAIL PROTECTED] sourceforge.net On Monday 10 March 2008, [EMAIL PROTECTED] wrote: Kirk, Yes, I have used the dampers and they work well. My motors at home don't have the dual shafts. I made due with some old motors. Things are working well for me right now without them. I could run faster if I had them on the motors. Here are work, I have seen the results and it's not pretty. Steppers do have a lot of oscillations during stepping. There is always a resonant speed where torque falls way off. With the electronic gearing of EMC, there is no way to avoid this condition. This statement is grossly unfair to emc. This problem will exist for stepper motors regardless of the driver software chosen. One just has to make sure there is still enough torque to continue the motion without breaking the phase. Jim C Kirk Wallace [EMAIL PROTECTED] company.com To Sent by: Enhanced Machine Controller (EMC) emc-users-bounces emc-users@lists.sourceforge.net @lists.sourceforg cc e.net Subject Re: [Emc-users] Stepper speed 03/07/2008 03:13 PM Please respond to Enhanced Machine Controller (EMC) [EMAIL PROTECTED] sourceforge.net On Fri, 2008-03-07 at 14:19 -0500, [EMAIL PROTECTED] wrote: Ian, I am using the basic output from HAL via a 1284 parallel printer port, (mode 2). The stepper motor drivers are just doing the chopping to limit current. I didn't change HAL in any way. The one thing you might try is to limit the acceleration. I was surprised when I raised the motor voltage and started missing steps. That was not at all what I expected. I am driving a 2.5mm pitch lead screw with 1.8 degree steppers (NEMA 14) Jim Combs Lexington, Ky Others on this list have used mass and/or fluid dampers to deal with stepper resonance problems. I wonder if a high resolution encoder and Halscope could be used to study inter-step movement at speed? Maybe running on another EMC PC? -- 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) I'd put my money where my mouth is, but my mouth keeps moving. -- Larry Wall in [EMAIL PROTECTED] - This SF.net email is sponsored by: Microsoft Defy
[Emc-users] Radius to start differs from radius to end...
I'm pretty sure I've seen this asked before, but I couldn't find it in the archives for this mail list. I'm running EMC2. I get this error on lines with G2 or G3 in them. (The code is output from Synergy). If I get this error, is there still a setting (like INCH_TOLERANCE) that will relax the conditions that produce this error? Also: is this affected by cutter diameter compensation settings, or by relative vs incremental vs absolute modes? Google has showed me some mention of this on other mail lists, but I fiddled with those settings and couldn't resolve it that way. Is there a place in the documentation where I can read about this? Thanks in advance! Ben - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Radius to start differs from radius to end...
Hi Ben, Remember, Synergy does things differently. It writes code that is offset by cutter radius and also uses G41/G42. This means the tool table diameters need to be zero. Small deviations are then entered into the tool table to compensate for sharpening or small adjustments in dimensioning. I've not been successful in making that work so I just live with zero. If anyone knows how to make that work I'd be interested. Synergy will let you rough with a tool that is tool big and then come back with a smaller tool and just cleanup the inside corners. Really a handy feature. HTH Dave On Mar 10, 2008, at 4:26 AM, Ben Dugan wrote: I'm pretty sure I've seen this asked before, but I couldn't find it in the archives for this mail list. I'm running EMC2. I get this error on lines with G2 or G3 in them. (The code is output from Synergy). If I get this error, is there still a setting (like INCH_TOLERANCE) that will relax the conditions that produce this error? Also: is this affected by cutter diameter compensation settings, or by relative vs incremental vs absolute modes? Google has showed me some mention of this on other mail lists, but I fiddled with those settings and couldn't resolve it that way. Is there a place in the documentation where I can read about this? Thanks in advance! Ben -- --- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Stepper speed
On Mon, 2008-03-10 at 10:49 -0400, [EMAIL PROTECTED] wrote: Please, I did not in any way mean to be unfair to EMC. I did not mean it in that way at all. EMC is a fantastic program. What I mean is that by doing the electronic gearing there is no way to avoid a condition where a stepper motor is operating at a step rate where resonance is present. It will happen and there is not anything EMC can do to prevent it. Its just a condition of steppers that cannot be avoided. It's hard to read E-mail and not have the writing be taken in the wrong way. Don't take my comments to be bashing EMC in any way. It has been everything I have been looking for in CNC control. I have no issues with EMC at all. It's a fantastic package and there has been a ton of work put into it. Jim C I am brainstorming here. I think you stated the crux of the problem with there is no way to avoid a condition where a stepper motor is operating at a step rate where resonance is present. The mechanical damping can move where resonance happens. I also noticed from other threads, that the voltage the stepper is driven with can change the resonance frequency. I think the ideal would be to move the resonance above the maximum operating speed, so you never see it in normal operation. Isn't micro stepping the most effective tool against resonance? Or maybe an RC filter on the driver outputs to help shape the voltage. Of course EMC is flexible enough to be able to set up some sort of feedback to mechanically or electrically change the stepping characteristics. Brushless DC motors are just low pole count steppers aren't they? I wonder if a stepper driver could be used to drive a BLDC? Though I suppose a BLDC driver might be better. -- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC lathe, Bridgeport mill conversion, doing XY now, Zubal lathe conversion pending) - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Radius to start differs from radius to end...
So far, I have used Synergy to draw the part, then draw the tool paths and use the path way points to write G-code. That method may not be usable for complex parts, but I suppose it lets you use tool compensation. I have only written a few programs, so writing programs by hand is probably good, but I guess I will need to upgrade my skills in the near future. I am not sure of the term, but is there a mill and lathe machine personality that fits EMC? Kirk On Mon, 2008-03-10 at 08:37 -0700, Dave Engvall wrote: Hi Ben, Remember, Synergy does things differently. It writes code that is offset by cutter radius and also uses G41/G42. This means the tool table diameters need to be zero. Small deviations are then entered into the tool table to compensate for sharpening or small adjustments in dimensioning. I've not been successful in making that work so I just live with zero. If anyone knows how to make that work I'd be interested. Synergy will let you rough with a tool that is tool big and then come back with a smaller tool and just cleanup the inside corners. Really a handy feature. HTH Dave On Mar 10, 2008, at 4:26 AM, Ben Dugan wrote: I'm pretty sure I've seen this asked before, but I couldn't find it in the archives for this mail list. I'm running EMC2. I get this error on lines with G2 or G3 in them. (The code is output from Synergy). If I get this error, is there still a setting (like INCH_TOLERANCE) that will relax the conditions that produce this error? Also: is this affected by cutter diameter compensation settings, or by relative vs incremental vs absolute modes? Google has showed me some mention of this on other mail lists, but I fiddled with those settings and couldn't resolve it that way. Is there a place in the documentation where I can read about this? Thanks in advance! Ben -- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC lathe, Bridgeport mill conversion, doing XY now, Zubal lathe conversion pending) - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Stepper speed
On Monday 10 March 2008, [EMAIL PROTECTED] wrote: Please, I did not in any way mean to be unfair to EMC. I did not mean it in that way at all. EMC is a fantastic program. What I mean is that by doing the electronic gearing there is no way to avoid a condition where a stepper motor is operating at a step rate where resonance is present. It will happen and there is not anything EMC can do to prevent it. Its just a condition of steppers that cannot be avoided. It's hard to read E-mail and not have the writing be taken in the wrong way. Don't take my comments to be bashing EMC in any way. It has been everything I have been looking for in CNC control. I have no issues with EMC at all. It's a fantastic package and there has been a ton of work put into it. Jim C I may have been a bit defensive there, I agree that emc is at least as good as sliced bread and bottled beer, but not quite up to competing with instant sex yet as I'm only 73. :) I'm also not at all fam with how other software packages intended to drive steppers may or may not handle the getting through the critical speed problem. I suspect they make no attempt to work around it either. I have dampers on mine, all 4 axis's now, and they somewhat resemble the ones Jeff may have a pix of on the xylotex site, and they seem to work quite well, allowing me to get decent speeds (far faster than it can cut) on my micromill, but I pretty much limit it to something that keeps it well below those speeds while actually cutting even if its a tool up rapid. They are cobble jobs for sure, and don't even fit the shaft of the motor all that well so they wobble a bit, the 1/4 drill bit that mic's at 0.2477 I used apparently was drilling about a 0.265 hole by the time it got to the deep end of the through-hole. :( You can see mine at http://gene.homelinux.net:85/gene/emc along with the rest of the old farts messy machineing corner in my wood working shop. That *was* an HF MicroMill at one point in past history, not sure what it should be called now. The Z axis motor is a 425oz, and I can now exert 150 pounds of push on a drill bit, so I can actually drill decent sized holes in steel with gcode. The rest of the motors are 262oz motors. xylotex drivers. -- 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) A black cat crossing your path signifies that the animal is going somewhere. -- Groucho Marx - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] fanuc
patrice.vallade Vallade wrote: Is il possible to use emc2 whit a Fanuc, but i dont now what sort of fanuc it is. Fanuc makes machine controls, not machine tools. EMC is usually used to REPLACE a dead machine tool control unit. We replaced the Fanuc control on a Mazak VMC-5 at Roland Freistad's shop with EMC, and now EMC2. It controls the basic machine as well as the toolchanger. Jon - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Radius to start differs from radius to end...
Hi Kirk, I have two EMC posts on my machine. The standard one labeled EMC and one that uses R rather than I,J for circular interp. D On Mar 10, 2008, at 9:30 AM, Kirk Wallace wrote: So far, I have used Synergy to draw the part, then draw the tool paths and use the path way points to write G-code. That method may not be usable for complex parts, but I suppose it lets you use tool compensation. I have only written a few programs, so writing programs by hand is probably good, but I guess I will need to upgrade my skills in the near future. I am not sure of the term, but is there a mill and lathe machine personality that fits EMC? Kirk On Mon, 2008-03-10 at 08:37 -0700, Dave Engvall wrote: Hi Ben, Remember, Synergy does things differently. It writes code that is offset by cutter radius and also uses G41/G42. This means the tool table diameters need to be zero. Small deviations are then entered into the tool table to compensate for sharpening or small adjustments in dimensioning. I've not been successful in making that work so I just live with zero. If anyone knows how to make that work I'd be interested. Synergy will let you rough with a tool that is tool big and then come back with a smaller tool and just cleanup the inside corners. Really a handy feature. HTH Dave On Mar 10, 2008, at 4:26 AM, Ben Dugan wrote: I'm pretty sure I've seen this asked before, but I couldn't find it in the archives for this mail list. I'm running EMC2. I get this error on lines with G2 or G3 in them. (The code is output from Synergy). If I get this error, is there still a setting (like INCH_TOLERANCE) that will relax the conditions that produce this error? Also: is this affected by cutter diameter compensation settings, or by relative vs incremental vs absolute modes? Google has showed me some mention of this on other mail lists, but I fiddled with those settings and couldn't resolve it that way. Is there a place in the documentation where I can read about this? Thanks in advance! Ben -- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC lathe, Bridgeport mill conversion, doing XY now, Zubal lathe conversion pending) -- --- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Serial Encoders
I am looking into adding a knob for setting spindle speed manually. This serial encoder is close to what I am looking for: http://www.usdigital.com/products/a2/ but is over-kill and way too expensive. Does anyone have a link to an 8 or 10 bit serial (SPI like) absolute encoder? I checked Digikey but didn't find anything. Other options are to use a potentiometer and serial ADC or PWM to serial, but an inexpensive single unit would be better. Thanks. -- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC lathe, Bridgeport mill conversion, doing XY now, Zubal lathe conversion pending) - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Stepper speed
On Monday 10 March 2008, Kirk Wallace wrote: On Mon, 2008-03-10 at 10:49 -0400, [EMAIL PROTECTED] wrote: Please, I did not in any way mean to be unfair to EMC. I did not mean it in that way at all. EMC is a fantastic program. What I mean is that by doing the electronic gearing there is no way to avoid a condition where a stepper motor is operating at a step rate where resonance is present. It will happen and there is not anything EMC can do to prevent it. Its just a condition of steppers that cannot be avoided. It's hard to read E-mail and not have the writing be taken in the wrong way. Don't take my comments to be bashing EMC in any way. It has been everything I have been looking for in CNC control. I have no issues with EMC at all. It's a fantastic package and there has been a ton of work put into it. Jim C I am brainstorming here. I think you stated the crux of the problem with there is no way to avoid a condition where a stepper motor is operating at a step rate where resonance is present. The mechanical damping can move where resonance happens. No, it can serve to absorb it, quite well from my experiences so far. Common sense says the weight of the damper will lower that frequency somewhat also. In the dampers I have, I can magic marker all those fender washers, run that azis to its limits each way once, and no washer will be where I marked it. They work by slipping against the rubber, maybe as little as .001 degrees per step per washer, but that slippage energy is subtracked from the stored energy, encouraging the motor to move smoother because the slippage can be and is, both ways on a given step's motion. The inner shaft is 2 or 3 thou smaller than a 5/8 hole fender washer, but the rubber washers have only about a 1/2 hole, and roughly carved at that, so that the rubber washers are reasonably well locked to the inner shaft, and bulge out at the center when forced over the inner shaft to lightly grip the fender washers near their centers. Leave the retainer collar loose enough that you can turn any of the fender washers by hand fairly easily. I also noticed from other threads, that the voltage the stepper is driven with can change the resonance frequency. Yes, the higher the voltage, within limits the stiffer it will be in that rpm range where the inductance of the motor is costing it torque. Below that range it should be a wash cuz the driver is chopper regulating the current and therefore the strength of the magnetic spring action. I think the ideal would be to move the resonance above the maximum operating speed, so you never see it in normal operation. That would take a new concept in current profile control, and even then may not work well as the spikes of high current that would imply might be high enough to demagnetize the rotor, and effectively reduce its power forever. Isn't micro stepping the most effective tool against resonance? Yes, the finer the better although going beyond 8 steps does seem to be an area of diminishing returns. Or maybe an RC filter on the driver outputs to help shape the voltage. Absolutely not. The inrush currents in any capacitance would quickly overheat and destroy the H bridge components in the output stage, and any resistance there is pure power loss. We are cautioned to not even hook a scope probe to a motor lead because of its added capacitance. Of course EMC is flexible enough to be able to set up some sort of feedback to mechanically or electrically change the stepping characteristics. There are others here who can describe the sharpness of the stones in that path far better than I. I'll only say its a rocky road. :) Brushless DC motors are just low pole count steppers aren't they? I wonder if a stepper driver could be used to drive a BLDC? Though I suppose a BLDC driver might be better. And that is another area I'll invite others to comment on. -- 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) QOTD: Even the Statue of Liberty shaves her pits. - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Serial Encoders
Kirk Wallace wrote: I am looking into adding a knob for setting spindle speed manually. This serial encoder is close to what I am looking for: http://www.usdigital.com/products/a2/ but is over-kill and way too expensive. Does anyone have a link to an 8 or 10 bit serial (SPI like) absolute encoder? I checked Digikey but didn't find anything. Other options are to use a potentiometer and serial ADC or PWM to serial, but an inexpensive single unit would be better. Thanks. I would not recommend absolute encoders (or pots with A/Ds, which are also absolute). Think about something like feed override, where the is a slider on the GUI as well as a physical knob. If you turn the knob, EMC will adjust the position of the slider to match. But if you move the GUI slider, it is impossible to turn the knob to match. If you use an incremental encoder with no scale, then it can coexist nicely with the GUI slider (or with other physical controls - for example you could have a knob at the machine control, and another knob located on the far side of a large machine table. Another example would be on-off controls like spindle or coolant. If you use a toggle switch, you can have only one. If you use start and stop buttons, you can have as many of each as you want. This concept of using incremental controls is a fundamental principle adopted by NIST when they were designing EMC. Think long and hard about the implications before you switch to absolute controls. Regards, John Kasunich - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Stepper speed
Gene, I may have to investigate adding dampers like you have done. I didn't consider adding it between the motor and the machine. I had always seen dampers on the back side of the steppers. Jim C - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Stepper speed
On Monday 10 March 2008, [EMAIL PROTECTED] wrote: Gene, I may have to investigate adding dampers like you have done. I didn't consider adding it between the motor and the machine. I had always seen dampers on the back side of the steppers. Jim C Those aren't dampers on the work end of the motor, those are the slip joint couplings I made by hand as nearly the first parts that mill made. The dampers are the striped things on the rear. A drum to hold all the washers with the flange as part of the barrel on one end, and a collar to retain the washers on the other end. Alternating fender washers with a 5/8 hole, and some sort of a fairly dead rubber sheet cut into washers with only about a 1/2 hole, so the rubber expands sideways and lightly grips the fender washers when forced over the 5/8 partion of the drum. - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- 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) MSDOS didn't get as bad as it is overnight -- it took over ten years of careful development. -- [EMAIL PROTECTED] - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Radius to start differs from radius to end
Gentlemen, Does Synergy's post allow you to specify the end point of the arc to be exactly on the circle? The distance between the starting point and the center of the radius AND the distance between the ending point and the center of the radius must match. I don't know the numeric precision of the calculations in EMC but on a Fanuc control I have had to round down by a part of one ten thousandth of an inch in some of my manual calculations to make the circle interpolation work. thanks Stuart - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Serial Encoders
On Mon, 10 Mar 2008, John Kasunich wrote: Kirk Wallace wrote: I am looking into adding a knob for setting spindle speed manually. This serial encoder is close to what I am looking for: http://www.usdigital.com/products/a2/ but is over-kill and way too expensive. Does anyone have a link to an 8 or 10 bit serial (SPI like) absolute encoder? I checked Digikey but didn't find anything. Other options are to use a potentiometer and serial ADC or PWM to serial, but an inexpensive single unit would be better. Thanks. I would not recommend absolute encoders (or pots with A/Ds, which are also absolute). Think about something like feed override, where the is a slider on the GUI as well as a physical knob. If you turn the knob, EMC will adjust the position of the slider to match. But if you move the GUI slider, it is impossible to turn the knob to match. If you use an incremental encoder with no scale, then it can coexist nicely with the GUI slider (or with other physical controls - for example you could have a knob at the machine control, and another knob located on the far side of a large machine table. Another example would be on-off controls like spindle or coolant. If you use a toggle switch, you can have only one. If you use start and stop buttons, you can have as many of each as you want. This concept of using incremental controls is a fundamental principle adopted by NIST when they were designing EMC. Think long and hard about the implications before you switch to absolute controls. Regards, John Kasunich I agree wholeheartedly with John. However if you do need an inexpensive absolute encoder, austria microsystems makes an interesting magnetic sensor with 8-12 bit precision for under $20: http://www.austriamicrosystems.com/03products/20_rotary_encoders.htm They have the magnets too. -fenn - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Stepper speed
Been reading through some old stuff recently and found the graphic I put in pastebin at http://imagebin.ca/view/clpgA5sW.html. It was in the graduate theses that Sagar wrote on his EMC propelled SCARA robot. IMO the zero torque portion of the speed/torque curve on the full step graph ought to say something to those of us that care about stepper motor position control. Rayh --- [EMAIL PROTECTED] wrote: From: Gene Heskett [EMAIL PROTECTED] To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Subject: Re: [Emc-users] Stepper speed Date: Mon, 10 Mar 2008 13:46:42 -0400 On Monday 10 March 2008, [EMAIL PROTECTED] wrote: Gene, I may have to investigate adding dampers like you have done. I didn't consider adding it between the motor and the machine. I had always seen dampers on the back side of the steppers. Jim C Those aren't dampers on the work end of the motor, those are the slip joint couplings I made by hand as nearly the first parts that mill made. The dampers are the striped things on the rear. A drum to hold all the washers with the flange as part of the barrel on one end, and a collar to retain the washers on the other end. Alternating fender washers with a 5/8 hole, and some sort of a fairly dead rubber sheet cut into washers with only about a 1/2 hole, so the rubber expands sideways and lightly grips the fender washers when forced over the 5/8 partion of the drum. - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- 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) MSDOS didn't get as bad as it is overnight -- it took over ten years of careful development. -- [EMAIL PROTECTED] - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Stepper speed
On Mon, 2008-03-10 at 12:55 -0400, Gene Heskett wrote: On Monday 10 March 2008, Kirk Wallace wrote: ...snip No, it can serve to absorb it, quite well from my experiences so far. Common sense says the weight of the damper will lower that frequency somewhat also. ... snip Yes, I agree. I must have gotten up on the dumb side of the bed today. I also noticed from other threads, that the voltage the stepper is driven with can change the resonance frequency. Yes, the higher the voltage, within limits the stiffer it will be in that rpm range where the inductance of the motor is costing it torque. Below that range it should be a wash cuz the driver is chopper regulating the current and therefore the strength of the magnetic spring action. I think the ideal would be to move the resonance above the maximum operating speed, so you never see it in normal operation. I should have said, move the resonance down. (or convert to heat or something else as you mention above.) That would take a new concept in current profile control, and even then may not work well as the spikes of high current that would imply might be high enough to demagnetize the rotor, and effectively reduce its power forever. Isn't micro stepping the most effective tool against resonance? Yes, the finer the better although going beyond 8 steps does seem to be an area of diminishing returns. Or maybe an RC filter on the driver outputs to help shape the voltage. Absolutely not. The inrush currents in any capacitance would quickly overheat and destroy the H bridge components in the output stage, and any resistance there is pure power loss. We are cautioned to not even hook a scope probe to a motor lead because of its added capacitance. Ops, another mistake. What I was trying to say is, there might be widely different ways to change the output signal shape. Of course EMC is flexible enough to be able to set up some sort of feedback to mechanically or electrically change the stepping characteristics. There are others here who can describe the sharpness of the stones in that path far better than I. I'll only say its a rocky road. :) Brushless DC motors are just low pole count steppers aren't they? I wonder if a stepper driver could be used to drive a BLDC? Though I suppose a BLDC driver might be better. And that is another area I'll invite others to comment on. -- Cheers, Gene Thanks. I knew there was a reason I keep yuz guys around. -- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC lathe, Bridgeport mill conversion, doing XY now, Zubal lathe conversion pending) - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Radius to start differs from radius to end
Hi Stuart, I have to play dumb here. I just let Synergy do it's thing. I didn't find anything in the post. If you draw it correctly it seems synergy will do it. I think emc is double precision internally. Plenty of resolution. :-) Someone will correct me if this is incorrect. ;-) Dave On Mar 10, 2008, at 11:01 AM, Stuart Stevenson wrote: Gentlemen, Does Synergy's post allow you to specify the end point of the arc to be exactly on the circle? The distance between the starting point and the center of the radius AND the distance between the ending point and the center of the radius must match. I don't know the numeric precision of the calculations in EMC but on a Fanuc control I have had to round down by a part of one ten thousandth of an inch in some of my manual calculations to make the circle interpolation work. thanks Stuart -- --- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Serial Encoders
--- [EMAIL PROTECTED] wrote: From: ben lipkowitz [EMAIL PROTECTED] To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Subject: Re: [Emc-users] Serial Encoders Date: Mon, 10 Mar 2008 17:46:26 + (UTC) ...if you do need an inexpensive absolute encoder, austria microsystems makes an interesting magnetic sensor with 8-12 bit precision for under $20: http://www.austriamicrosystems.com/03products/20_rotary_encoders.htm They have the magnets too. I used a quadrature encoder from a range control in a few experiments around here. Worked great for up/down stuff like spindle and feed override. Found one at an appliance repair shop with a 1/4 inch split shaft for a push on knob. Ray - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Stepper speed
On Mon, 2008-03-10 at 12:27 -0400, Gene Heskett wrote: ...snip You can see mine at http://gene.homelinux.net:85/gene/emc along with the rest of the old farts messy machineing corner in my wood working shop. That *was* an HF MicroMill at one point in past history, not sure what it should be called now. The Z axis motor is a 425oz, and I can now exert 150 pounds of push on a drill bit, so I can actually drill decent sized holes in steel with gcode. The rest of the motors are 262oz motors. xylotex drivers. I like the design of the CNC mill, I may need to copy some of it. What size and make is the lathe? That's clever how you kept the non-CNC look. -- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC lathe, Bridgeport mill conversion, doing XY now, Zubal lathe conversion pending) - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Radius to start differs from radius to end
At 01:01 PM 3/10/2008, you wrote: Gentlemen, Does Synergy's post allow you to specify the end point of the arc to be exactly on the circle? The distance between the starting point and the center of the radius AND the distance between the ending point and the center of the radius must match. I don't know the numeric precision of the calculations in EMC but on a Fanuc control I have had to round down by a part of one ten thousandth of an inch in some of my manual calculations to make the circle interpolation work. thanks Stuart There should be a parameter that you can set to the radius error you can live with, on the Fanuc's I have used it was 3410 but that may depend on which Fanuc control. On some controls I have changed this radius tolerance to 0.5 inches or more because they will then cut a smoothly changing radius from start to end, other controls are less useful and just cut the arc at the starting radius and then add a straight line move at the end to get to the programmed finish position. __ Andre' B. Clear Lake, Wi. - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Small CNC Build
Aram, (or anyone interested) I got to thinking about your CNC project. One way to save money and get help, might be to get a group of people together that want the same type of machine. Each member could contribute their skill or money to the cause. Each person contributes, each person gets a machine in the end. Plus there is the economy of scale. I could fabricate parts more efficiently if I made a batch of them. Just a thought. -- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC lathe, Bridgeport mill conversion, doing XY now, Zubal lathe conversion pending) - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Decompiling PLC file
No problem Dale. BTW, what is being controlled by the PLC now? John On 10 Mar 2008 at 6:02, [EMAIL PROTECTED] wrote: John, I will make the list in the next 2 or 3 weeks. By then I will finish reading HAL/Classic Ladder and then start the PLC program. If I have problems can I get some help from you? Thank you for the assistance Dale - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Stepper speed
On Monday 10 March 2008, Kirk Wallace wrote: On Mon, 2008-03-10 at 12:55 -0400, Gene Heskett wrote: On Monday 10 March 2008, Kirk Wallace wrote: ...snip No, it can serve to absorb it, quite well from my experiences so far. Common sense says the weight of the damper will lower that frequency somewhat also. ... snip Yes, I agree. I must have gotten up on the dumb side of the bed today. No comment, been there, bought the T-shirt for 4x what it was worth. :) I also noticed from other threads, that the voltage the stepper is driven with can change the resonance frequency. Yes, the higher the voltage, within limits the stiffer it will be in that rpm range where the inductance of the motor is costing it torque. Below that range it should be a wash cuz the driver is chopper regulating the current and therefore the strength of the magnetic spring action. I think the ideal would be to move the resonance above the maximum operating speed, so you never see it in normal operation. I should have said, move the resonance down. (or convert to heat or something else as you mention above.) Which to a small degree, is what the dampers do. I believe just as important is the energy recovery of the flywheel effect of the loosely coupled weight wanting to continue fwd when the motor has overshot its position and wants to spring back, the spring of the rubber washers being pushed forward by the fender washers then gives enough energy back to stop the motor on position much more quickly. Or at least that 'sequence of events' makes sense to this old fart. :) That would take a new concept in current profile control, and even then may not work well as the spikes of high current that would imply might be high enough to demagnetize the rotor, and effectively reduce its power forever. Isn't micro stepping the most effective tool against resonance? Yes, the finer the better although going beyond 8 steps does seem to be an area of diminishing returns. Or maybe an RC filter on the driver outputs to help shape the voltage. Absolutely not. The inrush currents in any capacitance would quickly overheat and destroy the H bridge components in the output stage, and any resistance there is pure power loss. We are cautioned to not even hook a scope probe to a motor lead because of its added capacitance. Ops, another mistake. What I was trying to say is, there might be widely different ways to change the output signal shape. With decent drivers, the output signal shape voltagewise is a rail to rail square wave at whatever the chopper frequency is, effectively pwm'd by the chopping action to maintain the setpoint current. Of course EMC is flexible enough to be able to set up some sort of feedback to mechanically or electrically change the stepping characteristics. There are others here who can describe the sharpness of the stones in that path far better than I. I'll only say its a rocky road. :) Brushless DC motors are just low pole count steppers aren't they? I wonder if a stepper driver could be used to drive a BLDC? Though I suppose a BLDC driver might be better. And that is another area I'll invite others to comment on. -- Cheers, Gene Thanks. I knew there was a reason I keep yuz guys around. Grin. Thanks. Now, if I could get some answers to my instant problems, the IRC channel seems pretty dead this afternon. But I'll make a seperate post of it. -- 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) Higher education helps your earning capacity. Ask any college professor. - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Stepper speed
On Monday 10 March 2008, Kirk Wallace wrote: On Mon, 2008-03-10 at 12:27 -0400, Gene Heskett wrote: ...snip You can see mine at http://gene.homelinux.net:85/gene/emc along with the rest of the old farts messy machineing corner in my wood working shop. That *was* an HF MicroMill at one point in past history, not sure what it should be called now. The Z axis motor is a 425oz, and I can now exert 150 pounds of push on a drill bit, so I can actually drill decent sized holes in steel with gcode. The rest of the motors are 262oz motors. xylotex drivers. I like the design of the CNC mill, I may need to copy some of it. Be my guest. What size and make is the lathe? That's clever how you kept the non-CNC look. Thats a std 7x12, but with bigger chucks, and it still has its cnc motors in a box sitting on the table saw. Shoemakers kids yadda yadda. :) I even have to replace the top of the compound, I pulled the threads out of the toolpost hole the other day. Probably helped along by my trying to get a stiff enough mount for a boring bar I made, from a 5/8 rod that I milled a slot in the side of and JB welded a much smaller bar with carbide inserts into it. Only about 10 long and I had about 3.5 of it hanging out when I bored that A motor mount out. Way the heck and gone too much bar for a lathe that size. -- 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) JOHN PAUL ELECTED POPE!! (George and Ringo miffed.) - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Stepper speed
On Monday 10 March 2008, [EMAIL PROTECTED] wrote: Been reading through some old stuff recently and found the graphic I put in pastebin at http://imagebin.ca/view/clpgA5sW.html. It was in the graduate theses that Sagar wrote on his EMC propelled SCARA robot. IMO the zero torque portion of the speed/torque curve on the full step graph ought to say something to those of us that care about stepper motor position control. Wow! I knew there was a hole there, but that's absolutely zero damping. Very educational Ray, thanks. BTW, did you know Wally Doerr? -- 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) Vital papers will demonstrate their vitality by spontaneously moving from where you left them to where you can't find them. - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] pwm-0-gen problems
Greetings all; I'm in the process of hooking up one of Steve Stallings #106 spindle controllers, and have run into either a config problem, a buglet or a hardware problem. I thought it might be a bios vs parport thing, and when I checked, I found the bios was setting it for SPP, so I changed it to ECP, which did at least enable the spindle dir output as an output, where before I don't know what it was other than it sat at 45mv regardless of what I did. I can, using the halmeter, see that its enable goes true/false according to the state of the spindle buttons in axis. I can also see the value going up and down when I hit the + and - keys, (BTW, those buttons should be auto-repeat, all three of them, having to click the mouse for every percent of speed increase is a PITA) but the output is false and stays there, both at pwmgen.0.pwm and at parport.0.pin-16-out. So it seems to me that pwmgen isn't genning any pwm's. Try saying that 3 times quickly. :-) So, what do I check next folks? -- 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) If God had intended Men to Smoke, He would have put Chimneys in their Heads. - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] pwm-0-gen problems
Gene Heskett wrote: Greetings all; I'm in the process of hooking up one of Steve Stallings #106 spindle controllers, and have run into either a config problem, a buglet or a hardware problem. I thought it might be a bios vs parport thing, and when I checked, I found the bios was setting it for SPP, so I changed it to ECP, which did at least enable the spindle dir output as an output, where before I don't know what it was other than it sat at 45mv regardless of what I did. I can, using the halmeter, see that its enable goes true/false according to the state of the spindle buttons in axis. I can also see the value going up and down when I hit the + and - keys, (BTW, those buttons should be auto-repeat, all three of them, having to click the mouse for every percent of speed increase is a PITA) but the output is false and stays there, both at pwmgen.0.pwm and at parport.0.pin-16-out. So it seems to me that pwmgen isn't genning any pwm's. Try saying that 3 times quickly. :-) So, what do I check next folks? Divide and conquer. Pwmgen is known to work, so thats not likely to be the problem. Ditto for parport. Test the two individually. Parport first since its easy to test. Use halcmd to hook a signal to it, something like: net testing parport.0.pin-whatever-out then toggle the signal: sets testing 1 sets testing 0 check with a voltmeter to see if its toggling. Then pwmgen - read the man page and hal documentation. There are two functions, one needs to be in the slow (servo) thread, the other needs to be in the fast (base) thread. If you miss either one, no output. There is an enable input - it needs to be true, or no output. You need to select the right PWM mode. You need to provide a non-zero input value. Use halscope to examine the pwmgen output until you get want you want, then connect it to the parport. Regards, John Kasunich - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] pwm-0-gen problems
On Monday 10 March 2008, Kirk Wallace wrote: On Mon, 2008-03-10 at 20:15 -0400, John Kasunich wrote: Gene Heskett wrote: Greetings all; I'm in the process of hooking up one of Steve Stallings #106 spindle ... snip So, what do I check next folks? Divide and conquer. Pwmgen is known to work, so thats not likely to be the problem. Ditto for parport. Test the two individually. Parport first since its easy to test. Use halcmd to hook a signal to it, something like: net testing parport.0.pin-whatever-out then toggle the signal: sets testing 1 sets testing 0 check with a voltmeter to see if its toggling. Then pwmgen - read the man page and hal documentation. There are two functions, one needs to be in the slow (servo) thread, the other needs to be in the fast (base) thread. If you miss either one, no output. There is an enable input - it needs to be true, or no output. You need to select the right PWM mode. You need to provide a non-zero input value. Use halscope to examine the pwmgen output until you get want you want, then connect it to the parport. Regards, John Kasunich I think John said it above, and please forgive me if you have already checked this, but the S value needs to be bigger than 0. M3/4 alone won't spin your spindle. I doesn't mine. I haven't even gotten that far, this is trying to use axis to enable it and 'spin' it by issueing the pwm and dir sigs. I don't have the outputs of Steve's card even connected to the spindle controller card yet, I'm at the point of trying to get the card to actually recognize that its supposed to do something, like run the relays etc. But there is nothing coming out of the pwm pin on the parport but a nice, solid at 50 mv, logic zero. I assume you meant the gcode S'number' command? I'm printing the hal manual right now. It might have a clue or 7, if I can recognize it when it bites me on the ankle. :) This is something that I configured the last time I ran stepconf, so theoretically, all I should have to do is hook it up and go unless theres a bug in stepconf or I have some duff hardware. These are pins that have not been previously utilized. Side note, this is a reversable motor and controller, and I was surprised to see that there isn't any provision for reversing it in axis. And I have used it in reverse a few times when sharpening a bit with a diamond wheel. However, with the A axis working so I can rotate the bit I'm sharpening accurately, I shouldn't have to do that any more. -- Cheers Kirk, 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) Function reject. - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Stepper speed
[EMAIL PROTECTED] wrote: Been reading through some old stuff recently and found the graphic I put in pastebin at http://imagebin.ca/view/clpgA5sW.html. It was in the graduate theses that Sagar wrote on his EMC propelled SCARA robot. IMO the zero torque portion of the speed/torque curve on the full step graph ought to say something to those of us that care about stepper motor position control. YOW! That top curve is the absolute worst-case! You can't get through that wall without great ingenuity or a big chance to lose steps or completely stall. Jon - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Serial Encoders
Since you're convinced you want a quadrature encoder now, here's a link: :) http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=GH6102-ND I've used these before, and they're good, robust controls. They have detents (pretty good clicky ones), and the switch is also a pushbutton with a separate contact pair. They're good for setting something like spindle speed or FO, but probably not for something like a jogwheel (only32 counts per rev). At $20 each (probably less at non-DK distributors), I think they're a good deal. - Steve Kirk Wallace wrote: I am looking into adding a knob for setting spindle speed manually. This serial encoder is close to what I am looking for: http://www.usdigital.com/products/a2/ but is over-kill and way too expensive. Does anyone have a link to an 8 or 10 bit serial (SPI like) absolute encoder? I checked Digikey but didn't find anything. Other options are to use a potentiometer and serial ADC or PWM to serial, but an inexpensive single unit would be better. Thanks. - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle Index
Kirk Wallace wrote: On Sun, 2008-03-09 at 16:29 -0700, Curtis W. Moore wrote: If I added pulses can it be done? My encoder is just a homebuilt opto switch. Cutting out a new wheel with more slots/holes would be trivial. Can EMC thread with just one train of pulses? Ie use just one pin of the parallel port? Just in case, the parallel port is fairly limited in speed. I am guessing 20 to 30 kHz is maximum. If you make a disk, the number of slots per revolution will be limited to something like 30kHz/3k RPM = 10 [snip] Note the common thinko here: 3k RPM is not the same as 3k RPS. 3kRPM = 50 RPS, so if you assume 30 kcounts/sec, you have 3 Hz / 50 = 600 counts/rev to play with. - Steve - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] pwm-0-gen problems
I haven't even gotten that far, this is trying to use axis to enable it and 'spin' it by issueing the pwm and dir sigs. I don't have the outputs of Steve's card even connected to the spindle controller card yet, I'm at the point of trying to get the card to actually recognize that its supposed to do something, like run the relays etc. But there is nothing coming out of the pwm pin on the parport but a nice, solid at 50 mv, logic zero. Just thinking out loud... If you have used the parallel port in X mode, some computers don't support this. Also I have a computer that 3 of the outputs do not work but the rest do -probably because it's not set up properly in the bios . I haven't bothered to fix it yet I mention this cause I think you said some pins work and some don't... _ Your chance to win great prizes with Windows Live Mail and Rogers MobileMail. Click here to learn how. http://g.msn.ca/ca55/207 - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Spindle Index
On Mon, 2008-03-10 at 22:38 -0400, Stephen Wille Padnos wrote: Kirk Wallace wrote: On Sun, 2008-03-09 at 16:29 -0700, Curtis W. Moore wrote: If I added pulses can it be done? My encoder is just a homebuilt opto switch. Cutting out a new wheel with more slots/holes would be trivial. Can EMC thread with just one train of pulses? Ie use just one pin of the parallel port? Just in case, the parallel port is fairly limited in speed. I am guessing 20 to 30 kHz is maximum. If you make a disk, the number of slots per revolution will be limited to something like 30kHz/3k RPM = 10 [snip] Note the common thinko here: 3k RPM is not the same as 3k RPS. 3kRPM = 50 RPS, so if you assume 30 kcounts/sec, you have 3 Hz / 50 = 600 counts/rev to play with. - Steve *%$# it, I've been doing this all day. Thanks for correcting me. Someone might have taken it as being correct. Question everything seems to be good advise. Plus, writing out your units in equations. I would think 50 slots per revolution would be plenty, making 200 quadrature counts per revolution, so with the correction, we go from being on the edge to being well within limits (10 kHz (?)). For Penance, I should build an encoder and test it. Let's see, a 3 disk is ~ 9 in circumference, 9/50 = .180 slot width, piece of cake. Although, I seem to remember someone has a bright yellow lathe with a disk like this. -- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC lathe, Bridgeport mill conversion, doing XY now, Zubal lathe conversion pending) - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse012070mrt/direct/01/ ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
