Re: [Emc-users] Timing Belt Config
On 11 Nov 2009 at 19:27, Jeshua Lacock wrote: Thanks John, If I am using a servo with 512 PPR, is a step 1/512 of a revolution? If your servo drives take step and direction signals then they are just like steppers to the software. If it takes 512 steps to go one revolution and it takes two revolutions to move one inch then your scale is 1024 = the number of steps to move one inch (or mm). I guess I do not know how step/microsteps apply to servos... It would not apply to servos only to drives that take step and direction signals. Steps and micro steps and gear ratios and pulleys all add up to one thing how many pulses does it take to go one unit. If you have servo drives that take PWM or 0-10v signals and feed back position info to EMC via an encoder then that is a whole different beast. Is it possible with EMC to command the servo to move 1 revolution (or a specific number of steps) instead of specifying a distance? If you set your scale correctly I assume you could... dunno why you would want to John -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Timing Belt Config
On Nov 12, 2009, at 4:55 AM, John Thornton wrote: If I am using a servo with 512 PPR, is a step 1/512 of a revolution? If your servo drives take step and direction signals then they are just like steppers to the software. If it takes 512 steps to go one revolution and it takes two revolutions to move one inch then your scale is 1024 = the number of steps to move one inch (or mm). Thanks for confirming that John. I guess I do not know how step/microsteps apply to servos... It would not apply to servos only to drives that take step and direction signals. Steps and micro steps and gear ratios and pulleys all add up to one thing how many pulses does it take to go one unit. If you have servo drives that take PWM or 0-10v signals and feed back position info to EMC via an encoder then that is a whole different beast. Got it. I thought I read somewhere that servos are treated like a step motor from EMC. My encoders send the signal back to the Gecko 320's. So I assume that the Gecko knows the position of the servo and EMC instructs it where to move. This is just speculation on my part, so I could be wrong. Is it possible with EMC to command the servo to move 1 revolution (or a specific number of steps) instead of specifying a distance? If you set your scale correctly I assume you could... dunno why you would want to I was thinking it would allow me to set the scale. I could tell it to do 512 steps and measure, or 25,600 steps and measure the distance the belt moves.. Thanks again, Jeshua Lacock Founder/Programmer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Timing Belt Config
Jeshua Lacock wrote: On Nov 12, 2009, at 4:55 AM, John Thornton wrote: If I am using a servo with 512 PPR, is a step 1/512 of a revolution? If your servo drives take step and direction signals then they are just like steppers to the software. If it takes 512 steps to go one revolution and it takes two revolutions to move one inch then your scale is 1024 = the number of steps to move one inch (or mm). Thanks for confirming that John. I guess I do not know how step/microsteps apply to servos... It would not apply to servos only to drives that take step and direction signals. Steps and micro steps and gear ratios and pulleys all add up to one thing how many pulses does it take to go one unit. If you have servo drives that take PWM or 0-10v signals and feed back position info to EMC via an encoder then that is a whole different beast. Got it. I thought I read somewhere that servos are treated like a step motor from EMC. No, that's only when you use step/dir servo drives, such as the Geckos. It is better to treat servos like servos, by using a drive that takes an analog command as input, and makes the motor go a certain speed (velocity mode) or apply a certain torque (torque mode) based on that input. My encoders send the signal back to the Gecko 320's. So I assume that the Gecko knows the position of the servo and EMC instructs it where to move. Sort of. The geckos have an internal counter. The counter is changed by the computer (from the step/dir signals) and by the encoder feedback signals. The electronics in the gecko will basically apply power to the motor to make the counter stay at zero, so when the PC issues a step (changing the counter to 1, for example), the motor will be pushed until the encoder feedback makes the counter zero again. This is just speculation on my part, so I could be wrong. Yep, you are, sort of :) Is it possible with EMC to command the servo to move 1 revolution (or a specific number of steps) instead of specifying a distance? If you set your scale correctly I assume you could... dunno why you would want to I was thinking it would allow me to set the scale. I could tell it to do 512 steps and measure, or 25,600 steps and measure the distance the belt moves.. Set the scale to something (like 1000), then tell EMC2 to move 1 inch. Measure the actual travel, and then re-set the scale to 1000*(expected travel)/(actual travel). Make sure the number looks sane - you should be able to verify it if you know the encoder resolution, gear ratio, and screw pitch. Use a longer test travel distance once you're close - the difference between 1000 count encoders and 1024 count encoders, or the difference between 5mm and 0.2 inches per screw turn can be pretty subtle. - Steve -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Timing Belt Config
On Nov 10, 2009, at 3:27 PM, John Thornton wrote: What you need to figure out is how far the axis moves per rotation. For example if your motor turns 4 times to turn the big pulley once and the table travels 2 inches then it is 2 turns per inch. If it is 200 pulses per revolution and 10 microsteps then you have 200 x 10 x 2 steps per inch. At the bottom of the page you can see the scale calculate as you enter in values. The only value that really matters is the actual scale number. Thanks John, If I am using a servo with 512 PPR, is a step 1/512 of a revolution? I guess I do not know how step/microsteps apply to servos... Is it possible with EMC to command the servo to move 1 revolution (or a specific number of steps) instead of specifying a distance? I have belt drive plasma cutter and the calculations don't quite come out exact with the belt. It depends on how much belt stretch you have. Once you get it close take a measurement and the move a large amount then measure. Do the math to figure out the exact scale you need to get a movement of one unit. For example one of my axis calculated scale is 4000 but because of belt stretch I need 3980 to get a more accurate movement. That makes sense! Thanks again, Jeshua Lacock Founder/Programmer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Timing Belt Config
Greetings, I am trying to calibrate my shiny new machine. I have opted to use timing belts instead of leadscrews. My servos have 512-count optical encoders driven by Gecko 320's. I have all the pins set up, and are working nicely! The servos are geared down 4 to 1 (four servo revolutions per pulley revolution that runs main timing belt). My question is, what would I put for the Leadscrew pitch in the Axis Configuration Page? I assume for the Pulley Teeth I would enter 4:1. I greatly appreciate any advice! In case anyone is interested, pics of the machine are at: http://OpenOSX.com/CNC-11.9.09/ Cheers, Jeshua Lacock Founder/Programmer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Timing Belt Config
2009/11/10 Jeshua Lacock jes...@3dtopo.com: My question is, what would I put for the Leadscrew pitch in the Axis Configuration Page? I assume for the Pulley Teeth I would enter 4:1. It will depend on how many teeth are on your axis belt pulleys, and the pitch. Stepconf will just put steps x microsteps x ratio x pitch into the AXIS_SCALE parameter in the .ini file which is the number of step pulses per unit of movement. It might be easiest to put nonsense in that part, then calculate the scale yourself and edit the ini file. In case anyone is interested, pics of the machine are at: http://OpenOSX.com/CNC-11.9.09/ I am interested to know if you have an EMC build for OSX :-) -- atp -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Timing Belt Config
What you need to figure out is how far the axis moves per rotation. For example if your motor turns 4 times to turn the big pulley once and the table travels 2 inches then it is 2 turns per inch. If it is 200 pulses per revolution and 10 microsteps then you have 200 x 10 x 2 steps per inch. At the bottom of the page you can see the scale calculate as you enter in values. The only value that really matters is the actual scale number. I have belt drive plasma cutter and the calculations don't quite come out exact with the belt. It depends on how much belt stretch you have. Once you get it close take a measurement and the move a large amount then measure. Do the math to figure out the exact scale you need to get a movement of one unit. For example one of my axis calculated scale is 4000 but because of belt stretch I need 3980 to get a more accurate movement. John On 10 Nov 2009 at 13:08, Jeshua Lacock wrote: Greetings, I am trying to calibrate my shiny new machine. I have opted to use timing belts instead of leadscrews. My servos have 512-count optical encoders driven by Gecko 320's. I have all the pins set up, and are working nicely! The servos are geared down 4 to 1 (four servo revolutions per pulley revolution that runs main timing belt). My question is, what would I put for the Leadscrew pitch in the Axis Configuration Page? I assume for the Pulley Teeth I would enter 4:1. I greatly appreciate any advice! In case anyone is interested, pics of the machine are at: http://OpenOSX.com/CNC-11.9.09/ Cheers, Jeshua Lacock Founder/Programmer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Timing Belt Config
If stepconf's questions to calculate SCALE don't fit your situation, then perform the calculation yourself to get steps/mm or steps/in. Enter this value in motor steps per revolution, and enter 1 for microstepping, pulley, and leadscrew pitch. This will let you use the number you calculated without hand-editing the inifile. Jeff -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Timing Belt Config
On Nov 10, 2009, at 3:10 PM, Andy Pugh wrote: In case anyone is interested, pics of the machine are at: http://OpenOSX.com/CNC-11.9.09/ I am interested to know if you have an EMC build for OSX :-) Thanks Andy! (Thanks everyone for your helpful suggestions!) The crux for me was lack of a working parallel port - I spent much time looking into it. There might be some USB solutions, but would like require developing a custom kernel extension. I think everything else including RTAI could pretty easily be ported. But I picked up a working PC from the dump, installed the EMC Live CD, and am quite happy. I can control the remote machine over VNC so it is pretty sweet. Cheers, Jeshua Lacock Founder/Programmer 3DTOPO Incorporated http://3DTOPO.com Phone: 208.462.4171 -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Timing Belt Config
On Tuesday 10 November 2009, Jeshua Lacock wrote: On Nov 10, 2009, at 3:10 PM, Andy Pugh wrote: In case anyone is interested, pics of the machine are at: http://OpenOSX.com/CNC-11.9.09/ I am interested to know if you have an EMC build for OSX :-) Thanks Andy! (Thanks everyone for your helpful suggestions!) The crux for me was lack of a working parallel port - I spent much time looking into it. There might be some USB solutions, but would like require developing a custom kernel extension. I think everything else including RTAI could pretty easily be ported. But I picked up a working PC from the dump, installed the EMC Live CD, and am quite happy. I can control the remote machine over VNC so it is pretty sweet. I start an ssh session with 'ssh -Y -l name shop.coyote.den' and just export the x sessions I run to my nice warm easy chair. Cheers, Jeshua Lacock Founder/Programmer 3DTOPO Incorporated http://3DTOPO.com Mmmm, good. You live in Gods country. Phone: 208.462.4171 -- 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) The NRA is offering FREE Associate memberships to anyone who wants them. https://www.nrahq.org/nrabonus/accept-membership.asp By failing to prepare, you are preparing to fail. -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
