Configure XY scale with belts
- nerdegutta
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29 May 2015 17:32 #59184
by nerdegutta
Configure XY scale with belts was created by nerdegutta
Hi.
I have a hard time configuring the scale on my homemade CNC router. I got a XYZ machine. The X and Y are on timing belts, and Z is on a 8mm threaded rod.
I've tried to find some answers with Google, but I haven't found any.
Which settings in StepConf do I change? My belt is GT2 with 20 tooth gears. Z-motor is connected directly to the rod. When I try to use a pencil to try to draw LinuxCNC - default text, it is much smaller than it should be.
The stepmotor driver is L297-L298.
- nerdegutta
I have a hard time configuring the scale on my homemade CNC router. I got a XYZ machine. The X and Y are on timing belts, and Z is on a 8mm threaded rod.
I've tried to find some answers with Google, but I haven't found any.
Which settings in StepConf do I change? My belt is GT2 with 20 tooth gears. Z-motor is connected directly to the rod. When I try to use a pencil to try to draw LinuxCNC - default text, it is much smaller than it should be.
The stepmotor driver is L297-L298.
- nerdegutta
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- Todd Zuercher
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29 May 2015 20:20 #59186
by Todd Zuercher
Replied by Todd Zuercher on topic Configure XY scale with belts
What is the pitch of your belts?
How many steps per revolution are your motors?
Do you have your drives set for half or full stepping?
Is your G-code set up for inches or mm, are you using the right G20/G21 command?
How many steps per revolution are your motors?
Do you have your drives set for half or full stepping?
Is your G-code set up for inches or mm, are you using the right G20/G21 command?
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29 May 2015 21:46 #59190
by andypugh
Replied by andypugh on topic Configure XY scale with belts
One solution is to not try to figure out the Stepconf values. The final output is a single number in the INI called STEPGEN_SCALE which is the number of step pulses LinuxCNC requires to move the axis by one machine unit.
If you calculate that you need 2000 step pulses to move 1" (or 1mm) then you can just set everything in Stepconf to 1 (not the veolicites or accel) and set the motor steps per rev to 2000 (or whatever you calculate)
If we assume x4 microstepping and a 200-step motor then a 20 tooth gear will move 20 x 2mm pitch for 800 step pulses.
So, 800 steps = 40 mm travel. So your steps-per-mm for a mm machine would be 20. For an inch machine the number would be 508.
If you calculate that you need 2000 step pulses to move 1" (or 1mm) then you can just set everything in Stepconf to 1 (not the veolicites or accel) and set the motor steps per rev to 2000 (or whatever you calculate)
If we assume x4 microstepping and a 200-step motor then a 20 tooth gear will move 20 x 2mm pitch for 800 step pulses.
So, 800 steps = 40 mm travel. So your steps-per-mm for a mm machine would be 20. For an inch machine the number would be 508.
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- nerdegutta
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30 May 2015 03:17 #59205
by nerdegutta
Replied by nerdegutta on topic Configure XY scale with belts
Motors are NEMA 17, 200 step
Set to full step.
Belts are bought on eBay.
I'll try the scale setting later. Do I need to edit the INI file with gedit?
Thanks for repying.
- nerdegutta
Set to full step.
Belts are bought on eBay.
I'll try the scale setting later. Do I need to edit the INI file with gedit?
Thanks for repying.
- nerdegutta
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- nerdegutta
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30 May 2015 19:24 - 30 May 2015 19:24 #59230
by nerdegutta
Replied by nerdegutta on topic Configure XY scale with belts
Thanks!
The *.INI file had a line
SCALE = 5.19xxxxx
I changed it to 10.19xxxx
And now I'm in scale.
Thanks again!
- nerdegutta
The *.INI file had a line
SCALE = 5.19xxxxx
I changed it to 10.19xxxx
And now I'm in scale.
Thanks again!
- nerdegutta
Last edit: 30 May 2015 19:24 by nerdegutta.
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