First of all: thanks for the cool Shield! I think mine is a cheap China-Board

I finished a ShapeOKO like build yesterday and ran the first test. My setup is the following:
- 3 axis, 4 motors (23LM-C355-34V motors) -> Y-axis is cloned to A
- it's moves on threaded bars
- CNC Shield V3.00 with 4 x DRV8825 and GRBL 0.9j
- Microstepping is set to 1/8
- 24V Switching Power Supply (10A)
- the first run was a bit "adventerous", since I did not configure the DRV8825-drivers. This gave me some stink (they got really hot)
- I then configured them to a Vref of 0.5V which made them stay cool (for quite a while)
- it worked quite ok but the movement was way too slow (fixed this by adjusting the step/mm setting)
- running the ShapeOKO "Hello World" G-Code would still have way too small movements (only about 1cm)
- running another GCode (just a square grid) worked well, but the stepper-driver got very hot again
- first of all: how do I figure out which microstepping option is the right one for me?
- I had to set the step/mm to 3125 to make the CNC move the correct distance, this seems extremely high, compared to other settings I've seen
- the cloned axis stops from time to time. I already replaced the stepper driver, but same issue. It might be mechanical problem too.
- after I ran the last job the drivers still got really hot (although Vref is set to 0.5V now), I attached the GCode
Tom
## GCode (sorry could not attach it as file)
Code: Select all
%
( File created using Intuwiz Software Service )
( http://www.intuwiz.com )
( More information: http://www.intuwiz.com/engraving-rectangle-grid.html )
( File created: 2016-06-18 22:27:20 )
G00 Z0.5 F70
G00 X0 Y0 F70
G01 Z-1 F50
G01 X0 Y50 F50
G00 Z0.5 F70
G00 X10 Y50 F70
G01 Z-1 F50
G01 X10 Y0 F50
G00 Z0.5 F70
G00 X20 Y0 F70
G01 Z-1 F50
G01 X20 Y50 F50
G00 Z0.5 F70
G00 X30 Y50 F70
G01 Z-1 F50
G01 X30 Y0 F50
G00 Z0.5 F70
G00 X40 Y0 F70
G01 Z-1 F50
G01 X40 Y50 F50
(do horizontal lines)
G00 Z0.5 F70
G00 X40 Y50 F70
G01 Z-1 F50
G01 X0 Y50 F50
G00 Z0.5 F70
G00 X0 Y40 F70
G01 Z-1 F50
G01 X40 Y40 F50
G00 Z0.5 F70
G00 X40 Y30 F70
G01 Z-1 F50
G01 X0 Y30 F50
G00 Z0.5 F70
G00 X0 Y20 F70
G01 Z-1 F50
G01 X40 Y20 F50
G00 Z0.5 F70
G00 X40 Y10 F70
G01 Z-1 F50
G01 X0 Y10 F50
G00 Z0.5 F70
G00 X0 Y0 F70
G01 Z-1 F50
G01 X40 Y0 F50
G00 Z0.5 F70
G00 X0 Y0 F70
M30
%