1
General Mach Discussion / Re: X Axis slowly goes wrong, every time.
« on: July 05, 2012, 12:54:14 PM »
Been busy!
Wrote some GCode that is basically G0 X0 Y0, G0 X30 Y30 in a loop, 200 times.
At the end I move to 0, 0 and then actually move to 0, 0 to see how far the machine has walked.
After 200 moves the machine had walked 2.5mm on the X axis.
I calculated 0.0125 mm backlash but after a retest it was still 2.5mm out. So it's not backlash.
I had some wobble on the bench from inertia from the motors so I broke out the welder for some angle supports. Solid now but a retest shows 2.5mm out.
Why always 2.5mm after 200 moves??
Changed Look-ahead to 1 move (Read this somewhere) No change, 2.5mm.....
Modded my CnC board to give some breakout wires, put these in to a new m542 driver board and...
Perfect!, no idea how a board was giving me 2.5mm error yet move the motors what seems perfectly.
So... Thead closed... Faulty control gear.
Thanks for your help.
Wrote some GCode that is basically G0 X0 Y0, G0 X30 Y30 in a loop, 200 times.
At the end I move to 0, 0 and then actually move to 0, 0 to see how far the machine has walked.
After 200 moves the machine had walked 2.5mm on the X axis.
I calculated 0.0125 mm backlash but after a retest it was still 2.5mm out. So it's not backlash.
I had some wobble on the bench from inertia from the motors so I broke out the welder for some angle supports. Solid now but a retest shows 2.5mm out.
Why always 2.5mm after 200 moves??
Changed Look-ahead to 1 move (Read this somewhere) No change, 2.5mm.....
Modded my CnC board to give some breakout wires, put these in to a new m542 driver board and...
Perfect!, no idea how a board was giving me 2.5mm error yet move the motors what seems perfectly.
So... Thead closed... Faulty control gear.
Thanks for your help.