[ozyjimbo]

I have been trying to nut this little problem out i have set my machine using mach3 steps. My table size is 1200x2400, the x axis is mm perfect however my y axis is misreading, i have that set to what i thought was mm perfect and it is up to a certain length eg y set at 0 run it to 100mm and it goes 100mm. The job that i'm doing is 2000mm long but when i do the job it's only going to 1900mm. I'm running direct drive rack in pinion mod 1 rack 40 tooth gear. I'm not loosing steps otherwise i would hear it and there is no backlash, M524 drivers set at 1600 pulse mema 23 420oz motors. Is there another way to set up so it's more accurate then what it is now or do i just put up with it and extend my design by 100mm to compensate?

[ger21]

I'm not loosing steps otherwise i would hear it and there is no backlash

I would say that you are most certainly losing steps. Or you have a serious mechanical problem. You don't just lose 100mm.

I would set the steps/mm so that it's accurate at 2400mm. This should evenly distribute any pitch errors in the rack. But it should never be off by much.

[ozyjimbo]

i'll try that thanx ger just seems odd if i'm loosing steps then it would do it way before going over 1000mm i'll do more adjusting very soon and see what i come up with and yes i agree there should be some error but not the 100mm i'm experiencing

[ozyjimbo]

Ger i reset the steps to 2400 i did a couple of tests still had the same problem however i decided to go into my motor tuning and discovered i had accel at 4000 i reduced it to 3000 and now after 5 tests repeatably 0 to 2400 so i was loosing steps due to the accel being high and a very small error margin i'm not worried about thanx for your help

[ozyjimbo]

sorry it wasn't accel it was velocity that was high