large programs drift

[bloo]

hi. i am using mach 3 and all wizzards work fine.
when i run large programs (1000 lines plus) the machine drifts out of algnment by about 5mm. this is progressive as the program runs. can anyone give me any idea's please.
Andy

[SCzEngrgGroup]

If you're thinking this is a problem with Mach3, think again. Your machine is losing steps, which means the drives are either under-designed, or you're pushing it too hard.

Regards,
Ray L.

[bloo]

i have run at very slow speeds but still get drift. it always seems to be exacly
in 5mm steps not 5.1 or 5.4 etc... this is why i think it is software not machanical. all axis are very smooth and my drivers are high quality vexta units. paid £250 each. these are matched with the correct motors as they came as a kit.
Andy..

[mrcodewiz]

I had a problem on my x2 a while back where it would routinely lose .1". I changed the motor speeds,etc but I think what may have fixed it was setting the kernel speed down to 25000.

[Fixittt]

i had this issue a few years back when the G540`s first came out. I was able to solve it by setting the sherline 1/2 Pulse mode.

my 3d tool paths would come out very distorted the longer the machine ran. maybe its worth a try on yours.

[rewster]

I could be misunderstanding your problem, but couldn't the culprit be incorrect backlash settings, especially noticeable on asymmetrical parts?

[bloo]

thanks for the comments. will give it a go the week end. will let you know how i get on.
Andy..