I am having issues when trying to cut shapes, I use my CNC for wood/resin projects so nothing to complicated. But when cutting out a shape I step down in small increments so a 20 mm thick piece of wood may take 40 passes to complete.

My problem is totally random it could successfully complete 15 passes and then on the 16th it will loose its direction and do something random, go off in a totally random direction, stop as if it's reached it's limit of travel or even step down and drill through the bed of the table.

The g code files I am using have successfully been used before so I have ruled out errors in the code and if i stop and then start the run from the beginning it may go passed the point it failed previously and then mess up again or may mess up again right at the beginning of the pass.

Anyone else experienced this?

Can you tell us more about your system please.

Mach3 or Mach4 ?
Motion Controller or Parallel Port ?
Windows OS ?
And any other info that you think may help us.

Tweakie.

I am very much a hobbyist so better you ask me the info you need but:

Mach 3
Motion sensor
Windows 10

What make and model of Motion Controller are you using ?

There are some isues with Win10 and Mach3 - check out this thread ; https://www.machsupport.com/forum/index.php?topic=37291.0

Tweakie.