Possible Bug?

[btp]

Can someone please check this out for me. My post processor for my CAM system posts my tool change as follows
T1 M6 G43 H1
etc..

Which is a perfectly fine way to do it, but it's causing issues in MSM. The issue is when I have the button checked to go to the tool change position at each tool change, it just races towards the limit switches until it eventually hits them and faulting the machine. Now if I edit the program manually (which I have to do at every tool change) to something like this
T1 M6
G0 Z1.0 G43 H1
etc...
It then work just fine. It just seems that if the tool change and tool length offset are on the same line it makes it go hay wire. It's not a huge deal, but it would be nice to be able to post my program and not have to manually edit each tool change.

Thanks

[DaveCVI]

Hi,

Can someone please check this out for me. My post processor for my CAM system posts my tool change as follows
T1 M6 G43 H1
etc..

Which is a perfectly fine way to do it, but it's causing issues in MSM.

You are correct that T# M6 G43 H# all on one line should be fine as gcode syntax.
I'm 99% sure you've been bit by a known mach 3 bug; Mach messes up and does not handle that gcode line correctly.
For more information please see item 4.27 in the MSM release notes in the "known errata in Mach3" section.

The solution is to change the CAM post so that instead of
T# M6 G43 H#
it is
T# M6
G43 h#
on two separate lines. That will avoid the Mach bug.

The issue is when I have the button checked to go to the tool change position at each tool change, it just races towards the limit switches until it eventually hits them and faulting the machine. Now if I edit the program manually (which I have to do at every tool change) to something like this
T1 M6
G0 Z1.0 G43 H1
etc...
It then work just fine. It just seems that if the tool change and tool length offset are on the same line it makes it go hay wire.

Yep, that's the symptom of this particular mach bug.

Hopefully it's easy to change the post processor for the CAM program.

Dave

[btp]

Thanks Dave. I should have figured it was Mach. I'll have to mess around with the post processor to see if I can get it to output like I need. Thanks for your help.