Hello,

I bought an elk head file from Vectric.  My machine roughed it out and finished nicely.

When I ran same file today the machine picked up and moved to do the antlers but it moved way to far and now the antlers are 2" away from the head.

Can anyone tell me what went wrong?

I don't have enough to go on so it is just guesses...

Guess 1.
Problems like this can result from Gcode files which do not fully meet the Mach3 criteria with respect to Modal commands.
Mach initially starts and runs just fine but when it shuts down it saves the current state of the Modal commands ready for the next run. If these commands are not re-set correctly at the start of the Gcode file then problems can arise. Check you Gcode file to ensure G90 / G91 (for example) commands are properly specified.

Guess 2.
One or more of your axes are stalling and loosing position. Check (in Motor Tuning) that your Velocity settings are no higher than 70% of the stall speed and that your Acceleration figure is 10% of the Velocity figure.

Tweakie.

Thanks tweekie,  I downloaded the file straight from Artsoft Vectric for VCarve Pro.  I'm betting your right about the velocity and acceleration.  I'm pretty new 21st this and got the motors running but I didn't know anything about those two things.  I have never messed with those settings.
Man, DIY stuff is fun but the school of hard knocks can be expensive and frustrating.

Man, DIY stuff is fun but the school of hard knocks can be expensive and frustrating.

Yes, but it's all a great adventure, good fortune my friend.

Tweakie.

So I changed my acceleration but either the cnc, gcode or mach3 keeps cutting the antlers about two inches above the head.  It's all one file but it keeps doing it at the same place.

Here is a picture of what's it's doing.  This tool path is a 3d rough cut so the detail is not yet there.  As you can see it's causing the antlers to be cut through the top edge of the material.

The problem could be within the purchased Gcode file (particularly if it was was compiled with anything other than the Mach2/3 post processor). If you would like it checked then Zip and send me a copy (my email is below my avatar).

Tweakie.