Hi, hello everyone here, this is my first post due to a really annoying problem once I've generated my nc code.

The problem I have is that the every now and again (maybe once in every 20 cuts) the tool plunges but does not go back to the cutting feed, stays at the plunge ie:

1479 L Z-.498 R F50 M
1480 L X+.64 Y-25.523 R F M

when it should look like :

3893 L Z-1.493 R F50 M
3894 L X+.558 Y-24.961 R F500 M


anyone know why it keeps doing this please? it just seems like a glitch, but its really annoying! :confused:



thanks for all the help

is there any way I can set the post processor to output all feeds instead of it using the last one as the default?

Exactly which version are you using?
Where did the post come from (did you write it)?
What type of toolpath are you using?

Most of the time when people want the poat changed because of bad toolpath, it's because they have a setting wring in Mastercam. The curse/blessing of Mastercam is that it's highly configurable. It's easy to miss a setting that might tell it to "stay down" or possibly your retract for a particular cust is not high enough. Something like that. Then you get a cut thru the part.

I think it was V9.1, on it's initial release, had a bug that caised it NOT to retract.

Mike Mattera

Hi Mike,

I'm using 9.1 mr304

The type of toolpath is a Surface Contour Finish using the original Heidenhain post that came with mastercam.


There's no problem with the retract, its just the plunge feed doesnt go back to the cutting speed when it starts to cut.

I've just tried the exact same toolpath parameters on a basic shape that is the same depth and it does it fine, so this leads me to think there is something in the geometry that mastercam doesnt like, even though its just a simple part, extruded to a depth.

can you post your file on here so we could have a look at it ?