Height Compensation

It depends on the control and how it is setup. I would prefer the G43 H# call up on it's own line until proven otherwise that it's necessary for it to be with a Z axis move. Depending on your software I would edit the post to output the code on separate lines. Some interesting reading in this previous thread about the topic: http://www.practicalmachinist.com/vb/cnc-machining/dumb-question-about-g43-303760/

I'm going to have to try and find someone that would be able to edit the post, as I'd have no idea how to do that

What software are you using?

Mastercam, I'm using the default Fanuc post

My posts (from Mastercam) all output like this -

G43 H1 Z3. T2 (< tool stage, may or may not apply to you)

Thinking... I believe every machine I have used output the G43 and z move on same line...

I'm looking at the post now and I don't see where it is, but I am just a beginner with post editing so don't take my word for it.

Question, does the G43 need a Z move to 'turn on', like using a G41/42 move?

Perhaps you need to cancel the offset before applying a new one. G49 is used to cancel a height offset.

One piece of information that would be helpful: what's the control?

That's exactly how mine outputs as well, but I just can't work out why sometimes the comp is activated and sometimes it doesn't. It doesn't seem to be related to what type of toolpath it is either, it happens when drilling, contouring, whatever. But I can then restart the same program and it will be fine... sometimes. The controller is called a GSK, the machine a Primener. The controller is a knockoff of a Fanuc, so I've been told

If you want to send me your post in a PM, I'd be happy to edit it so the G43 is on it's own line. I'm not sure it'll solve your problem, but it's a good place to start.


Do you have different Z offsets in G54, G55, etc.? If so, make them all the same, at least until you figure out what's going on.

Does your control have separate geometry and wear offsets? Zero out all the wear offsets, and just use geometry until you have it figured out. I never use the wear offsets at all, mostly because I tend to forget to zero them when I'm done.

Do you have a G92 anywhere in your program? If so, get rid of it. It's the most potentially disastrous G code, and should be avoided until you're more familiar with Fanuc. Even then, most people here would tell you to never use it.

After you take care of those potential problems, try running the program straight through three times, without hitting anything but the start button. If the second and third runs are exactly the same, but both are different from the first, you have a modal code that isn't being properly reset. If all three runs are different, you have a work shift that isn't being reset. If the first and second runs are the same, but the third is different, you need to call a GSK service tech. That shouldn't be possible.