Post Mod

[Bob K]

Hi all. Long time troller, very seldom poster.

Anyway, I need to do a simple (I think) change to my post. It's a customized MPFAN.

First I'll try to explain the problem we're having. We recently purchased 2 new VMC's. We are having a problem with the machine "thumping" as it begins a rapid move after almost any type of feeding. Not sure what is causing this, but we have come up with a temporary fix while the service reps investigate the bigger problem. If there is an "extra" line of code in the program before the rapid move that seems to help a lot. One of our other programmers, who uses a different CAM package, changed his post to output a G90 before any rapid move.

I would like to do the same thing. I'm not exactly sure how to accomplish this.

 

Thanks,

 

Bob K.

Mill Level 3 Version 8.1

[MACHINEMASTERG]

question are you turning off cuttercomp g40 before this thumping?? sounds to me like g41 or g42 is still active and its jumping to the point upon rapid just my thoughts

[Surface]

Bob, I don't think the G90 is going to help you. It may be something broken with the machine, but if you wish to put out a G90 with each G0, I think the easiest way would be to add G90 to that string.

Search though the post for Sg00, beside it add "G90" to the "G00" which is there.

 

Let us know how you make out

[chris m]

I don't know about the post mod but:

 

1) In Fanuc controls (at least all of the ones I've worked with) G90 is modal; so you shouldn't need it more than once

 

2) I can't fathom why G90 would have anything to do with a machine making noise or not; what kind of machine is this and what do you think the problem is?

 

C

[Bob K]

Thanks for the replies.

Surf: Tried putting the G90 next to the G00 after the sg00 with no success. I need the G90 on a seperate line before the G00.

Greg: We're not using cutter comp at all.

Chris: I realize that the G90 is modal, what I'm looking to do is add a line into the code before a rapid move to allow the machine just a second to "think" before the rapid move. We choose G90 because it had zero effect on the toolpaths.

The machines are Cincinatti Arrow 2 VMC's. We think the problem is with the acceleration/deceleration of the axis drives.

We've tried the extra line of code (G90) with success on the other CAM package. Again this is just a temporary fix while the deeper problem is being investigated by the service rep.

 

I have a busy day today, so forgive me if I do not reply right away. I will check in as often as I can.

 

Thanks again.

 

Bob K.

[iowajim62]

Hi Bob,

Sounds like the servo,servos are jumping to hold positional error to a minimum. If not that mechanical failure of some sort possibly. As far as a pause, find out what your machines use for dwell like in G82. On our machines we G04 with P for the amount of dwell.

Welcome to the Forum.

[Surface]

Bob, if you Email the post to me, I can fix you up pretty quick. Just let me know exactly where you want the "G90"

[Bob K]

Jim: We believe that's it is in ther servos also. Our service rep is working with us to try to resolve the problem.

Surf: Thanks for the offer, but it appears that I found the right place to put the G90. I entered "G90" on it's own line with the prapid and the pzrapid variables.

Re-posted a program that was in the machine & "thumping" this morning and it appears that the extra line is just enough of a delay before the rapid to stop noise.

 

Thanks again for the advice everyone.

 

Bob K