Hello all, I have had this problem cropping up with my system on and off now for a while. I know there are some settings in my MasterCam which are guilty of some of the problems and I have fixed them or so I think until suddenly there it is again. I wanted to see if anyone else out there had come across this issue. Attached is the GCODE of a peice I was working on, it got to line 3800 and then took off in a big loop right through the workpeice. These "arcs" or circles seem to occur randomly in some of my code and it seems to be related to my POST but it is hard to FIND them as they dont allways show up on the toolpath screen.  I seem unable to comprehend exactly what or why Mach three is following the arc the long way round or why the POST format is interpreted that way as I cant tell the difference between what works and what doesnt....G Code is still a foreign language to me. Anyone ever encounter this ? is there a permanent solution for my POST/MASTERCAM...?

Thanks in advance
Mike

Mike,

I don't use MasterCam so I can't address your specific problems, but I have had similar "circles," crop up in dxf files I have imported from CADX!! (a much less robust program than MC).  Not a solution, but as a precaution, I always run through any new code without the mill running - use the arrow key line-by-line approach - and watch for errant movements in the toolpath windows.  It may not be an elegant solution, but it has saved me from machine crashes.

Good luck with your work.

Bob @ BobsShop - Digiting his way through yet another fine mess he got himself into.

On smaller files I do that sometimes, but most of our files are pretty huge, and you have to hit the line right on the money and wait long enough for the toolpath window to update, so its not practical to scroll through 20,000 lines of gcode. As a guide I have been checking the program extrema to see if its within the right area, I got sloppy on this one and the problem showed up in the middle of the part. That the furstrating part, its not all the circles, its usually one or two in the middle or the END of the program so just when you think its all working great and you feel confortable focusing on something else then you hear that horrble screeching sound of step motors stalling as it tried to cut right through the table or workpeice. I have been playing with mastercam settings and I think I have a solution.... it just doesnt seem to be consistant, so I think that perhaps I am not understanding the problem completely, or.... I have a different problem and this is just a symptom. Its like a while back my system would loose position, over the course of one of the programs it "lost" 0.289 Inches on the x axis alone. I ran hundreds of tests and in the end didnt really change anything, just took forever to run the program because I would do it in steps and then check position.... it was all within spec.... never did get a good answer omn that one either.

If you would like to have the problem looked at you will have to make the file 5 lines long with the problem line in the middle of the file. The long files take about 30min to pare down and Art and I don't have the time to do that at this point

Thank you and hope we can get this fixed for you
Brian

Brian,
Thanks for that, I will keep an eye out for it in the future, I seem to have put together a machine def that is working well between Mastercam and Mach 3 I have tried all the problem files and they are cominh in clean. The issue may have been a post thing which only crops up if you dont have your default machine def's established properly in Mastercam. If I discover any more about this issue you can count on being the first to know. in the meantime I am sure both you and ART have bigger fish to fry..

Cheers

Mike