Hello all, I have recently started running a cmm again after not touching one for 5 years. My manager has told me to run through all the pcdmis programs that already exist and says that none can be trusted as the previous operator was not the best and crashed several times.
What are some good habits for running someone else's programs that cant be trusted?I could rewrite them but i feel i should be able to work through what is already there. I will be using breakpoints before Tip changes in the program and running it super slow. Any other tips for someone jumping back on a machine and dealing with a mess like this Thanks.
It has been my experience, most often, just delete the old program and make your own. It probably will be faster and you will have full confidence in the new program!
Often you may need to rewrite, BUT perhaps you may not.
I'd suggest the following approach.
1) First run the program offline (check all dimensions show zero deviation, if not it's likely garbage)
2) Check program structure (mainly alignments), verify all features have correct theoretical values - depending on the part this can either be quite easy (i.e. nice square vectors 0,0,1 / 0,-1,0 etc) or not (complex free form parts)
3) Check the reporting - if Legacy make sure dimensions are reported in correct alignment and that it's reflect the FCF. If GeoTols/Xact make sure the datums are specified correctly and measured as the correct feature type (i.e. Planes measured as planes where possible, same with holes (Cylinders and not circles).
4) Check constructions are correct, specifically Primary/Secondary/Tertiary datums where applicable, also makes sure In/Out is specified correctly on constructed diameters.
5) Check things like a sensible number of hits per feature, touchspeeds, prehit/retract values
6) If all that's okay then you may have a good program, if so then run collision detection
7) Execute carefully online
The other thing to keep in mind is how a rewrite will affect downstream operations. I've seen new inspectors change methods and reject fully functional parts. Program may not be the best but it is the way things have been done. At the very least run a few parts with the old program and rerun with the new and "improved" version. Show the reports to your customers to get their buy in before implementing the change.
When running someone elses programs i always do a CTRL+F and find all the tip angles and put a break point on each one. At least for the first run through. That way you step it through each articulation instead of finding out when things go bang.