PCMDIS/NC Expereinces?

[kiddo]

just out of curiosity what's the usual tolerance that u work with.

[kiddo]

Thanks jan:

Just one more question. Is pc-dmis nc worth on a 3 axis gantry? I mean does it work. I suppose you use it on a 4 or 5 axis machine.

[Jan d.]

I have machines that can hold 0.0001" repeatability (particularly in X and Y (non spindle axes)) with an MP700 and a 200mm stylus. My measurements agree with the CMM to within 0.0005" per meter.

All my machines are in a highly temperature controlled environment. The room we keep our machines in is probably better than most CMM rooms.

Typically, our parts have profile tolerances in the 0.001" range and TP as low as 0.0002" (all MMC) on mostly aluminum parts.

If you have accurate parts that you also want to measure accurately on your machine, your machine MUST be in an environment that is as good as your CMM. If you do not have that, you MUST really investigate what kind of uncertainty you will can expect due to excursions in temperature. Measure Invar master gauges to find out what the real accuarcy is.

Another solution, if your machine is not in a controlled environment, is to create a golden part. Measure this part on your CMM and use it on your machine as a reference, before measuring the part that got just machined. The problem with this is that it doubles the measuring time. A reduced featured artifact may also work for you, but that will also take time away from producing chips (just what management wants to hear).

A lot of people have said that you can not measure on machines. We have done it for 20 years. The problem is that our early measuring reports (post-it notes with sketches, or manually generated Excel spreadsheets etc) were never acceptable to our quality department. Now, with PC-DMIS, we can create acceptable reports that measure the features as they are called out on the print. V4.0 is very helpful in that regard.

Another company that has done a lot of work with measuring on machine tools is obviously Renishaw. Attached is a good article about their setup.

http://www.mmsonline.com/articles/059901.html


Jan.

[Jan d.]

I use it ONLY in 3 axis mode on 4 and 5 axis machines. When I need another axis, I do a re-datuming. I treat every angle as a separate part program. My fixtures have features machined on them that allow me to track back to the original datums. I have never tried to use the rotary axis in a part program, just because I do not need to.


Jan.

[kiddo]

Thanks for the reply Jan:

Are you a machine shop person or an inspection person. Just out of curiosity.

[Jan d.]

Inspection. Attempting to also become a machining guy.

[kayjiang]

new man,new question
about pcdims nc's calibration
our company have a case about pcdims nc, can connect pc&Makino V33
omp400 probe, calibration ball need 108 points, it's too slowly
if your case is successful, may you give some experiences to me, tks
kayjiang@126.com