View Full Version : CNC Machining Centers Capability

08-24-2001, 02:48 PM
I need to conduct capability studies on our CNC Machining Centers. I am familier with machining, but form a Quality Manager/CMM programer point of view. I need to determin repeatability and CPK's on all of our machine tools - are there standard methods for determining capability of CNC machines? What type of equipment is utilized?


keith walter
manager, quality
devonshire mfg

08-25-2001, 02:42 AM

I cannot tell you for sure, but I believe ASTM (formally known as "American Standard Testing Methods") or ASM International {American Society for Metals) could help you. ASTM produces standardized tests insure consistancy in Science and Industry. ASM also has numerous publications relating to the metal industry. If these groups cannot help you out I suggest contacting Starrett and asking them (they better know!).

Good luck
Dave Smith

08-25-2001, 12:38 PM
The best way is to use a laser. Check for
squareness in every direction. I'm sure there
are companies who do this kind of work.
A cheap way to to use a "Hineashaw" piece of equipment.


C. Tate
08-27-2001, 08:46 PM

The easiest way is to contact the machine tool dealer who represents your machine and tell their service department what your concerns are and they can outline the proper methods for inspection. These methods are usually printed in the maintaince portion of the manuals sent with the machine. If you find things to be out of alignment then a technician can come and check with the electronic equipment.

artificer in metal
09-13-2001, 01:26 PM
Most new CNC equipment is checked using a ball bar test. This tests movement in all 3 axis. As far as I know you can get tests accurate to 0.0001 mm. This may be somewhat expensive but there should be less strigent options.