Programming Question

[GoFlyers]

My cmm tech is having some issues with writing a program and I would appreciate if I am asking too much out of the cmm.

I have a forged shaft, about 2" diameter and 30" long. One end is milled and center drilled.

I need a program that gives me a diameter of the center drill in about .080" from the machined face.

I understand that the shaft is forged but wouldn't the program basically pick up the rough centerline from the forged diameter in two places then establish a plane from the machined face and then be able to go in and probe?

Thank you for your help.

[PixleyRichards]

If you go in manually and take three points, I'm not sure of the size of the hole this might not work, then have put it in DCC mode and have it take a circle, it might work. I'm not sure if this answers your question.

[Wes Cisco]

The CMM can do this easily. Manual plane on milled face. Lock the proper axis and take a manual circle in the centerdilled hole. (on the cone is fine). Level to plane and origin one axis to plane, origin other two axis on circle. Now DCC autofeature cone to measure as much of centerdrill cone as possible. Construct circle, use radio button near bottom and enter .080 for height, select the autocone, create. Dimension the constructed circle for diameter. Done Deal. Have him send me a pm and I will give him my phone number and walk him thru it if need be. HTH

[Paul Sarrach]

I would love to see a pic or print from that operation.

A couple things here. One if all you need is the diameter, the CMM is not the best tool to use. What type of CMM and Probe are you using. You should be able to do a alignment on the machine surface alone if all you want is the diameter, using the face as a plane, outside machined surface as the origin and then go in and measure.

What tolerance are you looking at? Using Check pins may be the way to go.