Anyone know how to check an external (due to old rule number 3) thread for pitch also so i can use it as a Datum ? Any simple step-by step direction would be awesome!!!
Anyone know how to check an external (due to old rule number 3) thread for pitch also so i can use it as a Datum ? Any simple step-by step direction would be awesome!!!
Old rule number 3? I do not know rule number 3, or I have forgotten it. Please explain.
Can't be done.
Shane,
Checking the pitch diameter is not possible, but you have options.
You can check the pitch diameter outside of the program, use a key-in dimension and input the measured value into a generic circle.
You can also forgo the pitch, and just measure the major diameter using auto-circle/cylinder and utilizing the pitch option.
Also, you can combine the two to get a relatively accurate center from the auto-feature, combined with the pitch measurement obtained outside the program in a generic circle.
If it is RFS, I would skip measuring the pitch diameter altogether. If it is MMC, I would still advise against using the pitch diameter. The way threads mate leaves practically no usable positional shift to make use of anyways.
I used to think it was not possible too, until I saw them doing it on a API taper thread at NIST!
You need a probe as close to the ideal wire size as possible.
You need one of the newer versions of pc-dmis that allows you to take a self-centered hit, or else you will need a lot of variable code to take a hit on each flank and then generate a midpoint between them.
Anyone know how to check an external (due to old rule number 3) thread for pitch also so i can use it as a Datum ? Any simple step-by step direction would be awesome!!!
Old rule number 3? I do not know rule number 3, or I have forgotten it. Please explain.
Can't be done.
Shane,
Checking the pitch diameter is not possible, but you have options.
You can check the pitch diameter outside of the program, use a key-in dimension and input the measured value into a generic circle.
You can also forgo the pitch, and just measure the major diameter using auto-circle/cylinder and utilizing the pitch option.
Also, you can combine the two to get a relatively accurate center from the auto-feature, combined with the pitch measurement obtained outside the program in a generic circle.
If it is RFS, I would skip measuring the pitch diameter altogether. If it is MMC, I would still advise against using the pitch diameter. The way threads mate leaves practically no usable positional shift to make use of anyways.
I used to think it was not possible too, until I saw them doing it on a API taper thread at NIST!
You need a probe as close to the ideal wire size as possible.
You need one of the newer versions of pc-dmis that allows you to take a self-centered hit, or else you will need a lot of variable code to take a hit on each flank and then generate a midpoint between them.
