Spline Gages ???? What?

Good Morning ladies and gents,

For those of you who have ordered Go/Nogo gages for splines... how do you confirm they are made correctly? Do you all have any information you can pass along to help me understand how to compare customer print with gage maker go/nogo print? I don't know a whole lot about spline gages or splines in general and would like to understand them a little better. I attached the part print for the spline of the part. Now how would i take this and determine the sizes/specs of a Involute spline go and nogo gage.

Thanks in advance

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DAN_M over 2 years ago

First- essentially you are going off of the assumption that it is correct because the P.O. stated the print spec and applicable standard and the manufacturer provided a cert of calibration saying it does.

How do I convince others that is enough? Also, I have a hard time fully swallowing that myself. I don't want to tell them how to make the gage. I just want to confirm that we are checking our parts at the proper limits. Ya know?

Second- The parts have changed. 100%. You would think that would be enough to convince them. We have a 3 pin method to check the parts and it shows them smaller than before. However, we also have a press fit shaft that we use on a force tester. This shaft is labeled "max" from the customer stating its the max size of the shafts they use. It slides right through. But our go gage stops about halfway through and requires some force to push it the rest of the way. So they assume that means the go gage is wrong.... I tried to explain that they are two different sizes and geometrically different however.... no dice.

First: I am not going off of an assumption. I am going off of a certificate of conformance from an accredited facility.

The data on my PO will simply state "Make 2 ID Spline gages that conform to AGMA XXXX-XXX Rev XX. Material shall be AMS XXX Rev X". WE DO NOT NOR WOULD WE EVER tell a gage house how to dimensionally make a spline gage. Nor should you
With all due respect, convincing your co-workers who don't understand a 17025 accreditation is not my concern.

Second: I believe you that the parts have changed. So the gage that worked before is now not working and you're saying the parts have changed...could they be....BAD??? :scream;

I can tell you from experience...measuring over pins CAN yield good results however it is very subjective. If gages bind/start to fit funky, there are CMM related things you can do to double check the spline itself. The things your struggling with are why companies like mine specialize in this stuff.

Every gage R&R I have ever done where inspectors have to check things over pins has a significant failure with regard to data repeatability.

After thinking about your issue, the best advise I can give you is:
You're dealing with a hard headed MFG Dept that appears to have more power than you. Measure over your pins and cross your fingers because they appear to be woefully unprepared for this.
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DAN_M over 2 years ago

First- essentially you are going off of the assumption that it is correct because the P.O. stated the print spec and applicable standard and the manufacturer provided a cert of calibration saying it does.

How do I convince others that is enough? Also, I have a hard time fully swallowing that myself. I don't want to tell them how to make the gage. I just want to confirm that we are checking our parts at the proper limits. Ya know?

Second- The parts have changed. 100%. You would think that would be enough to convince them. We have a 3 pin method to check the parts and it shows them smaller than before. However, we also have a press fit shaft that we use on a force tester. This shaft is labeled "max" from the customer stating its the max size of the shafts they use. It slides right through. But our go gage stops about halfway through and requires some force to push it the rest of the way. So they assume that means the go gage is wrong.... I tried to explain that they are two different sizes and geometrically different however.... no dice.

First: I am not going off of an assumption. I am going off of a certificate of conformance from an accredited facility.

The data on my PO will simply state "Make 2 ID Spline gages that conform to AGMA XXXX-XXX Rev XX. Material shall be AMS XXX Rev X". WE DO NOT NOR WOULD WE EVER tell a gage house how to dimensionally make a spline gage. Nor should you
With all due respect, convincing your co-workers who don't understand a 17025 accreditation is not my concern.

Second: I believe you that the parts have changed. So the gage that worked before is now not working and you're saying the parts have changed...could they be....BAD??? :scream;

I can tell you from experience...measuring over pins CAN yield good results however it is very subjective. If gages bind/start to fit funky, there are CMM related things you can do to double check the spline itself. The things your struggling with are why companies like mine specialize in this stuff.

Every gage R&R I have ever done where inspectors have to check things over pins has a significant failure with regard to data repeatability.

After thinking about your issue, the best advise I can give you is:
You're dealing with a hard headed MFG Dept that appears to have more power than you. Measure over your pins and cross your fingers because they appear to be woefully unprepared for this.
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cheesiechanman over 2 years ago in reply to DAN_M

They are ungodly unprepared. The part we are having all of these issues with has a duplicate mold that we just quoted. Like can we figure the first one out before we take on more work that we cant handle? lol

And yes.... the parts are bad. But its easier to blame the gage than the parts. We make more money that way.
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