Pitch Diameter Runout

[[Ni...]]

Hello,

I have a circular part with gear teeth on the center of its OD with 44 teeth around. I was trying to get the pitch diameter runout to datum A-B which are ODs at the end of the part.
The way i did it was that i probed in between two teeth and made a secondary alignment to it the center of those two points.
Then i went half the pitch diameter which was 1.100'' and did two points to that secondary alignment. Then I repeated the process all the way around.
I made sure it was exactly at 1.100 and it was at the same height.
Then i constructed a circle out of those points and did a radial runout to Datum A-B which was a 3D line between A and B. Step Cylinder gave the same results as 3D line.

I got this idea from the engineer as he explained this was how it technically works.

In the simulation the runout came out perfect. The actual part gave .0008'' over the limit. After looking at it many times to make sure it was accurate, i decided there was nothing more that could be done and left it as is. It will always repeat to .0003''.

Now the issue is a Wenzel or Gleason CMM checked those parts and the chart for the teeth came out good which means the runout should be good.
Also was told i couldn't properly check Pitch Diameter Runout without GearPro on the Zeiss CMM.

Just want to get ideas if it's not possible to check that without GearPro or not.

[[Ni...]]

Image of part

teeth part.PNG

[[Jo...]]

why do you say you could not correctly measure pitch runout with gear pro? Gear pro is much more accurate the gleason CMM, the older models won't repeat between them within .001 ... newer ones around .0005.... But without using gear pro, you should be using a self-centering point in the teeth. Should use the mid point eval if doing points or turn off stylus tip correction if doing inside of a circle.

[[Ni...]]

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WITHOUT.
i was told i cannot check pitch diameter runout WITHOUT gear pro since i tried doing it without it.
I just found the center and started going half the pitch diameter and made points there.
Then i created a circle and did runout to it.

Wanted to know if its true that it cannot be checked wtihtout gear pro.
Or if it is possible, then how exactly would it be done?

[[Jo...]]

Sorry misread. Using self-centering probing using a stylus tip close to what the pin size is for the part is the way to go. You can either use single points and select midpoint evaluation and recall in a circle or use in a circle feature with self-centering points. Either way in the circle feature, turn off stylus tip correction. This will mimic a manual check over pins. I use this method on splines without using gear pro.

[[Da...]]

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When I need to check a gear, I don't use self-centering. I don't really like it, because it requires a special probe that has a comparable diameter to the theoretical pins.

I measure every tooth with circles. I'm aware that an involute shape differs from a circle, but trust me, the difference in shape is minute for small circle sectors. Try it, load a CAD of a gear, put a circle on a tooth and look at the form. The form error is usually far less than a micron.

After measuring circle sectors on the teeth, I construct tangent circles within the teeth gaps of exactly the right pin diameters and use those to measure the run-out. Works perfectly for what I need.