Measuring Internal Involute Splines

[[Ja...]]

We have just quoted and are getting a job with two parts that have the same internal involute spline. Is there a way to measure this in Calypso without using Curve/FF/GearPro?

[[Ch...]]

Jake,

Hi. Gear + Spline guy here..

Answer is yes and no.

To be breif : splines can mostly be accepted with go/no-go certified spline gages. It helps to inspect a few individual items, such as root diameter, etc.

Even with gages, it is good practice to do CMM inspection on a 1st and last piece and maybe a few in between dependin on lot size.

If you had a Ø .108 probe bale you could measure the between wire size on the drawing. Also what is not listed is analytical toelrances from the spec, such as lead, profile, pitch (in lieu of gages)

There is another way of calculating the between pin size without a Ø .108, by measuring points on the flank at the pitch Ø and 'fitting' a .108 all in there but it would be involved... you'd be better off measuring between actual gage pins.

As far as measuring lead and involute (and pitch) in Calypso, theoretically its posssible, but its a long story. Suggest getting gages and use go/no-go, and inspect M.B.W + major/minor Ø and root radius.

I've measured pitch in Calypso and know how to check lead and profile, but its a bit tedious.

[[Ow...]]

I've attached a nice PDF that might help get you going in the right direction but, as Chris mentioned, reporting all the spline nomenclature as defined would be difficult.
If you plan to do a lot more in the future, gear-pro is priceless, especially if you consider the cost for go/no-go gauging for something you may not need long-term.

Splines without gear-pro.pdf

[[Ja...]]

Thanks guys. I have a quote from Michigan Spline for this, but it is just over $3k with 9wk lead time. We were just awarded the part, so we have time to get the gage in, but I want to see if we can measure it on the CMM as well for more information to give our EDM guy who will be machining the spline.

[[Ri...]]

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The Pitch portion is extremely easy as there is already a function for it. Both the Lead (Helix) and the Involute (Profile) can be handled with Curve.

The biggest issue would be getting an accurate spline model because most of these models aren't drawn to nominal.

Either way, I agree with getting a spline gauge. It is the most accurate way to ensure fit with a spline.

Also - every gear/spline manufacturer should have a piece of measurement equipment that can accurately measure gears/splines. That means a rotary table and GearPro.

I've attached your spline model (modeled nominal per GearPro) if you'd like to mess around with it.

Let me know if we can help out in any way - I love gears. 🙂

[[SH...]]

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Can I ask how to create a template program in gear pro, obviously not related to this topic.
We have gear pro but don't use that much..

[[Ka...]]

If you have PCM, it would be theoretically possible to do this, but it would take at least 3-4 years to develop code that would be, at best, an incredibly complex, rudimentary gear program.

Gear-pro is really easy to use, and not terribly expensive, you could just add this to the quote, or see if management wants to budget for this as a business development tool.