Metric Spline Callout
Metric Spline Callout
(OP)
I'm new to posting here but I've read through a couple of threads in the process of trying to figure this out and figured I'd be best off just posting a question, so here goes.
I'm in the process of trying to reverse engineer a spline. The issue is it was built to some kind of metric standard, and I'm not sure which. What I'm missing in the callout is the refernce diameter and the fit class. I have a module of 1.5, pressure angle 25, and 12 teeth. Any advice where to go next?
I'm in the process of trying to reverse engineer a spline. The issue is it was built to some kind of metric standard, and I'm not sure which. What I'm missing in the callout is the refernce diameter and the fit class. I have a module of 1.5, pressure angle 25, and 12 teeth. Any advice where to go next?





RE: Metric Spline Callout
There are three common metric standards; DIN 5480, DIN 5482 and ANSI B92.2M-1980.
The first place to start is by measuring the base pitch of the sample. This is done with a good set of verniers and measured tangentially in the normal plane over a certain number of teeth. The number of teeth over which to measure is worked out by laying the jaws of the verniers over the "best fitting" number of teeth. By this I mean the number of teeth that allow the jaws to contact the tooth profile somewhere around the pitch line (about half way down the profile from the tip of the tooth) and not allow the tips of the jaws to make contact in the root area nor have them make contact right up on the tips of the teeth. Then take the next best fitting measurement either side of that; so in your case the first measurement might be across 3 teeth, then take a measurement over 2 or 4 teeth, which ever fits best. Subtract the smaller measurement from the larger and what you have is the base pitch.
Then all the usual measurements are required such as major diam., minor diam. and any details on the mating part you might have.
Let me know what you measure and I’ll let you know what to do next.
RE: Metric Spline Callout
30 degrees in normal for most splines.
What else do you know? Bore, etc.?
RE: Metric Spline Callout
I took the measurements for the base pitch like you said gearcutter and came out with .280" across two teeth, and .445" across three. Which leaves me with .165" for the base pitch.
Thanks for the speedy response!
RE: Metric Spline Callout
and you have to have the standards to know how they
are enlarged. Because these profile shifts are standard,
using general equations or formulas will give you wrong results unless you know the amount of profile shift that
pertain to that particular spline. You might search on
metric spline standards and see if you can find the
standard.
RE: Metric Spline Callout
http://quickgear.bizland.com/id9.html
offers a spline calculator and is free
for 7 days. Do not know if this will help.
RE: Metric Spline Callout
RE: Metric Spline Callout
Great program. I assume you wrote it.
I could not remember the DIN 5480.
RE: Metric Spline Callout
I agree, it is a great program. It opens up with EXCEL.
No, I didn't write it. Below is link to the web site where you can purchase it.
http://www.emip.de/home_e.htm
RE: Metric Spline Callout