# PAW engine taper turning?



## jetstuff (Mar 18, 2021)

PAW 15 (2.5cc) early diesel has a taper on the 1/4" crankshaft,..... How do I turn that internal taper for the prop driver?
THANKS!

john


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## jetstuff (Mar 19, 2021)

I ended up by putting the crankshaft in the lathe and swinging the cross-slide until a DTI runs up and down the taper without moving..... turned out at an 8 degree taper over  5/16".


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## R Degen (Mar 19, 2021)

Thats the way I would have done it. Randy


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## Tim Wescott (Mar 19, 2021)

Of course!  The only discussion I've seen on this topic was for totally home-built engines, where the advise was to turn the taper on the crank and the prop driver with the same setup -- but that gives you no help when you're trying to make a part for an existing engine.


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## jetstuff (Mar 21, 2021)

Thanks, yes there's plenty of info on the web and youtube but most seems to detail complex (for me) maths and using 1,2,3" blocks, not very relevant to a very short taper.


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## nautilus29 (Mar 22, 2021)

If you have dros on your lath and an indicator you can figure out the angle using a triangle calculator from online, but looks like you already have good advice on how to proceed.


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