PAW engine taper turning?

[jetstuff]

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

 

[jetstuff]

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".

 

[R Degen]

Thats the way I would have done it. Randy

 

[Tim Wescott]

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.

 

[jetstuff]

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.

 

[nautilus29]

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.