looking for 500cc polaris (fuji) crankshaft taper dementions

[mad_max_500cc]

looking for a little help on this one guys im trying to find the dimensions for the taper on the crankshaft for my 90 polaris indy 500cc where the primary clutch mounts so i can have an adapter made. any clue where i can find it? i need the taper per inch and a start or stop diameter ive been doing some searching with not alot of luck!!!!

[liflod]

Digital Caliper on sale at Harbor Freight $9.99.

[hydromike]

Hey 'max....

The industry standard is usually the 30mm 10:1 taper (Chaparral, Rotax, Polaris, Kawasaki, Cuyuna all used them), but I don't know how that translates into "Taper per inch".

~m

[mad_max_500cc]

mike Ive seen those dimensions before when looking at aftermarket clutches in catalogs before so we are on to something here .... what I'm wondering is how do you decode those #s what does the 30mm represent ? is it outside diameter of the shaft at the big end of the taper, or is it the length of the taper? and is the 10:1 ratio the drop (for every 10mm it drops1mm) im no machinist but id like someone to explain how this works and what each # represents seems like a good thing to know!!!! and it would be no sweat to convert all of this to standard dimensions with a couple of quick formulas that i already know.... can any of you machinists out there give me a clue?

[jpswift1]

mike Ive seen those dimensions before when looking at aftermarket clutches in catalogs before so we are on to something here .... what I'm wondering is how do you decode those #s what does the 30mm represent ? is it outside diameter of the shaft at the big end of the taper, or is it the length of the taper? and is the 10:1 ratio the drop (for every 10mm it drops1mm) im no machinist but id like someone to explain how this works and what each # represents seems like a good thing to know!!!! and it would be no sweat to convert all of this to standard dimensions with a couple of quick formulas that i already know.... can any of you machinists out there give me a clue?

Take a trip up to Grand Island and talk to Mark M. He's a great machinist and I'm sure he could point you in the right direction. Dan might even have his number.

[mark m.]

Hmmm. 10:1 ratio angle. Is that half the angle or included angle? Ok Eric. Looks like I am going to need that crank end you showed me for investigation purposes. We will get to the bottom of this. The 30mm is the the large diameter.

[mad_max_500cc]

ok mark i was playing around with calipers at work today (cheep ones that i don't trust to be super accurate but the big end of the shaft before the taper is 30 mm and the thin end of the taper is abought 27mm and given the length of the taper 10:1 ratio seams right i can bring it over sometime this weekend my travels will bring me over the island once or twice this weekend we can stand around and scratch our heads, contemplate and have a beer.