Calculate degree of tapered shaft

Any trig experts here? I'm attempting to remove the Ducati ignition from my bike and replace it with an HPI system. I ordered a kit that should have worked, but ran into a few issues. The one I'm dealing with here, is the rotor(flywheel) they sent has a different taper than my crank.  I'm hoping there is someone here much smarter than I, that can figure out the degree of the taper. Unfortunately, HPI doesn't put any part numbers on their stuff and I'm trying to figure out if they sent the rotor that they think fits the Husky and they have wrong info or they just sent the wrong part. According to their site, this is the rotor that comes with the kit. http://www.hpi.be/item.php?item=210R283Unfortunately, there is a little language barrier since they are in Belgium and I'm trying to figure some of this stuff out myself.
Ducati flywheel 
Large end 14.25mm
Small end 13.35mm
Length of taper 22.25mm

HPI Flywheel
Large end 19.50mm
Small end 15.75mm
Length of taper 28mm

Tangent Theta = opposite/adjacent.

 

 

So, in your case, your angle is the inverse tangent (tan^-1) of the difference in radius, or difference in diameter over 2, divided by the length.

 

For the Ducati

 

Theta = tan^-1((14.25-13.35)/(2*22.25)) or 1.146 degrees

chit i just realized that you cant use that you have to buy it....
and it wont let me upload my excel spreadsheet :/

Edited by EnglertRacing

chit i just realized that you cant use that you have to buy it....

and it wont let me upload my excel spreadsheet :/

HA!!

 

I used wolfram alpha. But normally, I'd probably use solidworks, I'm lazy too. 

 

 

Side question, hows the SXV?

They're one of the bikes I've been thinking about picking up this summer. 

Edited by Wetbed0

HA!!

 

I used wolfram alpha. But normally, I'd probably use solidworks, I'm lazy too. 

 

 

Side question, hows the SXV?

They're one of the bikes I've been thinking about picking up this summer. 

 

 

well the sxv is a subject for a pm..... :/

Tangent Theta = opposite/adjacent.

 

 

So, in your case, your angle is the inverse tangent (tan^-1) of the difference in radius, or difference in diameter over 2, divided by the length.

 

For the Ducati

 

Theta = tan^-1((14.25-13.35)/(2*22.25)) or 1.146 degrees

There are a bunch of standard tapers with angles from center ranging from just over 1 to 2+ degrees.  Don't know about metric but you might Google and find more info.

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