This guide shows different methods to measure the taper of a shaft. Thanks to orangerobin for the reference.
Tapers of common components
According to Naz: "Most of the ones I’ve done all seem to be 5 degree, except the silly french of course, which is 4 degrees."
|Taper||Small End Dia (mm)||Large End Dia (mm)||Taper Length (mm)||Taper (mm/mm)||Resulting Angle (Degrees)||Taper (Degrees)|
|Peugeot Doppler Non Enduro (Fits Ducati CDI).||13.04||15.90||27.50||0.1040 ~0.10||3.0||6.0|
|Peugeot Doppler Enduro 441283 12/2009 "Problem Crank"||11.4||15.9||23.0||0.196||5.5||11|
|Pug MVT Premium Internal Rotor||13.40||16.00||31.87||0.0816||2.34||4.7|
|Puch, Tomos, Derbi, and Sachs 505 Ignition||N/A||15||18||-||5||10|
Cutting a Taper
Octavio: I just cut the taper for a Puch shaft last night. 5 degrees was dead on. My major ID ended up being 0.59” (15mm).
Here is the procedure for those who haven’t done this before:
- Set your compound slide angle to your taper angle.
- Square up your tiny boring bar.
- Take passes of material off using only the compound slide axis.
- Creep up to your final ID checking fit with your crank during the last 0.01”(0.25mm).
- If you’re not super confident. practice on a piece of Al stock ahead of time.
This procedure is pretty obvious to those that have a lot of machining experience, but if you like me and have some, but not loads, it takes some thinking and doing to get this all figured out. I practiced on a piece of Al stock before chucking up my actual rotor.