Base Tangent Calculation

[beltcob]

I'm looking for a graphical interpretation the the Base Tangent Calculation used for involute gears. Can this method also be used for odd numbered sprockets in a belt drive?

 

[dimjim]

Is the belt drive an involute system?

 

[beltcob]

No, it is not. Which is why I don't think it will work, but I wanted to ask. Also not understanding the calculation itself, I'm unsure.

 

[JCJackson]

DIN 3960 Art 2.7.2 and beyond. Toothed belt pulleys are usually "topped" by the hob; i.e. the major diameter is machined by the hob. Purveyors of such systems do not provide tooth geometry to facilitate such measurements. It is usually sufficient to verify the outeside/major diameter.