X-Mozilla-Keys:                                                                                 
Marc Pedings wrote:

Paul wrote:

Archie wrote:

requires Dynamic (not static) balancing.  That adds a $150 cost to the

DriveR

sprocket.

This seems a bit high.

I did go thru Wittichen (a secondary distributor) for this pricing, but yes, I
agree, VERY HIGH.  I figured one could take the cast sprocket and have it
digitally measured to CNC, cut one from aluminum, and have it dynamically
balanced.  Yes, $25 is the exact quote I had to have one balanced locally.  I
haven't checked the off the shelf for the 125mm (4.92") width sprockets and polychain,
but I did for the 98 mm (3.86") width, 14mm pitch:  28 tooth DriveR - $72.17, 60 tooth
DriveN - $152.42, and the 1120 Belt was $78.62.  They just charge out the Kazoo
to have something done in custom.

Marc Pedings

I'll bet it is almost cheaper to make one out of steel sheet (4130)
in a press brake with a custom die to form the teeth, roll it into a 
15" dia. circle and weld up a hub than have it CNC machined out of a 
huge chunk of 7075 T6 or 6061 T6 aluminum. On top of that there would be
less thermal expansion of the large pulley which could cause a belt
tension problem. 

Paul Lamar
 
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