What is the problem of passing the ERPM limit?

I usually get a small piece of wire and wrap it around the pulleys and then measure the wire. the length in inches is the part number of the belt. eg: 120 = 12.0 inches

also worth noting that the metric belts like 256 are in mm.

I calculated with a excel program, I’ll try the wire tactic

https://sdp-si.com/eStore/CenterDistanceDesigner

SDP/SI’s center distance calculator is spot on. It tells you center-to-center distance and also number of teeth in mesh

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I have always used this one: http://www.bbman.com/belt-length-calculator/

To answer your question about the ERPM Limit: Vesc is capable of 100.000, but with some setups it gets jerky, so the opinion is 60.000 to be absolutly safe. If you exceed that limit, vesc eventually loses connection to the motor and could start to stutter. And worst case is a fried DRV chip due to that. (And maybe some broken bones due to high-speed-motor-stuttering).

So be safe and stay in the limit :wink:

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@IsTalo

The 60K erpm is a recommendation base on efficiency due to the accumulative effect of losses in a BLDC motor.

You can read vedder explanations of the thinking behind this limit on this link. http://vedder.se/2014/10/chosing-the-right-bldc-motor-and-battery-setup-for-an-electric-skateboard/

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