Hope you guys are OK with a bike guy posting over here… This site has been very helpful.
I added a hill assist to my Mountain Bike using a Turnigy D5035 125KV Motor (the orange one) and a VESC.
https://endless-sphere.com/forums/viewtopic.php?f=28&t=96769&p=1426882#p1426882
I’m driving the crank directly using #25 chain with 10:1 reduction (9T, 90T sprockets). 4S battery. It works great, but I’m curious to see if a belt drive might work as well and be a bit quieter.
I read a bunch of threads here with lots of good information, but not quite what I’m looking for. I would really appreciate any advice/suggestions on design guides, sources for pulleys & belts (off the shelf and custom…), and any general thoughts.
Here are the design parameters:
At least 10:1 reduction ratio
450 Watts at 60 RPM Cadence, which works out to about 175 lb belt tension. (May be able to reduce watts/tension just a bit…)
7.2" max pulley diameter
.575" large pulley width, so 1/2" wide belt (Maybe 15mm with large effort)
Dust for sure, and possibly dirt.
Up to .010" radial runout on the large pulley
Prefer not to use an idler/tensioner, or crazy high tension
My initial feeling is that this is a difficult application for a belt. However, you guys seem to be able to make belts work in difficult conditions. Thanks!
I think you might have a chance at 20mm but I think the size of the wheel is just too much for it Not to mention if it was cold, they would snap like taffy