Re-working begins

Okay so the so I had some issues with the prototype (small cog slipping on the motor, stripping the belt and lowish top speed). Most of the problems stem from poor cog and belt selection, so its time to rethink these. As always I’ve been looking over other peoples sucessful projects.

youtube belt

Youtube clip of longboard

youtube belt 2

Endless Sphere shot previously highlighted on this blog
http://endless-sphere.com/forums/viewtopic.php?f=35&t=47176&start=100

evolve motor

Evole Stakeboard motor
http://evolveskateboards.com.au/

gates_belt

Gates belt – 375 5m
Evolve skateboards sell spares for their boards.
http://evolveskateboards.com.au/collections/all/products/gates-belt-made-in-uk-1

What do these have in common.

  • They all have wider belts than what I had. Somewhere between 9mm-15mm  wide
  • All have bigger teeth. Most are 5mm (mine was 2.03mm)
  • All have larger small cogs than what I selected.  (15t small to 30t large  a 2×1 ratio for the large 3000w motors for the Endless Project. While mine was 18t to 70t with a 2.03mm teeth spacing on the belt)

Some quick maths that I should have done on the gear ratio.

  • The NTM 5060 motor I selected has a 380kv (kv is a measure of rpm/v)
  • The batteries supply 22.2v
  • 380 x 22.2=8436 rpm
  • Wheel diameter = 70mm or 0.07m
  • Circumference =  pi x .07 = 0.2199 metres
  • Circumference x rpm = 2199 x 8436 =1855.17 meters per minute
  • in kilometers per hour = 111.3km/h (this is the speed of the motor itself)

My current gear ratio was 18 teeth to 70 teeth (3.8 ratio)  so the maximum speed was only ever going to be 29.3 kph if the motor was running at full steam under the best possible situation.

I should really be looking for about a 2.5 ratio making the max speed around 44.5kph

20 responses to “Re-working begins

  1. I can send you a link for the belt that is basicaly the same as Richards from endless sphere, also I have a motor pully to match, it has 7.93mm bore so it has to be pressed into the motor shaft and has a retention screw, and also u could find a big hub to match, and there all from small bearings and parts,

    • Cheers but I just gone for the following from https://sdp-si.com

      A 6R25M064090
      5 mm (HTD) Pitch, 64 Teeth, 9mm wide Single Sided Neoprene Belt with Fiberglass Cords 2 x $8.08 =$16.16

      A 6Z25M016DF0908
      5 mm (HTD) Pitch,16 Teeth, 8mm Bore, Aluminum Insert, Polycarbonate Timing Pulley for 9mm Wide Belt $7.06

      A 6L25M040DF0908
      5 mm (HTD) Pitch,40 Teeth, 8mm Bore, Plain Bore, No Insert, Polycarbonate Timing Pulley for 9mm Wide Belt $5.30
      Subtotal: $28.52 + Freight.

      • I live in Australia so the parts are still being delivered. I will update once they arrive.

        In the meantime another reader Vitali. Sent me some photos of his setup and he’s using GT2 15mm width and 5mm teeth distance belt, 20 teeth cog in the front and 30 teeth wheel cog and 70mm wheels which he picked up from SDP-SI. The GT2 might be the better belt for this purpose as they’re designed for high torque/horse power situations. See their website for more details. And I’ll add Vitali project pictures shortly.

        http://www.gates.com/brochure.cfm?brochure=7916&location_id=11539

    • Cheers mixedmeters. They seems to have updated the site with lots more parts which is nice. I did look at their trucks a long time ago but they looked just like the cheap and nasty ones that you can get off ebay so I decided to go it alone.

    • I think its going to have enough power.
      Most cheap Chinese boards have 800W motors, evolve boards use a 200w motor, boosted boards have 2000w total and this motor NTM 5060 360kv is 2000W at 22.2v. Should be good enough. The endless project is 2 x 3000w motors which is a ridiculous amount of power and he never gets near using all the power.

    • Been running it on my short tests and its not near empty yet. Once I get this reworked with the new cogs I will let you know the performance (distance, top speed etc) Unfortunately I stripped the belts before getting it going for long enough.

      • Cool man. Good luck. I will be around asking question since I might try what you are doing.

        Thanks for sharing the info.

    • he had to do a bit of tweaking. Check out the link and comments

      http://endless-sphere.com/forums/viewtopic.php?f=35&t=47176&start=200

      “just wonted to put up some pics of my build so far using Richard’s mounts, i had a few things i had to play with and modify to get the hole thing going, but know i think im happy and ready to start with the electronics.
      my motors where a bit smaller and the holes did not line up just right so i had to drill some new holes, and because my motors where smaller i could then angel the mounts a little bit up so know im only using 1/4 inch risers instead of 1/2. the loaded board im using is nice and smith when ride with the abec 11 wheels, big but it was what i was going for.”

    • The new cogs and belt were better suited to the smaller wheel size for the lower top speed. However, i have much more clearance with the abec 11. Use the excel speed calculator when looking at cog combinations. Go for a low top speed and a motor with a low kv

  2. Hey guys has anyone tried replacing the motor on the Evolve board with a lighter unit or one less prone to overheating? The Evolve motor runs very hot and then cuts out.

    • I haven’t heard that before. The Jeff at Evolve strikes me as a pretty decent block. Have you tried giving him a call about the issue? It might be a faulty motor. Let me know how you go.

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