friction drive for skatecycle

[jatgm1]

hello everyone. i have a question i thought i would ask the great minds of endless sphere about for expert advice. i have a brooklyn workshops skatecycle. i dont need it to go fast but i was wondering if there is some way i can make it electric. my first thought was, friction drive. the thing is im not sure how to mount it. i didnt take pictures of mine but their all basicly the same. here is a link to one. http://marketgurney.com/p/2286067/Brooklyn%20Workshop%20Skatecycle%20Hubless%20Skateboard,%20White,%2030%20x%206.5%20x%208.5-Inch-%252d%252d-2Z2O003IVVYEZ98.html
where can i even buy a friction drive kit nevermind one that would work for this? i need one that would basicly be able to spin the outside of a wheel. the inside is stationary while the outside spins. hence the hubless wheel. its a fun toy for hills and its alright up hills if you really work but if i could make a friction drive that would be able to take me up the hill via electricity then that i can i guess turn off to go down the hill. also i wanted to be able to use the friction drive in reverse as a brake, because stopping while going down a big hill is quite difficult. i was hoping that i could get a motor to press against the outside of the wheel and that i could get somthing similar to a vice that would grip the inside and then when i hit the throttle it would push it forward. and i was hoping as well that i would be able to do somthing simple like unhook somthing to disable the friction drive so i will still be able to pick up speed downhill but that i can engage while going to use it as a brake. thank you for any help beforehand. and i dont have a welder or know how to use one ow want to pay large amounts of money for someone to do it for me so i would prefer if it is somthing i can screw together myself.

 

[sk8norcal]

here's one,

http://wackyboards.blogspot.com/2013/09/electric-skatecycle.html

 

[melodious]

There is a vet member here (forgot the name though) that was part of a Kickstarter campaign for a friction drive on a skateboard wheel. The drive itself attaches to the axle (not sure before or after the wheel) then bolted on.

Not sure what happened if the product went through too. Too bad, I thought it was a good idea. You could disattach the friction part of the drive and ride the board with no motor assistance/resistance.

edit: woops. A skatecycle? I'm picturing an inline type wheel formation? In which case, not sure the device I was describing would be valid.

 

[beto_pty]

https://www.kickstarter.com/projects/424686603/kickr-electrify-every-longboard looks like they made it...

Perhaps there are heating issues? Im torn between thinking the motors heat would transfer to the wheel and then to the ground cooling the motor,
or
the friction between the wheel and the motor, would overheat the motor due to urethane being an insulator..


So I guess my profesional opinion is that it either might work really well or not at all..or maybe the opposite..

the problem might end up being kv&torque.. a 192 KV with 64 mm diameter on 6s will theretically do about 55 kph but with comparatively a very low torque... so you need to fins some small diameter very low kv motors to get this to work well, or use 2...

 

[jatgm1]

how the hell would i fit this onto a skate cycle.. that would be my question. i guess i could put a screw in where it connects to the wheel and put it inside the skatecycle wheel but how do i keep it in place without drilling holes in the skatecycle?

https://www.kickstarter.com/projects/424686603/kickr-electrify-every-longboard looks like they made it...

Perhaps there are heating issues? Im torn between thinking the motors heat would transfer to the wheel and then to the ground cooling the motor,
or
the friction between the wheel and the motor, would overheat the motor due to urethane being an insulator..


So I guess my profesional opinion is that it either might work really well or not at all..or maybe the opposite..

the problem might end up being kv&torque.. a 192 KV with 64 mm diameter on 6s will theretically do about 55 kph but with comparatively a very low torque... so you need to fins some small diameter very low kv motors to get this to work well, or use 2...

 

[beto_pty]

No drilling? probably no dice .....
You are planning on mounting the equivalent to a 2hp motor on this.. you cant just double sided tape it there... Be it either bolts, weleded-on supports or through holes you are going to have to modify the part to hold your motor mount or your motor..

Ideally you could mount the motor under the board next to one of the wheels both require either bolting on or an angle to be welded on the parts.., 7/8" to 1 inch minimum motor to ground clearance has worked well for me so far (as long as you use common sense of course).. the esc mounted vertically on the side away from you (square).. the batteries saddle bag mounted on the joining bar (large rectangle).. or tethered to you.. which in this case might not be a problem as the riding dynamics differ from skateboards (where in my opinion they are unacceptable)

However bear in mind the lower than normal torque problem has not been adressed.. unless you weigh 120 lbs a friction drive running at 168 kv 62 mm diameter motor might feel weak on on flats.. and struggle with any serious uphills.. Uless you friction drive the shaft (or the shaft with a larger diameter roller) in which case your torque problems are solved, but you run into potential placement issues where the motor ends up uncomfortably sticking out...

When is someone going to come out with a cool 50mm 100 kv motor.. . it would revolutionize the EV market allowing everything to be direct driven.. or wheel mounted...

 

[hillzofvalp]

https://www.kickstarter.com/projects/424686603/kickr-electrify-every-longboard looks like they made it...

the problem might end up being kv&torque.. a 192 KV with 64 mm diameter on 6s will theretically do about 55 kph but with comparatively a very low torque... so you need to fins some small diameter very low kv motors to get this to work well, or use 2...

Or design your own motor

Kickrs are almost ready to ship. I'd like to do a little write up on here for the more technical savvy people once they are out in the wild.

It doesn't look like skatecycle would be directly compatible with the Kickr motor mount, but otherwise a perfect motor for the application imho. It's hard to find an off the shelf low kv rc motor with good power density.

 

[beto_pty]

Or design your own motor
.

[/quote]
Lead the way I'll follow..
I have several projects that could use friction drives.