Portable friction drive setup

[sami]

hi guys,
i am planning on building a removable friction drive setup that can go on either my longboard or my penny board (for travelling/short trips).
the setup is similar to papertriping's idea and kickr.

hopefully i dont have too many questions but here is the list of current bits ordered:

Turnigy Aerodrive SK3 - 6364-190kv Brushless Outrunner Motor - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=37619
USB Programming Adapter for Hobbyking X-Car 120A & 60A ESC - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=47749
Hobbyking® X-Car 120A Brushless Car ESC (sensored/sensorless) - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=47748
ZIPPY Flightmax 5000mAh 3S1P 20C (AU Warehouse) - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=16748
Turnigy Accucel-6 80W 10A Balancer/Charger LiHV Capable - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=75601
XT-60 connectors (for batteries) - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=43416
XT60 - Series cable - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=44738
Low voltage alarm - http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=41060

After doing some more reading i hope i didnt order the wrong ESC! it says Battery: 2-3 cells Lipo and i was wanting to series the two 3S 5000mAH..

The two boards ill be using are the usual penny and a Apex 37 longboard in Cruiserweight (no im not that large ) http://originalskateboards.com/longboards/2011_apex_37

Cheers guys and i hope to update this in the coming weeks with progress.

 

[777arc]

Yeah 3S is pretty low, but then again since it is friction drive and a 190kv motor, you would have trouble getting to the top speeds anyway.

 

[sami]

2 x 3S 5000mAh in series is equal to 1 x 6S 5000mAh battery so i should look at a different ESC? that way my limitation is removed hey?

 

[777arc]

Yes if you want 6S, you need an ESC that supports 6S. But a 190kv motor running at 6S will give you a top speed of 30-40 mph, so the result is a board that goes too fast and does not have enough torque at the speeds that matter. Someone correct me if I'm wrong.

 

[sami]

cool thanks for the input mate, im not hung up on top speed. more for cruising. a future build will be dual motors for speed and climbing ability.
i thought the lower the kv the lower the top speed. back to more reading i think

 

[777arc]

the lower the kv the lower the top speed.

Yep this is true, but because friction drive is like a 1:1 ratio (that motor is roughly the size of a wheel), you need something even lower than 190kv. I think Alien Power has a 130kv motor.

Speed might not be a big deal, but what will be a big deal is if you build the board and it wont go uphill due to lack of torque =/

Just keep in mind that friction drive is far from the easiest way to make an electric skateboard, so unless portability between your 2 boards is really important, I would look into a traditional build with pulleys/belt and a motor that mounts to the trucks.

 

[sami]

yeh you are right, ill look into a more traditional build for the next one. this was more to see if i could make a friction setup to take travelling, buy a cheap board and off i go. without needing to lug a full board around (like a did a few years back).
could do the same with trucks and pulleys i guess .. i tend to do things the hard way

where i live there are minimal hills, and i guess i could kick assist up hill for the few i may encounter. thanks again for the feedback mate, i appreciate it.

 

[sami]

ok i built a bracket to go on the truck and it works! except my bracket isnt solid enough and flexes with the torque and bumps in the road.
ill make a new bracket today and have another go. i think it should work well for assisted cruising which is what i want.. pics to come

 

[sami]

Ghetto Mount #2 built and a few additions already.

tested it out and she got me up to 26km/h into the wind (very windy today).
need to tweak the accel curve as its a bit slow to give me full power.. a bit quicker would be nice.
added nonslip tape to the motor (bought at hardware store - 5m of it )
bracket is bent around a bit to protect the motor a little bit and i was lazy

so far i am really happy as it gets me up to a good cruise speed which i would normally push up to, and it cruises well. all on 3S with a 190kv motor.. any input on running 2 x 3S in parallel? or should i not bother?

cheers!

 

[sami]

and if anyone has some rough guidelines for setting up the ESC that would be great. saves me a lot of trial and error

 

[sami]

update, so far its going well. i have some 10mm aluminium plate (overkill i know) to build a more permanent bracket for the motor.
the one 5000mah 3S battery pack gives me about 7-8kms of riding flat out (25km/h)
once the bracket is sorted ill me much happier, and will then concentrate on a pulley/cog setup.

 

[torqueboards]

How's braking on the friction drive?

 

[sami]

hi Torqueboards, the braking is quite good. I have set maximum braking force to 75%. i only use it if i am coming up to a larger intersection a bit hot.
its definitely handy. my new bracket is near finished ill upload a few pics for it soon.

 

[torqueboards]

How is it climbing hills? It's pretty neat. You put sandpaper on the wheel, right?

I haven't seen anyone with a dual motor friction drive yet

 

[sami]

maybe i will make a dual friction then.. hrm haha
its not sandpaper but similar, it is step tread tape so its UV stable and long wearing, plus the glue is very strong.

it climbs slight gradients but that is probably where the 3S is letting me down. i havent tested or have a hill within range.

btw - braking is set to initial 20% and max of 75% (any more and it will slip)

 

[buzztiaan]

any pics of your new mount? :3

 

[papertriping]

My apologies for not updating the Pen-E drive thread here on ES. I've been battling many bouts of procrastination.

Hey Sami!

So a friction drive is awesome. It's fast- I clocked a maximum of 32 mph on my Pen-E. It doesn't heat up. It's pretty reliable on most skateboard able surfaces. Seems efficient enough- capable of 16+ kms on a single charge. It's compact- I carried it on vacation to hong kong and extensively tested it there. Clocked about 200miles!

But then!

200 miles on the friction drive killed the motor, so it seems. Now the motor when hooked up to the wheel wont rotate anymore- it just stutters - and seems like the bearing in the motor have gone bad.
Despite everyone's advice about friction drives and how it could ruin the motor bearings, I just had to build it to see for myself.
Pen-E was awesome! I loved riding her - but when the motor died I was too sad to do anything about it. I'm still not sure what is the problem with the motor. I intend to hook it all up again and troubleshoot whats wrong with the motor sometime soon.
But so far I believe- the motor died cuz of the stress caused in a friction drive setup.

I'm sorry to burst the bubble

I don't know how the Guys at Kickr are managing this stress on the motor. But there's is a custom design- probably re-enforced.

 

[Hummina Shadeeba]

I think kickr use a skirt bearing on the end of the rotor as apposed to a typical outrunner which is just a bell with a bearing only on one end.

 

[sami]

any pics of your new mount? :3

i do have some new pics then hacked the mount.. ill remake it and get it welded.. clamping force just doesnt seem to be enough. i thought of flat spotting the truck like people do with keyways on motor shafts for pulleys. i may even do both.
When i make another mount ill take measurements and draw it up in CAD.

** pic is very bad as it was a progress shot inside**

 

[sami]

My apologies for not updating the Pen-E drive thread here on ES. I've been battling many bouts of procrastination.
Hey Sami!
So a friction drive is awesome. It's fast- I clocked a maximum of 32 mph on my Pen-E. It doesn't heat up. It's pretty reliable on most skateboard able surfaces. Seems efficient enough- capable of 16+ kms on a single charge. It's compact- I carried it on vacation to hong kong and extensively tested it there. Clocked about 200miles!
...

shame to hear the motor died. but luckily you got to use it on your holiday, that is awesome. would have easily saved the cost of a new motor from less busses etc. and had more fun
if you find the time to update your thread that would be great as i am still keen on making a penny board for myself and a friend for travels. i am not too bothered with longevity as i will use it without the motor also.

thanks mate!

 

[sami]

some new pics, i hacked the previous mount to try a clamping style.. and it works quite well even if it isnt pretty!
i will remake the mount and weld it on permanently as im happy with the friction fit and tyre wear is minimal. it is a very tight fit and traction is great now, no slippage and braking works even better. enough acceleration to try to push me off the back of the board. top speed is now 24km/h which i think is attributed to the tight fit, may kill the motor but i figure hub motors have more stresses on them..

next bracket will be further up the truck to allow for more of a thorough contact patch.

 

[Frictiondrive3]

Hey I am new to this and am thinking about making a electric longboard. I have a few questions on makeing a friction drive longboard. I have made a gas friction drive bike before but am a little new to the electric ways. If there are any other threads that explane any of this I would be more than plased to know about them. The questions i have are what motor can you use and how to u get it ti spin the wheel? Is there a way of mounting it? Is it a spicific motor? Next how would you sugjest making a homeade mount? and finally is there anything cheeper than the 72$ motor that there is the link to.

Thanks a lot

 

[buzztiaan]

Thanks for the mount pictures! Looking good