Pair of 36V scooter hub motors for trike project

[iangreenhalgh]

I've been wanting to build a trike for ages so when I spotted this pair of hub motors with scooter wheels and tires for a silly price I grabbed them.

Don't have any info on them other than they are 36V and probably 800w.

Does anyone recognise what they are? Who made them etc?

I'm thinking I can put these on the back of a delta trike using a pair of 36V 800w controllers and two 36V 20A batteries (probably 10s10p 18650s but might go lead-acid to begin with for cheapness).

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[amberwolf]

I don't knwo what they are from, but they look like they'd work ok, depending on the load that axle was intended to take.

If you need a higher load than they can take without bending, you could add a bolt-on "pin" from or thru the outer cover's center that is supported by a pillow-block bearing under a frame bar on the outside of the wheel. (depends on your actual trike design how that would physically get installed).


The small diameter is probably good for torque vs load on the motor, but it will lower the ride quality on bad roads/etc.

(I'm using 20" wheels on SB Cruiser and bumps/holes are pretty hard on it, wihtout suspension...now that I've switched over to Shinko moped tires instead of the various bicycle tires I've tried, it's better, but still not as good as if it had larger diameter wheels. Main reason I did it was the design of the parts I had at hand vs the cargo bed height needed; if I did it from scratch I'd've done it with bigger wheels something like I did my new Mk IV trailer).

 

[iangreenhalgh]

Hi AW

Thanks for chiming in, always appreciated.

They are from a stand-up type scooter, I'm guessing similar to this one:

http://www.rnrassociates.com/wordpress/wp-content/uploads/2011/03/stand-up-electric-scooter.jpg

On those axles - I'm not sure how I will mount them on a tricycle, I need to build or buy a trike first!

As for bumps, the trike will probably be hardtail, but sometime I intend to put some much larger tyres on these wheels which should help smooth out some bumps.

I have about 80 18650s left over from building a 48v 20A pack and a 36v 20A pack for a pair of ebikes so I'm thinking I'll collect another 120 and build a big 10s20p 36v 40A pack for the trike and run a pair of Yiyun YK31C 36V 800w controllers. The cells I have are all in the 1700-2000mAh range and I think they have a constant discharge rate of about 4A so in a 20p pack they should give me 80A continuous, about double that for a 30s peak. 40A per motor sounds ample to me as the Yiyun YK31C controllers are only pulling about 22A max I think, 25A at most.

I'm not sure what amperage the motors are rated for, it would be nice to know as 22A may be too much for them. I guess I'll just have to try it and see how hot the motors get going up a few hills.

 

[iangreenhalgh]

The motors arrived and a couple of point. First, and disappointingly, they are smaller than I thought. Being labelled 16 inch I thought they would be measured like a motorbike wheel - 16 inches being the rim size so the wheel would be the same size as a 20 inch bicycle wheel. However, they are 16 inches including tyres so smaller than almost all adult bicycle wheels.

Secondly, they only have two wires coming out - red and black. So obviously, they have no hall sensors. Might have to chose different controllers due to this.

 

[amberwolf]

Means they are brushed motors.

Might have higher torque from a stop because of that, but they are less efficient than brushless, and will probably a little run hotter because of the brush arcing.

If I had a pair like that, I'd put them on a heavy-duty cargo trailer, to power it and provide really good electric braking, cuz you can just short the input wires and they will be pretty hard to turn; a simple DPDT contactor would let you do that with very little extra circuitry , even if hte contorller didn't support regen or plug braking directly. It'd be more controllable if done thru the controller, as it could PWM the braking just like the drive, assumign it has that function.

(I'd also do that outer-bearing thing I was talking about, to make it better able to handle really heavy cargoes of several hundred pounds, to maybe more than half a ton...I already have several trailers that can handle smaller loads).


BTW, my dual motors on the trike, using 80A (>3500w), acclerate the bare trike plus me to 20MPH in around 5-6 seconds. Takes a bit longer with Yogi in the new trailer, or Yogi in the old trailer and Tiny in the trike (haven't tested with Tiny in the trike and the new trailer).

Those are smaller wheels, so if you used the same power thru them you'd probably get more torque and be able to get started even quicker.

 

[iangreenhalgh]

Cheers AW, that's useful to know.

I have no problem with brushed motors, they are robust reliable things that can last a very long time if you replace the brushes.

I checked the controller I planned to use, its labelled 36V 800W but it has a max draw of 28A which makes it a 1.1kw controller really if using a 10s battery (42v x 28A = 1176W). I'm not sure these motors will handle 28A so I might have to use a less powerful controller.

Batteries, I plan to use a 200 cell 10s20p battery using 18650s that have a continuous rating of approx 4A. That would give 80A continuous which is quite a bit more than the 56A a pair of 28A controllers would draw and should mean the battery doesn't get overworked. I might add a second 200 cell battery later for more range.

I like the sound of regen braking, I'll have to see if the Yiyun controllers support that. If not, I'll see if I can find controllers that do.

Road legal limit for electric bikes here in the UK is 15.5mph and I weigh a bit over 300lbs so torque and load carrying ability is definitely more important than speed, so the smaller wheel size and high torque is a good thing really.

I like the trailer idea, I'll have to give that some thought.

Saw this disability trike on the web last night and this looks exactly like the sort of thing I'd like to build, it has the same wheel size as my motors too.

 

[docnjoj]

Don't forget that you probably want to run those motors in series rather than parallel to keep the amps down.
otherDoc

 

[iangreenhalgh]

Hi doc

I've never considered wiring motors in series, would that be both motors on one controller?

 

[amberwolf]

Yes. So you would doulbe the voltage of the battery pack and halve teh current draw.

 

[iangreenhalgh]

Cheers AW, so I'd use a 72V controller instead of 2x 36V. Makes sense, I'll consider doing it that way.

 

[John in CR]

Cheers AW, so I'd use a 72V controller instead of 2x 36V. Makes sense, I'll consider doing it that way.

I wouldn't spend that kind of $ on it. Just use a pair of super cheap low voltage brushed controllers. Of course, make sure they even work before spending a penny on controllers.

BTW, you may not have an issue with brushed motors, but as hubmotors they're a thing of the distant past for valid reasons.

 

[iangreenhalgh]

Hi John

I plan to use a couple of cheap 36V controllers as they are so cheap and common.

Would you mind explaining the issues with brushed hub motors please; I'm a bit ignorant on the subject.

 

[Rassy]

Looks like an interesting project.

I started with a few brushed hub motors about 10 years ago, and even though I have moved on, two of those motors are still in regular use and have never required any maintenance. One is on the front of a delta trike that my Daughter=in=Law has and the other is laced into a 16" wheel on a one wheel pusher trailer that a friend uses behind his handcycle (a trike with a hand crank).

For your project a two wheel trailer would simplify everything. You could use a delta or tadpole trike, or even a bicycle, which would not require any modifications except for a trailer hitch and a throttle. The big advantage is that you don't get involved in trying to make the bike's pedal, chain, and gearing system interface with the hub motors. Also, it gives you lots of latitude in constructing a trailer that is designed to accommodate the hub motors and batteries.

Good luck with the project no matter how you decide to proceed.

 

[iangreenhalgh]

Cheers Rassy.

I'm limited by living in a remote rural area so to find a secondhand trike of any kind is difficult, none locally.

 

[ScooterMan101]

I live in a very populated area, and the trikes that come up for sale are so expensive that I still have not done a trike conversion yet.

Are there reasonable priced welders in your area ? you could just build your own trike, and it could be longer, thereby more stable , and to what ever width you want . so as to have as much cargo area as you would like.

Cheers Rassy.

I'm limited by living in a remote rural area so to find a secondhand trike of any kind is difficult, none locally.

 

[amberwolf]

It's easy enough to do even if you do it from scratch; it doesnt' havet o be perfect just good enough to do the job. See my SB Cruiser thread for one example.

(and see the Delta Tripper thread for an example of what *doesn't* work).

 

[iangreenhalgh]

I can get welding done I think, I'm just a bit reluctant to go that route, preferring to get something 'off the peg' so to speak. However, I would love to build something custom one day.

 

[amberwolf]

Well, welding is not really very hard; it doesn't have to look pretty to work just fine. I'm a crappy welder but my stuff doesn't fall apart (at least, not at the welds :lol.

If you can't get what you want locally, and it costs too much to ship in, then getting a cheap wirefeed welder from harbor freight or similar, using flux-core wire, is a pretty simple way to build your own out of whatever metal you have around (old steel bikes is the easiest, if they are just laying around like in many places).


Around here used trikes can be sometimes found for as little as $150 or so; I saw one at Goodwill and if I had had the money I would've bought it just to motorize and resell it, as it wouldn't have been suitable for any of my own uses without enough mods to just be easier to build my own from "scratch".

 

[iangreenhalgh]

Actually, I learned to weld over 20 years ago as an apprentice, and my dad has a small arc welder; talking him into letting me use it is another matter though.

Maybe I should start collecting scrap bike frames - I see plenty of them lying around.

 

[amberwolf]

If you have the space for them, it doesn't hurt to have them around for all the bits and pieces as well as the frames, to fix up bikes you actually ride. (or to fix up and then barter to others for things you need).

 

[iangreenhalgh]

Indeed, if I had space I'd be collecting anything useful like that. Sadly I don't.