Farfle joins the MENS club

[Farfle]

Hello all, the itch is back, I need more speed, and I'm not going to get it with 30 pounds of hubmotor in the back. Im turning over to the dark side. The next motor Ill be building is a monster outrunner, but before I get into too much detail, lets play a game of "Guess the donor!"

the pics are of half the lam stack.

heres some stats:

stator diameter: 170 mm
stator width: 80mm
# teeth: 18
# mags: 16
lam thickness: .33 mm

[ZOMGVTEK]

Hmm.

What's this going to take, a Gen4 Size 8?

[Farfle]

Nah, just the baby sevcon. Its good to somewhere around 25 hp IIRC, and this motor should be pretty happy as at that much Power. Im aiming for somewhere around 4k rpm to keep the iron losses low.

[liveforphysics]

That motor doesn't look bad at all.

I'm going to guess it's from a quality electric mower perhaps?

[Farfle]

That motor doesn't look bad at all.

I'm going to guess it's from a quality electric mower perhaps?

Nope, quality yes, but mower no.

[Farfle]

IIRC docbass has dissasembled one of these motors before.

[boostjuice]

Im guessing your adapting some scooter hubmotor from some Alibaba/Aliexpress vendor or similar? (i see a spoke flange in the 2nd last pic) .....Nice looking stator, me-likey....Im tired of guessing....please reveal your source & price!

[johnrobholmes]

Washing machine or fancy fan motor?

[Farfle]

Its an ultramotor, similar to a bionx. Its wound with 30 turns of what looks like 18awg. They are found on stromer ebikes and on the A2B metro.

[boostjuice]

Its an ultramotor, similar to a bionx. Its wound with 30 turns of what looks like 18awg. They are found on stromer ebikes and on the A2B metro.

Nice. Price and Source for just the motors? (i assume you didnt strip these off complete bikes?)

[Farfle]

They were kinda hard to find, they are warranty failures, dead internal controllers IIRC. No idea where you would get more.

[Farfle]

Being new to the whole chain drive thing, what chain do I use? I only need a 3.5-1 or so reduction, would bike chain work?

[neptronix]

That thing looks really tough. If you were to wind it real fast and then gear it down, i bet it would stand up to some of the biggest motors being used on the forum..

2pi wasn't fast enough, or is it that you just wanna play with chain drive?

[Farfle]

2pi was almost fast enough, but it didnt handle well, being 31 pounds in a wheel. Im hoping to keep this guy under 20 pounds, It will be mounted on the swingarm close to the pivot point.

[nechaus]

subscribed

[acuteaero]

Use 219 chain or #35 chain. The benefits/disadvantages of each have been discussed in various threads around- 219 is smaller pitch so you can use a smaller sprocket (not needed in your application)- 35 can be stronger. Both chains can be found in high quality, strong chain for racing go-karts. (both can also be found cheap and crappy...) There is even some o-ring 219 but it's quite expensive. Another advantage to #35 is that sprockets in all sizes and configurations are available from surplus center, mcmaster, etc., instead of 219 which is really only available in kart-oriented sizes. For greater torque handling you could go to 420 but it's not likely to be necessary for your application and it's very big and wide.

Are you planning to make a freewheeling drive (with the regen on the sevcon I'd expect not-) Right hand drive? Left hand drive? If left (on the disk brake hub) will you put a mechanical rear brake on it? Rim brake? Something else?

Check out the sprockets and adapters from these guys http://kingssalesandservice.com/top-hat ... t-adaptor/ Maybe recumpence Matt may have a "top hat" of his own, not sure what his current designs look like.

Yay chain drives. You'll get it all worked out. I like the plan of using the hub as a chain drive motor on the swingarm close to the pivot. I will look forward to seeing how it comes together!

Nice score on the ultra motor. The funny integrated spoke flange/side cover/ split down the middle of the hub gives it away! I'd expect 25 horsepower is going to be pretty demanding for that motor- got any cooling planned?

[Farfle]

Thanks for the info on chain. The stock UM was fine at 5kw, this is two motors, rewound with a better copper fill, and spinning three times as fast with a slick centrifugal fan on the end, somewhat astro-esq. How much Hp do you think a well cooled 175x80mm outrunner can make?

[acuteaero]

Thanks for the info on chain. The stock UM was fine at 5kw, this is two motors, rewound with a better copper fill, and spinning three times as fast with a slick centrifugal fan on the end, somewhat astro-esq. How much Hp do you think a well cooled 175x80mm outrunner can make?

It should be a pretty beefy motor, for sure. Got any idea what it might weigh all built?

Start WAG:

There's two parts to the power question- one is will it saturate and get really inefficient at the current levels you will need to run for 25 horsepower- It's got a heck of a lot of stator and seems to be of good quality so I would guess that it might just do it without a problem here.

Part two is will it take the duty cycle- considering speed and current- putting around on the street might be fine, massive steep hill, or continuously repeated hard starts- might not. Kart track racing? I have no idea- depends too on the rider. It was amazing how much more the Perm motor on my kart heated during the course of consuming the same amount of battery power between running wide open on the long track and fooling around with lots of hard starts in the paddock.

End WAG.

[John in CR]

...an ultramotor...

Don't you mean 2 ? Sounds like a great project, can't wait to see the result.

[Farfle]

...an ultramotor...

Don't you mean 2 ? Sounds like a great project, can't wait to see the result.

Yeah, I have two of these stators that will be mated together, sorry for the confusion.

[John in CR]

...an ultramotor...

Don't you mean 2 ? Sounds like a great project, can't wait to see the result.

Yeah, I have two of these stators that will be mated together, sorry for the confusion.

When you said it was 80mm I figured it had to be 2, maybe even 3. With that wide a stator I'd definitely recommend one side intake and other side exhaust to ensure good air flow through the magnetic gap as well as through the stator. If you can work an even bigger axle pipe than the your double pie then it could be your intake point making lots of things possible including a ducted fan to force feed air as well as have good ventilation of 100% of your wiring length.

Do you have an idea of how many turns and the overall gauge of the windings?

Once I start doing a volume, I'll have to send you 2 motors just to see you work your double magic on an even bigger motor.

John

[Farfle]

I just cad-ed up the motor, have to head to work now, but ill try to post it up during lunch

[nicobie]

Think you'll have it done by the Sept. race?

Luke, and the others, might have a problem.

[fizzit]

That's awesome Farfle! I am really excited to see what you do with this motor and next year when I come to Bend we can compare chain drive setups and race

[Thud]

thumbs down on Bicycle chain.

you want easy & indestructable? use #40 industrial stuff for surpluss center. best bang for the buck.
if you want to get fancy go with 219 kart chain(unubtainium drive sprockets) but you prolly know a guy who can fab something LOL!