Lebowski's bike build #1 now with video

[Lebowski]

After about 6 months building a motor and a year building controllers (going through 3 different designs) I finally
got to put everything together

To start, this is the victim:

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It's a BeOne Team Replic from 2001 which I bought new and has around 40000 km on it (all hand-pedaled).

The motor is going to sit on the luggage rack (made from 15mm square alu tubing):

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Drive is to a sprocket in the rear wheel:

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I don't have a hall sensored throttle, I'm using a cable operated throttle (from a 3rd brake handle) to a potentiometer:

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Power will come from 20s 5Ah Zippy Lipo, guarded by simple beepers:

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The controller is a 6 FET 4115 with all 150 V hardware and 20A current sensors. I use a plain metal box
with a u-piece of aluminium for cooling (no cooling paste as dissipation is low, less than 0.5 W per FET)

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This by the way is the bottom of the controller circuit board, lots of work !

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The controller and batteries go in the triangle of the frame. A sheet of wood will be clamped in, batteries will
be on one side (in a laptop bag), controller on the other side.

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With the throttle hooked up:

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Last picture: motor is mounted and connected by chain (via chain tensioner) to the rear wheel:

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And that's it, my first e-bike build I haven't tried it out yet 'cause, well, I'm kind of chicken. It's the absolute
opposite of stealth and with the amount of police on the road here I'm sure to get stopped. It's not a question of whether,
just a question of how far I'll get before that happens There's lots of stuff for them to comment on (no cover on fast
spinning motor, electric connections in motor are bare metal, no lights, front fork is kept from falling out by hose clamps,
thing is driven by long haired hippy scum)...
Technically it's legal though. Power is limited to 500-ish W by setting the battery current to 7A (at 20s lipo, so around 80V).
Using a throttle is legal to 20 kmh, above this (to 25 kmh) the battery current limit is around 2A, so you have to pedal
to go upto 25 because the 150 W from the motor won't get you above 20. At 25 and over the rpm limiter cuts in and
prevents the motor from spinning faster.

[deVries]

thing is driven by long haired hippy scum)...

Come to Austin & you'll fit right in. Go shopping at Whole Foods. Plenty of hot... umm.

Police won't hassle you for the hippy look or eBike.

Ohhh, & just tooo cool you made this "E" of beauty all by your lonesome...

[XLR8]

I hope you take a video when you go for your a ride. It would be very interesting I'm sure.

[Jozzer]

Very intersting build - great work!

[John in CR]

Cool bike Lebowski. I had you pegged for an Atomic Zombie type build to live up to your forum name. You electronics guys are hard for me to read.

May you never break down.

John

[Lebowski]

May you never break down.

John

That would be so boring. Honestly

[flathill]

Taking DIY to the next level! Great job!

[mud2005]

amazing stuff, anyone who makes their own motor and controller is beyond cool in my book

my guess is you're going to hit the throttle and the torque is going to shift your rack enough for the chain to come off. how do I know? tried it with a rack that was about twice as beefy as the one you're using.

I ended up putting the motor in the triangle where I could clamp it down better. maybe you'll have better luck than I did though.

anyway, love the build and want to read more about your motor and controller, if you could put links to your other threads that would be awesome

rock on lebowski! or can I call you "the dude"?

[hjns]

Very cool, Lebowski!!!
Can you add some pics of the motor?

[Lebowski]

Very cool, Lebowski!!!
Can you add some pics of the motor?

My first thread here shows my motor:

viewtopic.php?f=30&t=30061


I rode around on the bike indoors yesterday 'cause it was kinda late (charging and balancing took
quite some time) so it was already dark out. Very very funny feeling to be pushed along by a
very silent motor, felt a bit like you're being pulled by an elastic band.

I can see now how people become Amp addicts, maybe there should be an Ampaholics Anonymous.
I had the phase amps to 8 to start but upped them to 12 (thinking about going to 16) almost immediately.
The current based throttle worked like a dream, beautiful smooth torque control even while
barely moving. I could just feel the strength of the silent push being modulated by the throttle, very
weird feeling.

Now I'm hoping for very nice weather this weekend (rain predicted though ) My GF wants to be there
for the first proper test with the fire extinguisher (she doesn't like fried nuts and wants to protect her investment).
Maybe I shouldn't have handed here the battery box saying 'here you have the explosi... battery the bike
runs on, just be careful'

[Arlo1]

Very cool, Lebowski!!!
Can you add some pics of the motor?

My first thread here shows my motor:

viewtopic.php?f=30&t=30061


I rode around on the bike indoors yesterday 'cause it was kinda late (charging and ballancing took
quite some time) so it was already dark out. Very very funny feeling to be pushed along by a
very silent motor, felt a bit like you're being pulled by an elastic band.

I can see now how people become Amp addicts, maybe there should be an Ampaholics Anonimous.
I had the phase amps to 8 to start but upped them to 12 (thinking about going to 16) almost immediately.
The current based throttle worked like a dream, beautiful smooth torque control even while
barely moving. I could just feel the strength of the silent push being modulated by the throttle, very
weird feeling.

Now I'm hoping for very nice weather this weekend (rain predicted though ) My GF wants to be there
for the first proper test with the fire extinguisher (she doesn't like fried nuts and wants to protect her investment).
Maybe I shouldn't have handed here the battery box saying 'here you have the explosi... battery the bike
runs on, just be careful'

Awesome to see you finaly road your first ebike lol. Now how about that big motor you have, before going to AA maybe you should run something with 700 phase amps at ~100v????

[Lebowski]

[deVries]

16amps already!

Think of the possibilities...

Focus on that ever increasing power you/we crave...

Build it and they will come...

[Miles]

Congratulations!

Both motor and controller actually working on a bike. Either one, on its own, would have been a first here, I think?

All I can hear is the chain, too....

[Drunkskunk]

Amazing! whats the efficancy like on that motor?

[Lebowski]

efficiency, that all depends on the speed and whatnot.
What I look at is the dissipation in the motor for a certain amount of phaseamps
With the motor resistance being what it is the dissipation works out to be

P_loss = I_phaseamp_amplitude ^ 2

So with the 12 Amps peak from the video the dissipation is 144 W but this is at
max throttle. At 25 kmh the motor needs around 50 V so for 200W that is 4 Amps_rms,
which is around 5.6 Amp amplitude in the motor phases, so dissipation will be 32 W.

[Lebowski]

Rode up a mayor local hill today. All was fine, nothing blew up motor and
controller got less than lukewarm, even though the dissipation in the motor was
around 200 W for 15 minutes straight. Axial flux really works if you want build-in
centrifugal type cooling To get more torque I upped the phase amps (amplitude)
to 16A before I set off. 16A is quite a lot for the 20A current sensors (which
are small 8 pins SOIC). The voltage per cell of the 20s 5Ah Zippy pack went from
3.95 to 3.78 during the trip, don't know how good this is.
The hill has an elevation of 350 metres and takes around 4.5 km, is rather flat at the
beginning and gets really steep the last 3 km (around 8 to 10 %). My normal
average speed up is a bit less than 9 kmh, at the end of the summer when I'm trained.
With the motor I went up at 17.5 kmh average mayor improvement ! I felt
like such a sissy
I only encountered one police officer on motorbike but he was coming towards me
so didn't see I was, eh, transporting a motor on my luggage carrier

[Ykick]

Congrats Lebowski, job well done!

[Ypedal]

now THAT is a diy project like no other !... way to go man !!!... love it !

[Lebowski]

And today I burned out the motor i kind of loosely interpreted Swiss law and rounded the 500W legal limit to 1.0 kW yesterday.
Everything worked great, it was going up the hills like a little moped . So today I decided to push it and go up a local hill which has 350m height increase and up to more than 10% slope. The motor acts as a little turbine sucking air on through the side and blowing it out over the coil plate, but only when it has enough rpm's... when it got really steep i did not add pedal power so motor speed dropped, reducing cooling. This is when it lost power and smoke came out of it . The motor had a freewheel so I was able to cycle home. The motors still wants to turn but the coil plate is burned and warped so it rubs on the magnet plates, unusable. Got a spare coil plates through so should not take to long to fix the motor. I'm most curious about the magnets though, whether they lost their magnetism or not. Got a spare set of those as well so, no biggie. Will post pictures when i've taken the motor apart.

The electronics are all fine, they will still turn the burned out motor!

[Jeremy Harris]

Sorry to hear that, but it's always useful to find out the true limit of something!

The airflow problem at low speed is a real problem for all ebike motors, potentially, as it's low speed when they are often drawing maximum current and generating most heat. The slower the motor the worse the problem is, which may be one reason why people adding extra cooling systems to hub motors are getting good results.

I've been thinking of using a separate fan to cool my new motorcycle motor system, perhaps switched thermostatically so it only comes on when the motor gets a bit warm. Might be worth considering for your motor, as it sounds as if all it needs is a bit more cooling when running slowly at high torque.

[Lebowski]

My main 'issue' I think was that I wanted to find the limit and therefore stubbornly did not pedal. With pedalling I
would have gone up the hill at a constant 20kmh (limit due to law) and the motor speed would have been
high enough to keep things cool. Max phase amps during the test were set at 16, battery at 13A (for 20s, 75 to 80V).
I think it was pulling the 16 A phase continuously, with the 0.65 Ohm resistance per phase, sinewave
etc etc dissipation in the coil plate was 256 Watts. At 20kmh (about 700 rpm at motor) cooling was fine
'cause the first 250 height meters the motor performed flawlessly. Only when the grade go so steep that
road speed dropped to 12 kmh (420 rpm motor) the cooling could not keep up anymore and the thing got
fried. But I'm still very impressed by the axial flux design, that it can get rid of so much heat without overheating,
just by it's own natural air flow (no fans added). Just got to keep the rpm's up

[Arlo1]

At least you can just build another one. Its nice when you build things your self!

[Warren]

Sweet motor! Amazing work. From the video, it appears your rear tire was almost flat. Please, when you rebuild it, run it through the gears. It will be bulletproof.

[hjns]

ouch, that must have been some nice steep hill. Well, now at least you have time to finish the high voltage controller....