BIONX PL250 hub motor revelated INSIDE !

[Doctorbass]

BIONX MOTOR TECHNICAL REVIEW:

Last weekend, When discussing about my 7 familly ebikes project to the boss of the "LE PEDALIER" bicycle store, he gaved me a broken BionX hub motor explaining me that the owner said it had water inside and did a strange sound and then stopped working. so it's a warranty return

As you know this hub motor have the controller inside the stator structure.

Here is some info i am getting from this motor:

- The number of winding tooth is 24 and the stator have a total diameter of 176.6mm

- it have 3 hall sensor with 120 degree spacing

- The controller board is located in the middle of the stator and the mosfet sink their heat with the stator aluminum central structure.

-The mosfet are the known IRF3205 also used in the crystalyte DC brushed controller.
it's the PL250 (250W) and it use 6 mosfet ( two per phase) but the board have placement for 6 other additional mosfet..
probably for the 350W model.

- Each phase of the winding have 7 run of wire with similar size of the nine continent and that have a AWG gauge size of AWG22 equivalent ( 0.62mm dia.) of max recommanded current of 7 amp and that have a max frequency ( skin) of 42kHz and i estimate the number of turn per tooth to around 10 turn ( ex: a 5304 have 4 turn)

-The rotor is made of 22 magnet of 20mm width and 3.1mm thick
-The central lpart of the stator is made of aluminum and the stator winding ring structure is fixed with screw to the aluminum central structure.

The controller board is definitively completly scrapp and a larg part of the PCB has burned... eee TOASTED dur to a mosfet explosion!

So the controller is no more usefull.

If the guys of the store accept to give it to me

I plan to remove and BYPASS the controller... and will push it with a 18 mosfet controller to the max temp limit ( around (135 degree C usually is the ok limit)

SO HOW MUCH POWER DO YOU THINK I'LL BE ABLE TO USE WITH IT BEFORE IT heat too much ?? 8) :wink:

Doc

 

[Anonymous]

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[Doctorbass]

Cool! Where is the torque sensor? Or did you not get that part?

The torque sensor is a straign gauge and is located on the center of the axel in the middle of the stator.

 

[dnmun]

looks like the red wire in jpg.898 looping around the outside of that FET that blew up may have shorted, and the power lead inside the pcb coming outa the sheath also melted. i think that is where the torque sensor normally mounts so the dissapearance of the torque sensor may have accompanied the "strange noise and then it quit working".

doc, it has the extra set of pads for the other FETS so you could use them for the replacement
FETs, maybe you could bypass the torque sensor and use a hall or resistance throttle and make that controller run again with some new FETs depending on the state of the drivers.

best pictures of the controller i have seen yet. maybe you can find a controller

 

[liveforphysics]

That looks like the worst design for a hub motor I've seen yet.

For the FET selection, they must have decided that it wasn't worth the extra $2 in parts to use real FETs that would have kept 75% of the heat out off the controller. And they ran d-packs sinked to the board, which is fine for things used only for bursts, and keeps manufactureing costs down to a minimum, but very poor for any continous power application.

The stator shape looks like the favored ease of winding over function. It also appears very small, and I suspect it would easily saturate, and overheat if you tried to run real power into it.

I'm certian you could simply run extend the phase wires and hall leads to run external, mount and external controller and make it run. However, if you are going to invest your time into making something, I would start from a better platform like a 9C and go from there. 9C is like 10x a better design of a motor.

 

[Doctorbass]

That looks like the worst design for a hub motor I've seen yet.

For the FET selection, they must have decided that it wasn't worth the extra $2 in parts to use real FETs that would have kept 75% of the heat out off the controller. And they ran d-packs sinked to the board, which is fine for things used only for bursts, and keeps manufactureing costs down to a minimum, but very poor for any continous power application.

The stator shape looks like the favored ease of winding over function. It also appears very small, and I suspect it would easily saturate, and overheat if you tried to run real power into it.

I'm certian you could simply run extend the phase wires and hall leads to run external, mount and external controller and make it run. However, if you are going to invest your time into making something, I would start from a better platform like a 9C and go from there. 9C is like 10x a better design of a motor.

I agree with the fet choice that it could be better.. .. I mean at least having lower rds on for similar price!.. the 4310 can do that for cheap or for few more $ the 4110...

However, the stator desing seems to have more cooper than the 9continent... and the winding runs is similar... so if we ccan put up to 3000W into a 9 continent, then i think that 2000W into this motor with carefill temp monitoring... and a great torque arm !

The diameter is also very similar thaqn the 9C.

anyway.. when i'll have time i'll mount it with an external controlelr ans will continu this review...

==== 2000W BIONX BOOST REVIEW === SOON.. I hope ...

Doc

 

[RoughRider]

ANY NEWS DOC????


@lifeforphysics
so, why do you think, that the wiring design is bad? Why would it "easily saturate"
To my opinion the wiring design is better than the 9C

 

[liveforphysics]

ANY NEWS DOC????


@lifeforphysics
so, why do you think, that the wiring design is bad? Why would it "easily saturate"
To my opinion the wiring design is better than the 9C

The stator setup is what would saturate. It appears to have about 4-5mm of back-iron behind the stator teeth laminations. This would saturate at low flux levels, which is find, because as it was intended to be setup, it would never experience high flux levels.

 

[Doctorbass]

Winter is always a great time to:

Test: build, blow up something, overvolt etc...

We have 2 foot of snow outside here now.. the ebikes sit in the garage... everything to test, build, overvolt etc is in my lab ready and waiting for me... IT'S TIME!

Doc

 

[RoughRider]

ohhh...yes...now i understand what you mean

i agree with you...the backiron of the sheet metal is realy smal...
the backiron of the magnets looks good(thick enough)...but rusty...


GO DOC GO...

 

[dennis]

I was wondering if you would be interesting in tinkering with a PL500W Bionx motor? I just blew the controller inside the motor today. see link http://endless-sphere.com/forums/viewtopic.php?f=2&t=15434

I would like to be able to mod it with an external controller for my set up and with a switch that can disconnect the battery for high speed downhill runs...in excess of 51 mph ...It would be fun to document this on the forum.

Please send me a PM if you are interested.
Thank you
Dennis

 

[Doctorbass]

I was wondering if you would be interesting in tinkering with a PL500W Bionx motor? I just blew the controller inside the motor today. see link http://endless-sphere.com/forums/viewtopic.php?f=2&t=15434

I would like to be able to mod it with an external controller for my set up and with a switch that can disconnect the battery for high speed downhill runs...in excess of 51 mph ...It would be fun to document this on the forum.

Please send me a PM if you are interested.
Thank you
Dennis

that's i my plans for summer 2010 :wink: .. still a big list of project to do!

Btw, great find for Bugs Bunny!

Doc