=== 3000W BionX Project ===

[Doctorbass]

Remember when I got a deffective BionX motor few weeks ago??

I want to play with and explore how tough it is!!

And when it will let the magic smoke as well

context:
These motor got very popular around the planet and i want to see if they can play hard!

Now I plan to boost it during automn and winter and to monitor everything to not let it going in smoke!.

Begining:
I have one 18 fets controller left just for it
I removed every pieces of the burned inside controller.


Hall sensor re-location:

I have few question. Should i relocate the hall sensor (ex, like on the 9C) or should leave them as is and try with our usuall controller? I never had to play with motor hall sensor so..

On the BionX, the Hall sensor are located between two pole and have a spacing of 120 degree

On the 9C.. or Crystalyte, they are located differently, two are right on the center of a pole and one is between two...

Doc

 

[Doctorbass]

Here is some pics to compare:

BionX:

and

9C:

Doc

 

[nineball]

From the looks of that board, you may have more problems than Hall sensors?

 

[dnmun]

doc, i think the7 may know a lot about the poles and sensors.

when i opened the goldenmotor, i counted 46 magnets and there were 51 stator poles, 3x17 so there are 5 more stator poles than magnets. the hall sensors are spread across 3 stator poles so the difference in spacing between the first hall sensor toggled and the last is 3 stator poles so the effective number of stator poles is 48 but that is still 2 more than the number of magnets. the 2 magnets create a 360o rotation in the field to any sensor so divide the 360o by 3 sensors and that gives you 120o spacing between sensors. but i don't know if that really makes sense.

if you try to do a similar analysis of the bionx, then you may be able to determine whether it is using a 60o or 120o spacing or maybe something entirely different.

i think i read somewhere that the tidalforce hubmotor has 11 phases, not three, and that is why the power is so smooth on the tidlforce. but don't know if that is true.

did you consider rebuilding that controller board and testing it with larger FETs?

 

[John in CR]

I don't know if it's just me, but that Bionx doesn't look like it with last more than a few minutes of Doc's "hard play".

John

 

[Anonymous]

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[voicecoils]

What's the material the windings are wound around? looks like....plastic

And I thought the Bafang's were dodgy being held together with string... :lol:

Doc, it should be easy to bench test both of those hall spacing configurations. Even loosely taping some hall sensors in place temporarily to try alternatitive positions...

 

[Miles]

What's the material the windings are wound around? looks like....plastic

What's wrong with plastic? I think it's probably an epoxy coating....

 

[Doctorbass]

What's the material the windings are wound around? looks like....plastic

And I thought the Bafang's were dodgy being held together with string... :lol:

Doc, it should be easy to bench test both of those hall spacing configurations. Even loosely taping some hall sensors in place temporarily to try alternatitive positions...

I think it's epoxy or... ceramic coating. ( nice idea... for high power!)

Doc

 

[wrobinson0413]

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[Doctorbass]

Hey Doc

Could you post some pictures of the backside of that power board? Is BionX a single board solution with the micro built on it? Just curious. I always like to see what other designers have come up with for solutions to the hole in the middle problem. Getting nice clean pwm amplifier layouts designed around a hole is not always easy. Would be interesting to see where their strain gauge is located on the shaft too.

Just go here: http://www.endless-sphere.com/forums/viewtopic.php?f=4&t=12165&start=0 it,s the original thread about the opened motor.

Doc

 

[wrobinson0413]

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[Doctorbass]

Thanks for posting the link Doc. I saw the strain gauge location there, but no pictures of the other side of the pcb board other then the peep holes that you can see from the other side of the stator. Have you pulled out the old burned up board yet?

Yes.. and it goes directly in the garbadge!.. it smell so bad!!! burned mosfet and pcb odor around our house is not very good for health.. .. I mean... IT SMELL VERY BAD !

Doc

 

[wrobinson0413]

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[Doctorbass]

This evening ive investigated to find how much current i could put into it ( I supposed 3000W burst but.. I still need to approve.. :lol: )


The method I choosed is by comparing an existing motor winding to thisone.

I remember I've calcualted the 5305 motor winding size already.

The measured winding wire diameter: 28.5mil dia

= AWG 21 !! but there are 4 parallels in a 5305...

And.. the BionX i have have 7 strands of wire of 0.60mm dia = 23.6mil dia = AWG 23

-BionX have 7 x AWG23
-5305 have 4 x AWG21

According to the AWG guide
AWG 21 have a current rating of 9 A
AWG 23 have a current rating of 4.7A


5305 have 4 x 9.0A= 36A per phase
BionX have 7 x 4.7A= 32.9A per phase

the mass of a 5305 is 24 lbs
the mass of a bionX is 7.7 lbs

According to the winding, if a crystalyte can take 2500W continous (tested), a bionx can take 32.9/36 =2250W continous

But the mass of the bionX is lower... around 3 times lower so the heat dissipation with the surface area and the thermal inertia are different between both.

let say that 3 time less mass and two time less external surface and 91% the winding size of a crystalyte would cut the continuous power by 2.

so accordiong to the maximum continuous power a bionX can take ( with abuse) would be 1250Watts... ( 350W rated)

so if a crystalyte can take burst of 10kW, a bionX can take probably 3000W burst no prob



Here BURST mean: 5-10 sec at full power while continuous power is the avg

Doc

 

[Cephalotus]

How did that project end?

Anyone who used a BionX motor with an external controller?

 

[Doctorbass]

How did that project end?

Anyone who used a BionX motor with an external controller?

Few tried to use thes emotor with external controller and it worked well unitil they increase power and break the axel wich is by far not mad efor additional torque.

I still have all the parts but did not managed to finish that 3000W bionX becaus ei got all parts for another more interesting project.. the 5403!!

Doc

 

[Farfle]

We took an ultramotor to 70A at 24s, and it stayed cool as a cucumber. The bionx is skinnier (25 mm stator vs 40 IIRC) but should be able to handle some abuse. They are incredibly well designed motors, and have very low iron losses. You should be able to use the halls as-is, that worked on our ultramotor conversion.

 

[Cephalotus]

Few tried to use thes emotor with external controller and it worked well unitil they increase power and break the axel wich is by far not mad efor additional torque.

Thank you. The SL motors have a much thicker axle and since 2012 the material of the axle has been improved, afaik.

With the standard BionX controller and the 48V (13s) battery those motors take up to 1300W from the battery without breaking so far and without being illegal (250W "limit" in EU)

To my knowledge the BionX SL motor is still the most lightweight direct drive hub motor available (3,4kg incl. controller). And the BionX motors do have that 250W and CE and RoHS stickers, which could be quite useful over here...

 

[chefkoch]

Any news with the BionX project?

I have also a defect PL250 HT (which is the P350) here and would be interested in the KV rating rsp. what rpm this motor would do on 48V with a crazyman contzroller...

cheers

 

[chefkoch]

The sicker on the 350W motor says 36V 300rpm.
Is this the freerunning rpm or the max. running rpm under normal condition, which would by about 36km/h or 22mph?