Powerchair Direct Drive Brushless Motor (High-Torque)

[texaspyro]

One day we will banish him from our universe!

Ain't gonna happen... ever... no way...

[texaspyro]

Teh good news is that even Murphy can go wrong sometimes, so that everything actually goes right!

Ain't gonna happen... no way... ever...

[amberwolf]

ur right about muprhy; couldn't get my moto r or ocntroller so got my han d worse instead.

t/s of controller using this from mdd0127

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shows the two red-cirecled ones just flash a bit dimly and go out every cycle, while other four rotate in pairs, when i couple phase and halls on tester to motor color-to-color. so i assume that means something s wrong with whichecer phase/hall thar t horizontal pair is for. dunno yet how to tell wich one.

meant to take vid but forgot till adter all unhooked.

[amberwolf]

I hooked up the Timing Adjuster 2 from Mdd0127 today, and did a bit of basic experimentation.

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i don't know yet if adjusting the tming of the halls will actually do anything helpful, but the results are visible and audible in the videos below.

retarding timing from 0 to 10 degrees using potentiometer



advancing timing from 0 to -10 degrees using potentiometer


current doesn't change much when retarding, but it increases aby up to 10% during advance, depending on speed and degree of advance.


i think for more experiments with this i need to bolt the motor down to something immovable, because at one point i accidentally changed the wrong data set and clicked to send changes to the TA2, and forced the timing to change from -6 degrees advance to 5 degrees retard instantly at full speed. it almost pulled everything off the table as it suddenly just STOPPED and dissipated the rotor's momentum into the rest of the motor and the connected equipment. Nothing broke, but it could've been disastrous. op:


Further experiments once I learn what i am actually doing with this thing.

[bluesrocks]

Wow, Amberwolf rocks! Looks like a cool topic too, I wanna see how good the motor ends up. I didn't know a person can know that much about motors and controllers.

[amberwolf]

I know almost nothing about them...if you want someone that really knows about them, talk to Lebowski, Rickynz, Bigmoose, Miles, Jeremy Harris, Arlo1, Liveforphysics, Thud, Methods, and list of others that would take too long to type out.

I do hope I get time to go back to this experiment again soon, though. I really wanna see what happens on a bike with this thing, and I am sad that I don't know yet.

[amberwolf]

I have come up with an idea for moutning this motor in a bike-usable way without nearly as much effort as I had thought, though it makes it a direct-drive, rather than thru a transmission--but it would at least let me test it's usability under power and load.

This is a sketch from the Loooooooongbike thread, where idea pondering while at lunchtime at work inspired this idea:

loooooooongbike rev b1.JPG

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All I have to build to make it work is a plate that bolts to the hubmotor's magnet ring cover bolt holes, and to the five outer bolt holes on the powerchair motor's rotor face. I'd also want to lathe the rotor outer circumference just a tad, so that the magnet ring will slip all the way down to the tirebead seating ring on it.


The bad part is that the magnets themselves would be loadbearing in this case, unless I also made another ring for the inside face of the ring that extends just a hair beyond them, to rest on the powerchair motor's rotor.


Then I would need to make a plate that is welded to or bolted to the rear triangle of a bike, that the backside of the powerchair motor can bolt to. It has to be stiff as it must bear the torsional forces of the weight of the bike, as it's effectively a single-sided "swingarm" without being a suspension element (fixed in place).


None of the needed things are very hard to do, and would mean I could bolt this thing onto AFAIK *any* existing 9C or MXUS DD hubmotor magnet ring thats' already built into a wheel of any size. Even some GM hubs should fit it, though the bolt holes might be differently sized or spaced on the magnet ring.





I dunno if I will have time to do the experiment, but I'm a step closer now.

[amberwolf]

Another sketch from lunchtimes:

powerchair motor in hubmotor sketch 1.JPG (63.82 KiB) Viewed 171 times

Shown as mounted by the right side, I think I would actually mount by left side, so that I can bolt a freewheel-threaded hub flange to the right side, to be able to still have a "legal" bicycle, with the chain still attached to the wheel.

Also, if I use a pillow bearing on the right side I can add a short bolt or axle threaded into the center hole of the powerchair motor's rotor, to give support on the right side, so it doesn't have twisting forces from weight/load on the left side mounts.


To test on CrazyBike2, I would have to replace the present bottom rackmount strip cargo pod support with 1" square tubing, same as the top, to give a sturdier place to bolt the motor itself to. This is something I have planned to do just for stiffer cargo pod support anyway, but never gotten round to.


Right now the thing mainly keeping me from just going ahead and doing this is that my lathe is buried under a bunch of stuff int eh back room (which will take me at least a day or two to move, as I wont' have the energy to do it all at once), and I am not sure that the bed is large enough to hold the discs I have to make the adapter plate and ring from.

I might have to find someone else here on ES that could do it and trade them work or parts or something. I guess when I get to where I have time to try this whole thing out I can put up a want ad for that. Doesnt' need a lathe, even a 2D CNC could do it, if it can cut thin steel (1/8"?) or thick aluminum (1/4"?), as they are just flat plates.

I *might* be able to cut them out by hand, using a compass to scribe lines and then cut roughly with angle grinder, then file and sand until as close as I can get them, but I expect a fair bit of runout this way.

The rotor I can "lathe" by simply bolting the motor down flat and then bolting the lathe's toolholder down to the same table, or strapping the motor down to the lathe bed sideways, close to the toolholder, once I unbury the lathe itself.


Then I have to locate bolts (m7? m8? bigger?) that will fit the threads/holes on the rotor face for the outer holes, and then longer ones than presently there for the center of the rotor to secure the freewheel to it as well as the rotor to the axle inside. Also need cover bolts for the hub flange, as I know I don't have enough of those without taking them out of a working hubmotor. (M3? M4?)

Pretty sure I already have a bolt or axle the right size for the center hole, and I have a pillow bearing I can use that I got from (I think) mud2005, along with some other stuff (might've been someone else--veloman maybe?). (I usually label the boxes I keep stuff in so I knwo where ti came from, but I forgot to with a coupel of them and can't recall right now--would have to look thru my build threads to see if I noted it down there).





Getting the other stuff done to the bike to bea ble to put hte motor on is relatively trivial, I just have to do it in a way that doesn't preclude taking it right back off and putting the regular motor wheel back on--should be easy enough.