Perm 132 disassembled.

Joined
Oct 28, 2008
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Location
Manhattan Beach, CA, USA
Methy sent me a Perm 132 motor that had a very rough turning rotor. He didn't want to mess with it, and I figured ehhh, what the heck.

So, I would say it took about 20ft-lbs to make the shaft rotate when I got it, so I figured I would take a few minutes to pull the heavy boat anchor apart and see what was going on inside.

I found zero data or photos online of taking these apart, including searching the mfg's site, which only covered brush replacement. I found it pretty simple to do though, only took about 10-15mins to strip it down to it's bare parts. I took some pics of the process I used to potentially help somebody else looking to take one apart.

132brushes.jpg


132magnets.jpg


132puller.jpg


132extraction.jpg


You can see this rotor got hot enough to sling out some solder onto the outside of the stator.
132solderflow.jpg


Solder spray close-up.
132solder.jpg


132rotor.jpg


I took the time to hand scrape off the thick enamel coating off the outside edge of every cooling plate blade. This took more time than the whole procedure, fortunately I did it during an online meeting at work so it didn't take any of MY time. ;)

132fins.jpg


On assembly, I noticed a crack in the hub of the rotor... look at about the 9:30 o'clock position at area where the rotor meets the shaft. I dumped some alcohol on it, and it's a real crack, and it does run clear through, and out the other side on both sides of the shaft...

132rotor.jpg


After cleaning all the solder particles off the edges of the motor and magnets, it turns freely now. I connected it to a 3V source, and it spins, though it draws a few hundred amps of no-load current.
132assembled.jpg




Overall, I would say it's the most crude motor I've ever worked with in my life. Even the industrial multi-hundred HP motors at work use better casting and attention to detail.

Things I liked:
The brush layout is pretty slick.
The magnets are bonded in a very solid way.
Controllers are dirt cheap and/or easy to make.


Things I didn't like:
Rotor is the source of all the heating in this motor, and it's dipped in a thick enamel. This really hurts the cooling ability of the aluminum cooling plates poked around the edges of the rotor. It likely wouldn't have melted the first time if the cooling fins weren't all wearing an enamel blanket.
Crude! Think 1970's ford/GM/Mopar quality exhaust manfold casting crude.
Weight of this thing is massive. It's like the weight of 10 RC motors. lol
The rotor was cracked at the hub, and the whole thing has that crap engineering/metalurgy/plastic feeling you get with most German-made stuff. Definately has that "built by and for the lowest bidder" type feeling to the whole thing.
 
I can't imagine you will be using this though Luke brushed motors make you tired and sleepy no wait, thats frock motors and automatic transmissions :lol: i know you don't like brushed motors though, so how much juicy you think will have to be pumped through this to see how fast it can spin before self destructs? *subscribed* :mrgreen:

KiM
 
Miles said:
:D Thanks for the pics, Luke.


My pleasure Miles.

Another thing to note, a very real risk of finger pinch exists during many steps of the disassembly-assembly. Be clever and always set things between the end-plate and the case that are bigger than your fingers, because I would estimate ~100ish lbs of pinch force between the cover and the case from the magnets.


Since it's got a cracked rotor, and maybe shorted windings (I don't even care to check), the plan is to see if it will handle ~80vdc @ 300amps or so with out the rotor exploding from the RPM, and if it stays together, I'm going to stick it in the middle of a little steel frame BMX fitted with dual broached freewheels on a splined hub, gear it for maybe 120mph no-load speed, a back-pack full of LiPo, and see if it will reach 100mph before it melts down.

This will have to be when I find time though... which seems to never happen anymore... :(
 
AussieJester said:
I can't imagine you will be using this though Luke brushed motors make you tired and sleepy no wait, thats frock motors and automatic transmissions :lol: i know you don't like brushed motors though, so how much juicy you think will have to be pumped through this to see how fast it can spin before self destructs? *subscribed* :mrgreen:

KiM

It says 3,400RPM Maximum on the sticker for it, which evidently is the 72v no-load speed. That's for one with a non-cracked rotor though... So, naturally I'm going to over-volt the piss out of it, run the camera, and just see what happens. :) So far the total investment in the motor is 1 flat-rate shipping box and about an hour of time at work, so I've got no real concern either way it goes. Kinda rather have it explode the rotor from over-speed actually, seems like it would be more exciting than actually using a brushed motor for something. :)
 
HAL9000v2.0 said:
Sad, Perm use to have high quality few years ago...

This one says it was made in mid 2009. Maybe they've out sourced to China or something? The covers are like 4mm from lineing up... Some holes were so off-set drilled to line up with the parts below they were almost slots rather than holes. lol. Chipping out the casting flash left me with a pile of just loose casting flash chunks, and it would only take 1 of them to side inside the flux gap and convert the motor into a self-powered rotor-grinder. Rotor also has some run-out in it, but it's been cracked, so you can't fault them for that, it may have been perfect before cracking.
 
Malcolm said:
Wouldn't the casing and magnets make a good start for a powerful brushless motor?


Hardwire up the rotor and fix it stationary to turn it into a stator, then spin the case around it? No reason it wouldn't work like that I supose. I think the colossus motor Hal9000 is working with is a much better platform to start from for doing a brushless design though. This thing is absurdly heavy, and uses loads of cheaply cast iron rather than beautiful machined aluminum. :)


I'm thinkin, maybe even no controller, just copper plate and a welding lead clamp comming off 4kwhr's of LiPo on a tiny BMX. Pedal it up as fast as I can, clamp the lead on, and see if it will get to 100mph before it melts and/or explodes. I'm pretty determined to be the first bicycle to 100mph. I even asked Markcycle to buy his giant frocky to put on a little BMX with DIY rear wheel stays, hit it with as much voltage as possible (which I think may be a recipe for a 100mph bicycle), but he turned me down for safety reasons... :( So this looks like an even less safe, cheap and dirty method to get the job done. Cheap N Dirty are two of my favorite things in life. :twisted: :mrgreen: :twisted: :mrgreen:
 
liveforphysics said:
Cheap N Dirty are two of my favorite things in life. :twisted: :mrgreen: :twisted: :mrgreen:

i like that equation...lol.

that is a lot more poles than im used to seeing. :lol: good pics

i guess theres an advantage to the brushed motors. there cheap and simple and get the job done :mrgreen: . id like to see a bmx hit 100 mph...lol
 
def215 said:
that is a lot more poles than im used to seeing. :lol: good pics

Yep, 2 DSLR cameras sitting on the shelf where I'm working, and I used my cell phone for all these pics. :)

def215 said:
id like to see a bmx hit 100 mph...lol

That's the plan for now. :) I just realized that if I do the clip-on method rather than a controller, I'm either going to need to reach down at 100mph and unclip the welding lead, or tie a string from it to around my neck or something so when I pull my head up, it pulls the lead off. I guess the string solution is simple enough, I should quit being such a safety ninny and worry more about getting to 100mph than what happens after.
 
I was just playing with this thing at home in bed (trying to fall asleep), and I was spinning it up at 48v with a power supply, just messing around with it, lifting up on the individual brushes and seeing how the current changes and basically just playing around. Anyways, I lifted up on two brushes, a + and - brush, and ended up smashing them together in my fingers. LOL!!! This 25lbs motor with the 15lbs rotor spinning at 2400rpm jumped in the air, slammed off my shoulder, and dragged the leads and power supply across the room in a split second and fortunately hit my laundry hamper. LOL!!!! Funny how that 15lbs rotor at 2400rpm didn't like the idea of becoming a dead-shorted generator in a split second. The outside stator part just locked up with the rotor that had a LOT of kinetic energy stored in it, and they decided to find a new place to be in my room. I had to snip the brush leads apart from where they arc-welded together. LOL!

Just watching it leap has made the whole motor worth the trouble. This has some serious kinetic energy when it's at 48v. I can't await to see +80v, and now I want to get it on video, doing an 80v spin-up, followed by just mashing the power leads together and see what sorts of acrobatic tricks it does. :) I'm 100% certain if you had this thing in a little BMX with no rider on it, just free spinning up the motor, then shorted the leads together, it would flip the bike up for some aerial somersault action. And now after thinking of it, I have a duty to find out. :)
 
Is the problematic casting flash visible without taking the motor apart? I've got a pre-2009 motor that has no varnish on the outer clips/fins and would like to minimize any potential problems before I build it into a project. I'm starting to think this motor is best suited to momentary high loads with mostly low continuous loads.
 
gogo said:
Is the problematic casting flash visible without taking the motor apart? I've got a pre-2009 motor that has no varnish on the outer clips/fins and would like to minimize any potential problems before I build it into a project. I'm starting to think this motor is best suited to momentary high loads with mostly low continuous loads.


Yep. At the base of every one of the cooling slots was a chunk of loose casting flash. The inside surfaces get touched by a lathe to clean them all up, but that doesn't help if every vent hole has a chunk of steel just waiting to fall into the flux gap... It was very obvious on my motor, sometimes blocking a quarter or so of the slot! We're talking some crude casting! lol The varnish was also very thick on the heat fins on the rotor, with visible drips pooled on one side. If your motor has no obvious flash in the slots, and no varnish on the aluminum, then perhaps you've got an "A" grade motor or something, and I've got a "D" grade motor or something. lol Or maybe my motor was an out-sourced to China thing, and your's was made in-house still. I'm just taking wild guesses, no idea really. Mine has settled down to having a 3.4amp no-load current at 15v though, and before running for a while it was about 6amps at 15v no-load current, so the brushes are breaking on the commutator a bit I guess. :)

If anyone else would like to let me know what the no-load current they have is at any voltage at or below 15v, that would help me find out if I've got any shorted windings in my rotor.
 
liveforphysics said:
And now after thinking of it, I have a duty to find out. :)

Get Methy over there dressed in all his nanny protective gear don't tells him what your going to do just tells him to get on :mrgreen:

KiM
 
Hi Luke,
nice pics.
I was always curious how it looked inside. Do you think the housing is iron because it's a magnetic return path?
Very sad, they are of such cheap quality, 'cause they are expensive too :evil:
I think when you try to spin up the motor the crack will widen up and the rotor will make a shortcut to the housing. Have you seen any plasma marks?
-Olaf
 
I made a little video of spinning it up on the 1010B motor break-in program. These chargers are so slick. :)

-Luke

***edit- I was like half asleep when I made this video... and managed to randomly cover the microphone on the camera through various parts of the video. lol Perhaps my worst quality video to date. :oops:

[youtube]evOZs8RCFDw[/youtube]
 
Ok, the last video was so bad, I re-filmed it with me awake, and in 720P HD. I also poked around with adding tension to the brushes and lifting brushes to see how it effects no-load power draw. Brushes are kinda a new thing for me, so it's been interesting to poke around with them a bit.

[youtube]7MZLE88fvLs[/youtube]
 
Also remember about the lower power draw with lifted brushes--if this is a multipole motor (4-poles is common for high-torque typically-3600RPM motors, might be an 8-pole for this model), rather than the typical 2-pole (~7200RPM typical), then lifting a brush actually disconnects one of the current paths completely (a whole set of coils), which will affect the current dramatically under load but perhaps not so much no-load, depending on motor design and conditions it's running under right then.
 
amberwolf said:
Also remember about the lower power draw with lifted brushes--if this is a multipole motor (4-poles is common for high-torque typically-3600RPM motors), rather than the typical 2-pole (~7200RPM typical), then lifting a brush actually disconnects one of the current paths completely (a whole set of coils), which will affect the current dramatically under load but perhaps not so much no-load, depending on motor design and conditions it's running under right then.


Yep. From looking at the rotor layout, and pokeing it a bit with the DMM, it seems this motor operates like 4 completely seperate brushed motors on a common rotor.

For the no-load speed at 15v to be maintained, when you lift up 3 brush sets, it just dumps 4x the current through the contacting brush set, and keeps going at the same speed drawing the same power (roughly, the tiny drop comes from brush drag being reduced IMO).
 
If you close one eye and squint with the other that motor looks pretty good. Have you estimated friction losses of all those brushes on that not too smooth commutator? It would be considerable from my layman viewpoint.
 
salty9 said:
If you close one eye and squint with the other that motor looks pretty good. Have you estimated friction losses of all those brushes on that not too smooth commutator? It would be considerable from my layman viewpoint.

Yes, It's between 12-24watts at 750rpm. With this type of friction being like a flat-tax on torque, it means roughly 54-108watts at 3400rpm (peak rated RPM).

I gotta get on a plane for Atlanta Georgia in an hour and a half, or I would do the 80vdc test on this thing right now and find out if that cracked rotor just explodes, or if it's able to handle it. That test will have to wait until I get back from my trip though, which is for "undetermined amount of days"...

If it can handle it for a few minutes of running at 80vdc, then I'm going to buy a cheap steel frame BMX, throw this pig in there, put on my full superbike race suit, hit it with everything it's got and see if it makes it to 100mph.
 
gogo said:
In case you haven't seen this thread LFP, here's where my Perm came from.
electric bike super fast neukin 48v killer!!! 63MPH


Interesting. It looks like it worked pretty decent on a bicycle, but the battery choice was fairly pathetic, they could only deliver 48v and maybe 150-200amps at the most.

I'm going to hit this thing with 80v, and no current limit, just whatever the motor resistance and the battery resistance on an 8P pack of 5Ah 25C lipo's ends up being able to dump into it before something melts. Get it all on video, and hope it reaches 100mph before what ever happens to be the weak link happens to fail.

I'm going to put DOT approved scooter tires on the BMX, like Arlo1 and Thud have done.
 
I always thought that these motors are of high quality for being German-made & pricey compared to Chinese... I guess now, its the other way around :shock:
Thats one helluva humongous gear puller, thanks for sharing!
 
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