BMC V1Geared400W36VDC - TakeApart+PutTogether with Mods!

[markz]

Just bought this BMC motor today and I am excited!!!! Should be a step up from the used department store geared ebike I bought about 8 months ago. I rode that one for a few good long rides, but unfortunately I roasted that motor on a long hill and stalled the motor. I think it just needed new brushes and springs for replacement, but it did stink badly when I opened it up. I chucked that whole assembly when I couldnt easily find brushes for it. Brushes are old school plus this was a 250W gear motor with a real small sensorless controller. For this BMC geared motor, I dont want to fry this geared motor, so I wont stall it again, but I do want more volts and watts out of the motor. The Grin motor simulator states I can run the motor at 72V and 65A which gets me 55kph, it does seem illogical. 25 minutes to overheat at 100% throttle, 55 seconds at 20% grade, 330lbs load. I dont want to run it that high anyway, as I want higher Ah then faster speeds for a cost analysis. 36V gets me 33kph, and with 4 extra batteries in series I can go 48V which gets me 40kph,

Here is what I got, as a complete package. BMC 400W 36V laced in a Sun rim 507x34, with a Hookworm tire in 24x2.5, with the letters Downhill on the sidewall. I dont know why they used that term, the tread is slick smooth in the middle, grippy on the outter sides. I have no clue whats left on the tire, but yeah its smooth about 3/4" to 1" wide, with some ledge left in the squirly pattern. I'd say a little more then a fingernail. Awesome deal for $20 now that I got it opened, inspected it and found one gear stripped badly, other 2 gears have a few teeth missing.

Got it from a bike shop that did not know what to do with it and did not know the true cost of the package. The spokes alone would cost $30. Add in the rim, $10 and the tire $5. The worker did say there is something wrong with it, and it didnt work. The previous owner striped the gears, doesnt seem to smell of roasted windings, axle spinout doesn`t seem to have occured. Its a a score for me, and I can use it. The 3 phase wires look really small, 2mm with insulation so 12 or 14 guage phase wires, halls seem normal size wire.

From what I gather, I have a BMC Version 1,

https://endless-sphere.com/forums/viewtopic.php?f=28&t=20910&hilit=timing#p304945
https://endless-sphere.com/forums/viewtopic.php?f=2&t=67342#p1014112
https://endless-sphere.com/forums/viewtopic.php?f=6&t=36959&start=75#p589121
https://endless-sphere.com/forums/viewtopic.php?f=16&t=51310


Questions

Whats the best way to pop the cover plate off with the bolts off without nicking the motor?
Well a 2 gear puller seems to be useless, a 3 gear seems to be what everyone uses. I bought a 2 gear puller, and couldnt pop the cover.
I ended up slamming the motor down and popping everything loose.

Where do I buy better gear clutchs for it, from that video looks like I can go Composite V2 one piece and get 1000W.
ebikes.ca sells clutch, gear assembly for $100 + $10s/h, em3ev sells gears, clutch, axle, cover plate, ring gear. Only compatable parts would be clutch and gears.

How much higher voltage and wattage can I go with this motor?
From what I gather, 72V and 65A is doable, but it does seem illogical. I viewed the motor simulator on ebikes.ca, and specifically looked at "Overheats In" column with different slopes. I guess it boils down to what the gears can handle. From my research, Nylon gears are only good for 400W maybe 500W if you lay off the juice. Composite and Steel I havent been able to find any info on power limits. I've read that you can just replace one out of the 3 gears and the pressure load is put on the strongest gear. I am tempted to just replace my one gear that is completely totalled, but one of the other 2 gears has 2 teeth missing that are beside each other.

 

[motomech]

Basicly the same motor as the original Ezee.
I would do a hall sensor test first, out-lined at Ebike CA
Ezee's from that period had a factory cold solder fault where the Hall wire attached to the PCB.
Here is a video of the repair;
https://www.youtube.com/watch?v=ArTM_Jelt1U
Ebike Ca can sell you the up-dated PCB and Halls if needed .
The cover prys off once the screws are out. Here is Ypedal's site that mostly deals with an early Ezee.
Ebike NYC still has parts for early Ezee's.
https://www.youtube.com/watch?v=ArTM_Jelt1U

You don't need to uprgade if you plan to stick w/ 48V/20 to 25A.
I have some spare parts too.
Don't let your imagination run away till you see what's going on.

 

[markz]

I dont even know why I bother with cheap tools anymore from Princess Auto (Harbor Freight) I even had to fab up longer arms. I dont mind wasting $4 on it as I found some other stuff I needed for the shop. Just eat up my wires, with nut halfway on so it wouldnt slide off, and wires tucked, the puller would angle, never being straight up and down and did not even pull it out a mm. Good ole brute strength works great. I kept the nut halfway on and wires tucked away and tried to keep the entire assembly level and one hit it open on the concrete floor.

If you look at one of the pictures on the inside of where the disc brake goes, it does not look good. I triple checked and I didnt have no nuts on it, I DO! remember seeing it without so I dont know how or why they got like that from the previous owner.

To my eye everything seems good to go, I didnt want to run the motor at all until I saw the inside. I believe I learned this from one of YPedals YouTube Video's. It makes common sense. Sometimes I dont have that.

These pictures where the best I could get.


View attachment 6



View attachment 2

 

[markz]

Here are some better pictures.
View attachment 12









View attachment 3

 

[markz]

Well I think I will see whats under that PCB, check out continuity, rewire, clean. I will see if I can get continuity on the windings, I have not done that yet. Epoxy is real hard to take off with a rotary tool, I will leave it. I wonder if I can buy the PCB board, halls are honeywell which are easily obtainable.

All the gears look intact, no stripping. I find no metal shavings anywhere. (This turned out to be false, I was looking at the ring gear not the 3 orbital gears) Just concerned about the disc brake mounts on inside cover plate.

I will inspect the cover plate bolt holes for cracking beyond the holes themselves, and the shell itself for cracking.
All in all it looks very good. I cleaned it all up, just used some Isopropyl alcohol.

I'd still like to know, What is the recommended product to clean?
What grease should I use and where should I put it? Just slather it on until it looks like how it was when I opened it all up?

 

[markz]

My windings look darker then average, but I can't smell anything. Looks like someone had it open, there is very hard expoxy holding wires in place. I hope the windings are ok, then I can rewire the phase and hall wires. I've been doing random, continuity checks placing my probes on the same winding wire and the varnish seems to still be intact as I am getting an infinite open reading. Reading 0.5ohms from the end of the phase wires, to the windings. There is too much epoxy gooped on the hall sensors.

Found this picture below in a thread about BMC's. My windings look darker, so it must have had some heat issues, perhaps when the gears where stripping.
https://endless-sphere.com/forums/viewtopic.php?f=28&t=45245&p=671005&hilit=Internals+BMC#p670288
View attachment 4

My winding color







The next step is to go for a test run. Once I get my welder, one or 2 more weeks.
Is there a way to just hook up 36V 2Ah straight to the phase wires?

 

[markz]

After reviewing this thread I found the problem the previous owner had. $110 shipped for these gears, on par with EM3EV but might not fit, will fling em an email, or EM3EV.com, might not fit. The clutch look exactly the same. Not bad $47 shipped for gears alone, $75 with clutch shipped, or $165 for everything shipped. Which material will last the longest ebikes.ca Nylon or em3ev's Composite?

ebikes.ca

Freewheel Clutch and Machined Nylon Gears

em3ev

composite gear

Nylon, Composite and Steel Gears, from an EU company, language looks to me to be German, no easily definable location by address which makes me think its operating out of their residential house. Which isn't a bad thing, its just another factor that I factor in when buying online.

EM3EV's website







Someone had really long disc brake bolts.





Cleaned up some more


Gears Cog Planetary Gear Sources
Lyen sold some years ago, useful info right off the bat in his post. I highly doubt he is selling anymore

You only need to replace one to reduce the stresses for the existing nylon/composite sprockets. You only need to replace one to relief the stress on the other two existing sprockets.

Heinzman use 1 metal gear only, they do not use 3 gears as is typical for pretty much every other geared hub motor.

http://www.ebikes.ca
http://www.em3ev.com
http://www.ebike-solutions.com/en/shop/motors/motor-replacement-parts/fits-puma-and-bmc-motors.html

----------------------------------------------------------------------------------------------------------------

Nest is to upgrade the phase wires and install new hall wires.

 

[markz]

I took apart the one bad gear.



Bearing is Z809 Bearing 22mm(OD) x 7.0mm (H) and inside hole is 8mm diameter.

The CNC/Machine shop here took a look at it, they arent that busy so maybe I can get a special deal on it.
I will put a feeler out in the For Sale section to see who else wants some.

--------------------------------------------------------

I got some 12 awg Teflon wire in there, it took a ton of work, some chain oil down the shaft and on the 3rd wire a ton of twisting and turning and an every so slight, with the perfect angle and length with precise, careful bend of the end of the wire and about 4 cut-offs of the end of the wire (because it became too mangled) and presto this baby is done!!!!

I taped a stock wire that came with the motor, to my 12awg Teflon so compare. Now I need to wiggle 5 or 6 large guage = very thin wires in, I will find the biggest guage (thinnest) wire I can find, I will find some 30awg magnet wire. The toughest part of this type of job, and I have done it twice now, is getting around the curve.

Measured 1.75mm diameter with the insulation (1.40 diameter wire) to 3mm with insulation (2.22mm diameter wire).

Yes, I did rip out the wire coil and sleeve on the inside of the axle. It gave me more room to work with, I dont think I could have done it without removing those pieces.



I also was able to slide in a 1mm picture frame wire, so 5 magnet wires of appropriate guage 34 to 38awg will fit nicely. This will make it easier to pull the magnet wire through the axle. I dont know how strong the magnet wires are, I will convert to ribbon cable once it leaves the axle.

--------------------------------------------------------

I ended up cutting an ethernet cable, taking all the wires out of the axle, putting the small wires in first, then stuffing in the larger wires. I am getting better at it everytime now. I actually went in from the other side of the picture, it seemed to work better. Then using pliers from same side, I would push the large wires in, easily at first until you reach the bend. I could get a running start at it so to speak. Pull the wire out a bit, and shove it in, do it until you reach that critical point where the wire bends abit (its hard to explain, but you feel it, and see it), then when you feel friction push in about 5mm at a time and that worked great!!! Even the 3rd and final phase wire took only 5 minutes. I did not use any oil, just whatever was left as residue from last night getting all 3 phase wires in and no sensor wires.



Time to solder all the wires, my gears are over at the CNC/Machine Shop for laser cutting, I dunno if they will do a sample because I cancelled the order. Ordering the actual gears from a source. Its the expensive S/H that makes it a bit of a downer.

I might put this motor as a front so it can easily swap to other bikes. And I can have 2wd, not to sure how well that will work with 2 completely different motors turning at different speeds. MXUS 3KW V2 rear and BMC V1 400W.

--------------------------------------------------------

 

[markz]

The black ground wire broke off too easily.

 

[motomech]

Well, if you would have taken the time to read my post and aswk me a question or two, you could have saved yourself a lot of time and trouble.

Good luck.