Golden Motor Build 48v and Beyond!

[icecube57]

Oh sweet Jesus!. 24s 72v 20AH 1.44kwh Thundersky Packs. Each half is 20lbs for a 40lb total. I can go anywhere! They neatly fit in my pannier perfectly. Wrapped in Gorilla Tape. Armored with sticky back floor tiles. 12G discharge wires. Balanced with 4 Battery Medics. Charged in parallel with a Meanwell power supply to 44.4v. 88.8v off the charger. 79v Nominal. 68-70v under load. Controller LVC is set at 60v for 2.5v per cell. 2C continuous rated (40A) 10C Peak (200A). I have a 45A controller with peaks well into the 80's. Expected speed 35-40mph on flats. Should be able to peak into low 50s with mixed rolling terrain. Expected range at top speed 25-30 miles motor willing.. 70-80m at 20mph. 100+ at 15mph.

 

[The Stig]

There you go. It seems like you've tried so many different battery packs, bosch ping lipo... and finally you've settled on your own "duct tape" lifepo pack. A little ironic, lol, albeit its high quality duct tape, I use gorilla tape all the time 1 well built lifepo4 pack is definately an excellent choice.

 

[icecube57]

Gorilla tape is strong sleek and black. I tried 4 other brands of ductape at the home depot and the Gorilla Tape beats them all. The durability is outstanding. Its alot thicker than all the other tapes. The strength is hard to beat. It doesnt stick to itself like other flimsy tapes. You can almost reuse again after you are done with it.

The simplicity and capacity of the 20AH cells is pretty oustanding. For controllers between 40-60A these cells are hard to beat. You have to deal with a little voltage sag but its the best of both worlds Voltage and Capacity. They are just bulky and heavy as hell compared to other lithium cell formats and chemistries. But the cycle life should be worth it. If i upgrade to anything else it would be LIPO.

 

[icecube57]

[youtube]JEOKKR0JPrs[/youtube]

 

[ambroseliao]

That looks like toooo much fun! You guys should at least pedal to make it look more like you are real bikers!

DervAtl, your motor sounds VERY loud. Is it really that loud or is it the mic on the camera picking it up more than usual?

Ambrose

 

[Hyena]

Cool vid.
Yeah the BMC sounds loud! I thought they were rediculously fast too until I heard your voices and realised it was sped up. Cheater

 

[icecube57]

The mic is picking up the resonance of the motor through the frame of the bike.

The video was 12 minutes long i had to reduce the time somehow. The original uncut video was about 1hr 30min. I did you guys a favor.

 

[icecube57]

THE GM IS DEAD! As far as im concerned this motor toast. Literally. I went to test out my 72v 20AH Thundersky pack. Also to test out Justins Lumenator. That thing rocks for night riding. But the GM didnt fair to well. I got about 3-4 miles down the road i started hearing a scraping coming from the motor then it became more and more pronounced as something was stuck inside the motor?. Pulled over check my wires and everything they were solid. I spun the wheel with my hand I didnt hear anything. I headed back to my house and it got worse and worse and worse. The motor still had power but it was sucking juice like mad. 4-5k watts. My CA said my battery current peaked at 110A. I was pulling 50-70A during the ride which sparked my intrest cause at 60v i never could get it to sustain that many amps. I made it home parked in my garage and smoke was billowing from my motor. I know I pushed this thing way harder than this.

I let it cool down and tended to my battery which had some issues. I left one terminal loose while assembling my Thundersky batteries. It was bad connection that was heating up while I was riding. I felt it loose power when I hit a bump. Now i realize what it was now. So i had to tear the pack down and tighten all the screw and ill reassemble it in the morning.

I come back to check on the motor. I look in the motor holes and the windings are BLACK. Not a hit of amber in sight. I spin the wheel and it feels free like there is nothing wrong. The wheel speens freely several rounds. Maybe a magnet is loose but i doubt it. Spinning the wheel even makes my CA and Tail Light come on. So the motor is still working. I noticed several agressive rides before when i was running 90+ volts that when the motor was getting hot you hear a scraping but i backed off and it went away after a mile or two. Im thinking the tolerances are so close that when it heats up it causes clearance issues in the air gap between the magnets and rotor. But it sounds like something scraping the side covers. I know its not the phase wires or halls.

 

[Hyena]

I made it home parked in my garage and smoke was billowing from my motor

Where's the photos !? You can't post that and not have pics or a video

Bugger, looks like the canary just fell off the perch :|

 

[DervAtl]

Bummer dude. Doesn't sound good for the GM. You can take stock tomorrow when everything has cooled. Probably not good though.

The noise. Yes, this was the first video I've used my new Biologic iphone mount. It's a nice mount, but the mic on the iphone is picking up the resonance of the motor through the frame ---- very badly. I think the mic on the iphone is too good and there is not a way to turn it down. It's automatic gain. In actuality, the BMC is the quietest motor I've heard. It's much quieter than the GM Chris is running and also quieter than my Amped Bike dd motor. Got to figure out a way to isolate it from the bike frame though.

 

[icecube57]

I think im going to rework the 1606 with fatter phase wires and see if i can get a torque arm to fit on the wheel real snug.The 1606 is a death trap waiting to happen. The machining on the axle is really bad. I might just give up on everything and get out of the whole thing. Maybe start a new build. I have a 5303 rear that should be in a 20inch wheel. I might respoke it to a 26 inch rim. Then I need to get a rear rack because the rack I have goes through the QR. I have another GM with bad halls and a crappy rim. Time to go sensorless. OH YEAH!

 

[The Stig]

I have this old bmc puma with dead hall sensors.

What' is the most powerfull sensorless controller out there...

 

[DSX]

Lyen has some good ones (if I had the money....) look in the new stuff for sale.
DSX

 

[icecube57]

When the windings and stator got saturated with heat they expanded and started scrubbing the magnets. All the magnets have light scrub marks on them pretty much. One is sitting slighly higher than the other so it got scrubbed more which probably was the one making the racket every revolution. That stator has scrub marks on one side but not the other. It spins fine without scrubbing now but as i said earlier the clearance changes in the motor when it gets hot. The windings werent black although they are very very dark. The white fabric insulations are dark brown and black. The zip ties holding the hall board to the motor are melted. The hall board has seen better days. Phase and hall wires are fine. That yellow plastic stuff behind the stator windings was melting wicking into the windings. Since the windings were super heated it started to smoke and smell. At 60v it was fine and I really had to be agressive to heat it to the point to where it started scraping but that extra heat and current at 72v put it over the edge. Ill post pictures of the magnet ring and the windings and stator in a little while.

 

[icecube57]

THe windings look darker but they could be be worse. The magnet ring has scuff marks. The startor has scuff marks on half of the stator width and circumference. This suggests that is perfect enough to spin and run in normal operation but not under extended stress.

 

[icecube57]

The stator in my cooked GM didnt look as bad as i though it did. Im going to reuse it. I can't reuse it in the original housing because of the motor stator and magnet clearance issues when it gets hot. I had a brain fart and didnt realize that the other motors I have were almost identical therfore the stator could be changed to another rim/housing. So I pulled my stator out of my old wheel and pulled the stator out of the donor wheel. I noticed that the magnet width and stator width on the donor wheel is shorter than the one Im pulling from my GM. But the GM stator fits in the donor motor housing fine and has alot more clearance than the original housing. Its still a pretty tight airgap but I dont see the stator scrubbing the magnets anytime soon. What would be the downside of using this motor housing with the smaller magnets. Less torque and more speed Im thinking but this changes the characteristics of the motor. The magnets wont be strong enough to induce current into the windings to produce back emf and make my current consumption go down when cruising at top speed. I would like some input because i have another motor that has magnets at the regular width that can work also but ive spent two hours drilling out side covers to do this stator swap.

 

[Hyena]

Why don't you swap the side covers too? Or are they completely different makes with different hole patterns for the screws ?
I scrubbed the magnets in one of my hubs like that, although mine was because the magnets became coated in iron filings that were grinding when the stator turned (made the mistake of cutting adn grinding hte steel stator with it still in the hub - opps)
It was fine after cleaning it out so if you don't get yours too hot it will probably be ok too.

I also noticed the different height stators when pulling apart my GM hubs - the 500w front motor is a little shorter than the 1000w rear.
I can't comment on the back emf and torque issue though - I'd think the differences would be too negligable to really notice on the road

1000w on the left, 500w on the right

 

[icecube57]

My first GM donor replica had a 500w stator and magnet ring. My 1000w stator fits fine in the 500w magnet ring but when i put the side covers on there was scrubbing of the magnets and stator. The 9c 9x7 which was painfully torqueless has almost the same body, motor housing, and stator as the GM 1000w. I pop the stator in this shell and it didnt scrub so i now have a 9C 9x7 housing with a GM stator. The cogging is a bit more with this combination. I get 1 1/2 to 2 turns with a good spin. Either i got super magnets or the air gap may be tighter than on the original GM configuration. My GM was fine when cool but scrubbed when hot but i was hoping to find something with a little bit more clearance so i could push it a little bit harder without that annoying scrubbing.

 

[icecube57]

I spent the most part of the day fittin motors stators and side covers. But for every housing i changed to ... it had virgin motor sealed side covers. I felt that i need to step up my cooling efforts from my previous setup so I put twice as many holes into the side covers. Both side covers are identical. 12 holes in a 6 point star pattern. 24 holes total. Air cooling goodness at its best.

Also here is a bit of a throw back video. I felt this best suited what this motor was going through.

[youtube]HofoK_QQxGc[/youtube]

 

[icecube57]

Update: So I give my thanks to Lyen for supplying me with some 4310 mosfets to repair my controller. I cracked her open today and it looked like something exploded in there. I knew I that two mosfets shorted but i didnt expect for there to be a charred mess in there. (Mosfets didnt explode.) I fully opened her up and I saw what happened. I had a wire tapping off the + battery near the caps to go to a switch that fed the MCU. The wire was laying across the shunt. The insulation melted off the wire and caused a direct short between + and the - shunt. This melted the solder on the trace on the bottom of the board. Needless to say i removed the wire. Removed the switch. Removed the anyvoltage mod and stripped her back down to a "Plain Jane" controller. I removed the shorted mosfets. Soldered the new ones back in. Put some solder on the shunt because it was nearly vaporized. I reprogrammed the controller an reduced Block Time from 10 to 3. Reduced my phase current from 135 down to 115. I changed the rated current from 57 down to 45. I set my LVC to 60v.

All of this to reduce the strain on the motor and controller. I fired her up and put her through her paces. I couldnt play to hard. I have a half charged pack and a charger in the mail somewhere. But the hybrid 9C shell and GM stator is working out alright. It sound different with the covers drilled out more. Its more quiet than before. Controller is getting somewhat warm for the 10 minutes I was playing around testing it out. Its 86 degrees and 57% humidity. The motor was a little over luke warm. My battery voltage was at 70.5 heavy load 40-50A. (3500w). Alot better since I tightened the loose screw causing a hot high resistance connection on one of the Thundersky Cells. Resting voltage is 79-80v. She pulls up my hill with very light assistance. Easily gets up to 35mph in the flats. Im happy so far. Still need to get a backup controller cause this one has been butchered.

 

[icecube57]

I did my 1st ride post controller and motor repair. I expected the worst but ended up with the best results. This was a night ride. I was pimped out with all my lights. My Lumenator, my flashing epilepsy inducing seatpost light, and my Ebikes.ca 8 led tail light.

Im still without a charger so i went out with a 60% discharged pack. 79.5v resting 70.5 under load. Since i tuned my settings back it does feel lack luster and anemic not in a bad way but having that 5kw on acceleration and extra torque on hills was nice. Now the ride feels like there is nice gentle acceleration all the way through the curve. It gets into the 30s in a reasonable time but to get to top speed in the high 30s to lower 40s. Its going to take a minute.

The torque is noticeable. I did notice more cogging with this motor housing. I barely could get 2 spin when spinning the front wheel with my hands. I tested her earlier today on the hill leaving my house with the normal running start it made it 80% up the hill before requiring input. Not that the motor was stalling it was just lugging at 5-7mph and i thought it would be nice to help it out. It seem stronger in the 9C housing than when the stator was in the original GM motor housing. That maybe a sign that there was some demagnetization in the GM housing maybe.

I took the same route I killed the original GM on my last ride. Normally on my GM a few minutes of 2-3kw running through it the motor would be super saturated with heat and I normally start to hear the stator scraping the magnets. I didnt notice any of that on this ride. After I got done with the ride and I pulled her back in the garage I check the motor side covers. They were above luke warm. I waited a few minutes to let the heat soak set in. The cover was warm to hot. I could leave my hand on it indefintely without being uncomfortable. I did slightly smell the unforgettable smell of the windings but it wasnt smoking or strong. With the extra holes in the side covers i think the air flow in the motor is a lot less restricted and can cool more efficiently. The cooling doesnt quite cancel out the motor heating and eventually it will get critical eventally.

But my ride tonight was to test the new motor house and controller and to really stress it to see if I could replicate the events of the failure. I pushed it just as hard as i did on the previous ride and I must say im overall satisfied. After the tweaks and changes I lost the agressive feel the bike had before but its seems alot more solid and reliable. After I get my charger and few more bouts of stressing it out and getting a feel for the bike at 72v I can probably put her back into normal use by the end of the week.

 

[icecube57]

Just some photo updates. My panniers are swollen with watt hours. They are going to burst.

 

[John in CR]

Icecube,

If the magnets on the rotor are rubbing on just one side of your stator, then the perimeter of the stator is not perfectly centered in relation to the axle. How to repair that I don't know. I don't know if sanding or grinding in that area will create conductivity between the laminations or not. If not, then the would fix the rubbing, though it doesn't really correct the problem, since the stator is farther than it should be from the magnets on the other side.

 

[icecube57]

John thanks for that insight. To repair the issue it would well beyond my scope of skills and tools. I honestly think there were some imperfection with the side covers. Its always scraped when it got hot. I ended up taking the 9C motor ring and side covers and used the GM stator and I havent had any problems since. Running rocks solid with 3kw continuous.

 

[John in CR]

John thanks for that insight. To repair the issue it would well beyond my scope of skills and tools. I honestly think there were some imperfection with the side covers. Its always scraped when it got hot. I ended up taking the 9C motor ring and side covers and used the GM stator and I havent had any problems since. Running rocks solid with 3kw continuous.

A side cover problem would put the rotor off center, and some of the magnets would rub all around the stator. The exception would be a bit of slop in the side covers or bearings where the weight on the bike pushes the bottom portion of the stator closer to the road leading to wear primarily on the lowest part of the stator and all around the magnets. Maybe that's what it was, a bit of looseness in the bearings, since different covers seems to have cleared it up.

Going forward, it's good to put alignment marks on the covers and rotor, so if something is a bit off but working fine, then you put it back together in the same position.

John