Changing Brushes on BD36
Any tips on taking apart the hub so I can replace the brushes?
It seems like a pretty tight fit, and I don't want to start forcing things apart without knowing how the motor comes apart.
Thanks!!
Nick
ps - Pics would be great!!
Nice sequence on cleaning your EV's motor.
Cheers, Gary
Once you get inside, mark where the brush holder sits, so you can put the new one in the same way. Brushed hubs are timed, and it will run slow and hot if you mess up the timing of it. You don't need to pull the magnet core out of the hub, which is good, those things can take a fingetip off. Just pop off the cover. It's pretty easy, just take it slow and pry gently, minding the wires so they don't cut the insulation.
Thanks for the info!
I'm going to try and take care of it tonight.
I was able to get the cover off and found out that the wires to the brushes had sliced through and shorted out against the frame. I cleaned them up, soldered new connectors and put it all back together.
Unfortunately, the motor won't turn.........
The batter pack is fully charged and reading about 39 volts going into the controller. I am getting about 37 volts constant from the controller (regardless of throttle) to the motor power line, and still no turn.....
So, it looks like I have a toasted controller, but I'm stumped on the motor. I put a meter across the input and showed zero ohms on all ranges except mega-ohms, which was about .004 meg.
I'm guessing I should open it up again and install the new brushes??
Any other suggestions or trouble shooting ideas??
Thanks for your help!!
And if you could recommend a vendor for replacement parts?
Thanks again!!
Bummer, I mean about the controller. If hooking it up straight to a 12 v battery won't make it turn, then you need to open it up and look for something wrong. Maybe a brush is stuck in the holder and not contacting the rotor or something like that. Shorting the wires can blow a controller, been there done that.
Lotsa places for controllers, ebay for one. Brushed controllers are pretty cheap, but some of the ones on ebay are pretty weak, like 10 amps, and the we one is 35 amp. Ebikes-ca sells a 30 amp brushed controller. Some other places that sell WE stuff have replacement WE brushed controllers. Just google
we for that. And over on the endless sphere, I am selling a used brushed hub and controller in the for sale section. You can look at it, and pm me on this forum if you aren't a member at es.
Thanks for the tip!
I was able to find a dealer in MI that had a new brushed motor and controller.
He wanted to get rid of the brushed stuff, so he sold them both for less than $200 shipped. Fortunately I have a new set of brushes and will take apart the old motor and see if I can't figure out why it won't spin, before I install the new controller....
Cool, the brushed hubs are nice because of the simplicity of them, cheaper controllers, in a pinch you could get home by plugging the motor right into a battery. But where I live, they run too hot. It's the desert, so everything gets too hot.
We're in FL so I know about hot and humid!
Fortunately the trike is for my 91 yr old father in law. Who only rides it 4 miles a day to and from the gold course, 6 days a week.
He can't really peddle to start so I wanted a motor with enough torque to get him started.
At least humidity helps the air cool the motor. I just had problems with 5% or less humidity, and temps around 105. With no water molecules in the air, the motor would run hot. And I was trying to ride it 15 miles all uphill. So that was the real problem.
So, after cutting the wires into the hub 3 times, I've gotten pretty good at opening up the motor and replacing the wires. Turns out the fork on the Miami Sun Trike had rounded out and was no longer stopping the hub from spinning. I tried making larger locking tabs, but it just kept spinning and breaking. So, I'm replacing the fork with one from a used mountain bike that seems to be a lot stronger. Hopefully this will take care of the problem, if not I'm going to throw a rim on the front and get rid of the trike.
The bike shop near us sell IZip trikes. I like the fact that the motor is gear driven on the rear axle. But I'm concerned the 450 watt motor won't have enough guts to push it through the grass.
If that doesn't work I'm going to start looking for a small single seat golf cart or a decent used 2 seater.....
I opened up my hub a few months ago and changed the brushes. It was easier than anticipated. I followed instructions f/ V forum & Endless forum and it turned out fine. The main concerns are: do not mess up timing and be careful the hex screws don't fall into motor. When finished, I used a little caulking to zip up the seam.
Dogman. do you think that not setting my timing properly after replacing my brushes would cause the motor to die prematurely when i put a full load on it? My 48v lithium batt going into my 48volt crystilyte controller into my 36v bd WE wheel is dying on me and I dont know why? help!!!
I also need to pop open my bd36 motor to replace the wires coming out of the motor. One of the has been completely cut in half. I got the screws off and I cannot open the case.
I read you link David up there and its interesting, someone else mentioned using a gear puller or flywheel puller but I don't know what size.
Can we get a thread devoted to showing exactly how to open a hub motor case?
Also any tips? I don't have the pullers.
Thanks a lot.
You don't need a 2 jaw or 3 jaw puller. the way I have done it is: 1) remove allen bolts 2) go around hub crease
with a thin knife or razor blade to create bigger crease for about 5 or 10 minutes 3) insert flat head screw drivers into crease and eventually the hub cover will pop upwards 4) be careful not to pry hard with screw driver near allen bolt holes. Those allen holes are the weakest part on hub cover.
using this method it takes a solid 15 minutes to open BD36 Hub (wired side).
I've never opened the unwired side. read Dogman's advice on the timing above. Changing the brushes requires removing the allen bolts that hold down brush plate. Make sure allen bolts don't fall inside motor.
Also, it's a good idea to wipe up or blow off as much carbon dust as possible. Endless sphere has a BD36 exposed pics & info.
The timing problem will prob not ruin the motor. You'll just lose some speed/power. Ask dogman?
Once the brush plate is removed, don't spin the axle around. I put a little touch up paint near brushplate, magnets etc. That way I know axle hasn't moved and timing is ok..
Thanks for the advice, with your help I quickly got the cover open and I was able to replace the wires coming out.
I don't think I need to change the brushes yet, I was only replacing the wires since one was completely severed, and the other was exposing wires.
It's not hard to open wire side of motor. Just takes persistence, patience and caution.
Do you have a source of replacement brushes?
This may give you some ideas: http://www.7gen.com/book/my-ev-projects/cleaning-evt-hub-motor/701
That's instructions I wrote some time ago for cleaning an EVT 4000 hub motor. Of course the details will be different with the WE BD motor but the general principles should be the same. I just went outside to look at the motor on my bike and see there's a circle of screws on both sides and you'd start by undoing the screws. But there's going to be magnets inside there holding it together and the gear puller idea I used for the EVT hub motor should work on this motor too.
- David Herron, Green Transportation Examiner, davidherron.com, 7gen.com, What is Reiki
- EVT 4000, Charger bike (rebuilt), Vego 600sx (rebuilt), Electrified Electra Townie
- Lectra motorcycle