How to bypass internal controller on brushless motors?

[august23]

You might find this thread helpful:
http://endless-sphere.com/forums/viewtopic.php?f=16&t=11772

I bypassed the internal controller on my BMC long ago. It's not that hard but depending on how long they left the wires, soldering extensions can be challenging. With forced air cooling, I can run it at over 2kW.

Also keep in mind that not just any controller will work well with these motors due to the hall timing.
A sensorless controller avoids this problem and you don't need to worry about the hall wires, but finding a good sensorless controller is still difficult.

I looked hard and long for a page just like that... what key words did you use? excellent find!!!! thanx

[august23]

You might find this thread helpful:
http://endless-sphere.com/forums/viewtopic.php?f=16&t=11772

I bypassed the internal controller on my BMC long ago. It's not that hard but depending on how long they left the wires, soldering extensions can be challenging. With forced air cooling, I can run it at over 2kW.

Also keep in mind that not just any controller will work well with these motors due to the hall timing.
A sensorless controller avoids this problem and you don't need to worry about the hall wires, but finding a good sensorless controller is still difficult.

you the man!!!!

[Kin]

I think he might not have needed to use keywords . That was his thread; he was the one who replaced his internal controller.

I don't know if you tried google, but often that helps find things better than the forum search engine. google "blah blah blah endless-sphere.com" (without quotes) and you typically get better results.

[fechter]

Actually, I tried using the forum's search function knowing the thread was there. It did not find it. Forum search sucks. I found it by exercising the few remaining brain cells and remembered where I put it originally.
The Google domain search is much more effective.

[august23]

I should have figured that out. ah I assumed the search function on here was sufficient. and in case you didn't know: the easiest way to seach a domain on google is like this:

site:endless-sphere.com keyword1 keyword2

example:
site:endless-sphere.com (this would show every page index google has on the site)
site:endless-sphere.com BMC bypass (this would show everypage that has BOTH key words in it. (About 234 results))

thanks folks!

[august23]

Actually, I tried using the forum's search function knowing the thread was there. It did not find it. Forum search sucks. I found it by exercising the few remaining brain cells and remembered where I put it originally.
The Google domain search is much more effective.

fletch you have been busy:
https://www.google.com/search?num=20&hl ... 4l7.7l14l0

[friedwires]

i boiled the controllers out of the ones i've done viewtopic.php?f=2&t=17404 viewtopic.php?f=28&t=32059 i need to update my mongoose thread, the bike is a little monster!

[august23]

i boiled the controllers out of the ones i've done viewtopic.php?f=2&t=17404 viewtopic.php?f=28&t=32059 i need to update my mongoose thread, the bike is a little monster!

yeah I saw that on some other thread.. but it wasn't as complete as these 2. from what I can tell, it's not necessary to completely remove the old controller. though I like those nice long wires you managed to extract!

any ideas on what kind of ribbon I'll need for the hall effect wires?
and where did you get your replacement controller?

[august23]

i boiled the controllers out of the ones i've done viewtopic.php?f=2&t=17404 viewtopic.php?f=28&t=32059 i need to update my mongoose thread, the bike is a little monster!

also, I didn't see any wiring diagrams. can you help?

[friedwires]

forget repairing the original controller. its fully potted, making it impossible to work on. what you need to do is get that controller out of there. there are three pairs of large wires(phase wires) and a five wire ribbon(halls wires) you need to get to them without damaging them so you can solder to them and bring the wires outside the motor. i found the best way is to get the controller right out of the way. boiling will soften the potting enough for you to dig it out to get at the screws that fasten the controller to the inside of the face plate.once the screws are out,you can pry up under the circuit board and break it out of there piece by piece with pliers. as far as wiring diagrams go you're gonna have to wing it. i may have kept some notes somewhere but either way we can walk you through it. i would recommend a lyen 12 fet controller for this motor,and i'd also recommend running at 48-60v

[august23]

forget repairing the original controller. its fully potted, making it impossible to work on. what you need to do is get that controller out of there. there are three pairs of large wires(phase wires) and a five wire ribbon(halls wires) you need to get to them without damaging them so you can solder to them and bring the wires outside the motor. i found the best way is to get the controller right out of the way. boiling will soften the potting enough for you to dig it out to get at the screws that fasten the controller to the inside of the face plate.once the screws are out,you can pry up under the circuit board and break it out of there piece by piece with pliers. as far as wiring diagrams go you're gonna have to wing it. i may have kept some notes somewhere but either way we can walk you through it. i would recommend a lyen 12 fet controller for this motor,and i'd also recommend running at 48-60v

awesome. again, where can I find ribbon?
which Lyen FET? http://lyen.com/ please link

[fechter]

I doesn't have to be a ribbon, just any cable with at least 5 conductors. A round cable will probably be less prone to damage. I used a piece of cord off a telephone (6 cond.), and used the modular connector to make the connection to the controller. I have tons of ribbon cables from old computer stuff. You can 'zip' off 5 strands from a wider cable.

[august23]

I doesn't have to be a ribbon, just any cable with at least 5 conductors. A round cable will probably be less prone to damage. I used a piece of cord off a telephone (6 cond.), and used the modular connector to make the connection to the controller. I have tons of ribbon cables from old computer stuff. You can 'zip' off 5 strands from a wider cable.

good ideas!
which Lyen FET? http://lyen.com/ please link

[august23]

can I reverse these motors?

[fechter]

Yes, but may require swapping hall / phase wires.

One quirky feature of these motors is the hall sensors are located between the teeth in such a way that they are NOT neutrally timed. This causes compatibility issues with some controllers. With an analog Crystalyte controller, it runs OK, but has quite a bit of advance on the timing. This causes a higher than normal no-load current and probably some efficiency loss. It also makes it blow chunks if you try to use the reverse switch on the controller. It can only be set up to run one direction, but can be set up in either direction.

Apparently there are some controllers specifically matched for BMC motors that compensate for the timing advance. A sensorless controller would do this too.

When looking for a controller, be sure it has been successfully tested on a BMC motor. BMC hub motors have the same winding / hall configuration.

[friedwires]

i have two of these controllers running bmc motors without issues http://endless-sphere.com/forums/viewto ... 31&t=17683 but if you're on a budget, i have one i can sell you. its a bmc 36v 20a that i ran on my first bmc build . its a good controller but it has a soft start. it was also made to mount on top of the motor with spacers.

[august23]

i have two of these controllers running bmc motors without issues http://endless-sphere.com/forums/viewto ... 31&t=17683 but if you're on a budget, i have one i can sell you. its a bmc 36v 20a that i ran on my first bmc build . its a good controller but it has a soft start. it was also made to mount on top of the motor with spacers.

I appreciate that... but I would want to get at least 40a/36v-48v controller. so far the cheapest I can find is about $200.

I bought a 600w 24v BMC motor from thesuperkids.com. hooked it up and turned on the switch, and blew my 40a fuse. double checked everything. even tried my 300w bmc successfully. totally bummed. it came with several CAPs installed on the power line into the motor (with shrink wrapping). I didn't expect to see those. I guess it makes sense, incase something burns out.... im guessing the caps are what go first.

[august23]

here is the one I am thinking about getting. I dont know much about these controllers... yet. sounds like you do though! if you know a better product for less price... I am all ears (eyes).
http://www.electricrider.com/crystalyte/x-ct3640d.htm
and this looks about the same... im surprised there are so many styles.
http://www.ebay.com/itm/Crystalyte-36-4 ... 500wt_1185

[friedwires]

this is your best bet http://endless-sphere.com/forums/viewto ... 31&t=17683

[august23]

this is your best bet http://endless-sphere.com/forums/viewto ... 31&t=17683

I saw that but it says
Low voltage cut-off: 62.5v

[fechter]

The low voltage cutoff is fairly easy to change. I'm not sure if it can all be done in software, but Lyen can tell you how to do it.

[friedwires]

lyen can set lvc to whatever you want.

[august23]

ok I bought one of lynn's controllers. I look forward to using it.
then today I just found this... scroll down about half way down the page to where it says "Magic Brushless Dual-Mode Cruise Controller -- for Electric Bicycles, Scooters!" (BAC-281P). looks like it's $65 w/the programming cable.
http://www.goldenmotor.com/frame-controllers.htm

thoughts? opinions? seems too good to be true.

be sure to check out the home page if you wanna see some super bad ass motors http://www.goldenmotor.com

[august23]

ok to follow up. I bought an older burned out 600w MAC/BMC motor (fried internal controller) originally for a synergy/lashout e-bike. I successfully bypassed the internal controller and hooked up a Lyen 12 fet 45amp controller set for 36v(viewtopic.php?f=31&t=17683), wired for CCW direction for my scooter (mongoose FS rocket). Thanx Lyen!
Prior to switching to this new setup, I was using the mongoose's original 450w 24v (model:XYG-6B) overvolted to 36v using a currie style 36v/30a controller. I haven't done any efficiency tests yet. so this reply is mostly about speed and power observations between these 2 motors.

Originally on my scooter:
Brushed motor:
24v/20a= 480w (about 15mph) (5mph uphill and sometimes quits)(http://www.monsterscooterparts.com/24v45moupkit.html)
and when over volted:
36v X 30a = 1080w (about 24mph) (7mph uphill and quits less often)
note: at speeds over 2600rpm any throttle action beside FULL confuses to motor and creates bad thumping/knocking noises. if I need to slow down, I have to slow down below 2600rpm to accelerate again. and as long as I do this, no bad noises occur.

New to my scooter:
Brushless 600w MAC/BMC (originally rated 600w w/internal controller... which I bypassed):
24v x 25a = 600w (I haven't rode one of these so dont know how fast it went/goes)
NOW: 36v x 45a = 1620w (presumably) (about 15mph) (about 8mph uphill)

My initial observations:
Im thinking something might be wrong. I haven't done any metering yet. I expected the MAC/BMC motor to perform as well in speed, if not better, than my over volted brushed motor. but sadly it does not. the MAC makes a pretty loud winding sound, especially with more load... and aside from the winding, seems to perform properly (I think?)... just not what I expected at all. infact now that Im writing this, I'm thinking maybe I got the hall sensors wrong? anyone have any experiences like this?

Is there a test I can do to figure out whats going on? or if you have any info that can help me understand why it's not to my expectations, please comment. like old magnets? or inferior version of this motor (not a super MAC)?
I should also mention, when I was testing it, and had it in it's original turning direction (CW) it sounded like it spun about 20% faster....!?!?

[fechter]

The BMC motors have an odd hall timing that does not play nicely with some controllers.
It would be important to get some current measurments while running the motor but this would require an ammeter with sufficient range or a large precision shunt. If the timing is the issue, the efficiency will suck and the motor will take much more current than it should for a given power output.

There are some threads burried around that describe this timing issue. One person was able to re-time the hall sensors, which is done my mechanically moving them. Since they are in the slots, the slots had to be ground away slightly on one side to make room. It doesn't take much, maybe half the width of the hall sensor. The inherent timing is quite advanced, so retarding the halls could bring it back to neutral. This means move the hall sensors in the same direction as the rotor will be going.