Bypassing a brushless 600w MAC/BMC

I will edit and add stuff as I go, but for now, here are the photos to go with the thread.

I was able to get the stator off of the rest of the motor. I did this by, assuming you already have the shaft/cup off, put a half dollar sized washer in the top where the inside most baring goes, acting as a little platform. then I used a 3/4" socket and placed it right on the washer (or whatever works to extend it up). then, while holding the stator firmly in one hand, hit the socket with a hammer as hard as you can (with the other hand). keep doing this. the impact will start to pull the stator up and off, along with the attached wires. once it's up, say a quarter inch, you can clip ALL the wires at the potting side of the wires (giving yourself some length to play with). Once you have them all clipped. you can continue to hammer away until the stator comes off. I bought some red locktite for when I put it back together. Once you are to this point, you can use a heavy duty screw driver and a hammer to chisel away at the potting. the first one I bypassed, I drilled holes all over the potting first (with the biggest bit I had). then I chiseled away. I haven't ever totally cleaned one out. infact, the last 2 I did I left the potting intact except near the exit hole where it tends to get a little tight.
here is a video of me taking off the stator: http://www.youtube.com/watch?v=xU6tsiEftCU

Once you have the stator off, you can easily get at the wires. you have to pair up the duplicate phase colors (yellow to yellow, red to red, and blue to blue).
working with the stator upside down makes it very easy. to put it back together I put it back together by hand as much as I could, then put it upside down (so that the stator is on the carpet) on the basement floor with a piece of carpet. I used a piece of scrap wood between the hammer and the aluminum when I pounded it back down. I did this in several stages, picking it up and examining the 'fit' and making any final wire positioning adjustments before finally having it all back in place. I was also quite premeditated about the wire placements before I prepped the stator phase wires for extension.... which really made this step smooth and easy. keep in mind that putting the stator back on is probably the most likely step to introduce a short of some sort.... but not as likely to mess it up as when trying to do it with the stator still on the base.

I should note that I have bypassed a few 300/400w macs too. But they can be a bit trickier. the hall sensors and sensor circuit board is on the bottom of the stator, next to the controller. and on about half of the ones I opened (5 of 10) had the board in the potting.... and the hall wires are nearly impossible to reuse. I was able to get several of them repaired by putting new wires directly on to the board contacts/original solder points. though this takes some expert solder experience. and the stator HAS to be off the base to get at the board. I used a sharp flat head screw driver and a hammer to crack the potting near the board so that when I went to detach the stator, the board would come with it freely. The power I get from these little 400w motors after being bypassed is quite noticeable and with a 15t sprocket/free wheel or more, it goes about 19-20mph on my scooter at 36v.


Relevant links/threads:
http://endless-sphere.com/forums/viewtopic.php?f=16&t=11772 (basically the same as this thread)
http://endless-sphere.com/forums/viewtopic.php?f=31&t=17683 (Lynn's controller works AWESOME for this and he is very helpful too)

Have you tried running the motor sensorless? When I disassembled my 400W BMC the hall wires were so damned flimsy I tore them apart trying to solder to them, all I have left is the phase wires.

JoramsWeapon said:

Have you tried running the motor sensorless? When I disassembled my 400W BMC the hall wires were so damned flimsy I tore them apart trying to solder to them, all I have left is the phase wires.

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I haven't. but I dont see why the right controller wouldn't work. actually I did try it with a golden motor magic controller. but not with much success (runs wrong).
I have a bypassed 400w for sale if you like. $30 + shipping

The reason I assumed it might now work is because sensorless controllers still need the stator to move in order to send pulses through the phases. This motor is attached to a freewheel and the stator is immobile. I hope that makes sense. Hold that thought about the motor for sale, I want to resolve this possible issue first before getting another one.

JoramsWeapon said:

The reason I assumed it might now work is because sensorless controllers still need the stator to move in order to send pulses through the phases. This motor is attached to a freewheel and the stator is immobile. I hope that makes sense. Hold that thought about the motor for sale, I want to resolve this possible issue first before getting another one.

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you would have to swap out the free wheel for a sprocket.... it's a 8mm d-bore w/10mm collar.

Why dont you detach the stator and repair the wires to the hall sensor circuit board? it's a little tricky if you dont have the right solder and solder gun.... but totally possible. I posted the pic of the contacts on the board. you just have to make sure the potting is not holding it down when you go to take the stator off like I described above.

Well, I managed to extricate the original hall sensor wires that I had nearly destroyed.

I should note that I have bypassed a few 300/400w macs too. But they can be a bit trickier. the hall sensors and sensor circuit board is on the bottom of the stator, next to the controller. and on about half of the ones I opened (5 of 10) had the board in the potting.... and the hall wires are nearly impossible to reuse. I was able to get several of them repaired by putting new wires directly on to the board contacts/original solder points. though this takes some expert solder experience. and the stator HAS to be off the base to get at the board.

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My version 400W bmc/mac is arranged much like your 600W version with the exception of their being two wires per phase instead of four. I still need the planetary reduction that comes with the lashout spoke-drive unit so replacing the d-bore for a sprocket is a no-go. I'll try one more time to strip the hall wires. Did you record the hall/phase combination that consumed the least power at no-load?

I did write down the combinations for Lynn controllers. if you look at my last photo, you can see the colored dots which relate to lynn's colors. But I'm not 100% certain it's right... kinda remember changing it? it's a good place to start anyway.
if you use a volt meter, you can test the AMP flow while testing the combinations. Lynn controllers can handle over 10amps for more enough time it takes to get a reading (which is only takes a couple seconds... the controller can handle 10amps for several minutes easily).

I can explain in more detail if you need.

http://endless-sphere.com/forums/download/file.php?id=82020

Awesome photo that is exactly what I needed to see. I'll try the motor sensored and sensorless, see what I come up with and report back here.

wow the shaft on your motor is really thick! or is that just an illusion? my 600w has a 12mm shaft, which I had machined down to fit a freewheel sprocket I had. on my scooter I top out at 30mph and I can coast about 3 or 4 blocks... and further with the wind on my back (of course).I can run it full throttle with 36v on a 10ah SLA setup for about 6-7miles. but I can get as much as 15 miles on one charge if I slow down and throttle wisely. my next upgrade is to go with a LifePo 48v 20ah battery. The Cycle Analyst is a MUST HAVE if you dont have one already.

Not an illusion it's a much thicker shaft at 17mm and uses 6203-RS bearings as opposed to 6201Z bearings found on the 600W version. You achieved 30mph on 36V with the 600W motor? Impressive! I was going to use 12S lithium (44.4) but it looks as if I can just use 10S and save some weight and reduce charging complexity. Because it's a spoke-drive I don't want to pump more than 800W peak through this motor using a 36V 20A controller and expect a top speed of 20 - 22mph.

yeah 30mph! the torque isn't super high... but it's enough. when I ride it side by side with my other 1000w scooter ( currie direct drive over volted), the 1000w takes the line and feels WAY torqueier... but tops out at about 23mph. but I also get 3-4x the distance when comparing full throttle to full throttle (between the 2).

could someone kindly tell me how to get the stator off the shaft ?

okmate said:

could someone kindly tell me how to get the stator off the shaft ?

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you didn't read the post did you?
read the very first paragraph.

JoramsWeapon: Did you take the stator off or not?

august23 said:

JoramsWeapon: Did you take the stator off or not?

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i'm so sorry i'm so eager

lol
i was just about to delete the post before someone read it
is it best to heat the unit up then try and release the stator as the epoxy is rock hard cold ?

the epoxy (potting) isn't holding the stator... unless the hall sensor circuit board is on the bottom of the stator and was included in the original potting (some are and some aren't). I didn't use heat at all (except for soldering of course). they use LockTite to keep the stator from spinning. as you should too, when you put it back together.

ok i got the stator off and clipped the wires as far down as possible' (the stator came off great with your socket hint )

so all i need to do now is connect the wires i think ?
i did open a post so please have alook and maybe you could advise me

http://endless-sphere.com/forums/viewtopic.php?f=2&t=39366&p=577864#p577864

just read my post in full. and look at the steps in the pics. (for some reason not all the pics are showing a thumbnail... but still have a link). in the 2nd or 3rd pic you can see my phase wire prep job. keep track of your colors... take pics etc.

august23 said:

just read my post in full. and look at the steps in the pics. (for some reason not all the pics are showing a thumbnail... but still have a link). in the 2nd or 3rd pic you can see my phase wire prep job. keep track of your colors... take pics etc.

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thanks mate i did see the pictures but wasnt aware that the wiring should be the same for all controllers thanks again mate

august23 said:

JoramsWeapon: Did you take the stator off or not?

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No I haven't pulled the stator yet. Below are pics of the 400W and 600W MAC/BMC motors. I also want to improve the airflow in the motor as once I pull this thing out I'm going to melt that epoxy with a heatgun and scoop it out like I did with the 400W. This motor is going to get some forced-air cooling on a mid-drive reduction setup similar to how the RC guys do it. The 600W stator has 18 poles with 9 turns per pole and the 400W stator has 18 poles with 12 turns per pole, so the 600W motor has a higher kV. Is there documentation somewhere for this info or do you know what the kV is?

okmate said:

august23 said:

just read my post in full. and look at the steps in the pics. (for some reason not all the pics are showing a thumbnail... but still have a link). in the 2nd or 3rd pic you can see my phase wire prep job. keep track of your colors... take pics etc.

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thanks mate i did see the pictures but wasnt aware that the wiring should be the same for all controllers thanks again mate

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Okmate what power rating or version of MAC/BMC do you have? That has to be the thinnest stator I've seen yet.

JoramsWeapon said:

okmate said:

august23 said:

just read my post in full. and look at the steps in the pics. (for some reason not all the pics are showing a thumbnail... but still have a link). in the 2nd or 3rd pic you can see my phase wire prep job. keep track of your colors... take pics etc.

Click to expand...

thanks mate i did see the pictures but wasnt aware that the wiring should be the same for all controllers thanks again mate

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Okmate what power rating or version of MAC/BMC do you have? That has to be the thinnest stator I've seen yet.

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I have 300w, 400w, and 600w versions. looks like you have the 300w. which you can run at 600w effectively.

and I have only had success with the lynn controller. the only other one I tried was the golden motor's magic controller. there is a thread on here somewhere that shows all the different custom hall sensor placements you can do for different controllers. Im considering trying this myself, because otherwise this controller is sitting here unused.

JoramsWeapon: nice shot side by side like that! I highly suggest taking the stator off if you really want to clean out the potting. I used a drill to get most of it out quickly. but like I said, it really not necessary to take out the potting on the 600w.

it says 300w on the label so i guess i would like a 600 watt controller if that would be ok i guess i need somewhere that sells the controllers
i have managed to get all the epoxy out so will post some more pics tomoz need to pick up some heatshrink to

okmate said:

it says 300w on the label so i guess i would like a 600 watt controller if that would be ok i guess i need somewhere that sells the controllers
i have managed to get all the epoxy out so will post some more pics tomoz need to pick up some heatshrink to

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shrink tubing... yeah great stuff.
there is a link to the controller at the top of the post. just leave a reply to the thread and Ed Lynn will write you back. I have several bypassed 300w's like yours for $30 each.