advice on new controller needed, bmc V1 review

[creativeadapter1990]

I have a diy setup running a BMC V1 "puma" 400 watt rear geared hub on a comfort cruiser frame, and powered by 36 volt 26 amp hour SLA battery bank. I have not weighed the bike but it is very heavy for an aluminum frame. I weigh over 90kg and the batteries weigh 26 kg in total. I ordered the motor kit from ExtremeRC Hobbies in Florida, Initial support was good, providing an alternative 48v compatible twist throttle when told I would be going to doing more motoring than pedaling. Upon request for a VIN they made sure I got a motor with a number cut directly into the metal instead of painted on. Their website has been down for about a year now and I never got an extended warranty, so going to them is out of the question, I am unsure if they are even in business.

A warning about the bolts on The Puma V1: I had two heads shear off under a hand screwdriver the very first time I opened the motor.

Cheap bolts aside workmanship is first class, motor and drive gears are generously lubricated with what I think is white lithium grease. Gears are white plastic, probably a very high grade of nylon, I would prefer steel.

Performance is stellar except on steep hills, motor is quiet but not silent despite having all 3 gears made of plastic and running well greased.

I initially used a stock 25 amp controller but it broke and now all it does is get hot when you attach the batteries to it. I live at the top of a hill so steep that I slow to little more than a walking pace at full throttle and that may have something to do with it.

I am considering replacing it with a 35 amp Infineon controller that has been ruggedized by Grin Technologies: http://www.ebikes.ca/store/store_controllers.php

They cost $130 canadian plus shipping to the northeast US from Vancouver

How good are these controllers and is it worth the premium they cost. I have a long history of cheap components failing me at important times. In fact I had promised the Society of Environmental Scientists at my university a demonstration of my ebike, the aforementioned original controller failed the very morning I was preparing to drive it there to show it off. I have learned the hard way and firmly believe that the stingy pay the most and in terms of safety related items occasionally pay in blood. The twist grip that came with it (from ExtremeRC hobbies) failed the first day I ever ran the bike under power and tore down the driveway at full power and flipped backwards landing upside down, motor still spinning at full speed. I avoided a hospital stay because I was walking the bike, not riding it when this happened. I gave it a twist to get it up a ridge in front of my garage and it shot forward and the twist part of the half twist throttle came off.

Are they compatible with the geared brushless BMC motors and if not what adapters will be needed. I know of no nearby reliable sources for controllers at reasonable prices with good customer service, so long distance shipping is a given.

Would you recommend buying the Grin Cyclery controllers and are there any better options?

 

[neptronix]

Actually i would get one of the cell_man 12FET controllers. The eb3xx is excellent with the big BMC/MAC motors. They are as close to perfect as you're going to get, other than using a big, heavy, no longer produced crystalyte analog controller.
Get the programming cable and set it to about 30-33a and have a blast .. it would never overheat at that level.

It sounds like you overheated your controller running a higher voltage on it. These big geared motors are typically amp hungry.. and the higher voltage you run, the more amps you use at cruise. So you were probably pegging the 25A limit the majority of the time.

 

[creativeadapter1990]

I confess to murdering a cheapo controller.

It was a 36 volt 25 amp controller, I was and am running a 36 volt bank of monster 26 amp hour semi deep cycle powersonic AGM batts. There is a plug you can pull to improve hill performance or run at over 20 mph, on the cheap controller I suspect what does is override the 25 amp limit the mosfets and turn off the legal speed limiter. I think they use are continuous rated at something like 50 or 70 amps each and there are 6 of them in my controller. I used cable rated for 150 amps and 600 volts for battery wire. I weigh over 200 lb and the batteries alone weigh over 55 lb. Said batteries are rated to pull over 300 amps at a mere 20 Fahrenheit until the voltage drops too low to turn a heavily loaded motor. These cell will take loads that will set the same capacity lithium pack on fire. I was riding up a veritable mountain at full speed that slowed me to a walking pace on a sunny day in early fall.

I wonder how many amps I was pulling :lol:

Perhaps the question should be why did it manage to do that so many times before breaking it :wink:

Problem is my house is at the top of that hill, and any bike I ever own will invariably have to scale it, I have no intent of walking a heavy moped up that thing.

Can Cell_Man's controllers survive being derestricted and put to the task at hand pulling just as many amps as I did that day every time I ever come home? Does cell man have a web site if so what url ? How much do they cost? are they stock infineons that are less rugged than the grin cyclery ones. These are serious questions. The controller am looking at supposedly has the mosfets soldered to a solid copper bus bar and solid copper power traces

 

[neptronix]

The controller at the end of the day controls how many amps are drawn, no matter what battery is hooked up at the end. Do you have a watt meter or cycle analyst? you should get one if you are unsure of what's happening, as they will show you that data in real time.

I doubt you were drawing 48v x 70a = 3360W. If you had been doing that for a long time continuous, the gears in your motor would have melted by now.

An ordinary 12FET controller can handle 40-50 amps continuous non-stop, and short peaks up to about 60-70a wouldn't be too much of an issue... as long as said peaks were short but really.. that's too much power for the motor anyway, these geared motors are best at under 2000w.

Anyway the controller you're looking at is basically what cell_man is selling, with some minor improvements, but it could very well be an EB2xx which is quite problematic with the BMC/MAC style motors. You will have to ask them.

I recommended the cell_man controller because it's the smoothest one out of many that i've tried; it is specifically designed to work well with the MAC/BMC style.

His site is here: http://emissions-free.com/.

He lists some controllers in his kits, but not as a la carte items, though i know he'll sell them as individual units, so just contact him.

He also has some 'for sale' threads on this site, thought they might be a bit buried..

 

[DAND214]

The V1 is not a monster! The controller just wasn't any good.

I have 2 V1's one with the 6 fet controller and it still works but gets too hot and shuts down in about 4 miles. The larger controller just blew up. Both being BMC controllers. Now using 9 fet Infinions. 3 years old and still running. No big hills here but they will climb hills without a problem.

As for a 12fet Infinion working, should be an under statement for that setup.

I am running a old 12 fet Infinion stock fets but bigger caps on a 8t MAC with 15s4p LiPo's and it doesn't get warm. Climbs the sled hill with a breeze, only hill I can find close to home.
Will be changing to a new 6fet as soo as Keywin gets them here.


As for the steel gear, it is louder than the plasric but much stronger. I got the gear from Lyen. He also has controllers.

Dan

 

[fechter]

I've seen issues with some controllers on that motor. A controller that is specifically made for the BMC motor is advised or be sure the exact model you are considering has been tested with one of those motors. Most controllers can be made to work, but may have an abnormally high no-load current which wastes power and adds to heating.

I've heard that while the steel gears are stronger, they wear out faster than the plastic ones. One idea is to use one steel gear and two plastic. This way the steel gear prevents the plastic ones from getting stripped, yet wears slower since the load is shared with the plastic ones most of the time.

 

[neptronix]

What Fechter says is so true. You can find many threads on here of people complaining about how crappy their MAC/BMC motors work with infineons, that includes the non-hub types. Even cell_man's previous generation of controllers were not all that great ( jerking and stuttering at partial throttle on higher voltages, and about 1 degree of the throttle rotation worth of power modulation - the motor was either 100% on or 100% off, ). You really do have to get a controller suited for the motor.

A really poor, and non-suitable controller will jerk/stutter throughout the RPM range and do other awful things, resulting in a very early death of the clutch and/or gears.

Forget those steel gears, those are outdated and noisy as hell and i would not be surprised if they ate at the sun gear or left metal shavings in the lubricant over time if you failed to do an 'oil change' :lol: . BMC and MAC have both came out with better gears since then. the gray gears from cell_man ( from MAC ) are stupidly cheap. Or you can fork over for the $$$ BMC clutch + gear assy since the original BMC clutch design has some flaws.

 

[creativeadapter1990]

Does Cell_Man have a web site and what controller of his should I buy, and what does he charge?

 

[neptronix]

see my post about 4 posts up.

 

[creativeadapter1990]

Found someone selling the newest sensorless crystalyte controllers, very expensive but would they be a better match?
It's just they want $200 for the 40 amp 36 or 48 volt unit. They replaced the mosfets; the new mosfets are continuous, not peak rated at 100 volts and 100 amps PER EACH TRANSISTOR! there are 12 of them soldered directly to the heat sink. Capacitors the size used in camera flashes.
THAT ought to get me up the hill!

I think I would leave the 40 amp limit where it is on that one. That thing is just too hot to handle.

I would probably be better with the 25 amp version that only has 6 of the 100 amp continuous mosfets. I am sure there is a lot of room to derestrict

ALSO:

I did an advanced search for controller author Cell_Man in new for sale. not a single controller at least on it's own. Something doesn't feel right.

 

[neptronix]

Sensorless controllers won't work on a geared motor that was not designed for it. I cannot think of a worse controller to use.

Like i said in my post 5 posts up, he sells a kit with customized infineon controllers on his site. you can buy those controllers seperate. He is a small 1 man operation.

If you still don't feel confident, at the very least ask lyen or ebikes.ca if their controller is an eb3xx, and are customized to work with BMC/MAC motors. Many people have reported that stuttering is a problem with those controllers however. But there is at least 1 person who doesn't have a problem, out of many who do.

If you don't feel confident in that still, get a crystalyte analog controller if you can find one.

Read about my MAC build here. ( Our motors experience the same problems and have the same stator/windings, same gears etc. So whatever you read about a MAC is applicable to a BMC. )

http://endless-sphere.com/forums/viewtopic.php?f=6&t=25889

 

[fechter]

I ran my BMC motor with a Castle Creations HV140 sensorless controller and it seemed to work quite well, so I'd say with the right sensorless controller it may be a good match. A sensorless controller will take care of the timing advance issue that causes problems with most sensored controllers.

 

[Icewrench]

My BMC v1 400 watt motor was unimpressive to me on 36 volts 20 amps and set it aside for a while. Then I put it on a lighter frame and fed it 48 volts still @ 20 amps now i like it alot. It is powered with a 9 fet infineon controller and is pretty good, but flat out at top speed the motor becomes noisey. I just back off the throttle a touch and the noise goes away. The controller and motor are not a perfect match for some reason.

 

[creativeadapter1990]

I am going to call grin cyclery and see what they have to say about issues with the Bmc and their controllers; the modded infineons, and the sensorless crystalytes which they claim will work with a motor that normally uses hall sensors. The website mentions that the infineons have the same connectors as the bmc, right down to the color codes of the wires.

 

[neptronix]

My BMC v1 400 watt motor was unimpressive to me on 36 volts 20 amps and set it aside for a while. Then I put it on a lighter frame and fed it 48 volts still @ 20 amps now i like it alot. It is powered with a 9 fet infineon controller and is pretty good, but flat out at top speed the motor becomes noisey. I just back off the throttle a touch and the noise goes away. The controller and motor are not a perfect match for some reason.

Try 30 amps and call me in the morning. You're not even making that motor sweat