Locking clutch/freewheel in geared hub motor for regen?

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Aug 16, 2016
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I could not find any answers to this question...

Is there any examples of a sucessfull modification of a MAC geared hub motor (or similar) where the clutch/freewheel has been "locked" so that the motor can be used for regen as well?

I have a MAC myself but would like regen...
 
of course it will work. putting epoxy in it may not work though. there is a lot of grease in it. getting all that out before applying the epoxy can be impossible to do.
you can easily weld it all together.
but i wouldn't do that. it will add A LOT of drag to the motor if unpowered. with it's 5:1 gearing the motor runs at quite high rpm ...
 
Yes, the few that I read about doing it melted the gears from the constant high rpm with the motor never getting to cool due to the regen.
Not saying it can't be done, esp if you had one with a blown clutch laying around to mess with.
 
A geared motor with locked gears is a direct drive motor. Just keep it simple and get a direct drive motor. Available from 150 watts to over 5000 continuous.

Tom
 
Thanks for all the quick replies:)

Drag: when turning the wheel backwards I notice only slightly more drag than my Golden motor DD motor, so I does not consider drag as a major drawback

Locking: Yes welding seems to be a better option than epoxy, thanks!

Melting gears: this seems to me as the biggest issue. I have the newer MAC motor. There was a change in gear types some years ago. Does this matter, or are the new gears just as much exposed to melting..?

DD: yes I would rather like a direct drive motor, but since I allready have a geared one I should use that one...
 
Over the years, a couple of members here have "locked-up" geared mini motors because of clutch failures and neither of them liked the results.
It's hard for me to see the reasoning of what you want to do, especially since the MAC is a very desirable motor, worth at least 2 times the value of the inexpensive 9C DD motors (since you haven't filled out your profile, we don't know where you are at, but in the States, you can buy a 48V 500/1000 Watt DD kit starting at $150).
Besides, regen is over-rated and most of the time it's biggest benefit is reducing wear on the brakes.
Why not sell the MAC and buy a DD motor?
Or keep the MAC, because after you try a DD motor you may well want to go back to the MAC.
 
Thanks for sharing your opinions motomech! I live in Norway. Here the market is not as large as in the states, and we have to pay a lot in shipping + taxes when importing things:-/ I bought the MAC realtively cheap at the second hand market (but the motor kit is not used)

I have desided to build the MAC into my bike with or without a locked clutch. I like the idea of charging when braking because here my town we have A LOT of hills. And I wear out my brakes all the time..
 
litespeed makes a valid point: if you want regen: get a DD. if you want a small package sized high torque motor for a bike: go for the MAC.
the problem i see with welded freewheel: you add complexity to such a simple design, which an electric motor is, by adding gears and a freewheel, and then you weld it.
one big issue the MAC (and every other small geared motor) has: they have an additional layer of metal (the outer case) with insulation air between the motor and the case. this makes cooling very difficult. this is no big deal if you keep the power at "legal" levels, but if you start hotrodding it becomes imminent. and if you then weld the freewheel the motor is 100% powered. normally the motor has some time too cool down when you coast or brake, but with the welded freewheel it will jump between motor and generator all the time. and both produces heat. you can choose how much heat, by programming the controller, limiting phase amps and limiting braking power, but why choose the use regen when you limit it afterwards?!
 
I contacted em3ev and they sendt me a fixed plate "clutch" from the MAC producers (see attachment).
The bike works fine with the fixed plate, and very little drag. But the regen current could been higher (approx 4A at 55V). I use infineon 9 fet 3077 controller and have programmed it using the 12fet setup as described by em3ev. There is three regen levels to choose, but not much noticable difference I think. Is there any way to modify the controllers to give higher regen current/power?
 
Go with our OpenSource firmware where you can define the max regen current.

I even put my ebike regen working like coast brakes:

https://opensourceebikefirmware.bitbucket.io/development/Various--2017.12.01_-_Regen_ebrake_like_coast_brakes.html
 
bendik.vignes@gmail.com said:
But the regen current could been higher (approx 4A at 55V).
Using the S06S controller, 15 Amps max current, I defined max regen current to be also 15 Amps and the bike brakes a lot!! :)
Seems 15 amps for regen is ok if only for some seconds, not to use on long downhills.

Here a video showing fast ebrake:
[youtube]m-Ha64Rqd70[/youtube]
 
Thanks for the link casainho! Looks like it is a lot of interssting information on that site!
I must admit I am a dummy especially when it comes to software and computers:-/ So if this open source software does not have a very simple interface, I might have problems using it;) Does this software work fine with my infineon 3077 controller and the usb adapter i got from em3ev?
I also found this thread: https://endless-sphere.com/forums/viewtopic.php?f=30&t=72165
I will try to try to raise the current limit in the controller program (from 30A to 60A for example) and see if that also alters the current for regen. I use a Cycle Analyst V3 that limit the motoring current/power, so it should be ok to increase the current parameter in the controller I believe. If this does not help, I could also try to modify the shunt in the controller as described in the thread (but then I need to change the shunt resistance in the Cycle Analyst...

Merry christmas to all:)
 
bendik.vignes@gmail.com said:
Does this software work fine with my infineon 3077 controller and the usb adapter i got from em3ev?
This OpenSource firmware/embedded software runs on the BMSBattery S/Kunteng KT EBike motor controllers.
The main advantages of this controllers are:
1. sine wave/"FOC": motors run silent and very efficient
2. cheap: starting at 20€
3. widely available: many online shops sell them and ship to worldwide
4. various sizes e powers: from 0.25kW up to 5kW (72V, 70A, 24 mosfets)
5. supports LCD and Bluetooth mobile app
6. schematic available: important if you want to mod/hack, repair or even build your own controller
7. generic brushless motor controller: can work as a generic brushless motor controller and be commanded by an Arduino or other similar external microcontroller board. This feature is only available when using our OpenSource firmware.

The main advantages of our flexible OpenSource firmware/embedded software are:
1. sine wave/"FOC" max efficiency: motors run silent and very efficient and is possible to tune a parameter to get the best efficiency possible for a specific motor
2. flexible and OpenSource: more than customization, any feature for some specific need can be easily implemented and for free (no need to pay any commercial license)
3. throttle, PAS and torque sensor: all of them are supported
4. LCD3 and LCD5: all of them are supported
5. regen/ebrake: works very well on the direct drive motors
6. motor torque controller/motor current controller
7. motor speed controller
8. generic brushless motor controller: using the UART connection (the same that is used for the LCD and Bluetooth module), this controller can work as a generic brushless motor controller. Can be commanded by an Arduino or other similar external microcontroller board.
 
Thanks for the advices casahino! I will consider that if I cannot get my infineon to behave..

I tested a bit more and found someting strange: regen torque is much higher when the wheel turns backwards...!
Anyone know what is wrong?
 
so doing this in a oil (ATF) cooled motor will work fine right, my myatu clutch is slipping and i run it on throttle 99.7% of the time anyway (still help with pedels), but will take too long to get clutch home and bike "works" but takes forever to get up to speed and makes a hell of a racket doing so, seems like at the moment it will only take 3-400W before slipping, so i have no other choice then to weld it or drill it so i have it working fully, thought i broke the nylon sprockets but they are still ok, worn down some after about 7000km, but clutch is slipping now... and this happend after about 50km after putting 14S battery on it vs stock 10S
 
litespeed said:
A geared motor with locked gears is a direct drive motor. Just keep it simple and get a direct drive motor. Available from 150 watts to over 5000 continuous.

Tom

Well, the future proved you wrong I guess
 
litespeed said:

Well a geared motor is very different than a direct drive, it has a lot of torque to get going from a start compared to DD. Also, it can be made quite lighter. The GMAC now has regen capabilities since it cannot freewheel, and a lot of break torque since it also used the mechanical advantage of the gearing. That's what I meant to say. The only thing I wish for the future is that they'd make a beefier one that could handle a little more power ( about 2000W peak). I'm currently getting away with 1400W peak and 15A max regen. The motor is getting in the 100s °C, but been consistently using it that way and I'm up to 7500km on it now, so far I haven't noticed any degradation. Pretty impressive.
 
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