Edit: GMAC in stock now

[zdoor]

Been waiting on a GMAC hub since September. It was delayed again yesterday. New expected arrival is 11/30. Really want this motor and built my bike with this motor in mind. But getting frustrated it keeps getting pushed back. Any good alternatives than would still provide regen braking?

Edit: ETA now shows 11/10!

 

[neptronix]

I don't know of any other geared motor on the market that has a fixed clutch, other than maybe an "aliexpress special".

IMHO The GMAC is worth waiting for, we also are seeing goofy stuff happen in China due to their zero covid policy, so this is just going to be a bad season for ebike parts again.. my suggestion is to hang in there.

 

[electric_nz]

You could always experiment with a cheap and cheerful Bafang BPM. These are nominal 500W at 48V but don’t even get warm at 1000 and many here have experience running them at 1500W for extended periods.

No regen but perhaps you could weld them up?

 

[zdoor]

Actually thought about ordering a cheap motor/wheel but seems like a waste. I do have my wife’s bike as my next project but that’s going to be a beach cruiser with a front hub. So don’t think I could buy something I could throw in that later. Looked at Grins rh212 kit. Which looks like a nice motor. But, don’t think that will work in my wife’s bike down the road…

 

[zdoor]

So was poking around Grins site and spent a little time on their motor simulator. Comparing the GMAC8T to the RH212 Fast Wind, both with the same parameters, I was surprised the RH212 ran cooler by a significant amount and had nearly the same performance numbers… Maybe I dismissed DD motors too quickly…

 

[neptronix]

DD motors as a whole have many times better heat dispersion because the case acts as a heatsink ( magnet ring has direct contact with the case; stator coils are also very close to the case ).

This is the achilles heel of the geared motor for high power use; the motor is in the center, only having direct contact with the axle. Heat dispersion is 25-50% as good as a DD..

RH212 is a particularly light DD motor for the power it puts out and if you have a 26" or taller wheel, it'd be a good motor because it has a little higher pole count than most DDs - it should produce good low end torque as a result. Not a bad alternative.

 

[pwd]

So was poking around Grins site and spent a little time on their motor simulator. Comparing the GMAC8T to the RH212 Fast Wind, both with the same parameters, I was surprised the RH212 ran cooler by a significant amount and had nearly the same performance numbers… Maybe I dismissed DD motors too quickly…60AB12D5-1E7F-416E-8169-750F67D583F1.png5496D70C-5724-4CC4-8F7D-E30D0C8B8F66.pngBD37A0BC-78C9-4AC1-A722-8BE77E5F1EC8.png

Maybe you just selected it for the simulator sake but I'd choose a controller with more phase current than the baserunner if you plan to use either motor at those input power levels ... that flat torque line shows what I'm referring too
EDIT: That will also give you a more apples to apples comparison of the motors

 

[zdoor]

The baserunner is the controller I already have. Trying to stick with that…

 

[zdoor]

So was poking around Grins site and spent a little time on their motor simulator. Comparing the GMAC8T to the RH212 Fast Wind, both with the same parameters, I was surprised the RH212 ran cooler by a significant amount and had nearly the same performance numbers… Maybe I dismissed DD motors too quickly…60AB12D5-1E7F-416E-8169-750F67D583F1.png5496D70C-5724-4CC4-8F7D-E30D0C8B8F66.pngBD37A0BC-78C9-4AC1-A722-8BE77E5F1EC8.png

Maybe you just selected it for the simulator sake but I'd choose a controller with more phase current than the baserunner if you plan to use either motor at those input power levels ... that flat torque line shows what I'm referring too
EDIT: That will also give you a more apples to apples comparison of the motors

I see what you’re saying though. On flat ground there was not much difference in controllers. But with grade I can see the difference.

 

[neptronix]

RH212 can handle 60 amps, maybe more in bursts.... yeah, you'll want a bigger controller than a baserunner.

 

[zdoor]

RH212 can handle 60 amps, maybe more in bursts.... yeah, you'll want a bigger controller than a baserunner.

So the drawback for now is current is limited by the baserunner which limits torque, correct? If I went with the setup I have and upgraded later, the current would be limited by the base runners settings but wouldn’t be at risk of frying controllers or worse?

 

[neptronix]

Yep, that would limit torque output, and some motors will run inefficiently if you don't feed them enough power. I'm not sure what a realistic continuous current for the baserunner is, but it's not a particularly strong controller to begin with.

Beating a controller to the edge of it's limits can overheat it and bad things can happen, yup.. but i believe the baserunner may have thermal rollback ( lowering the amps ) when it gets too hot ( check grin's site ).

You'll want a bigger controller for either of these motors.

 

[electric_nz]

Could look at the new Bafang 1000w geared Hub

https://www.endless-sphere.com/forums/viewtopic.php?f=3&t=115726

 

[zdoor]

Saw this AM that the GMAC is now expected to arrive 10/11 which isn’t too bad… no just got to make up my mind on what I’m doing…

 

[zdoor]

So my original plan was the GMAC 8T paired with the baserunner after talking to Grin about options. Torque limiting based on the baserunner limits still come into effect with this option. Did confirm thermal rollback is there to prevent overheating of controller. But, I’ll probably want to upgrade controller at some point to squeeze everything I can out of the setup. But I’m thinking I’ll probably still go with the GMAC setup.

Getting a better understanding of the motor simulator now. Didn’t even realize the torque limit issue was showing, even though I’ve stared at that graph a hundred times lol

 

[neptronix]

The GMAC can take a lot of power.. i used to run a 2011 version of the MAC 8T at 40 amps / 57v.. the fun starts at 35 amps irregardless of voltage.. i recommend stating with a bigger controller..

 

[zdoor]

The GMAC can take a lot of power.. i used to run a 2011 version of the MAC 8T at 40 amps / 57v.. the fun starts at 35 amps irregardless of voltage.. i recommend stating with a bigger controller..

Just a matter of budget. Will stay baserunner until I can replace it for a more powerful controller. Will probably use the phaserunner and move the baserunner I already have to my wife’s bike which I’ll be putting a front motor on after this bike is done.

Edit: Actually should say leaning phaserunner controller as an upgrade to baserunner. Been happy with the grim products and the fact they took time to answer my barrage of likely stupid questions. But will do some research and get feedback here which has been an excellent spot to learn!

 

[Triketech]

I happen to have a MAC 10T 26" rim + 10Spd Cassette with a Phaserunner, CA3, Thun Torque Sensing Hub sitting on a shelf that needs a new owner. It has about 1000 miles on it and is in great shape. Cabling is custom length for an HPV Scorpion FS26.

I paid over $1000. $500. Send me a PM if interested.

Here is an article on the trike before the Phaserunner was added.

http://www.triketech.com/Drivetrain/PowerAssist/HPV-MAC.html

 

[zdoor]

I happen to have a MAC 10T 26" rim + 10Spd Cassette with a Phaserunner, CA3, Thun Torque Sensing Hub sitting on a shelf that needs a new owner. It has about 1000 miles on it and is in great shape. Cabling is custom length for an HPV Scorpion FS26.

I paid over $1000. $500. Send me a PM if interested.

Here is an article on the trike before the Phaserunner was added.

http://www.triketech.com/Drivetrain/PowerAssist/HPV-MAC.html

Going with a GMAC for current build as I need the regen. But doing another after this one and interested. Sent you a PM