Bafang G310 geared hub - 11:1 reduction ratio!!!

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john61ct   100 GW

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by john61ct » Oct 16 2019 2:43pm

Interesting idea, would like to see this discussed in greater depth.

Worth its own dedicated thread though
zukster wrote:I just built a little throttle cutoff harness for over-volted/watted motors that uses a mini 5v thermostat board, that cuts off the throttle when the motor internals hit 120 degrees Celsius.

LM YN Digital Thermostat Module DC 5V -10℃ to +210℃ Electronic Temperature Control Module Switch Waterproof Sensor Probe Dual LED Display Red+Green

https://www.amazon.com/gp/product/B01M1 ... UTF8&psc=1

The board works off 5v and can use the VCC of the throttle wire to power the board. Then the board relay cuts off power to the throttle when over 120 degrees. Works like a charm.

I made a throttle cable harness that can be easily removed if the board dies on a ride.

The beauty about this is that you can use the throttle wires to both power the board and cut-off the throttle, making it a somewhat clean setup. I prefer this over techniques that cut off power to the motor or controller.

You have to open the motor, epoxy the thermostat to the windings, and poke the wire out of the existing hall/phase hole. Next I'm going to install the board into a clear plastic case to semi-waterproof it.

Image

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zukster   1 kW

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by zukster » Oct 16 2019 3:11pm

I'll post it to its own thread once I install it into a clear case and take some pictures. Its pretty simple.

Also, for those who are concerned about cutting off the throttle unexpectedly, many of these boards have an alarm buzzer.

When the temp gets above 120 or so, you can set it up to sound the alarm only. You don't have to use the relay. Come to think of it, I might actually prefer that too as long as I can hear it okay. Maybe putting the board under the seat would be loud enough.

Anyway, this is not the thread for this. I'll start its own thread in a bit.

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by 1N4001 » Oct 16 2019 3:25pm

zukster wrote:
Oct 16 2019 12:31pm
You need to get the wire out where the phase/hall wires come out. If you can't do that, it won't work.
Yes, I'm aware. We are talking about the G310, correct? I can't tell how you managed to route them out.

https://i.imgur.com/mdgisRG.jpg

Here's the stator. On the bottom is where the phase wires come in. I'm assuming you glued your temp sensor onto the coils on this side? How did you route the sensor wires back to the other side? There's little room, seeing as the rotor will be occupying the middle of this assembly. Did you route in between the stator teeth maybe?

https://i.imgur.com/GHw7cmm.jpg

And here's the other side, where we trying to get to. Did you remove all this potting around the phase/hall wires to add the thermistor wire?

Thanks!

john61ct   100 GW

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by john61ct » Oct 16 2019 4:05pm

zukster wrote:I'll post it to its own thread once I install it into a clear case and take some pictures. Its pretty simple.

Also, for those who are concerned about cutting off the throttle unexpectedly, many of these boards have an alarm buzzer.

When the temp gets above 120 or so, you can set it up to sound the alarm only. You don't have to use the relay. Come to think of it, I might actually prefer that too as long as I can hear it okay. Maybe putting the board under the seat would be loud enough.

Anyway, this is not the thread for this. I'll start its own thread in a bit.
Great, just link back to your post above as well.

The ideal is two adjustable setpoints, one for audio/visual alerts, the next for actual cutoff, if not ramping down.

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zukster   1 kW

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by zukster » Oct 16 2019 4:59pm

1N4001 wrote:
Oct 16 2019 3:25pm
Yes, I'm aware. We are talking about the G310, correct? I can't tell how you managed to route them out.
https://i.imgur.com/mdgisRG.jpg
I did this on a Cute 100 CST and may do it on a G370 rear as soon as I can get my hands on another one. I had problems with the G370 I was working on. For the Cute 100, the wires come out the very end of the axle. For the G370, it looked like there was room where the main cable came out. I don't have a G310, but I think its similar to the G370. If you want this to work you need to try to squeeze the thermistor wire through the hole where the main wire exits the motor.

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by hias9 » Jan 09 2020 2:04am

To look for a spot for a temperature sensor, I have disassembled the case of my G310 like in Justin's video which was very easy.
However I cannot separate the motor+gear from the freewheel by hand (in the video it works with minimal force). Is this normal?

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by amberwolf » Jan 09 2020 3:48am

is there a circlip retaining ring (may look like a thin washer) on the shaft preventing it?

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by hias9 » Jan 09 2020 12:29pm

Yes, there is a circlip retaining ring, but it is on the left side (motor/gears side).

The flywheel side looks like this after I have removed the nut:
Image
The metal part below the nut has flats, but it is not possible to grab them.

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by drdrs » Jan 09 2020 3:07pm

I had to remove that second nut to get it open. I agree it is hard to access with a normal wrench.
viewtopic.php?f=6&t=101184
5kW ASI 2000, Crystalyte, Vruzend

viewtopic.php?f=6&t=104324
VESC, MG 310, Vruzend

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by hias9 » Jan 09 2020 3:11pm

Ok, the metal part with the flats was a second nut. There was minimal space to grab the flats, but after that you can easily separate the 2 parts.

Now I am struggling to get the case back on. I just cannot get the bearing on the cable side back to where it should sit. Even not by pressing on a concrete floor or with a 3-arm puller.

edit: Well, it worked by pressing the axle on a concrete floor with some angle to get the bearing on its place on the axle.

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by rheo » Feb 16 2020 6:35am

Where can I buy this thing in a wheel or kit without battery other than grin? nothing against them but I'm in Australia and the shipping from Canada is expensive

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by hias9 » Feb 26 2020 12:41am

After my G310 was running a bit without load on the bench (not above 42 kph), it started squeaking.
Do you think it's the bearings which are squeaking?

Videos:
https://streamable.com/rzq58
https://streamable.com/nbtb6

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by hias9 » Mar 13 2020 3:53pm

My G310 only had one bearing standoff ring on the left (cable) side and none on the right side.
The G310 in the Grin video has 2 bearing standoff rings on the right.

How was it on your G310s?

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by qwerkus » Mar 13 2020 4:34pm

Hello, anyone succeeded running a g310 with a kt controller on stock firmware ? Which parameter did you use ?

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by hias9 » Mar 13 2020 5:01pm

Yes, it is working fine. Do you mean the parameter for the number of magnets (P1)? It should be 16*11.1=178

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by qwerkus » Mar 13 2020 6:12pm

hias9 wrote:
Mar 13 2020 5:01pm
Yes, it is working fine. Do you mean the parameter for the number of magnets (P1)? It should be 16*11.1=178
Awesome - thanks! And what do you use as c2 parameter ?

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by hias9 » Mar 13 2020 6:45pm

I did not change it. I think default value was zero and worked fine.

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by hias9 » Mar 14 2020 3:53pm

I had a squeaking noise on my G310 which was caused by the black rubber ring on the cable side. I put some silicone spray on it and the squeaking noise was gone, but the rubber ring is not staying in place because it is too elastic. The rubber ring makes one turn about every 30 seconds when the motor is running without load.

Do you guys have the same issues? I think I will just remove the rubber ring.

edit: I have glued the ring to the axle and it is working fine so far.

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by qwerkus » Mar 15 2020 4:51pm

Tried it today: g310 + kts controller 6Fet hailong integrated @48V. Pretty much plug and play, though the motor seems a bit noisy when compared to some youtube videos. I'm going to try other c2 parameters. Also, any chance to get pwm speed (p2) somehow accurate ? Right now the display shows only motor speed, which is 0 when coasting or pedaling.

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by hias9 » Mar 15 2020 11:32pm

P2 should be 6 because it has 6 pulses per turn. It worked fine for me.

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by qwerkus » Mar 16 2020 5:38am

hias9 wrote:
Mar 15 2020 11:32pm
P2 should be 6 because it has 6 pulses per turn. It worked fine for me.
Hmmm. My speedometer stays at 0 not matter what. Tried 2 different displays without success. Could it be a mismatch between the bafang 910 connector and the kt connector (speed signal on the wrong wire?). It proved awfully difficult to plug into each other. Otherwise only explanation would be a defective speed sensor in the motor, but that would be surprising for a brand new unit.

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by hias9 » Mar 16 2020 9:21am

For my G310 it was basically plug and play (and set parameters) to match with a KT controller. White cable is the speed sensor cable.

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by oger » Apr 11 2020 5:17am

I got the G310 finall running with VESC.
Pretty good result actually. Real quiet.
But a bit slow.
I'm running a 12s 44v Pack and have 28" Wheels.
Does anyone know how to tell which version of the motor I have?
There are supposed to be 3 versions.
Can I tell by the writings on the motor?
I bought it here:
https://motowoks.com/collections/electr ... 6834568310

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by mongrol » May 21 2020 9:04am

rheo wrote:
Feb 16 2020 6:35am
Where can I buy this thing in a wheel or kit without battery other than grin? nothing against them but I'm in Australia and the shipping from Canada is expensive
Did you find one?

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Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Post by rheo » May 22 2020 8:10am

Yeah I bought it unlaced from grin. Had my local bike shop build it into a wheel here. Shipping was a bit cheaper that way.

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