Search found 154 matches

by hias9
Apr 25 2020 5:41pm
Forum: E-Bike Technical
Topic: Measuring airflow to optimize cooling of hub motor
Replies: 19
Views: 486

Re: Measuring airflow to optimize cooling of hub motor

I mean if somebody made simulations for a rear hub motor ebike using existing programs. Yes, doing that would be very time consuming I think and probably not worth the effort. Better just trial and error and test it practically. Is anybody using sheets to direct air to the hub motor and did you noti...
by hias9
Apr 25 2020 7:18am
Forum: E-Bike Technical
Topic: Measuring airflow to optimize cooling of hub motor
Replies: 19
Views: 486

Re: Measuring airflow to optimize cooling of hub motor

Well, I guess you are right. It's much easier to try to make 2 comparable runs while only measuring motor temperature.

Are there any Fluid Dynamics simulations available for larger hub motor bikes?
by hias9
Apr 22 2020 8:21pm
Forum: E-Bike Technical
Topic: Measuring airflow to optimize cooling of hub motor
Replies: 19
Views: 486

Re: Measuring airflow to optimize cooling of hub motor

Wow, there are really a lot of different ideas/approaches here. Thanks! The idea is optimizing cooling at higher speeds (about 60mph). The motor is a 3kw hub motor with Statorade and Hubsinks. Of course it has a temperature sensor and temperatures are monitored. Just measuring motor temperature woul...
by hias9
Apr 17 2020 10:14am
Forum: E-Bike Technical
Topic: Measuring airflow to optimize cooling of hub motor
Replies: 19
Views: 486

Re: Measuring airflow to optimize cooling of hub motor

Not really. I would need some kind of sensor I could mount on the hub motor or hubsinks and it should log data. I did not find anything that would do the job.
by hias9
Apr 16 2020 10:52pm
Forum: E-Bike Technical
Topic: Measuring airflow to optimize cooling of hub motor
Replies: 19
Views: 486

Measuring airflow to optimize cooling of hub motor

I am looking for a way to measure air velocity on a certain spot (like somewhere on the hub motor/hubsinks) to optimize cooling.

My plan is to make sheets that direct air to the hub motor to improve cooling at higher speeds.
by hias9
Mar 16 2020 9:21am
Forum: E-Bike Technical
Topic: Bafang G310 geared hub - 11:1 reduction ratio!!!
Replies: 174
Views: 32983

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

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.
by hias9
Mar 15 2020 11:32pm
Forum: E-Bike Technical
Topic: Bafang G310 geared hub - 11:1 reduction ratio!!!
Replies: 174
Views: 32983

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

P2 should be 6 because it has 6 pulses per turn. It worked fine for me.
by hias9
Mar 14 2020 3:53pm
Forum: E-Bike Technical
Topic: Bafang G310 geared hub - 11:1 reduction ratio!!!
Replies: 174
Views: 32983

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

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 moto...
by hias9
Mar 13 2020 6:59pm
Forum: E-Bike General Discussion
Topic: Where to get those Bearing Standoff Rings for Hub Motors
Replies: 1
Views: 289

Where to get those Bearing Standoff Rings for Hub Motors

I think there are one or two of those thin bearing standoff rings missing on my Bafang G310.

Image

Does anybody know where to get those rings which are used in hub motors?
by hias9
Mar 13 2020 6:45pm
Forum: E-Bike Technical
Topic: Bafang G310 geared hub - 11:1 reduction ratio!!!
Replies: 174
Views: 32983

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

I did not change it. I think default value was zero and worked fine.
by hias9
Mar 13 2020 5:01pm
Forum: E-Bike Technical
Topic: Bafang G310 geared hub - 11:1 reduction ratio!!!
Replies: 174
Views: 32983

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

Yes, it is working fine. Do you mean the parameter for the number of magnets (P1)? It should be 16*11.1=178
by hias9
Mar 13 2020 3:53pm
Forum: E-Bike Technical
Topic: Bafang G310 geared hub - 11:1 reduction ratio!!!
Replies: 174
Views: 32983

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

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?
by hias9
Feb 26 2020 12:41am
Forum: E-Bike Technical
Topic: Bafang G310 geared hub - 11:1 reduction ratio!!!
Replies: 174
Views: 32983

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

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
by hias9
Jan 09 2020 3:11pm
Forum: E-Bike Technical
Topic: Bafang G310 geared hub - 11:1 reduction ratio!!!
Replies: 174
Views: 32983

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

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 concr...
by hias9
Jan 09 2020 12:29pm
Forum: E-Bike Technical
Topic: Bafang G310 geared hub - 11:1 reduction ratio!!!
Replies: 174
Views: 32983

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

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.
by hias9
Jan 09 2020 2:04am
Forum: E-Bike Technical
Topic: Bafang G310 geared hub - 11:1 reduction ratio!!!
Replies: 174
Views: 32983

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

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?
by hias9
Jan 09 2020 12:23am
Forum: E-Bike Technical
Topic: Common signal cable for both speed and temp sensor
Replies: 13
Views: 505

Re: Common signal cable for both speed and temp sensor

Thanks a lot. I will get some small capacitors and try it soon.

It behaves like this:

0 rpm, sensor voltage: 2.45V
Motor turning, no-load: 2.3V (with load it would be the same)
Motor stops turning: 2,2V for a split-second
0 rpm: 2.45V
by hias9
Jan 08 2020 11:17pm
Forum: E-Bike Technical
Topic: Common signal cable for both speed and temp sensor
Replies: 13
Views: 505

Re: Common signal cable for both speed and temp sensor

Thanks, but this also happens when there is only a thermistor and no speed sensor at all.
I have this effect also on my direct drive motors.
Also it does not seem to be much related to how fast the motor is turning.
by hias9
Jan 08 2020 10:55pm
Forum: E-Bike Technical
Topic: Common signal cable for both speed and temp sensor
Replies: 13
Views: 505

Re: Common signal cable for both speed and temp sensor

On all controllers with a temp sensor input I tried so far, the shown motor temperature was lower when the motor is turning. Could anybody explain why? Usually the temperature will not be more than 10 degrees celsius lower, but with this setup using a 5k or 10k PTC thermistor, the temperature would ...
by hias9
Jan 07 2020 10:11pm
Forum: Items for Sale - New
Topic: Compact Field Oriented Controller, ASI + Grin, limited run
Replies: 1239
Views: 249736

Re: Compact Field Oriented Controller, ASI + Grin, limited run

I have compared the noise of a Bafang G310 powered by an ASI BAC500 against a sinewave KT controller. The result was that both subjective and measured noise level was clearly lower with the KT controller. Measured (with an iPad, so don‘t take the values too serious) from about 70cm away at 200rpm: A...
by hias9
Jan 06 2020 7:21pm
Forum: E-Bike Technical
Topic: Common signal cable for both speed and temp sensor
Replies: 13
Views: 505

Re: Common signal cable for both speed and temp sensor

Thanks. There are some 10k PTC thermistors available and these should do the job.
by hias9
Jan 06 2020 5:40pm
Forum: E-Bike Technical
Topic: Common signal cable for both speed and temp sensor
Replies: 13
Views: 505

Re: Common signal cable for both speed and temp sensor

If the resistance (wired between signal and GND) of the thermistor is always higher than about 4kOhm, the speed sensor works fine. It should also be a thermistor which has increasing resistance with increasing temperature (like Kty, not like 10k ntc). Are there any thermistors that meet those requir...
by hias9
Jan 05 2020 10:52pm
Forum: E-Bike Technical
Topic: Common signal cable for both speed and temp sensor
Replies: 13
Views: 505

Re: Common signal cable for both speed and temp sensor

Yes, the alternative if I cannot get it working is to use an external speed sensor and use the signal cable for the temp sensor instead of the speed sensor. Just wondering if it can be done without an external speed sensor. I have used kty and ntc sensors (resistances that vary with temperature) so ...
by hias9
Jan 05 2020 9:18pm
Forum: E-Bike Technical
Topic: Common signal cable for both speed and temp sensor
Replies: 13
Views: 505

Re: Common signal cable for both speed and temp sensor

On the ASI I have tested to wire a resistance in series with the signal cable. What happens is that while there is no speed sensor pulse, the voltage is the same as without the resistance in series (a bit less than 5V). While there is a speed sensor pulse, voltage is higher than without the resistan...
by hias9
Jan 05 2020 6:59pm
Forum: E-Bike Technical
Topic: Common signal cable for both speed and temp sensor
Replies: 13
Views: 505

Common signal cable for both speed and temp sensor

Is it somehow possible to wire a temperature sensor to a motor with an existing speed sensor without having to add an additional signal cable? So that voltage between signal cable and GND would be some voltage (maybe 2.5-5V) which corresponds to a certain temperature when there is no pulse from the ...