Search found 359 matches

by hias9
May 23 2022 9:10pm
Forum: EBike Technical
Topic: Hole Shot Device / Lower Fork Travel
Replies: 1
Views: 19

Hole Shot Device / Lower Fork Travel

I am looking for a device (or ideas to build it) which significantly lowers my fork‘s travel while riding so I can use more torque without wheelieing when accelerating from a standstill or out of corners or when accelerating uphill. The only available system I found is called leveLOC (just google it...
by hias9
May 23 2022 4:11pm
Forum: Stand-up EScooter/ESkateboards
Topic: Hub motor magnets
Replies: 11
Views: 771

Re: Hub motor magnets

It's not free power. With stronger magnets on a hub motor you have decreased copper losses because you need less amps for the same torque, but you get increased iron (hysteresis+eddy) losses and increased drag when coasting. Depending on your riding style this could increase or decrease efficiency. ...
by hias9
May 14 2022 12:08pm
Forum: EBike Technical
Topic: Vent Hole to let Moisture escape
Replies: 17
Views: 404

Re: Vent Hole to let Moisture escape

I have also sealed the phase cable ends with silicone to avoid that moisture comes inside that way. The sidecovers are sealed with high temp silicone and also the wire channel through the axle is sealed with silicone from both sides. I run the motor quite hot. Thermal foldback is not applied before ...
by hias9
May 10 2022 9:18pm
Forum: EBike Technical
Topic: Vent Hole to let Moisture escape
Replies: 17
Views: 404

Re: Vent Hole to let Moisture escape

When I think again about it, I am not sure if it really makes sense.
Wouldn't a (sealed) hub motor only suck air+moisture inside when the inside temperature is lower than the outside temperature?
Normally the inside temperature would almost always be higher than the ambient temperature.
by hias9
May 10 2022 8:43pm
Forum: EBike Technical
Topic: Vent Hole to let Moisture escape
Replies: 17
Views: 404

Re: Vent Hole to let Moisture escape

On my motors which use Statorade, I have the sidecovers and the wire channel through the axle sealed. I think moisture (as a vapor) can however still get sucked into the motor when pressure inside the motor is lower than outside. These vents let air through, so the pressure can equalize. Not sure ho...
by hias9
May 10 2022 7:42pm
Forum: EBike Technical
Topic: Vent Hole to let Moisture escape
Replies: 17
Views: 404

Re: Vent Hole to let Moisture escape

Good idea. Do you have experience with these?
I think I am going to try the standard size (M12) instead of the XS size (M6) because they are IP69k rated.
by hias9
May 09 2022 11:38pm
Forum: EBike Technical
Topic: Vent Hole to let Moisture escape
Replies: 17
Views: 404

Vent Hole to let Moisture escape

Are there any long term experiences on DD hubs with a vent hole in one sidecover which is sealed while riding, but open when not using the bike?
If the bike is stored inside, could this be an alternative to painting the stator with varnish?
by hias9
May 03 2022 3:01pm
Forum: EBike Technical
Topic: Low voltage circuit in bac 8000
Replies: 3
Views: 117

Re: Low voltage circuit in bac 8000

It has a 12V output, but only up to 100mA.
by hias9
Apr 19 2022 7:29am
Forum: Items Wanted
Topic: (Burned) Mxus 3k Stator
Replies: 1
Views: 160

(Burned) Mxus 3k Stator

I am looking for a Mxus 3k stator.
It could be a burned one as well because it will get a rewinding anyway.
Location: EU
by hias9
Mar 20 2022 11:35pm
Forum: EBike Technical
Topic: Reducing Rotor back-iron
Replies: 13
Views: 503

Re: Reducing Rotor back-iron

Thank you. How would you cut the circumferential grooves? I am pretty sure that a slightly lighter motor with the added weight of cooling fins can take more continuous power than a motor which has that weight added in terms of a slightly wider stator+magnets, but no cooling fins. Do you have experie...
by hias9
Mar 20 2022 9:18pm
Forum: EBike Technical
Topic: Reducing Rotor back-iron
Replies: 13
Views: 503

Re: Reducing Rotor back-iron

After removing the excessive back iron on a lathe, the available solutions for cooling fins like Hubsinks would not fit any more.
What would be a good way to machine custom cooling fins? I guess EDM cutting them would be extremely expensive.
by hias9
Mar 19 2022 1:22pm
Forum: Items Wanted
Topic: (Broken) V5 ASI Controller
Replies: 0
Views: 188

(Broken) V5 ASI Controller

I am looking for a ASI controller with V5 hardware/firmware (if it was built in 2019 or before it's probably V5). It does not matter which model.
It could be one with blown FETs as well. It only needs to boot and connection via bluetooth or USB needs to be still working.
by hias9
Mar 08 2022 10:44pm
Forum: Items Wanted
Topic: Broken (or working) QS205 50H Stator
Replies: 0
Views: 282

Broken (or working) QS205 50H Stator

I am looking for a QS205 stator. Preferable a broken one because it will be rewound and hall sensors replaced anyway.

Best would be if it is located in the EU.
by hias9
Mar 08 2022 3:17pm
Forum: EBike Technical
Topic: Vibrations because of BEMF Harmonics?
Replies: 20
Views: 552

Re: Vibrations because of BEMF Harmonics?

I keep posting old information multiple times because most people do not read the whole thread.
As already mentioned, scoping bemf voltage open circuit gives a perfect sine waveform when turning the motor by hand. No harmonics noticeable.

What should I measure and take a picture/video of?
by hias9
Mar 07 2022 1:12pm
Forum: EBike Technical
Topic: Vibrations because of BEMF Harmonics?
Replies: 20
Views: 552

Re: Vibrations because of BEMF Harmonics?

I have a simple digital one channel scope. I made it portable and had it mounted at the handlebar while riding. It was connected to a current sensor on one phase wire. Waveform looked like a normal sine wave also while the vibrations occurred. How can I scope bemf voltage at 75kph? When I turn the w...
by hias9
Mar 06 2022 4:35pm
Forum: EBike Technical
Topic: Vibrations because of BEMF Harmonics?
Replies: 20
Views: 552

Re: Vibrations because of BEMF Harmonics?

The controller uses only PI gains, not PID gains. Yes, I tuned current regulator loop and phase-locked loop gains properly. These vibrations cannot be tuned away however. The rpm range where those vibrations happen depends on the switching frequency. Lowering the switching frequency by 15% makes the...
by hias9
Mar 05 2022 9:53am
Forum: EBike Technical
Topic: Vibrations because of BEMF Harmonics?
Replies: 20
Views: 552

Re: Vibrations because of BEMF Harmonics?

No, I am using an ASI controller. Some vibrations I had on other motors can be tuned away by tuning current regulator loop or phase-locked loop. In this case however, tuning current regulator loop has no effect at all on these vibrations. Tuning phase-locked loop has some effect. It changes the qual...
by hias9
Mar 02 2022 1:59pm
Forum: EBike Technical
Topic: Vibrations because of BEMF Harmonics?
Replies: 20
Views: 552

Re: Vibrations because of BEMF Harmonics?

Today I mounted a small digital oscilloscope on the handlebar connected to a current sensor that measures phase current. The waveform was a normal sine wave also while the vibrations occurred. Earlier I mentioned that lowering switching frequency makes the vibrations occur at less rpm. But if it is ...
by hias9
Feb 26 2022 12:03pm
Forum: EBike Technical
Topic: Vibrations because of BEMF Harmonics?
Replies: 20
Views: 552

Re: Vibrations because of BEMF Harmonics?

Today I limited power and phase current to 80% of what I usually set it to and had it at full throttle while pulling the brake lever hard. After about 3 seconds I released the brake lever. The brake was not able to get speed below 75kph and speed already started to rise after 2 seconds. After releas...
by hias9
Feb 25 2022 9:45pm
Forum: EBike Technical
Topic: Vibrations because of BEMF Harmonics?
Replies: 20
Views: 552

Re: Vibrations because of BEMF Harmonics?

So you mean it is probably caused by the magnetostriction of the stator laminations?

I was thinking about buying a mcc118 or 128 and a raspberry pi.
by hias9
Feb 25 2022 9:29pm
Forum: EBike Technical
Topic: Vibrations because of BEMF Harmonics?
Replies: 20
Views: 552

Re: Vibrations because of BEMF Harmonics?

I tuned some low power motors like this, but for over 300 phase amps vs. bicycle brake pads at 75kph+, I will probably need many sets of brake pads. We are talking about around 20 horsepowers of mechanical power against bicycle brake pads. I would also need to buy measuring equipment. What exactly d...
by hias9
Feb 25 2022 5:04pm
Forum: EBike Technical
Topic: Vibrations because of BEMF Harmonics?
Replies: 20
Views: 552

Re: Vibrations because of BEMF Harmonics?

The motor is running great and efficient. I have fine tuned all proportional and integral gains. It's not an inverter fault because changing the inverter did not change it. I guess I would need to measure the waveform while riding (because the vibration only occur at high load around 75kph) ? I thou...
by hias9
Feb 24 2022 10:35pm
Forum: EBike Technical
Topic: Vibrations because of BEMF Harmonics?
Replies: 20
Views: 552

Vibrations because of BEMF Harmonics?

On a 23 pole pair 51 slot direct drive hub motor I have vibrations at around 650rpm (250Hz), but only if phase current is still above approximately 300 phase amps at that moment. If I only accelerate with 50% or 70% throttle for example, there are no vibrations because phase current is lower. I am u...
by hias9
Feb 18 2022 11:47pm
Forum: EBike Troubleshooting
Topic: DD hub Magnets rubbing Stator after adding Statorade
Replies: 28
Views: 878

Re: DD hub Magnets rubbing Stator after adding Statoradeunti

So here is a little update on this. I measured the rotor and it is round. I eliminated the axial play (which was about 0.4mm) with additional washers. Now the stator was sitting perfectly inside the rotor, but the noise did not change at all. The noise is in fact caused by the Statorade. The noise i...