Endless Sphere

There are some existing magnetic gear setups. https://www1.grc.nasa.gov/wp-content/uploads/2018EATS-Magnetic-Gear-Scheidler-6.2018-4988.pdf If designed properly, the gears have nearly zero loss and zero wear. Most of the systems involve both attraction and repulsion and the gears will "slip&quo...

It's easy enough to create a new category, but super time consuming to attempt to sort out all the old posts. I don't see that ever happening.

Depending on the motor type, you may need a speed controller just to make it run. With a speed controller, you can lower the speed to anywhere you want, down to zero. At partial throttle, the motor will pull less from the battery.

I've seen a dent like that cause an internal short and made the cell go off immediately. Like a little rocket motor. If the cell didn't go off, it was likely on the verge of it. Good idea to totally discharge it. I think you got lucky this time.

You want to be sure the output drops instantly if the input drops (for safety). I rode something one time that had a lag in the downward throttle action that I thought was going to kill me. Let off the throttle and the motor keeps going for a while.

I’m trying to think of an easy test you can do to determine if the controller or the motor is the limiting factor. If you watch the amps while increasing the load (brake?) if the controller is limiting you will reach the limit and stay there as load is further increased. If the motor is the limiting...

I put the Yawn-tan controller back on today, and gave it a voltage sag test, 66v to 58v at 1200w, roughly. Seems like a lot. That does seem like quite a bit of sag for 20A, but not so much that it would be your limiting factor. 58v is still enough to get some power. Is anything getting hot during t...

You can't measure temperature with a near-IR camera. Thermal IR cameras are expensive, but you can get IR non-contact spot thermometers for pretty cheap. These work like the camera, but only a single pixel.

Unleaded regular is up to $6.29/gal at the "cheap" place near here. We are within 10 miles of several large refineries, but if you go inland, further away from the refineries, the gas is a lot cheaper. We are just getting ripped off in this area.

The easy test is to measure the voltage sag on the pack going from no load to full load. This will tell you a lot about the pack.

The gap between magnet sections won't make much difference in performance unless it gets up to about the magnet thickness. Perfectly symmetrical spacing is more important. I've seen various recommendations for glue. You want something that stays strong at higher temps. Normal epoxy can get pretty so...

There is probably not much benefit to using magnets over a certain strength. With a higher flux, the hysteresis and eddy current losses will increase to the point of cancelling out the gain in torque. There are trade-offs in most aspects of motor design. Having magnets with a higher temperature rati...

Either the controller isn't allowing more current, or the motor winding resistance is doing it. At near zero RPM, the motor resistance will be very low, so shouldn't be the limiting factor, but hard to say. If you are at the limit over a fairly wide RPM range, it would indicate the controller. Tryin...

It looks just like the A2B Metro motor but with a different controller board. A comm error would indicate a problem somewhere between the controller and the display. I would carefully trace the entire cable that goes to the display and look for possible damaged spots. Also unplug any connectors and ...

The CA has several connections it needs to work. Power is pretty straightforward. It needs a current sensor input that is a shunt either inside the controller or an external one. In your case, you might want an external one, but you'd have to buy one. There is also a speed input, either from a wheel...

It is not uncommon for many models of BMS to blow a shunt transistor. These are incredibly small, surface mounted things. Unless you have the skill and equipment, replacing it is very difficult. I would recommend replacing the entire BMS unit. You might be able to get one under warranty if you ask t...

Cool. So assuming I grab 2 phases at random to do this test. The positive and neg from my DC source makes those 2 phases unique and the 3rd phase is not used in the test. So does this mean all the info I need to parallel them is all gained from just one test? So just to check my understanding here....

As long as the rotors and stators are aligned properly, you can parallel the windings and just use one of the hall sets. You can put the rotors as close as you want. Just make sure the rotor magnets are aligned the same before joining. One way to do this is to apply a steady DC (like 12v) to a pair ...

If both batteries are connected at the discharge port, only the one getting the charger will be protected during charge. To charge safely, you need to disconnect the packs from each other and charge separately. This will be sort of a pain and if you forget something and connect them when the voltage...

It sounds like there's a short in the phase wires somewhere. To test, you need to disconnect the motor from the controller and see if the drag goes away. If the motor spins freely when the controller is unplugged, then most likely the controller shorted. If the motor still has drag, then the problem...

Thanks again for posting the instructions. It's been a long time since I installed mine. I typically charge my pack to 58v and had the "full" voltage set to 58v. But over time, the voltage reading had drifted upward so when it was 58v, the TK15 was reading 59v. I didn't see a way to calibr...

One thing you might consider is looking for a motor sprocket with more teeth. The one that's on there is extremely small and that can't be good for noise and wear. By going to a larger front sprocket, the motor will be geared higher, so more likely to hit the current limit and less likely to wheelie...

So how's the acceleration? That is a big controller, but there is plenty of room for it. I think you're going to want bigger batteries :wink: Looks like you could possibly mount the controller between the frame and the seat cushion if you needed a higher (and warmer) seat. Is there a way to re-insta...

Pack output is up to 1300w, and the fact that it's climbing tells me that there isn't any hard current restriction from the controller or system components. However, it occurred to me that the 18" 8awg battery wires might be sucking up some watts. (36" round trip.) Putting the BMS in the ...

Excellent work! Thanks for sharing it here.

I don't think I've ever seen hub motors like those. Are those geared? Most of them are made to go too fast.