Motor commutation chatter with EZEE and Phaserunner?

NotTheBus

100 µW
Joined
Feb 21, 2018
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I just finished building my 2nd ebike last night. The setup is an EZEE rear gear hub motor, the 350RC model from Grin. The motor is powered by the Phaserunner. My battery is a 14S4P from EM3EV. The bike is a longtail, and Xtracycle Edgerunner swoop.

The problem I am having is that the motor usually is stuck in a chattery mode of operation - it sounds like a kid making machine gun noises or maybe the end of woody woodpecker's laugh. I think this is a commutation issue, because about 1/5th of the time I can get the motor to run smooth. I can cut and restart the motor on the run to try and get the smooth running mode. It seems to run smoother under high load, like a steep hill. The chattery behavior exhibits itself under both throttle and cadence PAS modes. If I am able to lock into a smooth commutation, it stays that way until the motor is let off. The chattering behavior is enough to shake the bike. I have witnessed this before with a wrongly tuned brushless motor with FOC in an industrial application.

During the autotune of the phaserunner, I was only able to pass the static test 2/4 times that I tried it. It did make the same buzz each time. The phaserunner is set with the proper number of poles (80), and adjusted the Kv away from nominal on its own. The phaserunner is in "Hall start, sensorless run" mode. I tried setting to pure hall mode, but it changed itself right back. I then read that sensorless run is better for a FOC anyway.

Do the orientation of the phase wires into the phaserunner matter? I did reterminate the phase wires with the MT60 connector so that I could direct plug into the controller, without using the patch harness. In doing so, I noticed that the EZEE pigtail and the extension harness were setup from Grin to swap the positions of the green and blue wires, so I copied the effective pinout that would be achieved using their harness, with the layout that they had for the andersons.

Very frustrating.... I had such an easy time getting my first build going. That used the Grin AA hub motor with a phaserunner. Smooth as can be.
 
Solved with help from Robbie at Grin. For thread completeness, here is what he had me do in the phaserunner setup:
"Increase Current Regulator Bandwidth to 3000 Rad and the PLL Bandwidth to 3.0"

That was 3x over what it defaulted to. Works very nicely now. I also increased the ramp up time to 500ms, which suits me nicer.

Bike rides wonderfully now. I am still not a complete convert to simple cadence PAS... its too easy to let bike speed get away from you and end up clown pedaling, and it feels scary. I will probably be installing a torque sensing bottom bracket, which unfortunately will need an alternate crankset since pretty much all sensing BB are square taper. Nothing short of excellent will suffice! It is tempting to go lean - ditching the CA and just use throttle only into phaserunner. However, I have my sights set on outdoing the Bosch edgerunner experience.

After the near complete silence of a Grin AA hub, the gear whine on the EZEE is taking some getting used to. My daughter keyed in immediately "Daddy - when you pedal the bike goes whirrrrr and when you stop pedalling it goes bzzzzzz (EZEE freewheel is rather loud too). On the Grin hub bike, I just hear the high frequency whine of the phaserunner. However, definitely a stronger climber than the grinhub, despite small differences in the sim. Also drinks a fair bit more power (~18wh / mile vs ~15 wh / mile), likely due to the increased drag and weight of a kitted out Edgerunner vs the BF family tandem, and the extra assist available on hills.
 
..... , the gear whine on the EZEE is taking some getting used to
Perhaps the gear material has something to do w/ it. I have a couple of original Ezee V1's that came w/ the white nylon gears, which I suspect are softer than the later blue composite gears.
Motor "whine", is of course subjective, but above 5 or 10 mph, all I hear is the tire.
If you are using the Enoch DNP free wheel, they can be hit or miss. The first one I had was rough and noisy, while the most recent one is smooth and quiet. Many think it has a lot to do w/ the amount of lube inside and there is a long thread here where different techniques are used(like injecting). I soaked my second one in a bucket of gear oil for a day before installing it. But, of course, it made a mess for a month or two.
 
I just ran across this, have you upgraded to a torque sensing BB yet?

We have a Bosch CX box bike and a Mac + Phaserunner + CA3 + Sempu box bike, and I feel like I did eventually make something that is nicer than the Bosch, but it took a fair bit of tweaking. It might also just be that I like that it has more power. I use the handlebar potentiometer to adjust the assist level, and the digital aux to switch between three presets which have different min and max multipliers and power levels.
 
I have not gone torque sensing yet. For the remainder of cold (bar mitten) weather, I’ve gone throttle only. Easier to modulate on snow and ice, and the bar mitten kept pushing into my aux button and raising the level. I wish there was a way to use the CA3 buttons to adjust assist, quickly.

I like the sounds of that setup with torque BB, pot, and buttons. For this bike it would need a new crank set as well (stock is octalink) and I got a bit fatigued with swapping parts.

Overall the system works well. Doing it again, I might go with DD rear hub. I do wish the Grin hub were available with a 9 speed cassette body, that’d be very nice for the small rear wheel cargo bikes. It would also be neat to deploy the kickback stand and use the bike as an inefficient generator / trainer; it looks like Bike Friday has played with this on the Haul a day.
 
I have an ezee in a 20" wheel.
The whirring you hear is of course the cassette freewheel. It seems solid but certainly makes it's presence known. You'd probably have a similar issue on any hub. Especially on a 20 inch wheel.

Torque BB would probably be good, but to eliminate the ghost pedaling issue, you just need a gearing setup on the cranks that matches the top speed of your motor. Bigger chainring, smaller tooth gear in the crankset, or some combination of both will do.

This is a problem even if you go to a throttle.

I agree with you on magnet pulse PAS a ton. I think it's a dangerous and finnicky way to control an ebike once the power levels go above 500w or so. I've torn magnet pulse PAS sensors off everything i've ridden, including the Bafang BBS02. Can't stand them; and tuning options don't help make them much better.
 
I bought a complete Phaserunner kit with eZee motor, CA and torque sensor from Grin last year.

The controller was supposed to arrive pre-tuned. And yet I experienced very similar problems to the ones described in this thread. Since then I've had 25 emails back and forth with Grin. I made the adjustments suggested by Robbie. Things run much better now but the acceleration still starts with a mild but annoying jerk. Still nowhere near as smooth as another kit I have.

I'm wondering if I should replace the Phaserunner with an eZee specific controller. At $160 it feels like a lot of money to fix a problem that I shouldn't have had in the first place.
 
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