Ezee geared hub motor - slipping?

My motor seems to be slipping under torque.

I've taken it apart and have marked the large internal gear that is pressed into the hub, then ran the motor and got it to slip. Opened it up again and checked my marks and the alignment of the gear in the hub had not changed, so that's not moving.

I put a large pipe wrench on the one-way clutch and tested it, then spun it a little, tested again, etc. Never got it to slip there. What else could be "giving"? The shaft key in the clutch appears to be intact, although i couldn't seem to pull the clutch off the shaft to get a better look at things there. Anyway, if it was bad, my pipe wrench test would have revealed it.

Any ideas what's slipping?

A note that may be relevant. When i first assembled this bike (a year ago), I had the same problem a couple of times, but it simply went away and hasn't been a problem in the year since. I've just installed a new controller and now the slippage is occurring again. The thing that is in common between these two occurrences is that each time i had to troubleshoot the matching of the phase wiring between motor and controller. Of course, on the wrong matches the motor sometimes chattered or ran backwards. Might this have anything to do with it?

Much thanks for any help!

Are you absolutely sure it's slipping and not mis-firing electrically ?

A severe slipping will sound like the motor is running perfectly smooth but just has no forward pull.... a electrical issue is a much rougher sounding problem.

if possible, a short 10 second video would help greatly.

The bike will sometimes pull and operate just fine. However, if i come to a steep hill, or sometimes even not on a hill, it will sound as if it's running, but then provide no forward thrust. It doesn't sound bad, just swishing noise. When i let off the throttle it doesn't stop immediately, but "freewheels" for maybe 2 seconds, coming to a stop gradually. Not a grinding or rough sound at all.

I would almost guess it could be running backwards, except that many times it works as it should, and sometimes i'll be going forward, under power, then it will slip when i begin up a hill.

By the way, thanks for your website ypedal. It's what gave me the idea to check if the outer gear is slipping in the hub.

Here's a video, hope it's helpful.

https://youtu.be/8sc36iiT63g

Wonder if the stator is spinning freely on the axle rod.
Or the gear that spins the planetary gear might be spinning freely on the shaft.

Is the stator the part with the coils? I wondered about that but realized that if it was spinning then the wires would all be sheared off where they exit the axle.

Rotor slip?

That's when the field switches before the magnets have moved far enough. Kind of like the "misfire" previously described.

If its using Hall driven switching the hall triggers may be a bit off. Some controllers allow a timing compensation.

If its a feedback loop system there may be a bad cap in the feedback loop on the PCB.

Using s12sh controller from BMS battery

It's the Sprage clutch.
Whether the metal surfaces have worn " shinny", or the rollers have worn a flat spot, the ASM is failing to get a good grip.
Or maybe even the springs have broken or grown weak.
Since that clutch is not made to come apart, it would be a pain to look. Actually, Getting it apart doesn't look that bad, one would have to grind off the heads of the holding pins..
But re-staking it looks like a pain.
I would soak it in some solvent for a while and maybe a light oil afterwards.
The clutchs are still avail. and I think the BMC V2 clutch/gear ASM swaps in as well(Ck. w/ Ebike NY, maybe).
I have a couple of litely used ones, but I don't think I want to start selling off my Ezee original parts yet.

It had been working fine for a year until i installed this new controller. Could something in that process have caused it to stop locking when it should?

it would be an impressive coincidence if the gear ring was stopping at the same place every time but it is easy enough to drill a small hole and pin it, rule out that possibility regardless of it being the problem or not. ( just make sure to clean all metal shavings carefully and make sure the pin does not go too far and hit the planetary gear teeth .

if the stator budged, the wires would be severed...

TroySmith80 said:

It had been working fine for a year until i installed this new controller. Could something in that process have caused it to stop locking when it should?

Click to expand...

Yeah, and I had a horse that was fine for 25 years and then, one day he was dead.
I'm telling you it's the clutch, I have seen it before.
Take it out and try turning it by hand and see if it grabs.

motomech said:

TroySmith80 said:

It had been working fine for a year until i installed this new controller. Could something in that process have caused it to stop locking when it should?

Click to expand...

Yeah, and I had a horse that was fine for 25 years and then, one day he was dead.

Click to expand...

To back up Troy, I had Q100H that started slipping immediately after I changed controller. I took the clutch out, put new springs in, made sure that it was gripping (it was), and then put it back on the bike. Worked perfectly on no load (wheel in the air), So I put everything back together and went for a ride. It then worked some times and not others, just like he's describing: Swishing noise, no motion. If I back off completely and try again, after 3 or 4 goes, it almost always gets there eventually.

I have bought a completely new Q100H, but haven't fitted it yet. If it does exactly the same thing, then I'll know it is the controller. If it doesn't, then I know either I didn't fix the clutch properly, or it's something else damaged in the motor.

How many amps.. new vs old controller

Ok, I guess I jumped the gun.
guess it's time for the Hall test proceedure.
the original Ezees were notorious for cold solder joints where the wires enter the PCB.
To check it physically, warm the epoxy covering the PCB and gently peel it back. I wouldn't be suprised if one or two of the Hall wires pop out.
The problem is intermitent because the epoxyy is the only thing holding the wire to make contact, the solder joint is broken.

Thanks for the feedback.

I guess one thing i could do is plug it back in to the old controller and see if anything is different. If that doesn't solve the problem, i'll open it up again and check the hall wires as mentioned.

This motor was one that I scrounged up cheap by putting together pieces from 2 or more broken/ruined motors to make one good motor. If i remember correctly, i did have to do a little soldering on something in there when i got it. I don't remember what exactly. I'll take a look at all of it when i open it up again.

Update, the motor still works fine with the old controller! I would have bet good money that the problem was mechanical, but it seems that it must have been electrical.

I haven't solved it, but it doesn't matter because im going to keep the old controller with this motor and ive got a couple Q128H motors that ill be using with the newer controllers on my next projects.

The stock eZee controller is 20 amps limit ... what was the other one ?

TroySmith80 said:

Update, the motor still works fine with the old controller! I would have bet good money that the problem was mechanical, but it seems that it must have been electrical.

I haven't solved it, but it doesn't matter because im going to keep the old controller with this motor and ive got a couple Q128H motors that ill be using with the newer controllers on my next projects.

Click to expand...

Wow! After looking at that video, I would not have guessed that. What is making that noise then?

Colin

Sorry, I have kind of moved on to other tasks in life... maybe getting back to this soon. It's been snowy/icy/dark/cold here so i haven't been riding.

The old controller is an infineon 12 fet with CAv3. The controller will pull a lot of current if i let it, I think around 40A? I pay more attention to power (48v system) than current and usually keep it under 1500w max, with most usage around 200-800w.

The new controller is an S12SH from BMSBattery.