Help me disassemble this aikema motor

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specing   1 mW

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Help me disassemble this aikema motor

Post by specing » Aug 12 2019 11:37am

Greetings all, sadly this motor left its last breath near the top of a 300m hill (grade ~15)

Symptoms (bicycle flipped upside down = almost no load):
- when starting, it jerks back & forth.
- when it picks up speed, it produces much more noise than it used to.

Any ideas how to open it up? I've removed the three ~1cm screws that used to be in those three holes, but the side plate does not come off. There is also something within the motor that can be seen through those holes and that moves together with the axle. That is what the screws screw into.
sideways.jpg
sideways.jpg (187.43 KiB) Viewed 196 times

Voltron   1 MW

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Re: Help me disassemble this aikema motor

Post by Voltron » Aug 12 2019 11:51am

The whole sideplate is threaded around the edge and unscrews instead of popping off. You need to get or make a tool to stick in the holes to get the leverage to unscrew the plate.

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motomech   1 GW

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Re: Help me disassemble this aikema motor

Post by motomech » Aug 12 2019 4:22pm

Aside from the clutch (springs), there's nothing you can repair inside the motor. Even the smallest/simplist part, the Hall sensor(s), can not be replaced on the Q100.
From what you are describing, it's more likely the controller has developed a problem.
Also, ck the phase wires to make sure they didn't melt, especially the bullet connectors.
Last edited by motomech on Aug 12 2019 7:24pm, edited 2 times in total.
Motomech

'03 Rocky Mountain Edge 2WD 260 Q100H frt and Ezee V1 rear 2 Elifebike 20A & 25A 9-FET controllers 12S/10Ah Multistar Lipo rear 4Ah Turnigy frt Luna Cyclops Extra lite Alex 24DM rims, Crazy Bobs run ghetto tubeless. 25 mph. Mean Well HLG-320H-54A
https://endless-sphere.com/forums/viewt ... =3&t=83430
'07 GT Idive 4 4.0, Q100C 201 14S LiPoly elifebike 9-FET 20A controller. 23 MPH.
https://endless-sphere.com/forums/viewt ... 4#p1378484

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Drunkskunk   100 GW

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Re: Help me disassemble this aikema motor

Post by Drunkskunk » Aug 12 2019 6:29pm

Pic is from one of D8veh's posts, ( here ) this shows the threads in the side.

But really, this sounds like a controller issue.

Image
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Voltron   1 MW

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Re: Help me disassemble this aikema motor

Post by Voltron » Aug 12 2019 7:01pm

Could also be a Hall sensor issue making the controller switch to sensorless mode, so it still runs but has jerky start up...

specing   1 mW

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Re: Help me disassemble this aikema motor

Post by specing » Aug 13 2019 4:14am

Thanks for the response
Voltron wrote:
Aug 12 2019 11:51am
I have drilled into a block of wood and mounted screws in it, but all I achieved was the wood cracking. I'll need a stronger piece of wood. Any idea of the required force to unscrew it? Max motor force + max pedal force applied in reverse? How much is this?
motomech wrote:
Aug 12 2019 4:22pm
Drunkskunk wrote:
Aug 12 2019 6:29pm
The motor's connector is a 3-pin plastic thing, there are no sensor/temp/etc wires but the phase ones, and the connector looks good.

I have tested this motor on another controller and it has the same issue. Though, admittedly, I did not test all 3 rotations of the phase connector in case that matters.

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motomech   1 GW

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Re: Help me disassemble this aikema motor

Post by motomech » Aug 13 2019 6:33am

download/file.php?id=143199
I've seen a much cruder version consisting of a rectangle piece of flat steel (approx. 1/4" thick) w/ a hole cut in one end to slip over the axle. The rough edges leads me to believe it was cut w/ an act/oyx torch. The three "tangs" consisted of hex-head bolts "double nutted" to a-line w/ the indentations in the side cover.
Yes, the side cover turns off normally, counter clock-wise (lefty loosey), but on the rear motor versions, the cover is extremely tight because the action of the pedal drive tightens it.
Motomech

'03 Rocky Mountain Edge 2WD 260 Q100H frt and Ezee V1 rear 2 Elifebike 20A & 25A 9-FET controllers 12S/10Ah Multistar Lipo rear 4Ah Turnigy frt Luna Cyclops Extra lite Alex 24DM rims, Crazy Bobs run ghetto tubeless. 25 mph. Mean Well HLG-320H-54A
https://endless-sphere.com/forums/viewt ... =3&t=83430
'07 GT Idive 4 4.0, Q100C 201 14S LiPoly elifebike 9-FET 20A controller. 23 MPH.
https://endless-sphere.com/forums/viewt ... 4#p1378484

specing   1 mW

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Re: Help me disassemble this aikema motor

Post by specing » Aug 13 2019 2:30pm

I saw one of those crude solutions (however the target motor was different). My problem with this is that I simply have nothing with which to make a 35mm hole into metal. Thus my option is some hard wood with perhaps a metal plate added to the side to reinforce it (a plate that only has a hole for the axle, which I can drill). Even drilling a cheap standard thread-on cassette removal tool to widen the hole took forever, though that was probably hardened tool steel....

Perhaps I should consider purchasing a new motor, since this repair will likely take months. Any recommendations for a 200-300W hub that is most efficient at ~15km/h = 120 rpm, 28" (steep hills around here). I've looked at the ebike simulator for MXUS XF07 and the efficiency under those conditions left much to be desired.

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motomech   1 GW

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Re: Help me disassemble this aikema motor

Post by motomech » Aug 13 2019 3:29pm

specing wrote:
Aug 13 2019 2:30pm
I saw one of those crude solutions (however the target motor was different). My problem with this is that I simply have nothing with which to make a 35mm hole into metal. Thus my option is some hard wood with perhaps a metal plate added to the side to reinforce it (a plate that only has a hole for the axle, which I can drill). Even drilling a cheap standard thread-on cassette removal tool to widen the hole took forever, though that was probably hardened tool steel....

Perhaps I should consider purchasing a new motor, since this repair will likely take months. Any recommendations for a 200-300W hub that is most efficient at ~15km/h = 120 rpm, 28" (steep hills around here). I've looked at the ebike simulator for MXUS XF07 and the efficiency under those conditions left much to be desired.
There is a home-made set-up that might work, but I doubt it because it's a rear motor. Take a 4' X 4' piece of 3/4" plywood and double-nut the hex-head bolts w/ large flat washers, lay it on the ground, stand on it and drop the whl. ASM on it and turn the whl.
Really, I've been though this several times and you need a wrench tool at least 2' long. The idea is, you have a machine shop make it, but machine shops are few and far between these days. Plus it would be at least $50.
You could order another another mini-motor, the Q100 is cheap enough, but you get killed w/ the freight. If you need some other stuff, it would be easier to justify.
I had a MXUS years ago and it's the top mini motor, partly because it's slightly bigger than Cute and absorbs more heat.
Any recommendations for a 200-300W hub that is most efficient at ~15km/h = 120 rpm, 28" (steep hills around here).
There are a couple things wrong w/ this statement. First off, efficiency is not the main thing when climbing hills w/ a hub motor, all geared minis are about the same in this respect. Motor speed range and driving whl size are what;s important. The first rule is, NEVER allow the climbing speed (or RPM) fall below 1/2 the top speed (No-load RPM), at which point, the system is generating more heat than motive force. You don't give us the speed range of your motor, but your target climbing RPM is too close to 1/2 of even the "201", not to mention the "328" (which would be a huge mistake in a 28" whl. (Big whl.s are hard on mini's in regards to hill climbing).
If you want to stick with a mini, your best bet is to run a low-speed (201) motor on 52 Volts (w/ a 48 V controller, w/ at least a 20 Amp max. It may seem counter-intuitive to run more power thru a mini, but that's the best way to tackle hills. The idea is, hit the bottom as fast as possible and try and maintain as much speed as possible until you either crest or realize that your motor speed is going to drop too far. At which point, it's time to jump off and push.
I don't think any mini is much better than a Q100H 201 because of the Cute"s compound gears. It spins fast.
The next step up would be the larger "5 Kg." geared motor like the MAC or BPM. You would have to make sure your Pack is stout enough to drive it.
Motomech

'03 Rocky Mountain Edge 2WD 260 Q100H frt and Ezee V1 rear 2 Elifebike 20A & 25A 9-FET controllers 12S/10Ah Multistar Lipo rear 4Ah Turnigy frt Luna Cyclops Extra lite Alex 24DM rims, Crazy Bobs run ghetto tubeless. 25 mph. Mean Well HLG-320H-54A
https://endless-sphere.com/forums/viewt ... =3&t=83430
'07 GT Idive 4 4.0, Q100C 201 14S LiPoly elifebike 9-FET 20A controller. 23 MPH.
https://endless-sphere.com/forums/viewt ... 4#p1378484

specing   1 mW

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Re: Help me disassemble this aikema motor

Post by specing » Aug 13 2019 7:00pm

motomech wrote:
Aug 13 2019 3:29pm
I'm not sure if I understand that set-up...

I've looked into ordering and shipping is indeed hella expensive, even the basic KT sinewave controllers (which I'd like for the FOSS firmware upgrade) that are listed for ~$25 add $20(bmsbatery)-$50(pswpower) when checkout is attempted. What is going on? I can get stuff that weighs the same, like disk brake rotors from ali for a few dollars, shipping included.

What does "crest" mean in this context?

Yes, the requirements of stealth, efficient hill climbing and low power really don't go together, it seems. And the other hidden requirement that I forgot to mention, I already have a 36V battery. Would the motor+gears still be >80% efficient at their optimum point with 52V 20A? That is a kilowatt and would mean 200W of heating, the same as 200W of heating when ran at 450W with 55% efficiency.. but with a much shorter duration. 800W of mechanical power + 250W from legs would indeed allow me to climb the steepest hills around here with >20km/h.

I'm not looking at large geared hub due to wanting a bicycle that looks like a bicycle and not an expensive thief bait. For other bicycles I am already looking at tsdz2 (power meter yay).

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motomech   1 GW

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Re: Help me disassemble this aikema motor

Post by motomech » Aug 13 2019 11:16pm

To "crest" the hill- go over the top.
You are really stuck on the "efficiency" thing, throwing out percentages of efficiency and Watts of heating and I'm telling you what I've learned using more than a half a dozen Cutes over 7 years (since they first came out).
I will say this about efficiency as it relates to overall performance and hill climbing;
To reach a desired top speed, the use of a higher Volt system (in the case of the Cute, 52 Volts is about max., as going higher yields deminishing results) and a lower speed range motor/whl. combo, will be more efficient than achieving the same top speed w/ with a lower Volt system and a higher speed range motor/whl. combo.
To illustrate the advantage of a higher Voltage system when climbing, plug in the parameters into the Grim sim.
(Since you have not yet told us what your system actually consists of, I'm doing a little detective work to glean what they are. Since the Q100H only comes in two speed ranges; the "low-speed" 201 and the extremely "high-speed" 328 and since the motor is marked 28" wheel (hard to see in pic), one would assume that it would be the 201 version. Also most kits would come w/ a low-power controller, I will assume it's around 15 Amps max.)
Using the MXUS XF07, the only 201 mini Grin lists and other "middle of the road" numbers ie; 242 lb.s total weight, 150 Watts rider input and upright bike, we get these results;
On a rather steep 7% hill, the climbing speed quickly drops to 12 to 13 mph and the top speed in the flat is about 18 MPH.
Plugging in a 52 V batt. and a 20 Amp controller (everything else the same), we now see a climbing speed of 17 MPH and a top speed, a much more entertaining 23 MPH.
As the Motor RPM falls and the load increases (or remains the same), the controller struggles and attemps to provide the motor everything it possibly can and this is what melts things.
Rather than fuss over the details of the electrical system, it's way more important to get the mechanicals right first. And in this regard, the choice of 28" whl, a 36 V pack for "steep" (hard to quantify, I'm going by your description) hills is less than optimum.
A Q100H 201 in a 24 or 26" whl., drawing from a 52 V pack, will still have a top speed of over 20 MPH and climb just about any hill one would encounter on public roads.
I know, I run a Q100CST that way.
Motomech

'03 Rocky Mountain Edge 2WD 260 Q100H frt and Ezee V1 rear 2 Elifebike 20A & 25A 9-FET controllers 12S/10Ah Multistar Lipo rear 4Ah Turnigy frt Luna Cyclops Extra lite Alex 24DM rims, Crazy Bobs run ghetto tubeless. 25 mph. Mean Well HLG-320H-54A
https://endless-sphere.com/forums/viewt ... =3&t=83430
'07 GT Idive 4 4.0, Q100C 201 14S LiPoly elifebike 9-FET 20A controller. 23 MPH.
https://endless-sphere.com/forums/viewt ... 4#p1378484

specing   1 mW

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Re: Help me disassemble this aikema motor

Post by specing » Aug 14 2019 6:09am

motomech wrote:
Aug 13 2019 11:16pm
7% is not steep at all, I can do 10-15 km/h up such a hill on leg power alone. One of the hills around here that I climb is 26% of the trip in the 10-15% grade, 7% in 16+% grade and is representative of the hill roads around here:
https://maps.openrouteservice.org/direc ... n-US&k2=km

Still bad efficiency:
https://www.ebikes.ca/tools/simulator.h ... &wheel=28i

A bbs02 mid-drive would be 81% efficient. This is not fair......
https://www.ebikes.ca/tools/simulator.h ... e&gear=1.3

I guess at this point it is better to just convert yet another bicycle with a tsdz2 for touring purposes and get one MXUS for commuting/errands (mostly flat terrain). Are you aware of any efficiency characterizations of the tsdz2? Given that it has an integrated controler and a torque sensor at a lower price point, it is quite a bit better bang/buck than the bafang. It is also stocked by pswpower here in europe, so no ludicrous shipping costs either (as compared to mxus + dedicated controller).

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