Leaf / leafmotor / leafbike high efficiency 1500w motor

[ABritInNY]

Did ZombieSS chime in? because he showed that PWM = more controller heat = less efficiency. Maybe it's just a few percent? but why lose a few percent of efficiency if you can avoid it, eh?

Of course a lower turn count can handle more battery/phase amps. It needs them to produce the right amount of torque to hit and maintain the speeds you're looking for.

Torque per amp & speed per volt is going to be different for each winding. A high turn count winding produces very little torque per amp, but high speed per volt, yet you need the right amperage to produce enough torque to hit the speed you're looking for, yes?
So if you are limited on amps from your battery/controller, you are very much limited on torque on a very high speed winding. This is a very poor choice to make. You will always be in PWM mode taking a few % efficiency at the controller, and you'll have less torque due to the 30A limit.

Nep, were you following the MXUS 3000 thread?

I thought the conclusion over there was that the PWM losses are negligible, and a lower turn wind is better able to handle high phase amps with the only catch being a controller that can handle it.

Cheers

@Neptronix, Isn't what he's saying about the conclusion of the 4T MXUS thread, basically the same as your saying of..."always use the right winding for the job." So obviously a 72v system limited to a 30 amp controller would not be ideal and the wrong winding...The assumption in later comments also seemed to be that the 4T in the MXUS has the most copper fill of all windings, which is better for amp soak and again in line with what you say, that..." of course a lower turn count can handle more battery..." since e.g with a more than adequeate 18fet 65A 4110 Lyen mark 11 overclocker controller, mated to a high drain lifepo4 (or rc Lipo packs) @72v (or really 76.8v nom on lifepo4) with a 60-120a BMS on the pack the "Catch" would seem to be 'Met' My question to you is that with such an equipped controller and battery would you STILL reccomend the 5T winding @72v? Or like your bike, incrementaly tested, escalating ramped amp tests, until you discover the bikes happy "sweet spot?"

 

[Allex]

Raised with another 40USD, thank you Martin!
We now have 80USD, about half the motor without shipping

Any one else feeling brave to chip in? Looks like the interest is a bit chilly on this one.

 

[Kodin]

Screw it, added another $60. Come on guys, even if it's $3.50, it's something.

 

[madin88]

i believe most who plan to support are now waiting for Lukes dyno results :lol:

 

[Allex]

Well, if Lukes Dyno test is enough. I can just return the money to you guys

 

[madin88]

It would be good to have the motor in the simulator no matter how it performs on the dyno where it will be pushed way above for what it's rated for. at least i believe luke will do so

what i would like to know is the saturation point or with other words at what torque level the relation between current and torque output discontinue to be linear.

@ LUKE
you have mentioned that you could not feel higher torque with much higher current settings in boost mode. may it be possible that max current was already limited by battery voltage and the motors resistance?
is there any news?

 

[Cowardlyduck]

So I just cracked open my Leaf motor for the first time. I plan on changing phase wires, bearings, painting it, cutting vent holes, and adding cooling fans...it's the whole lot for this motor.

Things I notice:
The side covers are strange...those cracks are just on the surface, so not structural. It must be a side-effect of the way they make them. Anyone care to comment?

The windings are still perfect. I got it up to about 80C on the covers a few times, but it's still in great condition.
The bearings are bad. I've only gone on a few off road rides on this bike. They feel like they have sand in them...just bad quality I guess.
It's great that the holes in all the motors are roughly the same size...makes fan cooling mods much easier.

Cheers

 

[Kodin]

Yeah the crazing on the outside is from the casting. That's simply an umachined surface for the side cover interior, so you see what the mold looks like. I noticed one of my bearings was a tiny bit crunchy too. Kind of to be expected; In my younger days I installed a really nice quality bearing improperly and it exhibited similar results, could be the bearings are cheap, or could be they were pressed from the wrong surface. How'd you push the bearing out of the side cover on the phase wire side without cutting your bundle? Still trying to figure out a reasonable solution for this that won't shoot parts all over my shop when I throw it in the press... I don't have tube that large of diameter to just make a spacer for, and I assume the cover needs to be held by the perimeter to not damage it. (bearing has to stay on the shaft while cover comes off)

 

[speedmd]

Clearly a defective casting that was allowed to be sent. Just plain poor quality casting. Not something you can rely on for extreme duty.

 

[Kodin]

It's simply an unfinished casting. How many people do you think actually look at the inside of a motor? Manufacturers don't think about making the inside "pretty". So long as there aren't voids in the casting, it should be fine.

 

[speedmd]

If they are cracks, they are not fine. They had a mold that was much too cold. Clear defect. May last forever in road use. Use at your own risk.

 

[liveforphysics]

Got it setup to test, including a FLIR view of heat path during a long sustained loading before and after adding ferro fluid. However, due to some technical dyno issues I didn't get to test. Soon!

 

[speedmd]

Luke, you have one lucky lady!

 

[neptronix]

So I just cracked open my Leaf motor for the first time. I plan on changing phase wires, bearings, painting it, cutting vent holes, and adding cooling fans...it's the whole lot for this motor.

I do not like the look of that. I hope that it is just poor finishing.

You might be the first one to get a funky cover.

 

[Cowardlyduck]

Thanks all for the comments on the side cover surface. It's hard to see from the photo, but it's really only on the surface, so I'm not overly concerned. Nevertheless, I've emailed Leafbike to ask them about it just to be sure.
I plan on drilling the side covers soon anyway, so if the cracking does extend into the main metal itself I should be able to see it in the cross-section of the drilled holes.

How'd you push the bearing out of the side cover on the phase wire side without cutting your bundle? Still trying to figure out a reasonable solution for this that won't shoot parts all over my shop when I throw it in the press... I don't have tube that large of diameter to just make a spacer for, and I assume the cover needs to be held by the perimeter to not damage it. (bearing has to stay on the shaft while cover comes off)

I didn't...yet. I'm planning on upgrading the phases anyway so might just cut them, then pull the hall wires through before taking the side cover off.
In all my dealings with hub motor's, I've had a number of occasions where for whatever reason the bearing stay's on the shaft when taking the side covers off. I do tend to put grease in the side cover bearing slot before fitting new bearings so that might help it pop out more easily, so that might be worth doing before you put the wire side cover back on next time.

Got it setup to test, including a FLIR view of heat path during a long sustained loading before and after adding ferro fluid. However, due to some technical dyno issues I didn't get to test. Soon!

Thanks for testing this Luke. Looking forward to the results.

I do not like the look of that. I hope that it is just poor finishing.<br abp="693"><br abp="694">You might be the first one to get a funky cover.

Yeah, I think it's just on the surface...when I drill it, it should show whether or not it runs deeper.
Worst case, I will try and get new side covers from Leafbike under warranty if they will honour it.

Cheers

 

[speedmd]

There is a reason it is marked with a X, unless you put it there. No such thing as cracks just in the surface. Every one of them is a major fault where cold material failed to solidify /fuse fully before cooling or cooled too quickly at the surface. If you used die penetrant ( http://www.zoro.com/crc-weld-check-penetrant-105-oz-03106/i/G5180445/?gclid=CP2twKP9z8gCFcEXHwodWO0O7A&gclsrc=aw.ds ) on this I bet you would find it is much more than skin deep. I would make sure you can get a replacement cover before you make it even less supportive with vent holes.

 

[Cowardlyduck]

There is a reason it is marked with a X, unless you put it there. No such thing as cracks just in the surface. Every one of them is a major fault where cold material failed to solidify /fuse fully before cooling or cooled too quickly at the surface. If you used die penetrant ( http://www.zoro.com/crc-weld-check-penetrant-105-oz-03106/i/G5180445/?gclid=CP2twKP9z8gCFcEXHwodWO0O7A&gclsrc=aw.ds ) on this I bet you would find it is much more than skin deep. I would make sure you can get a replacement cover before you make it even less supportive with vent holes.

I'm not so sure about that. I emailed them and got this response:

Hello
It’s normal. Motor may work in the rain or web environment. Shaft is steel, will be rust.
This rust will not effect noisy.
If you would like to pay shipping cost, we can send new cover with bearing to you.

Not that the explanation makes much sense mind you...so I honestly don't know at this stage.

I'm currently seeing if they can bundle some replacement side covers with a new motor purchase. In a separate email, they also had this to say:

We also have 2000w. 2000w can use 42mm or 50mm height magnet,phase wire,max 6mm.

Has anyone else heard about these other Leafbike motor's? Seems like they might be about to release something new.
A 42mm wide motor would be in direct competition with the MXUS 3000 or HS40xx motor's. Not sure a 50mm motor would fit with a freewheel on my bike, but would be nice if it did, although the weight might be too much for me.

Cheers

 

[Kodin]

Probably the motorcycle-style larger motor.

http://leafbike.com/products/e-moto...-48v-2000w-electric-motorcycle-motor-961.html

Tempting for higher power output, but no idea if they have freewheel covers or bicycle-sized dropout shafts.

Also, for what it's worth, all of my side covers show this sort of "crack" like outer surface irregularity. In my case it's not cracks, as the lines are convex, not concave.

You can see it to a far lesser degree here:

For your own reference, the bearings in the side covers appear to be glued in with some sort of bearing seat adhesive. I typically see it used in car parts, but this is the first time I've seen it in a motor. It's why I said I need a way of removing the bearing from the cover without destroying the cover.

 

[Punx0r]

The covers of my Goldenmotor 9C clone has similar but slightly less extensive surface crazing as that. No doubt potential stress raisers, but no signs of failure yet.

 

[speedmd]

No doubt they will try to ignore the questions of the bad flow / surface cracks as someone in management decided to ship borderline parts. Get some new covers. No excuse for this. Normal to see grain boundary blotching, but when cracks are throughout as on the photo, they should never be used in a structural application IMO. This paper is for zinc but will maybe help a bit understanding the dynamics of the casting process. http://www.eazall.com/classification-of-zinc-die-casting-defects

The bearing is most likely held with a retaining compound. Ask them what the release temperature is or what exactly is used. It will tap out easily with a wooden dowel once you get to the correct temp. 250C for most. Wear old winter gloves. http://www.henkelna.com/industrial/retaining-compounds-14963.htm

 

[Cowardlyduck]

New freewheel side cover on it's way. $40 shipping
Nothing was acknowledged, but the fact that they are sending me a replacement kind of indicates it is not normal.

As suspected, the 42-50mm wide motor was the motorcycle one. I suggested they would get some decent sales if they made a 40-45mm motor for 150mm dropouts. We'll see what they say.

Cheers

 

[Cowardlyduck]

Just got my disc side cover off and bearings out.
The disc side cover came off easy without damaging the wires at all. Because the axle narrows for the threaded section just where the wires exit the hole and there is a minor recess there, the wire actually fits under the bearing without issue. This is the first hub motor with this design I've ever been able to remove the wire side cover off without destroying the wires. Good design IMO.

To get the bearings out I used a flame torch to heat up the outside edge evenly around the bearing, then used a hole saw drill piece matched to the size of the inner race to punch them out using a few blows from a hammer. Worked well, and both bearings came out very easily intact with only 2-3 blows. If there was any glue in there I didn't feel it.

I've just ordered some high efficiently replacement bearings.
http://au.rs-online.com/web/p/ball-bearings/7192042 - This one for the freewheel side.

http://au.rs-online.com/web/p/ball-bearings/7192052And this one for the wire side.

I've used these bearings successfully on my other motor's and they work well.

Cheers

 

[bowlofsalad]

Just got my disc side cover off and bearings out.
The disc side cover came off easy without damaging the wires at all. Because the axle narrows for the threaded section just where the wires exit the hole and there is a minor recess there, the wire actually fits under the bearing without issue. This is the first hub motor with this design I've ever been able to remove the wire side cover off without destroying the wires. Good design IMO.

To get the bearings out I used a flame torch to heat up the outside edge evenly around the bearing, then used a hole saw drill piece matched to the size of the inner race to punch them out using a few blows from a hammer. Worked well, and both bearings came out very easily intact with only 2-3 blows. If there was any glue in there I didn't feel it.

I've just ordered some high efficiently replacement bearings.
http://au.rs-online.com/web/p/ball-bearings/7192042 - This one for the freewheel side.

http://au.rs-online.com/web/p/ball-bearings/7192052And this one for the wire side.

I've used these bearings successfully on my other motor's and they work well.

Cheers

Are you going to measure the power difference in watts between one bearing and another?

Why did you choose shielded bearings?

 

[Cowardlyduck]

Are you going to measure the power difference in watts between one bearing and another?

Lol, no, that's ridiculous. I just like the idea of them...they are barely more expensive, and I was replacing them anyway. The difference is probably minuscule.

Why did you choose shielded bearings?

Why not? Actually I tried fully sealed bearings last time and I didn't like them. Sure they might be better at keeping crap out, but one; I've never had issues with dirt messing up shielded bearings in any of my motor's, two; the increased resistance is definately noticible at least when turning by hand, and three; you only need the shield on one side, the inside since the other side is up against the side cover.

Cheers

 

[bowlofsalad]

Why not? Actually I tried fully sealed bearings last time and I didn't like them. Sure they might be better at keeping crap out, but one; I've never had issues with dirt messing up shielded bearings in any of my motor's, two; the increased resistance is definately noticible at least when turning by hand, and three; you only need the shield on one side, the inside since the other side is up against the side cover.

Why do seals exist?