Modifying a DD hub motor.

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Modifying a DD hub motor.

Post by ScooterMan101 » Feb 04 2019 1:41am

Since many of the long time members here on E.S. like DD rear hub motors, about a year ago I bought a Rear DD for experimenting with .
However is has a sticker on it that says 26 inch/36volt and a low speed , of which I forgot as I write this. it was rated at either 350 or 500 watt. ( not the V2 1500 watt)

As far as I can tell it is one of the early MXUS Rear DD's like a V1 ?

So it does not have the aluminium core, it has the heavier steel core.

What can I do to get more speed and amp ability out of this ?

Would having a machinist shave off some of the metal core work ? as from what I have read the newer V2's with the aluminium core are lighter weight and can disipate heat more ? ( somewhere there is a spinningmagnet's article on the V2 MXUS that describes the aluminium core ( if I am even describing it as a core correctly ? ).

The whole thing weighs in at 14.5 + pounds for the hub/spokes/rim. So I would like to shave of some weight and provide some cooling abilities ( I do not ride in the rain and I can use compressed air to get out dust every once in a while, since I keep it inside on carpet I do not want to use statoraid and fins would add weight so those are out as well )
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Re: Modifying a DD hub motor.

Post by amberwolf » Feb 04 2019 2:48am

From what Iv'e seen, the "v1" "v2" "v3" MXUS people generally write about (the last few years, at least) are the MXUS "3K" or "3000 watt" (in a 20" wheel, at least), more specifically known as the 450x series (where x is the winding number, the turns).

They're pretty heavy motors, over 17 pounds bare motor.

Specs here, along with discussion of the various versions:
https://endless-sphere.com/forums/viewt ... =mxus+3000

MXUS does make a bunch of different motors, and different versions of probably most of them, including geared hubs (which are usually the kind of things rated in the 200-350w range, vs DD hubs that are usually rated 500w and up) and various DD hubs. AFAICR they are also the originators of the very common "9C" type motor of a few years back, which was typically rated at 500w. They make a more recent version of it that I think has a slightly wider stator and magnets, that is a 1000w or 1500w. I think it's called the XF40 or something like that. Pretty sure it's in the http://ebikes.ca/simulator at Grin Tech, if you want to play around with what it can do.


Without pics/etc I can't tell if what you have is the 450x series or something smaller, but it's more likely at that wattage rating and weight to be a smaller motor.


Regarding removing any of the steel support structure, I don't recommend it. It's there to keep the stator in place under the stresses of applied power, so if you also want to get more power out of it, removing support increases risk of structural failure under power. (the wheel wouldn't collapse, as it's supported by the case and bearings, but the stator could break off the axle.

Not a likely scenario, but possible; it has actually happened to people with the aluminum stators on some older motors, I think mostly Crystalyte brand, but not because of shaving down the supports, rather from manufacturing defects and "overclocking" the motor with more current (torque) than it could handle).

Besides, you couldn't remove enough metal off the stator supports to make a significant weight difference, even if you removed it entirely. Almost all the weight is in the laminations and copper, and the magnets and iron backing of those (which is part of the spoke flange / rotor).

Also, the more weight you remove, the less mass it has to make a heatsink to help keep the stator a bit cooler on average, by soaking up some of the heat from acceleration bursts and regen braking.


If you're actually talking about the steel laminations the copper is wound around, you don't want to remove any of that, as it's actively part of the magnetic "circuit" of the motor.



If you are completely against adding even the tiny weight of statorade (and if necessary, the small weight of fins), and instead must remove weight, then the best method of cooling is one of the various ways people have done of drilling holes in the covers. There are a number of methods, from giant holes that can compromise teh structural integrity of the covers, to lots of little holes around the periphery of the cover on one side, and other little holes around the bearing area of the other cover. And other variations on that. They'll all remove a tiny amount of weight, but not very much.

There is a good thread by Justin_LE, something like "definitive testing of heating and cooling of hubmotors", that has significant amounts of actual testing data on which methods do what kind of cooling, so you could decide which method(s) to use. There's also discussion there of various other methods, but not much (if any) actual test data to support the ideas (mostly just anecdotal).



To get more speed, you either use a bigger wheel, or a higher voltage.


To get more power, you need more current, so a bigger controller and battery. Higher voltage often works to get higher power, too, but you may also need higher current, depending on what you are after.

The simulator will help you figure out what combination of factors will do what you want the best way, if your motor is one of the ones on there, or at least if there is a similar one there.

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Re: Modifying a DD hub motor.

Post by ScooterMan101 » Feb 04 2019 3:55am

I just took a close look at it, it says on one of the covers XF40 1202 0222

Then on a sticker it says 36v , 26 " K.T. / then L ?

Diameter is around 220 mm wide not including the flanges, and width is around 40-43 wide not including the bulges of outer covers ( measured 43mm outside at thinnest parts of the covers .

I looked before and could not find the XF40 on the Grin Calculator ,

( Nor could I find the MXUS 08 either )

Is there a motor just like it ( XF40 and 08 ) ?

Main reason for wanting some weight reduction is because it is going on a aluminium bike that does not have much material at the rear dropouts .
it is about 16-17 lbs with the freewheel.

Main reason for wanting holes in the side covers is to allow me to over volt and over amp it.

If anyone has experience with a XF40 what is the Max Volts can I put through it and max amps ?

I will look for spinningmagnets article on the older MXUS's latter ( the google search only turned up his article on the newer and higher power ones done on December 18 2016 there was an earlier one that google does not find that was a year or two/three before that one, that showed the difference between the steel and aluminium cores )
My first conversion ...

https://endless-sphere.com/forums/viewt ... 1#p1077497

It's 2018 already, lets get some real , improved e-bike / e-velomobile / e-motorcycle designs .

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Re: Modifying a DD hub motor.

Post by amberwolf » Feb 04 2019 11:18am

ScooterMan101 wrote:
Feb 04 2019 3:55am
I just took a close look at it, it says on one of the covers XF40 1202 0222
AFAICR, the 1202-0222 is just manufacture date and serial number. To get the winding you have to open it up and look on the stator or stator support, if they wrote it on there (they don't always). If it's not on there, you won't know what winding it is, but you can assume it's the most common for that type, whatever that happens to be.


Then on a sticker it says 36v , 26 " K.T. / then L ?
That probably only means something to whoever sold it in a kit form, and likely doesn't have anything to do with the manufacturer specs.
width is around 40-43 wide not including the bulges of outer covers ( measured 43mm outside at thinnest parts of the covers .
The important width is the stator and magnet width. Can't get those without opening it up. You don't have to take the stator out of the rotor once open; you can use a piece of paper stuck thru the gap, and mark it, to get that width. It's probably 35mm or so.
I looked before and could not find the XF40 on the Grin Calculator ,
If it's not there, you could probably use one of the other MXUS or "9C" / clone motors that is 35mm width, in the same winding as yours, and get results close enough for guesstimates on overheating/etc.

Main reason for wanting some weight reduction is because it is going on a aluminium bike that does not have much material at the rear dropouts .
I'm not sure I understand the reasoning? If you mean to help with torque resistance, you'd use tight-fitting well-mounted torque arms or plates for that.

If you mean that you don't think the dropouts would take the mass of the motor hanging from them unsupported, well, they shouldn't experience that in normal riding, and I wouldn't want to ride a bike that wasn't built to take hits on the wheels from impacts/bumps/curbs/etc., which is the opposite of the hanging mass.

If it's an unsprung-mass suspension issue, you couldn't take enough weight off the motor safely to make a significant difference.

Otherwise, I'm not sure what effect a small (tiny, really) weight reduction in the motor/wheel would have. I doubt you could take even half a pound off the motor safely, without compromising either magnetic or structural characteristics.

it is about 16-17 lbs with the freewheel.
You could probabably save more weight by going from a multi-sprocket freewheel cluster to a singlespeed freewheel than any other weight trimming on there.

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Re: Modifying a DD hub motor.

Post by markz » Feb 04 2019 6:49pm

MXUS 3000W is the XF40-45H on https://www.ebikes.ca/tools/spoke-calc. ... pair=false
and the 440x on https://www.ebikes.ca/tools/simulator.html
(x is the turn count)
ScooterMan101 wrote:
Feb 04 2019 3:55am
.

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Re: Modifying a DD hub motor.

Post by neptronix » Feb 04 2019 8:36pm

Sounds like a MXUS version of a 9C motor clone,based on the weight ( 27mm wide ). But we only know for sure if you open it up and measure the stator width.

Those motors are rated 500w, but can take more with an increase in voltage. You can use the ebikes.ca sim for this. You'll need to pick the closest equivalent to your motor. It's likely that it's a 9C 2707+ on the simulator. ( however you won't see such good efficiency because the 9C+ has 0.35mm laminations whereas yours has .50 - so just dock yourself a couple hundred watts and ~5% efficiency )

Forget everything you read about the 3kW 45mm wide motor. Not relevant to what you have.
My first major build: 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w on a Turner O2 full suspension.

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Re: Modifying a DD hub motor.

Post by dogman dan » Feb 05 2019 7:15am

Most likely you have a 27 or 28 mm stator. If you don't have 35 mm or more from spoke flange to spoke flange, then its the typical, 500w rated dd motor commonly called 9 continent type, but cheaper laminations as said above. Still, the cheapo motor is not a terrible, inefficient motor at all. They run good enough for millions.

You can run it at 1500 with no issues whatsoever, so a 48v 30 amps controller will be a good match for it. It can run double that, but the motor will melt if your battery lasts long enough.

It might be a low rpm version, intended for 36v use on cargo bikes, but they are kind of rare in a rear motor. If its the typical wind, you will see over 25 mph when you run 48v on it. 27-30 mph depending on 7turn or 6t wind.

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Re: Modifying a DD hub motor.

Post by 999zip999 » Feb 05 2019 9:48am

Whe you start going up steep hills lugging the motor it will get hot fast. But careful and out the old JohnCR motor thermometer your hand and feel how hot it is. Do this before melting as E.S. does encourage the melting of these motor. Just ask Dogman.

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Re: Modifying a DD hub motor.

Post by dogman dan » Feb 06 2019 7:53am

To melt one, just overload it with weight. 300 pound dude, or a trailer, and ride up a steep hill.

But a 200 pound guy + bike motor battery that weighs 100 pounds or less, will make it up long hills up to 10% grades without overheating. Most highway and state roads are 8% or less.

City streets, and especially driveways can be crazy steep, but usually are not miles long. So you get to the top hot, but not enough time to actually overheat and melt hall sensors.

But when you to to 3000w, 72v 40 amps, then just hauling ass on the flat 40 mph for an hour will melt one. You get into that area where you pour in energy, but still run inefficient because of wind resistance and the windings are just too small for that much current. To run 40 mph for a long time, you just simply need wider magnets and double the copper in the core.

But the cheap motor will run 30 mph on the flat all day, on 48v 30 amps.

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Re: Modifying a DD hub motor.

Post by spinningmagnets » Feb 06 2019 8:51am

These are so cheap, they have frequently been experimented on. I would have also assumed that the steel stator support would be heavier than the aluminum one, however, the aluminum one is actually heavier due to how thick it is.

Steel costs less, so the affordable model uses steel that is as thin as possible, however it is slow to absorb heat, and slow to shed that heat. The aluminum core has to be much thicker to be as strong as the steel version, but when that is done, it is more expensive. The value of the aluminum is that it quickly absorbs heat spikes, and sheds that heat over time.

The first consideration for hot-rodding is to disassemble and then swap-in the fattest copper wires that you can for the motor phases. The most affordable motors still run the phase wires through a hollow axle, so it is a pain. You "might" get better copper fill by using six paired wires instead of three fatter single wires. Teflon insulation is thinner and more heat resistant than the common PVC or silicone insulation. Thinner insulation will equal more copper fill in the given space...

At a couple of inches of phase wire outside of the axle, go to even fatter wire, since copper is a great heat conductor, and the two feet of wire between the hub and controller can actually work well as a heat sink. That was an unexpected result when hot-rodders went to fat wire.

An ebike will use high amps in the first few seconds of acceleration (longer if the system is underpowered). Then, the amps will slide down to the "cruise" level. If you can absorb and shed the heat of acceleration, you can raise the amount of amps you are using. There are three ways to do that.

1) First, is buy $25 worth of ferro fluid, which fills the air-gap between the stator and the magnets in the rotor. The side-plates on the hubmotor are aluminum, and they have a lot of area to shed heat to the air. Adding aluminum fins (hubsinks) to the rim has a measurable effect that is beneficial, but the first step would be FF as far as bang for your buck.

2) Add a coffee-cups' worth of automatic transmission fluid (ATF). Add a tiny vent on the chain side right by the teeth of the largest sprocket (away from the rim). Even after adding RTV sealant to the sideplates during assembly, it will occasionally leak a drop or two. This does the same thing as FF, connect the hot stator to the aluminum sideplates. It also provides mass to absorb heat spikes from the stator.

3) Its a good thing these motors are cheap, because the third method is to drill large holes in the sideplates mto simply let the heat out. Most of the builder who did this also sprayed the insides with a paint-like lacquer/epoxy coating to water-proof (made for motors).

One way to produce less heat in the first place is to use thinner laminations, to reduce eddy-current heat. Cheap motors use 0.50mm lams, and the more expensive Leafbike and MXUS (etc) use 0.35mm.

Another source of failure on cheap hubs is the Hall sensors, so you might consider using a sensorless controller. You'd simply have to move the pedals a 1/4 turn to get the power flowing. Its almost a safety feature when kids are around....

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Re: Modifying a DD hub motor.

Post by markz » Feb 06 2019 11:45pm

Sometimes when I look at my axle, it looks slightly bent to me, it still runs right.

How much do you think it would cost for a machinist to spin up a decent axle?
Phase/Halls/Temp cable: Better to come out early or stay in all the way through the axle?
10 gauge would be nice, even #8 if possible.

For my bike, I could make the drop out slot a tad bigger, its a freebie bike, just dont want it to degrade in structural integrity.

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Re: Modifying a DD hub motor.

Post by amberwolf » Feb 07 2019 1:30am

markz wrote:
Feb 06 2019 11:45pm

How much do you think it would cost for a machinist to spin up a decent axle?
Tench used to make and sell axles; you can look up his old thread for what he charged, to get an idea.

My guess is the average cost for a one-off will be more than the motor it's for. ;)
Phase/Halls/Temp cable: Better to come out early or stay in all the way through the axle?
Better not to go thru the axle at all. Been a number of threads/etc about it, but if you use a bearing with a larger ID, so there's enough space between it's ID and the OD of the axle to fit the largest single wire you want to use, then make a ring that fills taht space that has holes in it to fit those wires (one hole per wire). Most likely the OD of the bearing will now have to be larger, too, so you probably have to modify the sidecover to hold it (or make a new cover). If its' a disc-brake hubmotor, then don't use the disc, and have the wires exit on that side. Hollow out the former disc rotor holder for the new bearing size, if it's enough space, and expand the ID of that side cover's axle hole to match the ID of the bearing.

Now you can have a solid axle with no wiring hole in it weakening it's structure. (that's one common place they break)

Since another place they break is at the shoulders where diameters change, you can do what Farfle did for his dual-stator MP motor, and completely replace the old axle design with a straight hollow tube of much larger diameter, and make clamping dropouts like those on a motorcycle fork (that hold a large-diameter front axle). No axle flats needed; the surface of this is enough to handle the torque. If it isn't, you can add a cotter pin thru the tube and clamps. If you still need more, you can spline the tube and clamps to match.

One hole is drilled into the tube (if you have relatively small wires; if you want huge wires maybe several smaller holes would be better? dunno), inbaord of the bearings, and the wires pass thru into the hollow tube, and come out at either end.

If you're using a rear hub, you're limited in axle size only by the space inside the freewheel for a thread-on type, or by the ID of the cassette freehub bearings for the splined type. If you don't intend to put a normal bike chain drive to the wheel in the usual ways, then even that limitation is not present, and then you're only limited by the size of the stator support web core inside the motor. If you don't mind machining a new one of those, then the limit is the space inside the stator itself. ;)

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Re: Modifying a DD hub motor.

Post by ScooterMan101 » Feb 08 2019 12:38am

Spinningmagnets,

Thanks, I am sure I have the steel stator support . ( I tried to take off the cover on the disc brake side but after taking out all the bolts it the cover did not come off )
How do people take the covers off ?
I have not yet tried the screw on freewheel side as I have just gotten a freewheel removal tool that will go over the 14 mm axle.

I was thinking about using larger wires , or 6 phase wires like you said , and bigger sensor wires as well however ... it has the HiGo waterproof connector. And one of the Controllers I can use is a lyen that has the HiGo connector to the motor.
So it would be allot of work do to re-wiring.

Living in California , I do not ride in the Rain. we get only up to 20 or so days of rain, ( except for this year ) I just wait until a dry day to ride.

Ferro Fluid sounds ok, however since I only ride in dry conditions once I figure out how to take the side plates off I would like , when the summer arrives , to just drill holes in the covers. ( I can always tape over them temporally if I do ride on a moisture saturated day ) .

There is a question about holes though, for those who know , there is a way to drill a hole to have air go in, and a different way to drill to have air sucked out.

Who knows how this would work on a spinning hub motor ?
My first conversion ...

https://endless-sphere.com/forums/viewt ... 1#p1077497

It's 2018 already, lets get some real , improved e-bike / e-velomobile / e-motorcycle designs .

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Re: Modifying a DD hub motor.

Post by ScooterMan101 » Feb 08 2019 12:49am

Amberwolf,

I would love to be able to have the wires exit out the side cover. However my frame only has disc brake tabs.

If anyone knows of a link to how others have done this with pictures please link here so others could do that. It would be helpful to do so in order to have larger phase and hall wires. ( would have to cut off the HiGo connectors though )

I have thought about what you said before about a single cog freewheel.
so today I ordered both a 7 speed screw on freewheel
and
a single cog screw on freewheel.
since I plan on trying different voltages . ( I will have a C.A. 2.3 connected so I can change settings easily ) I can find the voltage that works for the 18 tooth freewheel that I ordered.
When I get it I will try it out with the 9 speed chain and front chainrings to see if it works or if I will have to put on a 7/8 speed chain and buy 7/8 chainrings/derailleur and shifter.
If I do use the single cog freewheel, I will grind off the teeth on the derailleur pully's to use it as a tensioner . ( I have other pully's I can put on later if I use that derailleur in the future as a 9 speed system.
My first conversion ...

https://endless-sphere.com/forums/viewt ... 1#p1077497

It's 2018 already, lets get some real , improved e-bike / e-velomobile / e-motorcycle designs .

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Re: Modifying a DD hub motor.

Post by ScooterMan101 » Feb 08 2019 12:57am

From all that I have read here, I will just use a 10s pack up to 14s pack with the Lyen Controller, or use a 36-72 volt 30 amp controller with 10s pack on up to 16/18 s pack .
And drill holes in the covers , later.
Thinking more about Ferro Fluid more ... well I park the bike on carpet , carpet that I do not own and would have to pay the management company to replace. So Ferro Fluid is out.

Angle the holes towards the Axle ? or towards the Rim ?
Which would push in Air and which would suck out air ?

It would be nice to know how many volts and amps the Lyen controller will work on.
Since it does connect nicely up with HiGo connector to the motor wires with HiGo connector.
My first conversion ...

https://endless-sphere.com/forums/viewt ... 1#p1077497

It's 2018 already, lets get some real , improved e-bike / e-velomobile / e-motorcycle designs .

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Re: Modifying a DD hub motor.

Post by amberwolf » Feb 08 2019 2:20am

ScooterMan101 wrote:
Feb 08 2019 12:57am

Thinking more about Ferro Fluid more ... well I park the bike on carpet , carpet that I do not own and would have to pay the management company to replace. So Ferro Fluid is out.
? As long as the covers are sealed to the rotor, it's not going to leak (not like using an oil-filled hub where it can leak out of all sorts of places). Generally you're only going to use a few mL of it at most, anyway. Not much of it to go anywhere. The only report I recall of leakage was during high enough motor RPM to fling tiny droplets out thru unsealed covers during a test by Justin_LE on the dyno. (in the "definitive testing" thread, IIRC)

If you're really worried about it, you could take a large cardboard box, and open it up flat, and lay it on the carpet where you park the bike.

Angle the holes towards the Axle ? or towards the Rim ?
Which would push in Air and which would suck out air ?
You should look thru the "defnitive testing" thread to see which experiments worked best. I don't remember; just that it's been done about every way there is. :)

But there should be no need to angle holes. Some have done it, but I don't recall taht they did any specific experiments or provided specific temperature data under controlled conditions to show it made any difference. I suspect that smoothing surfaces such that airflow is smoother would make some difference, but I don't know how much.

None of the holes will actually push in air, but centrifugal forces should, once the wheel has been spinning fast enough, long enough, cause air to flow outward from the center. So holes closer to axle will be inlets for the air that is thrown out by the holes closer to the flanges.


It would be nice to know how many volts and amps the Lyen controller will work on.
Lyen himself should know what any particular model of his controller can do, if it's not one of the ones listed on the Lyen site or one of his sale threads here. Don't know how easy he is to get hold of, though.

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Re: Modifying a DD hub motor.

Post by amberwolf » Feb 08 2019 2:35am

ScooterMan101 wrote:
Feb 08 2019 12:38am

How do people take the covers off ?
There's a number of threads that talk about motor disassembly specifics for different motors, but generally all the DD motor hubs simply have covers taht are glued on with silicone or the like, and then bolted down. So you just ahve to cut thru the sealant, usually with a razor blade or similar, or a chisel to tap into the joint between cover edge and rotor face. However, you must be VERY careful not to go further than the inner edge of the rotor, just past the screw holes, or else you may hit the windings and destroy the motor. :(

If you don't have to take the cover off, it's safer not to.

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Re: Modifying a DD hub motor.

Post by amberwolf » Feb 08 2019 2:43am

ScooterMan101 wrote:
Feb 08 2019 12:49am
( would have to cut off the HiGo connectors though )
If you used larger wires, you'd want larger connectors anyway, to carry the current.

If I do use the single cog freewheel, I will grind off the teeth on the derailleur pully's to use it as a tensioner .
I wouldn't do that. They're there to keep the chain *on* the pulleys. If you remove them, the chain will be able to move side to side more and rub on or even catch on the derailer cage.

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Re: Modifying a DD hub motor.

Post by spinningmagnets » Feb 08 2019 12:58pm

The five tiny sensor wires don't need to be larger, they only carry a signal. If you need to ever replace those, I like Teflon-insulated 24-ga.

The motor phase wires are what needs to be fat, in order to carry higher amps without overheating.

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Re: Modifying a DD hub motor.

Post by markz » Feb 08 2019 8:46pm

To take the motor off, take off the non drive side cover plate, leave the wires be.
The cover plate you took off is facing up. Quickly drop the axle onto something soft.
Putting it back in is dangerous, keep your fingers aware of your fingers surrounding.
You can also buy a puller from the usual scumbags, Harbor Freight, Princess Auto, KMS Tools, ebay, amazon.

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Re: Modifying a DD hub motor.

Post by ScooterMan101 » Feb 11 2019 12:22pm

Amberwolf,

I found a 8 speed derailleur I had not used in years so I will use that as a chain tensioner if I use the single speed BMX Freewheel.

Amberwolf and Spinningmagnets,

There is more rain this winter than in the last 8 years in Northern California , Yesterday I went to one of the trails I want to test this DD hub on with the hub not yet installed and there were large streams where before there were only low lying areas of the trail .
I will wait until the rainy season ends to use bigger or add a second set of the three phase wires , and to open up the motor .
Also
I tried hooking up the Lyen controller and throttle to the motor,
I got a spark when hooking up the battery to controller . ( until I made a harness adaptor with a XT90 spark resistant connector )
But I tried three different throttles and none of them worked / got the motor to run .
I put the red and black wires from each throttle to the black and red wires out of the controller the other wire was different color for each throttle.
So
How to connect a throttle to a controller when both are from different Mgf's ?
And ...
I tried to true the hub motor rim yesterday and got a disappointing surprise, I have three spoke wrenches, 3.2/3.3/3.5 mm , However the nipples measure 3.8 or 3.8 mm . So now I have to wait to install the motor until I can get the proper spoke wrench and true it since there is a noticeable wobble on it . ( Wheel came built up in China )
Last edited by ScooterMan101 on Feb 11 2019 12:32pm, edited 1 time in total.
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It's 2018 already, lets get some real , improved e-bike / e-velomobile / e-motorcycle designs .

ScooterMan101   1 MW

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Re: Modifying a DD hub motor.

Post by ScooterMan101 » Feb 11 2019 12:26pm

Markz,

Thank You for the description on how to take off the cover of the MXUS XF40.
I just went yesterday to research the condition of a local trail on the bike not yet with the motor installed. and it is a good thing I did. We have had record rains in my area this winter and the trail is full of streams and muddy.
So
I will not be opening up the motor for a couple of months .
My first conversion ...

https://endless-sphere.com/forums/viewt ... 1#p1077497

It's 2018 already, lets get some real , improved e-bike / e-velomobile / e-motorcycle designs .

ScooterMan101   1 MW

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Re: Modifying a DD hub motor.

Post by ScooterMan101 » Feb 23 2019 2:50am

I have been slowly building up the bike , and now ran into a problem

The MXUS XF-40 DD rear hub had a plastic spacer on the disc brake mounting area of the hub, there probably because of the fact that the hub motor housing on the disc brake side protudes outwards so as to be in the way of a disc caliper.
I installed a 180 mm rotor and when the wheel was bolted up to the frame I noticed that the rotor was warped, strange because it was not before I installed it .
I tried to bend the rotor to no avail , and looking at it more thought perhaps the plastic disc rotor spacer was to blame. sure enough it was, so I put on a aluminium one that I found in my e-motor parts box, however ...
I now had stripped two of the 4mm holes in the motor cover . ( metal of the motor threads stripped, not the shimano bolts I used , they are still good )

So I used allot of thread locker on them and put the rotor back on, and motor back into the frame , then noticed that the body of the caliper where the bolt holes are to secure the caliper to the 180 adaptor was rubbing on the outside of the rotor.
I have ordered a 203 size rotor and adaptor so as to get the caliper near to the top of the outward buldge .

In the meantime, I am thinking that drilling and making the next size up holes/threads in metric might be a little too much.
Has anyone re theaded any of the disc brake rotor holes to a standard size that would be between the 4mm and a 5 mm ?
or
Heli Coil such a small 4mm hole ?
My first conversion ...

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It's 2018 already, lets get some real , improved e-bike / e-velomobile / e-motorcycle designs .

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dogman dan   100 GW

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Re: Modifying a DD hub motor.

Post by dogman dan » Feb 25 2019 8:13am

Spacers as needed under the rotor so your caliper clears. Then same size spacer on the axle. You can flex out your frame 2-3 mm to make it fit no problem.

Should be able to use whatever size disk you need to fit your caliper setup now. Get a good straight disk, and bolt it on. Put some high temp expoxy like jb weld or pc7 on the stripped out bolts and snug up gently. Then they will not fall out, and still provide a stop from rotation. The other bolts should clamp it fine.

Re vent holes, unless huge, they don't do a lot while riding, but if you overclock that motor to 3000w, its worth it to drill some smallish holes, like half inch, every two inches around the outer edge. Now you can see the hot copper through the holes and see, and smell, when you cooked them off. Again, it won't cool that motor much while riding, but you will avoid what reallly tends to cook off hall sensors. When you stop, you lose the wind cooling, and motor core temps really climb. When stopped, your motor will vent out the top holes, and suck cool air in the bottom ones. Better still, do a slow roll cool down, about 10 mph for 10 min, after you start smelling your melting motor.

This will not do that much to cool the copper, but it can save your hall sensors. Those will cook off inside a really hot motor that stops before cooled some.

ScooterMan101   1 MW

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Re: Modifying a DD hub motor.

Post by ScooterMan101 » Mar 15 2019 2:07am

Well the Rains finally stopped a couple of days ago so I finally got to try out a DD rear hub for the first time. Not bad , I see why people like these , it was very smooth and quiet .
However it started to struggle on a shallow 4% hill and almost quit on 5 % to 10 % when I got to 10-11 % section of the hill I had to stop and turn around.

The hub has just one cable coming out of it , and it has a what looks like a HiGo connector, so to get it up and running faster I hooked up a small 6 fet controller to it . The controller only had one set of cable ( with a HiGo connector that plugged right into the motor cable) , and two wires for a throttle.

Well that mid size 6 fet controller was very weak. since there was no Cycle Analyst wire/connector out of the controller I put in the between battery and controller a Turnigy Watt Meter and Power Analyzer. the display of which has very small numbers , not good for a e-bike , it is only good for RC testing I found out by trying it on the bike.

I have now 3 test days on it, the first two I could not believe my eyes , it showed only 16.77 amps were being drawn from the battery pack into the controller . No wonder the bike was very slow to get up to speed. Top speed on a 12 s pack 20-21 mph .
On the 3rd day , today I hooked up the Turnigy Watt Meter without un pluging the anti-spark connector from the battery pack ... I heard a loud pop !
Now the display on the Turnigy does not work, the bike However does still run with the amps and volts running through it.
So
It is time to take off that controller and put on a different controller and a C.A. V2.3 I have lying around.
I have two controllers in which to use. The first one I want to use is a Lyen 9 fet 3077 controller ( 093077ST-MII-LYEN EDITION ) I don't know the upper voltage or amperage since neither is printed anywhere on the controller, nor is there a Ohm value to set it to the C.A. correctly ?
I want to use this lyen first since it also has the cable with the Phase wires and Hall Sensor wires in a cable with matching HiGo connector. So I don't have to try out different hall combos .

However I must get some information on the controller first .

I will ask the questions in the Technical E-Bike section.

If you had one of these 9 fet Lyen controllers from a few years ago, and only know the general info, that would be helpful here on this thread.
My first conversion ...

https://endless-sphere.com/forums/viewt ... 1#p1077497

It's 2018 already, lets get some real , improved e-bike / e-velomobile / e-motorcycle designs .

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