Questions about KT controller and Q100 hub motors

[clarkpark]

I have tentatively decided to convert my 29er hardtail to 2wd using the Cute Q100 (AKM-100) motors and KT sine wave controllers. Based on feedback read here, I will order from topbikekit rather than BMS. Questions:

1. topbikekit offers a dual motor controller, which is strangely more expensive than two individual controllers. I like the idea of reducing the number of cables, but couldn't I achieve the same thing by splicing cables for battery, display, throttle, PAS, brake on two separate controllers? Isn't it better to keep the controller closer to the motor? Any experience using this dual controller?
http://www.topbikekit.com/t06ss-36v48v-kt-dual-motor-driving-brushless-sine-wave-controller-p-904.html

2. Topbikekit also offers controllers with waterproof connectors. It appears this decreases the spaghetti quite a bit, but it seems that I will need matching cables and connectors for all components. Is there a guide somewhere to get this right? Any feedback on this system? This system is not offered on the dual motor controller, so how would I implement this on 2wd, since splicing would presumably not be a good idea on this conntector system?
http://www.topbikekit.com/t06s-24v36v250w-torque-simulation-sine-wave-with-julei-waterproof-connector-p-732.html

3. Topbikekits AKM-100 motors (AKM-100c and AKM-100h for me) are only offered in high and low speed windings (no mid speed). I understand high speed winding would not be good on 29" wheels, but since I will have twice the torque it seems like I should be OK with high speed windings. Looks OK on the simulator. On my commute, I have one ~1/2 mile moderate hill and a couple of short steep hills, on which I dont mind providing some extra watts. Any feedback is appreciated.

4. Any advice on source for 18650 cells? Right now I am leaning towards Queen Battery. I will build my own battery pack, and I dont mind checking all the cells before building.

Thanks for any feedback or advice,
Clark

 

[amberwolf]

you can order julet and higo connectors / etc from https://www.e-bike-technologies.de/index.php/en/ and probably other places; http://ebikes.ca has some other types, forget what they're called. you can splice waterproof connectors in fine and still get waterproof connnections, as long as you do the splices in a waterproof way. or remove the entire cable harness and directly solder the new cables to the board inside the controller.


the dual controller may be like the old crystalyte dual controllers, where they just have two smaller controllers inside one big case, and parallel the throttle, battery, ebrake, etc connectors inside the box.

personally i prefer two separate controllers, so i can replace just one when something fails.

one of the best threads for 2wd setup and wiring and whatnot is teklektik's yuba mundo 2wd build.

 

[docw009]

With a dual controller, I believe the major advantage is no second display to clutter up the cockpit. Having one display to set a common PAS level on both motors seems a plus. Having a built-in shared throttle is also nice.

Separate controllers means two displays and more wiring. While you can jumper a KT controller to run w/o a display, it's always ON, and it's not clear what the default PAS level is.

As for the AKM motors, I have one that has been spoked but not installed in a bike yet, and three BMSBattery Q100H that I've run for several years. I believe the Q100H are 12:1 internal gearing while the AKM is 5:1. I spoked them all into 20" rims, so it will be interesting to see how the AKM runs. I power these motors with 20A KT controllers, both square and sine wave.

For waterproofing, most of my motors used the 9 pin Bafang cables and I put a matching cable on the controller. It was a bear to splice those and have adequate strain relief. Then I realized I could run the cable right into the controller and the splicing was trivial. I discarded the idea of splicing in Higo/Julet for the other functions because it costs around $10 to replace a pair of connectors. On one bike, I made my own 4in1, splicing the throttle, LCD, and two brake levers directly to a 10 pin cable. Used two 5 pin JST's at the controller. Still not waterproof, but neater.

I did build a 2WD fatbike using separate controllers, two displays and two separate throttles up front. I could have dispensed with the 2nd display, but I had planned to hook up PAS. Never happened. It's now back to RWD.

 

[amberwolf]

With a dual controller, I believe the major advantage is no second display to clutter up the cockpit. Having one display to set a common PAS level on both motors seems a plus. Having a built-in shared throttle is also nice.

Separate controllers means two displays and more wiring. While you can jumper a KT controller to run w/o a display, it's always ON, and it's not clear what the default PAS level is.

it *should* work to use one display for two controllers (something I intend to test with a lishui/kingmeter setup at some point on the Raine Trike, now that i have a couple of the controller/display sets):

only one controller will be able to send data to the display, but the display can send data to both controllers.

wire the tx line from the display to the rx line on both controllers.

wire the rx line on the display to the tx line on just one controller. (if necessary, a switch can be used to be able to see data from either controller, but that should only be needed if troubleshooting things.

the controller gets power from either controller, and it's keyswitch/control output goes to both controllers.

ground is already common between the controllers, so display ground comes from either one.

this is probably how the "dual controller" is actually setup inside with just one display.



fwiw, a test can be done, by using two displays, with each one's rx line to it's own controller's tx line , but the tx line from one display to both controllers, and the tx line from the other display left unconnected.

so you get to see what both controllers are doing when you use the display to change settings.

 

[clarkpark]

I believe the Q100H are 12:1 internal gearing while the AKM is 5:1.

My understanding is that the BMS Q100 motors are the very same motors as the AKM-100 motors. Am I missing something here?

 

[docw009]

Clarpark, I take it back. Thinking about my MXUS motor, where I spent an hour trying to figure the gearing/magnet count from watching a hall sensor flash. The AKM's are 12.6:1 reduction ratio and you can get 201, 260 and 328 rpm.

Amberwolf - that's a nice trick to run two controllers off one display..

 

[motomech]

As I have probably run every combo of Q100 in 2WD drive over the years, the OP might want to search my posts using key-words like 2WD, Q100, Cute, etc.
The best was dual "260's" in 26" wheels and the biggest fail was a pair of 328's. The bike got off the line well enough and the top speed was an amazing 28 MPH(on 52 Volts), but it took forever as the mid range was really lazy. And although I can't go into the reasons why this happens here and now, running the high-speed 328 in a big whl. and adding hills can start melting things, usually in this order(even w/ 2WD);
1)Phase wire connectors, or if better ones were installed, the phase wires themselves.
2)something in the controller will smoke
3)Finally, something in the motor will melt, including the Halls
The 260's are far away the best for 24" whl.s and up and it's best to not start mixing motor speed ranges. So much so it's worth forgoing the CST and biting the bullet, buying the Enoch DNP and running Q100H's. The CST isn't very durable anyhow(I just melted something inside one and it took out the controller as well) and it's not like one would be shifting gears much w/ a 2WD anyhow.
Actually, after all my 2WD mini-motor builds, If I started anew, I would just do a single. Single motor on the frt. if the system is less than 1200 Watts or so. Rear for systems over that. Actually, that's where I'm @ here in Mexico where I can't get parts. After 6 months I'm down to one bike that's Q100 powered on the frt from the 2WD bike and the single Q100CST bike I started with.
I always did it the easiest way, 2 motors, 2 controllers, 2 packs, 2 complete systems w/ two throttles. Actually, the rear ran off PAS most of the time, added the frt via throttle when needed and that turned out to be 25% of the time for all the different combos I tried. And the frt pack was sized accordingly, 25% the size of the main pack.
All kinds of reasons are given in the anals of this site extolling the virtues of 2WD,, but unless one is dealing with snow and ice, none are really worth the extra added complexity, except maybe for being able to keep each system power low, helping the low-tech throttles we use, work smoother w/ it's motor.

 

[motomech]

Clarpark, I take it back. Thinking about my MXUS motor, where I spent an hour trying to figure the gearing/magnet count from watching a hall sensor flash. The AKM's are 12.6:1 reduction ratio and you can get 201, 260 and 328 rpm.

Actually, the different motor speed ranges each have their own compound gear ratios and even those have changed slightly over the years, especially between the Ananda's and the Aikema's in the "201" and "328" versions. As near as I can tell, the windings are all basicly the same with the CST having stators 30% narrower. Not sure about the magnets, thinking the "H" and the "C"'s hav e higher order strength magnets.
It's been a really long time since I tried using the first "KT"'s w/ the Q100, but I seem to recall I used "32 magnets"(16 poles?) while setting up the controller.

 

[clarkpark]

Being practical, I should also consider a larger RWD system as well. The Q128c / AKM-128CST seems like a candidate. How do I simulate that motor since it does not show up in the motor simulator tool? Is there a similar motor I could use as a proxy?
Are there other relatively small rear cassette hub motors to consider? Originally I was sold on the 2-speed Xiongda motor until I realized it doesn't fit in my aluminum frame dropouts and not available in cassette configuration. My bike has 2x10 SRAM drivetrain, so I don't think it works to go to freewheel without ditching the entire drive system. I also want to keep the entire bike light.

 

[docw009]

One thing that seems different with my AKM motor. I measured the O.L.D. at 137 mm. I never had a fit problem with the BMSBattery motors fitting into a frame, but I've got an alloy one that is exactly 135 mm, and that won't go.

I got it down to 135mm by taking 2mm off the spacer that sits inside the freewheel, but the freewheel is still too close to the frame. Hits the derailleur stop. There's room on the other end, but the way the axle is machined, I can't cut more thread on that side without a machine shop.

Maybe I'll mix/match the other Q100H's I have. The other frame may be bigger.