Kepler Bottom Bracket Friction Drive For Sale (Finally)

Hi Kepler,

please sign me up for one unit when they are done.

I would love to mount it on a folding bike, running a 170kv 63mm motor on 24V nominal with an older VESC version, hoping to use as many parts from my mountainboard build as possible.

Does anyone have experience with a similar combination of parts?

I would like to purchase 2 kits as available. Shipping to Wisconsin, USA.

Hey Kepler, let me know if you prefer PM, but I have some questions about operating the friction drive design with a torque-simulation controller like a S06s bmsbattery controller. The main issue I'm finding is that the controller has a very gentle ramp on the torque, so in turn it doesn't really want to climb into the tire. I assembled my bike a while ago, and got it tuned pretty nicely so that it is so *almost* touching normally, and the slightest touch goes into the wheel. When I lift the back wheel, I have no issue getting it to operate as designed and "climb" into the tire.

However, when I'm riding on the bike, the motor doesn't climb into the tire well enough because of that gentle slope. It slips and falls back. I tuned the spring to the point where it is overbalanced, and that can work, but then it doesn't really ever fall away from the wheel.

One solution I have is perhaps the only solution with the given controller I have. If I setup the motor so it's always touching the wheel as I''m not killed by the drag of such a small motor, but I can use it for assist. This is a little defeatist because afterall one of the most beautiful parts of this kepler drive is the fact you get a "drag free" motorless operation.

Another solution might be to get a VESC controller, or a different controller that doesn't sacrifice having sine-wave operation for normal use, but allowing me to use a different more aggressive current ramp to start the engagement process.

Maybe a third solution would be to go down the road of some of your alternative designs, and add a brake cable to force engagement into the tire.

What do you think? Any advice? I am also considering modifying the S06s controller to have a higher current draw. It's something like a measly 17A atm. I can swap the mosfets and double that, and will probably get a more aggressive ramp that might work for me.

I would like at least 2 brackets. Let me know when they're available

Hi Kin,

S06 has plenty of torque to maintain engagement. I have found that as litte as 100Ws will keep the motor engaged.

I would suggest problem lies with the setup geometry. Dont have motor pushing too had into the tire. With the motor fully engaged, you should be able hold the motor still overcome the grip of the motor by turn the tire with some moderate force.

Make sure you motor end stop is quite high. Have the motor just clear the chainstay by a few mm.

Make sure your gravity spring is taking the full weight of the motor so the motor becomes neutrally buoyant. With the motor gravity spring set correctly, the motor should be just lightly touching the tire. The bottom stop really isn't needed if the gravity spring is adjusted properly.

Lastly, make sure the pivot arm is moving freely. It can get jammed up with road grime and as such requires periodical cleaning.

Let me know how that goes.

Do yourself a favor though and get a Vesc. the Vesc Mini from Flipsky is a ripper. https://flipsky.net/collections/ele...esc-widely-used-in-eskateboard-escooter-ebike

I can make you Arduino interface if you need one.

aethyr said:

I would like at least 2 brackets. Let me know when they're available

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No problems, will let you know. Still waiting on parts from the laser cutters but I will have plenty of stock once these part arrives.

Kepler said:

Hi Kin,
[Kepler's response]
/quote]

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With respect to torque to maintain engagement, I think maybe I was confused a little when I posted. At first I was observing that I could cause engagement with the back wheel off the ground, and then it wouldn't work well when I was on the bike. This made me *say* that the issue was insufficient startup torque, but in retrospect the act of "starting engagement" requires pretty much the same startup torque in both cases, so the difference is something to do with the quality of the engagement I think.

This goes back to mechanics, as you said. I will look at the mechanics next chance I get. I think you're right that I have something off. I will dig into where I maybe did not originally install the system closely enough to your directions. I'll also take some pictures so I can send over some "what didn't work" and "what did work" pics.

My main reason for liking the S06s is that I have a few controllers floating around on different projects and it can be nice to become accustomed to a single platform. VESC has traditionally been a bit too expensive for some of my projects that have multiple motors, though the price of various VESC options has gotten a lot better recently. Might get into it soon.

Kepler,

Noticed you are responding to folks to say "Brackets" and I said "kits" in my initial, so I may have used wrong words... I would like 2 brackets when they are available.

Thanks.

Dear Kepler,
bought one of your brackets from second hand and I am in the progress of assembling everything. I have set up a arduino with a vesc and could activate the motor with a simple Hall sensored thumb throttle. I would like the arduino to act as your one button with a hall sensor setup, with an additional brake switch to meet your German laws. Do you sell your configured arduino code? Or could you please sent it to me via pm. Looking forward to build up more bike with your brackets. That code lines would be more that helpfully.
Many Thanks

At this stage I haven't done the combination of PAS and hall brake switches. I do have a PAS sketch and a separate hall brake sensor sketch though. Wouldn't be too hard to combine the sketches. I am not programmer though and use Visuino to write my programs. I could send you the Visunio files if that helps.

That would be a perfect, thank you!

Hi Kepler, two of us now have all the kit ready to go, just eagerly awaiting your mounts, so please do yell when you have some available. Thank you.

Finally, drive brackets are back in stock.

I have sent PMs to all that have reached out to me. If you didn't receive a PM please let me know and I will make contact with you.

I can provide Ardunio interfaces and button throttles if you are after these also.

Hi Kepler,

Great news! Please to hear the brackets are available again.

I posted that I was interested on 9th May but I don't appear to have received a PM.

I'd like a bracket and may also be interested in the kit you mentioned (back in June 2018) if you are still considering it as an option. I'd be looking for fully programmed Vesc, Arduino microcontroller, Button throttle interface, metr bluetooth, pedal cadance sensor etc.
Ideally I'd like to have a 'road legal' setting which, in the UK, involves:
- 25 km/h (15.5 mph) max assisted speed
- 250 Watts (maximum continuous rated power)
- The e-bike’s pedals must be in motion for motor assistance to be provided

Is the kit something you are still considering?

Either way, I'd like a bracket!

Thanks

Steve

No problems PM sent.

Laser cut parts are in. Now for assembly.

Also interested in getting the details of a similar setup to tallbally

PM sent.

Hi Kepler

Do you have any drive brackets in stock? If so could you let me know how to order one? I'm based in the UK.

Also - I am keen on finding out more about the kit that tallbally was enquiring about. Could you provide some details?

Thanks

I'm definitely interested in the kit, but didn't receive a PM.

Hi everybody!
does our friend Kepler still distribute this kit? where to buy?
the facebook page seems not up to date.
I am very interested by this system and am curious to test it with the VESC.
thanks.

Yes drive brackets are still for sale. Will send you a PM dirk pitt

I didn't get a PM either?

PM now sent

I need something helping me on hills (torque needed) in a rainy environment (london uk).

Could the friction drive be a solution?