Kepler Bottom Bracket Friction Drive For Sale (Finally)

Jestronix said:
How's everyone going on the waterproofing side of things , I've been thinking of power velocitys 6fet controller and a sensored motor if the vesc isn't water proofable.

Also no issues on suspensioned bikes the spring keeps contact ?

Also thoughts on roughing up the motor surface for wet and dry use ?

I don't know how thick the can metal on the motor is, but I was wondering about doing some creative light scoring with a dremel and a cut-off disc.

My bracket arrived here in the UK yesterday BTW :D
 
Jestronix said:
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Also no issues on suspensioned bikes the spring keeps contact ?

Also thoughts on roughing up the motor surface for wet and dry use ?

The drive is designed for hardtails. That being said, I have not tested it on a suspension rear. It may stay in contact ok with a higher then neutral buoyancy tension on the gravity spring. Will hopefully get a chance to test this in the next few weeks.

I have tried roughing up the motor surface. Made no difference in the wet. You need an aggressive knurled metal surface to grip in the wet. Something like this.
 

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Kepler said:
Keeping the drive bracket secure with it mounted to just one side of the bottom bracket does have some challenges. Adding the anti slip material to where the drive mates with the BB face has made a big difference but it still means the bottom bracket bearing cup needs to be very tight to keep the drive secure.

The drive will move on the bottom bracket more easily using a larger and heavier motor. I had very few issues with the 50mm motors but the extra weight of the 63mm motor caused more slippage issues. What I have found is that on shut down, the motor gets driven into the end stop bolt with quite a force. Against the end stop metal bolt, this creates a sharp "jack hammering" action. This makes a bit of an unpleasant knocking sound each time the drive disengages and is constantly trying to rotate the drive on the bottom bracket.

I have come up with a very simple fix for this which i have been testing for about a week now. Here it is:


I simply added 3 #7 o rings to the lower end stop bolt so that the swing arm now has a padded landing point when disengaging.

Firstly this modification has made disengagement silent rather then hearing a metallic clunk every time the drive disengaged. This is a nice improvement in itself. However I think the big advantage will be a lot less tenancy for the drive to move on the bottom bracket due to the reduced jack hammering action on disengagement.

The modification is super simple. Just unscrew the bottom end stop and install the 3 small o rings over the end stop screw. Once done, re set your end stop position to allow for the extra diameter of the o rings and you are ready to go.

All new drives will be shipped with this modification and i will send out o rings to all those that have perchased drives so far.

If you cant wait for my delivey, the o ring only cost a few cents and can be bought through most industrial suppliers.

The part is as follows: Neoprene #7 o ring. 5/32 ID x 9/32 OD x 1/16 Width.

This doesn't mean you cant use the drive as shipped as it works perfectly well. This is just an enhancement to the design.

Sadly the O-rings gave way after a week of use. Disappointing as it was shaping up to be a good solution. Need to find a more robust dampening material. :cry:
 
Use a piece of tubing.

Speaking of gravity springs will it handle being bent to allow it to work with the bracket reversed?
 
Perhaps contact Cane Creek, in North Carolina , U.S.A.
and tell them your need and ask them for the Type and Density of the Rubber they use on the ThudBuster Suspension Seat Post.
I have had two of them the LT and ST , and the Rubber has always held up , never did have to replace it.
Also remember the rubber spacers and sometimes dampeners in the old suspension forks ?
There might be something like that for Furniture that is small enough.




Kepler said:
Sadly the O-rings gave way after a week of use. Disappointing as it was shaping up to be a good solution. Need to find a more robust dampening material. :cry:
 
Hi Kepler,

Instead of O-rings I am trying out 4mm tubing used for water irrigation(super cheap at Bunnings), a perfect fit for the bolts. Will let you know how it goes.
Today I also swapped over to the smaller 5055 motor and rode my usual ride to work. I like it better as it seems to hook up easier and suits me regarding how much effort I want to put in. Times were the same. Battery usage the same. It did whine a little more although I always deactivate when near people or bikes.
My second bracket arrived yesterday. Spring is much better. Now to decide which bike to put it on. Still waiting on vesc-x to arrive so might try out a traditional e-bike controller in the meantime.
 
I will give that hose material a try. I think that should work quite well. Thanks for the heads up. I do like the smaller motor for stealth and weight and the power is still adequate. However lowest noise level possible is still my main focus.
 
Not sure if this is the best place to post it but I made a VESC-X mount to use with this power system.

H8Ggdi1.png

http://imgur.com/rkdRNUt
http://imgur.com/g4A2dCk
http://imgur.com/HwcDIgz

3d printed uses an existing water bottle mount and wraps around the Seat tube.

http://www.thingiverse.com/thing:2320385
 
Very neat. Nice work. Perhaps a water resistant cover could be incorporated into the design.

Do you have your system up and running now?

And good pickup on the gravity spring. It wont work if you reverse the mounting position of the drive. The spring is very easy to make though. it just 0.064" 16SWG piano wire. You can get it from most hobby shops.
 
I'm just waiting on some wire to get things wired up.

Thought I had some 14 gauge but seem to have used it all. So I am going to run the whole thing in 12 in case I decide I need more power.

I figure the gravity spring should be easy enough to make.

As far as a splash guard I plan on waterproofing the whole thing once it is ready to go.
 
Hello Kepler

Thank you for the great thread. I am also interested in getting one of your kits but the question is how to order how to pay etc. Do you have a web site?

The second question is - what else I should buy and probably from where (if I'm in EU). Again if you have a web site I could read myself I guess you are bored answering one and the same question 1 million times.

And the third and may be the most important one - I have a pretty large 48V (which actually measures 53 or even 55 when it is fully charged) - are there suitable 48V motors for that? (I'd like to keep using that battery).

Thanks!
 
Most 48v controllers have 60v or 63v caps. You can open up your controller and look. So what battery do you have ? Motors don't know voltage just watts. I think all your questions are in the thread my be a little hard for the eu .
 
The battert is LiFePO4 48V 10Ah

So what I should order in addition to Kepler's thing to create a full kit?
 
It is an out-runner. It would work ok however i cant guarantee that the bolt pattern matches my swing arm as some of these skateboard motors have gone to a non standard mounting centres.

The size and Kv would suit a 36V setup. You don't need hall sensors but if you are want to use them, you can.
 
Thanks, the drawing says the hole circle diameter is 38mm.

[edit] I'll just drill extra holes at 38mm circle diameter.
 
Got mine powered up today.

https://www.youtube.com/watch?v=62ZYj0bmXuk

I still haven't made a reverse gravity spring so I am having intermittent engagement if I am slow to turn the knob. Probably wont be an issue if I go to push button control.
 
Hello Kepler.im a newb to RC motors so its way over my head.but im pretty sure my 60s track bike needs this :wink: ..
 
I've just acquired a secondhand 'Specialized Globe' hybrid bike for this friction drive. The BB is British at 68mm width, but it has a screw-in sealed cartridge fitting rather than the cup and cone type. Will I have to convert it to cup and cone to attach the drive unit?.. it doesn't look as if there's enough of a lip on the cartridge to firmly clamp the drive unit between it and the BB.
 
My Turnigy SK3 6354 motor arrived today from hobbyking.... I paid €56 for the motor, €19 shipping for it to Dublin and then got stung with a further €48 import duty/admin/handling fee with DPD transport. Expensive in the end but looking forward to getting the FOCBOX motor controller to try the motor out.
 
liamcaff said:
My Turnigy SK3 6354 motor arrived today from hobbyking.... I paid €56 for the motor, €19 shipping for it to Dublin and then got stung with a further €48 import duty/admin/handling fee with DPD transport. Expensive in the end but looking forward to getting the FOCBOX motor controller to try the motor out.

€48 ! What kind of duty is this ! How come u wear the bill ?

Also where did u get the focbox , I couldn't find any in stock
 
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