Kepler Friction drive comes of age.

Discussions related to motors other than hub motors.
This includes R/C motors, botttom bracket, roller and geared drives.
User avatar
Kepler   1 GW

1 GW
Posts: 3228
Joined: Nov 08 2009 9:22pm
Location: Eastern suburbs Melbourne Australia

Re: Kepler Friction drive comes of age.

Post by Kepler » Jun 26 2018 4:29am

Most of the parts are now in for the new batch of drives. Just waiting on a bulk order of 304 Stainless steel fasteners.
DriveVer4.jpg
DriveVer4.jpg (131.3 KiB) Viewed 3967 times
And of course a new drive deserves a new bike. Went with a Cyclocross bike this time so i could fit wider tires to for a bit more comfort an grip during high speed commuting.
trek-boone-5-disc-2018-cyclocross-bike-grey-EV311934-7000-1.jpg
trek-boone-5-disc-2018-cyclocross-bike-grey-EV311934-7000-1.jpg (118.41 KiB) Viewed 3967 times
Should have the drives ready for shipping by the end of next week. Stay tuned.
Current Rides

Lightest true ebike on the planet: ON ROAD viewtopic.php?f=6&t=74269
eBoost on facebook: http://www.facebook.com/pages/Eboost/200306283342024/

Slopes   10 mW

10 mW
Posts: 25
Joined: Apr 01 2017 10:41am

Re: Kepler Friction drive comes of age.

Post by Slopes » Jun 29 2018 8:29am

Kepler wrote:
Jun 23 2018 4:52am
Need a bit more information.

Are you using a Hall throttle or a resistive throttle like a Magura?

...
Thanks for your suggestions, Kepler. Yes it is a hall-effect throttle.

I didn't have any luck following your wiring scheme... pic below (sorry for poor quality - the green wire from throttle going to the centre pin of where the pot used to be).

I firstly hooked up the servo tester - with its pot still attached - to the +5V and ground from the Vesc and that all worked fine (LEDs functioning). I then removed the pot and tacked on the rest of the wiring (inc. 'UART and PPM' in the BLDC Tool) following your advice. But when I power up the Vesc again everything's dead.

I could go back to the running the throttle through the ADC port but having bluetooth with the 'Vesc Monitor' app providing live feedback would be a great addition to the bike.

Image

User avatar
Kepler   1 GW

1 GW
Posts: 3228
Joined: Nov 08 2009 9:22pm
Location: Eastern suburbs Melbourne Australia

Re: Kepler Friction drive comes of age.

Post by Kepler » Jun 30 2018 2:51am

It might be just the type of servo tester you are using. The wiring looks correct.

I would try eliminating the Vesc and see if you can drive a servo.

Disconnect the yellow signal wire going to the vesc but keep the black and red connected from the vesc to power servo tester.
Connect a servo to the servo output of the servo tester and see if it dives the servo when the throttle is twisted.
52cdwz1.jpg
If it doesn't drive, you know the issue is with the servo tester.
Personally I would give the servo tester a miss and go to Arduino. Driving a servo with an analog signal is Arduino 101.
Current Rides

Lightest true ebike on the planet: ON ROAD viewtopic.php?f=6&t=74269
eBoost on facebook: http://www.facebook.com/pages/Eboost/200306283342024/

User avatar
Kepler   1 GW

1 GW
Posts: 3228
Joined: Nov 08 2009 9:22pm
Location: Eastern suburbs Melbourne Australia

Re: Kepler Friction drive comes of age.

Post by Kepler » Jun 30 2018 5:33pm

If you plan to have a go at using an Arduino to drive the vesc with a hall throttle, here is a simple guide to get there.

1- Purchase an Arduino Nano. The Nano has a USB connection built in for programming making connection straight forward.
2- Download the free Arduino software from here https://www.arduino.cc/
3- Wire the Nano as shown below.
arduino-original-boards-arduino-nano-27026601486_x700.jpg
arduino-original-boards-arduino-nano-27026601486_x700.jpg (182.26 KiB) Viewed 3862 times
4- Connect the Nano to your laptop through a USB conncetion
5- Start the Arduino software and set it to the correct port. (Go to Tools then Port)
6- Go to File - Examples - Servo - knob, and open the sketch. The code will now be displayed within the Arduino Sketchbook.
This code is for a potentiometer and as such the code expects a 0V to 5V sweep. We need a 1V to 4V sweep to suit a hall throttle and
as such the scaling in the code needs to be changed. instead of an input of 0 to 1023, we re scale this to 200 to 800.
7- Once you have made the change, compile the code and upload to the Arduino by clicking on the arrow pointing right in the the top
left hand corner pf the program.
Capture.JPG
Capture.JPG (100.81 KiB) Viewed 3862 times
This will now output a PPM signal to your Vesc that will need to be scaled in your Vesc Tool.

I hope that helps.
Current Rides

Lightest true ebike on the planet: ON ROAD viewtopic.php?f=6&t=74269
eBoost on facebook: http://www.facebook.com/pages/Eboost/200306283342024/

Slopes   10 mW

10 mW
Posts: 25
Joined: Apr 01 2017 10:41am

Re: Kepler Friction drive comes of age.

Post by Slopes » Jul 02 2018 5:28am

Thanks for this Kepler - it's very useful. I've given up on the servo-tester hack and have an Arduino Nano board on order.

User avatar
Kepler   1 GW

1 GW
Posts: 3228
Joined: Nov 08 2009 9:22pm
Location: Eastern suburbs Melbourne Australia

Re: Kepler Friction drive comes of age.

Post by Kepler » Jul 02 2018 6:05am

Good to hear. You wont regret going down the Arduino path. I have really enjoyed learning some basic programming and the opportunities it opens up.
Current Rides

Lightest true ebike on the planet: ON ROAD viewtopic.php?f=6&t=74269
eBoost on facebook: http://www.facebook.com/pages/Eboost/200306283342024/

ScooterMan101   1 MW

1 MW
Posts: 1871
Joined: Oct 06 2012 4:45pm
Location: South of San Jose, California.

Re: Kepler Friction drive comes of age.

Post by ScooterMan101 » Jul 02 2018 11:32am

What places sell the Arduino Nano ?

one place I found , Mouser sells it for $ 28.86 , but I see a different place Gearbest , that list's one for $ 4.22
My first conversion ... Sold

viewtopic.php?f=3&t=71378&p=1077497&hil ... 1#p1077497

It's 2018 already, ( now 2019 ) lets get some real , improved e-bike / e-velomobile / e-motorcycle designs .

Slopes   10 mW

10 mW
Posts: 25
Joined: Apr 01 2017 10:41am

Re: Kepler Friction drive comes of age.

Post by Slopes » Jul 02 2018 3:24pm

ScooterMan101 wrote:
Jul 02 2018 11:32am
What places sell the Arduino Nano ?

one place I found , Mouser sells it for $ 28.86 , but I see a different place Gearbest , that list's one for $ 4.22
I found ebay had a lot of them - for around the $4 mark.

User avatar
Kepler   1 GW

1 GW
Posts: 3228
Joined: Nov 08 2009 9:22pm
Location: Eastern suburbs Melbourne Australia

Re: Kepler Friction drive comes of age.

Post by Kepler » Jul 07 2018 6:35pm

The standard drive bracket suits probably %70 of bike frames however making the main plate in two pieces opens up opportunities to mount the drive on practically any type of frame you can imagine. This is achieved by either making your own custom Upper Main Plate that say attaches to your kickstand mount or you can use the recently designed optional extension Lower Main Plate that extends the drive mounting point up to 130mm (distance between the centre of bottom bracket and the face of the tire)
Drive7.jpg
Drive7.jpg (61.69 KiB) Viewed 3731 times
Drive8.jpg
Drive8.jpg (58.48 KiB) Viewed 3731 times
It should be noted that the current design using the split Main Plate design with the Anti Rotation Plate has reduced the overall adjustment of the standard drive to a range of 65mm to 95mm (BB to tire face). Its unfortunately a compromise I needed to make but I think was worth the trade off.
Current Rides

Lightest true ebike on the planet: ON ROAD viewtopic.php?f=6&t=74269
eBoost on facebook: http://www.facebook.com/pages/Eboost/200306283342024/

Aeron   10 W

10 W
Posts: 84
Joined: Jun 12 2018 8:04am
Location: Europe

Re: Kepler Friction drive comes of age.

Post by Aeron » Jul 12 2018 3:54am

Has someone though of using the HK "Sk8" series motors ? Like this 6354 or 5045 for example. I was wondering whether the ribbed can would be a problem.

User avatar
Kepler   1 GW

1 GW
Posts: 3228
Joined: Nov 08 2009 9:22pm
Location: Eastern suburbs Melbourne Australia

Re: Kepler Friction drive comes of age.

Post by Kepler » Jul 26 2018 5:39am

Lots of requests for pedal assist. I can see merit in using pedal assist but I like the idea of still using the single button for 2 speeds and kill but only operational if pedaling. Anyway working on the code at the moment. thought it would be piece of cake lol. Wrong!!!

Anyway, got my litte test jig built and trying a few ideas now. give me a week or two :D
Attachments
20180726_201216.jpg
20180726_201216.jpg (196.01 KiB) Viewed 3444 times
Current Rides

Lightest true ebike on the planet: ON ROAD viewtopic.php?f=6&t=74269
eBoost on facebook: http://www.facebook.com/pages/Eboost/200306283342024/

User avatar
Kepler   1 GW

1 GW
Posts: 3228
Joined: Nov 08 2009 9:22pm
Location: Eastern suburbs Melbourne Australia

Re: Kepler Friction drive comes of age.

Post by Kepler » Jul 28 2018 8:41pm

I am currently in the process of putting together some YouTube Tutorials for various aspects of the drive.

The video below is just to demonstrate the button action and usability in real world riding conditions.

The next series of videos will be be on setup of the Vesc to use in conjunction with the drive. As there have been quite a few of the Arduino button throttle interfaces released, I thought i would make the next video tutorial on calibrating the button throttle within the Vesc tool. Stay tuned for that one.

Also plan to do some drive assembly and fitment videos in the near future. Let me know if you have have any specific requests.

Current Rides

Lightest true ebike on the planet: ON ROAD viewtopic.php?f=6&t=74269
eBoost on facebook: http://www.facebook.com/pages/Eboost/200306283342024/

User avatar
Kepler   1 GW

1 GW
Posts: 3228
Joined: Nov 08 2009 9:22pm
Location: Eastern suburbs Melbourne Australia

Re: Kepler Friction drive comes of age.

Post by Kepler » Jul 28 2018 11:36pm

Here is a Video tutorial on scaling the button controller in the Vesc. Hope it helps. :)

Current Rides

Lightest true ebike on the planet: ON ROAD viewtopic.php?f=6&t=74269
eBoost on facebook: http://www.facebook.com/pages/Eboost/200306283342024/

Ebuilt   1 W

1 W
Posts: 54
Joined: Jun 19 2018 11:27pm
Location: West coast usa

Re: Kepler Friction drive comes of age.

Post by Ebuilt » Aug 04 2018 8:57pm

Holding on to our seats for the video of arduino onterface calibration! This unit is so cool and tiny in person! Thanks John!
:bolt: :bolt: :bolt: :bolt: :bolt: :bolt: :bolt: :bolt: :bolt: :bolt: :bolt: :bolt: :bolt: :bolt:

Aeron   10 W

10 W
Posts: 84
Joined: Jun 12 2018 8:04am
Location: Europe

Re: Kepler Friction drive comes of age.

Post by Aeron » Sep 18 2018 5:09am

Hello there,

I've received my drive mount and started its installation. I don't want to denigrate this excellent work, but a little thing bothers me and I wanted to ask here if I had missed something.

Here is the thing: by mounting between the BB and the BB shell on the crank side of the bike, the chainline is moved outwards from 2mm (and it's kind of a problem on my bike). Is there any particular reason for that ? I thought about mounting the thing on the opposite side, but then the gravity spring does not fit.

So, two questions: is there a particular reason to mount the drive on the crank side? If you think the drive could be mounted on the non-crank side, would it be possible to buy a "reverse" gravity spring (one with the locking pin on the other side)?

User avatar
Kepler   1 GW

1 GW
Posts: 3228
Joined: Nov 08 2009 9:22pm
Location: Eastern suburbs Melbourne Australia

Re: Kepler Friction drive comes of age.

Post by Kepler » Sep 18 2018 6:06am

the 2.5mm change in chain-line hasn't been a problem for me so far but if it doesn't work on your bike, by all means, mount the drive on the non drive side of BB.

I will place a reverse gravity spring in the post tomorrow for you. No charge of course :)
Current Rides

Lightest true ebike on the planet: ON ROAD viewtopic.php?f=6&t=74269
eBoost on facebook: http://www.facebook.com/pages/Eboost/200306283342024/

Aeron   10 W

10 W
Posts: 84
Joined: Jun 12 2018 8:04am
Location: Europe

Re: Kepler Friction drive comes of age.

Post by Aeron » Sep 18 2018 3:33pm

Great, thanks a lot !
I have a 1x10 drivetrain, I've found these sometimes sensitive to chainline adjustments.
Last edited by Aeron on Feb 01 2019 4:58am, edited 1 time in total.

User avatar
Kepler   1 GW

1 GW
Posts: 3228
Joined: Nov 08 2009 9:22pm
Location: Eastern suburbs Melbourne Australia

Re: Kepler Friction drive comes of age.

Post by Kepler » Sep 20 2018 4:13am

Spring posted yesterday. :)
Current Rides

Lightest true ebike on the planet: ON ROAD viewtopic.php?f=6&t=74269
eBoost on facebook: http://www.facebook.com/pages/Eboost/200306283342024/

Aeron   10 W

10 W
Posts: 84
Joined: Jun 12 2018 8:04am
Location: Europe

Re: Kepler Friction drive comes of age.

Post by Aeron » Oct 04 2018 11:17am

I forgot to let you know I received it. This is great, thanks !

User avatar
Kepler   1 GW

1 GW
Posts: 3228
Joined: Nov 08 2009 9:22pm
Location: Eastern suburbs Melbourne Australia

Re: Kepler Friction drive comes of age.

Post by Kepler » Nov 10 2018 11:16pm

Kepler wrote:
Jul 26 2018 5:39am
Lots of requests for pedal assist. I can see merit in using pedal assist but I like the idea of still using the single button for 2 speeds and kill but only operational if pedaling. Anyway working on the code at the moment. thought it would be piece of cake lol. Wrong!!!

Anyway, got my litte test jig built and trying a few ideas now. give me a week or two :D
Been distracted with my Mountain Bike friction drive setup over the past month or 2 https://www.endless-sphere.com/forums/v ... 8&t=96581 but with that done and dusted, I have been back working on an Arduino based PAS system for the drive.

Took me a little while to figure out how I wanted to do this but finally came up with a solution that I liked. Being a minimalistic drive system, I wanted to make sure the PAS system was also minimalistic and as such came up with a solution that uses a single PAS sensor and a single magnet.

The PAS works in conjunction with a a single button throttle.
After the battery is plugged in, the drive stays switch off until the button is held down for half a second.
With the PAS now active, the sensor needs the magnet to pass twice within a a given time period for the drive to activate.
This time period is equal to a cadence of around 40 to 50 RPM.
Once activated by the PAS sensor, the drive will output 60% throttle.
If you stop peddling or drop below the cadence threshold, the drive will deactivate.
The button throttle also acts as a boost button. Holding the button down will ramp the throttle to 100%
Releasing the throttle button will return the drive to cadence control.
A short push of the button will deactivate the assist completely.

Below is a short video of PAS and button throttle operation. Still to road test the system but I think it is looking promising.

Current Rides

Lightest true ebike on the planet: ON ROAD viewtopic.php?f=6&t=74269
eBoost on facebook: http://www.facebook.com/pages/Eboost/200306283342024/

cbr009   10 µW

10 µW
Posts: 5
Joined: Nov 01 2014 5:37pm
Location: Canberra, AU

Re: Kepler Friction drive comes of age.

Post by cbr009 » Nov 11 2018 4:26am

Great work John, look forward to seeing the road test results.
Mick

User avatar
Kepler   1 GW

1 GW
Posts: 3228
Joined: Nov 08 2009 9:22pm
Location: Eastern suburbs Melbourne Australia

Re: Kepler Friction drive comes of age.

Post by Kepler » Nov 18 2018 7:47pm

Road testing of the Arduino based PAS control is now complete. Settings that I came up with on the bench translated well to the road with the assist starting in a very predictable manor. Although theoretically two turns of the crank should start the drive, in real life it takes three or four turns to start the drive. This is because the cranks need to be up to speed before the assist requirement is registered. I quite like this as it means you can slow pedal when maneuvering say through a slow tight bend without the drive starting on you.

Stopping pedaling sees the drive hold for about a second before dropping off. This also has proven to be a nice length of time with no overrun experienced. A really quick stop might see an overrun issue but the Vesc can handle this ok.

And of course you can start the drive anytime by holding the boost button or stop the drive with a quick short press of the button. Again this work as designed.

60% pedal assist and 100% boost also works as hoped and as such see no reason to adjust this.

A slight change to hardware. The standard PAS sensor that is used on most ebikes was not as sensitive as I liked. So I used a OH090U. - H Uni-Polar Hall effect sensor instead. This sensor worked perfectly and allows the magnet to be a good 10mm away rom the sensor and still get a reliable trigger.
Attachments
Capture.PNG
Capture.PNG (46.13 KiB) Viewed 2301 times
Current Rides

Lightest true ebike on the planet: ON ROAD viewtopic.php?f=6&t=74269
eBoost on facebook: http://www.facebook.com/pages/Eboost/200306283342024/

juicy77   1 µW

1 µW
Posts: 4
Joined: Mar 18 2018 6:22am

Re: Kepler Friction drive comes of age.

Post by juicy77 » Jan 10 2019 12:06am

Has anyone tested the kepler drive on dirt/gravel/mud? How does it fare? Is there excessive slippage? I am considering doing a tour of South America e-assisted and weighing my options either Kepler v Hub driven.

User avatar
Kepler   1 GW

1 GW
Posts: 3228
Joined: Nov 08 2009 9:22pm
Location: Eastern suburbs Melbourne Australia

Re: Kepler Friction drive comes of age.

Post by Kepler » Jan 10 2019 12:23am

I have built a custom friction drive for my full suspension mountain bike which works well in most weather. Haven't done much mud testing but for road and gravel, the setup work great.

I don't think I would recommend it for extended touring around South America though.
viewtopic.php?f=28&t=96581
Current Rides

Lightest true ebike on the planet: ON ROAD viewtopic.php?f=6&t=74269
eBoost on facebook: http://www.facebook.com/pages/Eboost/200306283342024/

User avatar
cal3thousand   1.21 GW

1.21 GW
Posts: 3606
Joined: Mar 26 2012 4:47pm
Location: California

Re: Kepler Friction drive comes of age.

Post by cal3thousand » Mar 12 2019 6:48pm

Will these be back in production soon? Please? :D
Get a Cycle Analyst and a Multimeter, you're still a noob if you don't have at least one of each.

Planning on posting questions or buying anything on this site? Put up your country (at minimum) on your profile. This is a worldwide forum and we haven't reached clairvoyance.

Post Reply