Hillhaters Mk 3 Friction drive !

[deVries]

It may have been me playing with the "brake" programming and other settings at random ?
Ah well, waiting for the mail man again !

Just checking in with a bump to see what plans you may have for testing next?

I think Oatnet is focused on another build, not friction, and I don't know what Kepler is up to either? :wink:

 

[Hillhater]

I have been tinkering with other projects and waiting for some free time ( Xmas visitors etc etc).
I have now got the 3rd ESC to possibly try, but am considering a different motor , possibly fitted with Halls as this ESC can run that way also, but really hoping for more clues as to what to change next !
Watch this space...its going to be (ESC ) death or glory ! :lol:

 

[rearengine]

Hillhater... Just a thought .. You say the motor jitters.. that is what mine did ...It was voltage sag for sure... I rewired it from the bat turminals to the ESC with 12 gage wire.. No problems since ... I have no Idea how you are wired.. so this info may not pertain at all ... Bill

 

[Samd]

Hahaha. Just discovered this thread via google. What I thought last night was my illgotten idea has gone full circle.

I took a ride with Mr Kepler last month and have been in love with his drive ever since. I liked the way his latest drive connected where the kickstand attaches on a normal bike. Visibly stealth. I found a cheap ($30) 6354 200kV motor on ebay and ordered it thinking I would ghetto one up. But tried to think of alternative mounts that were easy to attach and cheaply available. I prefer component assembly of store bought consumer parts over manufacturing staff from raw material stock - suits the DIY folk.

So last night I got the idea to mount the drive suspended on one of the 30mm wide camlocked seat post racks I bought cheap at Aldi last month, mine has held up to about 40kg so far. There is always the option of adding struts between the rack and rear dropout zones if more strength needed (unless you are on a suspension bike).
And the battery could sit on top, with a small pannier the unit wouldnt be visible.


So I googled the phrase "Seat post rack" and clicked 'images' and about half way down was Hillhater's drive unit! He'd already been there and done that! Albeit with a headstem - which is a ripper of an idea. Which isn't surprising - Aprilia owners tend to be smart

What a small world this sphere is!

 

[Hillhater]

. Ha ! :lol: .. actually my "Mk1" prototype drive was mounted from a clamp on seat post rack ( K mart !).
... And Spinning Magnets further refined the "head stem" idea by sourcing a fully adjustable head stem,

I agree, Keplers latest drive is ultra stealthy, but lacks the quick removal functionality of the seat post mounted drives.
(complete drive, ESC, and battery pack all off in seconds for security in city use )

 

[Samd]

Hey in keeping with the repurposing idea, could you clamp an old front hub in the headstem to use as a pivot mount?

 

[Spicerack]

As long as the diameter of the centre part of the hub is right- or make up a solid spacer for it. Not a bad idea.

 

[deVries]

I took a ride with Mr Kepler last month and have been in love with his drive ever since. I liked the way his latest drive connected where the kickstand attaches on a normal bike. Visibly stealth. I found a cheap ($30) 6354 200kV motor on ebay and ordered it thinking I would ghetto one up. But tried to think of alternative mounts that were easy to attach and cheaply available. I prefer component assembly of store bought consumer parts over manufacturing staff from raw material stock - suits the DIY folk.

So last night I got the idea to mount the drive suspended on one of the 30mm wide camlocked seat post racks I bought cheap at Aldi last month, mine has held up to about 40kg so far. There is always the option of adding struts between the rack and rear dropout zones if more strength needed (unless you are on a suspension bike).
And the battery could sit on top, with a small pannier the unit wouldnt be visible.

Search on EVTodd... his success really got Kepler & others started on their own ideas... *amazingly* EVTodd's design is the winner in my books to this day, since he successfully produced a system that could start without pedaling off the line. He once had video posted that showed his bike to be very fast too. It is still an awesomely simple design that can be very stealthy too. It's just not as small as Kepler's, but it is still much better performance wise, imo, unless you just want some pedal assist during a normal bicycle ride with your velo spandex buds.

 

[rearengine]

Hillhater.. Do you have your drive up and running ?? You were having trouble with it about a year ago ... We see your posts on others threads , but nothing on your build ... Or have I missed it ?? I hope you got it working... Great idea with the stem ...

Devries... Your right ... EVTodd being the instigator ...


Bill

 

[Samd]

I had a good read of EV Todd's posts yesterday. He's done well! Think I prefer the friction off the can like Kepler's though.

Because of my design constraint to come up with something that is an off the shelf component assembly that requires no parts manufacture am sticking with Kepler's use of the can rather than a friction shaft. For me it's just tinkering - I won't be getting off my Aprilia electric anytime soon, but the outrunner seems like a good solution for mates trying to DIY their own for a under few hundred bucks.

I have one of these speed controllers in my shed (I brought to use with a bafang) I want to try with the outrunner before going down the route of (ESC with BEC + servo tester throttle). Anyone know if anyone has tried this yet? Maybe sync issues down low? I don't want to go over 500W.
http://www.ebay.com.au/itm/24V-500W-Brushless-E-bike-Controller-Without-Hall-/160481316074?pt=LH_DefaultDomain_0&hash=item255d6e8cea

I like this idea of using this controller because it's also plug and play , so is throttle. Maybe the low volt cutout will kill my ability to get the right speed for an outrunner setup.

 

[Hillhater]

Sam,
i suspect that controller will not run your RC outrunner at the rpm you expect. Its designed for low rpm ( <500) hub motors, not the >6000rpm of the RC motors.
also the 500W rating would worry me as the RC motors will pull 2+kW easily.
..But hey ! ..its worth a try ! :lol:
Bill, .. yes, i didnt run it long as i had many issues with motor/controller sync. I need a different motor and probably a CC ESC to eliminate my suspicions of causes. Turnigy motors dried up for a long while so other projects ( Aprilia mods etc) took priority .

 

[spinningmagnets]

The smaller 50mm outrunners have very high kV's, and the slightest hill can build up heat fairly fast, with the smallish motor not having enough mass to survive a hill thats a little too steep and a little too long. For the Kepler/Adrian style drive with the can being the drive surface, the 63mm motors seem to be the size that has the most satisfied customers.

If you have the budget, you will not be disappointed with the Castle Creations ESCs. I have had NO sync issues with my CC-ESC under ALL conditions, and I have TRIED to get it to bog. The Hobbywing ESC did have sync issues at the lower voltages (22V-24V) when I could feel the drive bogging down on hard acceleration. No sync issues using the Hobbywing with 10S (37V), and I suspect it would be even better at 12S (44V).

The very affordable high-amp generic ESCs I tried (Miking?), had sync issues under all conditions.

The problem with using higher voltages on a shell-drive is the high kVs available. I recently saw a 63mm motor with a low kV of 150 (Leader Hobby?). If I was using a shell-drive I think I would try that kV at 8S (28V) using the CC mid-price Phoenix-ICE line which will go as high as 8S.

"If you have a friction-drive where the roller and motor are separate"...on flat land the 1-1/4 inch roller using 22V and a CC ESC is IMHO the most affordable solution. For hills, the Hobbywing esc using voltages at 10S (or more) on a one-inch roller is my daily ride when the weather is nice (I'm a winter wimp).

I am happy with the Blue Exceed 63mm at a kV of 295, http://www.hobbypartz.com/mopose.html and the popular kV of 200 would allow 20-ish MPH at 44V-48V. Amp-draw on my friction drives is so consistently low (based on felt heat of the motor on hills, and reports from others) that I suspect the drives are not battery-chemistry limited (LiPo is good, but not required).

the website lists the 8S (33V max) Phoenix ICE-75A as 75A continuous, and 130A temporary peak. I made eight back-to-back hard acceleration runs on a slight uphill using 24V of SLA with a 1.0" diameter roller and the 295-kV motor, 180-lb rider on fat 26" tires.

The data-logging showed that all the runs were 60A peak, 30A to maintain constant top speed on a slight uphill, and downhill amps were almost unreadable because they were so low.

The Hobbywing ESC is a 70A continuous unit, and other than added input capacitors, I haven't been able to fry it, and I have hammered them all. For a shell-drive (which is effectively a 2-1/2 inch diameter roller), I would use a 120A ESC at a minimum.

I just looked for a CC ESC link, and found out they are now selling a 50V four-capacitor pack for $25. I highly recommend this for 10S and lower voltages (for 12S the 63V caps are best).
http://www.castlecreations.com/products/cc-cap-pack.html

 

[Alan B]

Clever designs, great work! Makes me want to try one!!