µk-drive

[HAL9000v2.0]

[micro-kilo drive]
Here is my version on small bike drive. I have been working on this allmost a year now and this combination of motor/controler/f....ng-EU-rules works the best.
It has 958 grams w/o batteries and up to 800W works fine. For bigger power it needs different rolling surface and maybe support bearing. This one acualy made 500km on training rollers with constant power output (on roller) between 720-775W with thermal equilibrium at 36°C with room temperature of 22°C. The drive can work constantly at 1kw up to room temperature of 42°C. After that controller thermal protection shuts down the controller. I think it is at some 85°C.
I have tryed all sort of engagement mechanisms and finaly I have decided to go with hand operated lever. The pressure will be controlled with 2 springs. Also I have to install current limiter but first I have to measure efficienci corectly. I want to have 249,99 W on the wheel. For now I have some 57% and I found out that it is proportional with roller pressure. The best way will be to make some adjustable pressure device...

Here are some pictures...

 

[drifter]

G'day Hal, very neat work, I was thinking about using a hand operated lever to remove any drag from the wheel while peddling only. Please keep us informed of any further developments. What is the controller and battery.
Robbo

 

[HAL9000v2.0]

controller: http://www.hobbycity.com/hobbyking/store/uh_viewItem.asp?idProduct=10331 heat sink is removed and board with fets is screwed directly to aluminium plate in the middle. On other side is CPU cooler and heat from motor "is comming" through one side mount.
motor: http://www.hobbycity.com/hobbyking/store/uh_viewItem.asp?idProduct=4913
Throtle for now: http://www.hobbycity.com/hobbyking/store/uh_viewItem.asp?idProduct=8296
batteries: 4S A123 20Ah

 

[adrian_sm]

Nice work, hal. Very similar components to what I am using.

Got a pic of it mounted on the bike.

For now I have some 57% and I found out that it is proportional with roller pressure. The best way will be to make some adjustable pressure device...

How you are doing your efficiency measurements? 57% sounds very low . And would love to get more info on how it changes with roller pressure.

Again great work.

- Adrian

 

[HAL9000v2.0]

Unfortunatly I have to return training rollers to my friend. It is two rollers connected to car alternator connected to some heater. He use it for winter training. I measured input and output current and voltage. I will say this is very good efficiency because in it is controllers, motor, frictiondrive, frictiondrive rollers, alternator. So I guess w/o alternator and with tyre rolling ressistance the overall efficiency will be at 50%.

 

[adrian_sm]

How does it mount to the bike?

 

[HAL9000v2.0]

I am building new engagement system with holder. I will take some pictures when it will be winished. It is connected to seat post and it can be removed together with seat.

 

[etard]

Very clean and easy on the eyes as always Hal. 8)

Who's next to throw thier hat in the ring for friction drive?

 

[def215]

one of the nicest friction drive systems ive seen yet! so many friction drives popping up, now i feel left out. i just need the $$$. do you know how the motor performs yet or does it still need to be tested?

 

[spinningmagnets]

Looks beautiful, very professional! I am not personally concerned about complying to the letter of the law as it concerns power levels. I will keep my speeds reasonable and safe, and operate my bike in a mature and safe manner. That being said, if I have two bags of groceries and I am about to tackle a hill, I want as much power as I can afford.

However, there are still many people who want to always stay within the lines, so, I believe there is still a very big market for drives like this. I am glad there are now so many examples gathering real road-data.

 

[HAL9000v2.0]

I mount it on the bike and make about 2km. Then motor disassembled itself.
I think the magnet part unscrew itself from rotor (see picture)

I haven't got any idea that it is screwed on. Actuly the screw direction was fine but the bike I tryed on has slightly untrue rear wheel (axialy).
When magnets are unsrewed they stucked on stator plates and spun it around. Now it slides nicely on aluminium part
There is no harm done except one wire is pulled from controller and few sctratches on magnets.

Well this is sign to make new motor for friction drive...

 

[drifter]

Hal, I had the same trouble with my 50-65 motor and I had to reverse the motor direction to stop it unscrewing. Did you take the pictures before using the motor because it looks like there is no marks on the motor casing.

 

[HAL9000v2.0]

The marks are on the magnets not outside. Later one of the magnets fell off and the contoller is dead.