the cruzbike electric

[bobmcree]

the motor is from china, they are not imported currently. the Cruzbike is sold as a complete bike or a kit that can be mounted on most suspension mt bikes. the frame they use is a generic taiwanese aluminum unit.

-bob

[nemo]

the motor is from china, they are not imported currently. ...
-bob

i got tarn motor on ebay with a bliss folding bike (UK).

The controller on the bike is based on MC33035. Unfortunately there is a part on PCB covered in black epoxy with some circuitry so nobody can copy/read it. (black square)It says 24V/7A/15A on the back.
the input/big cap is 50V.

The bike has 24V 9Ah Nimh battery that you can slide off the bike and switching charger(2a).

relatively small motor inside has interesting 12:1 planetary gearbox with no teeth (friction?). Very quiet.
Motor itself is quite small with coils on the outside and rotor inside.
i think it is 4 pole and 15 stator(coils) setup.Coil are from 0.5mm wire.
Inside of the motor is small paper label saying 24V...I wonder your TARN motor have 24V label inside.(same coils and thickness of the wire)

The top speed on 24V is only about 20km/h on 16 inch wheel.
It feels like 200W.

I couldn't resist to try bike on 33V.
Dewalt pack provided the power. Speed got to 26km/h, it felt like 300-400W. Much better and the controller took it just fine. runs cold.
I also shorted the current sens resistor(wire) by 1/4 to have more punch.
I didn't measured the current yet.
Since I can't modify the controller right away because of the black epoxy I'm stuck wit 33V. Overall i like the bike on 33V, not that much on 24V. It is relatively lightweight (aprox. 22kg?). Cheap, 230 pounds and folds quickly.
riding the bike is ok, not as comfortable/stable as bigger bikes.
I'm curious if I have the same controller as You and the same motor!
I can imagine that on 48V it can start to perform. But can I supply 48V into this controller? Perhaps not with the cap 50V.

Here are some photos.

[nemo]

the motor is from china, they are not imported currently. the Cruzbike is sold as a complete bike or a kit that can be mounted on most suspension mt bikes. the frame they use is a generic taiwanese aluminum unit.

-bob

3 more photos

[bobmcree]

The controller on the bike is based on MC33035. Unfortunately there is a part on PCB covered in black epoxy with some circuitry so nobody can copy/read it. (black square)It says 24V/7A/15A on the back.
the input/big cap is 50V.

the 33035 is a good controller chip but it is only rated to 30V. You are lucky you did not blow it with the a123 pack. this is the same controller design built into the kollmorgen 400w 24v motors i have been using and selling.

my motor is not the same as yours. neither is the controller. the motors are made by Nuergy and there is a lot of info on their site.

the particular controller i have is by ananda and is potted. it was an evaluation unit and has adjustable power limiting. it will allow 700w into the motor at 48v and the motor does very well at that voltage and seems reliable. this motor is 135 mm wide and will not fit in front forks, and there is not a mount on it for a rear sprocket like yours.

the internal electric motors are really cool, justin at ebikes.ca took the motors out of a couple and is using them in a powered skateboard.

[The7]

the particular controller i have is by ananda and is potted. it was an evaluation unit and has adjustable power limiting..

The stock controller from My AL1020 is also Ananda (24V 15A) which was working OK with 36V.
It is then upgraded with 20A X-controller which can work from 24V to 48V battery for AL1020.

[bobmcree]

the particular controller i have is by ananda and is potted. it was an evaluation unit and has adjustable power limiting..

The stock controller from My AL1020 is also Ananda (24V 15A) which was working OK with 36V.
It is then upgraded with 20A X-controller which can work from 24V to 48V battery for AL1020.

the one i have is a 36V15A model. before i got it someone added a pot on a short cable that adjusts the current limit. it runs fine at 48v so far.

i have used lots of the kollmorgens with the 33035 controller chip and many people have blown the internal controllers quickly at 36v; the 33035 is definitely only rated to 30v

did you have a question? yes it is a cool motor, no it is not exactly the same as yours, no i cannot get any more unless it is in quantity.

this motor was one of several sent here for evaluation. i don't have an exact part number and there are no numbers on it. friends who have taken them apart love them; i have had too many other things to do right now to take this one apart. i do know that they are very inexpensive, quiet, waterproof, and too wide to fit in any front fork used in the US. if somebody got some chinese forks they would fit in they would probably be quite successful.

the best thing is they weigh only 5 lbs and are very small. they are just not powerful enough for me, with long steep hills to climb.

[fechter]

The toothless planetary gear is interesting. Any idea how force is maintained on the rollers? What happens when the metal wears down a bit?

[The7]

The toothless planetary gear is interesting. Any idea how force is maintained on the rollers? What happens when the metal wears down a bit?

Very good question!?
I like to know the answer as well!

[The7]

this motor was one of several sent here for evaluation. i don't have an exact part number and there are no numbers on it. friends who have taken them apart love them;

What did your friends find? Are they using teethless gears as nemo's TARN motor?

[nemo]

The toothless planetary gear is interesting. Any idea how force is maintained on the rollers? What happens when the metal wears down a bit?

From what I saw inside:
I think that the force is maintained on rollers by clever mechanical design when the motor spindle(shaft?) in the middle is one firm point, 3 wheels can shift a little bit and engage themselves against barrel on the outside , again a firm point.
It's done by using needle bearing inside the 3 wheels with not enough needles.(img7973) so the wheels doesn't stay centered.
English is not my first language, sorry

What I didn't described when sending the pictures is that there is a one way clutch? on one side of the wheel to allow free wheeling(img7968)...again...doesn't make any sound... similar principle with some wheels put off the centre or something..I didn't opened that part. Unlike in the free wheeling part on the bike where it makes clicking sound.

It is quite interesting to see the level of engineering in these cheap chinese motors.

The only drawback I see with the enclosed motor is heat. You can't tell how hot it is inside because the enclosure have an air gap.

I wonder how reliable they are.
What is really interesting is that it all doesn't slip!
maybe somebody with an engineering background could answer the reliability and other questions.
I would be interested in loss comparation to a teethed one.
The magnet of the motor is not rare earth either.

[fechter]

Thanks, I see now. It's hard to see in the pics, but the rollers are offset slightly. This works similar to the roller clutch on a Currie drive.

After some miles, it may be necessary to clean and re-grease the rollers.

Heat buildup could be a problem. Forced-air cooling would be a bit tricky to set up on a hub motor.

[bobmcree]

the motors are rated 200-300w but mine seems to run fine at twice that. i have been told the plastic gear is available as a replacement part and that seems like the most likely part to fail. if i ever get around to taking it apart i will definitely add a thermal sensor to the motor.

i apologize for not knowing more about the motor; i tried it for a few weeks and decided to go for more power. i am keeping it around in case i need to use the bike somewhere that has more restrictive power limits. the motor is so small and quiet that i believe nobody would expect it to be over a 200-300w limit, and the adjustable controller makes that a reality if it is set low enough.

there is lots of data including mechanical drawings on nuergy.com

[TylerDurden]

Very intriguing planetary system! Are the rollers solid metal, or are they composite with nylon?

I tried to find more info on that type of drive, but no luck yet.

Bob: have you got a link or another address?

[The7]

From what I saw inside:
I think that the force is maintained on rollers by clever mechanical design when the motor spindle(shaft?) in the middle is one firm point, 3 wheels can shift a little bit and engage themselves against barrel on the outside , again a firm point.
It's done by using needle bearing inside the 3 wheels with not enough needles.(img7973) so the wheels doesn't stay centeredhere.

Agreed.
You have an excellent observation.
The motor spindle acts as the SUN gear.
The 3 wheels act as the 3 PLANET gears.
The barrel acts as the RING gear.
All these gears are teethless.
Friction is required for transmitting motion.

In my opinion, the shifting action of the PLANET gears could also act as an free-wheeling.

[Ypedal]

works like a Pull-Start on Nitro RC trucks. Grabs one way.. but slips the other.

[The7]

Thanks, I see now. It's hard to see in the pics, but the rollers are offset slightly. This works similar to the roller clutch on a Currie drive.
.

An site says about the free-wheel on an teethed planetary geared P3 motor:
"This motor uses a freewheel mechanism as shown below. Its a very robust design. The motor drives the planetary gears which in turn drive the circular metal plate shown with a red arrow indicating motor spinning direction. The small rollers wedge themselves onto the hardened metal plate but when the motor is not spinning the plate can rotate freely hence the wheel can rotate freely. There is negligible resistance when freewheeling the same as a normal biycycle wheel"

[bobmcree]

Very intriguing planetary system! Are the rollers solid metal, or are they composite with nylon?

I tried to find more info on that type of drive, but no luck yet.

Bob: have you got a link or another address?

sorry, the website is http://www.ethinkar.com

ethinkar / nuergy / tarn are all names used for these motors

[nemo]

[quote="bobmcree"][quote="TylerDurden"]Very intriguing planetary system! Are the rollers solid metal, or are they composite with nylon?

quote]

I'm 99% sure they are all metal. I tried to scratch the weels with the screwdriver.

[TylerDurden]

The only way I can understand this to work is for the carrier to be the driven element:

Carrier -> Green
Case -> Blue
Planets -> Red
Axle -> Purple

The space between the axle and the case is too small for the planet, so the planet must roll against both when pushed into the gap by the carrier.

Arrows indicate motion relative to axle.
Axle = 0 rpm
Carrier = 12 rpm
Planet = 4 rpm
Case = 1 rpm
(approx)

[The7]

Carrier -> Green = Planet CARRIER
Case -> Blue = RING gear
Planets -> Red = PLANET gears
Axle -> Purple = SUN gear

For panetary gear:
Any one of the four could be the INPUT.
Any other could be the OUTPUT.
See:
http://auto.howstuffworks.com/gear-ratio4.htm

Your ratio and direction are correct if the CARRIER is used as input and the RING is the output.

[The7]

For nemo's TARN motor:
The SUN is the input.
The CARRIER is stationary.
The RING is the output.

Talked with a good friend of mine who is in mechanical engineeing/profession yesterday.
He commented that the teethless planetary gear has shorter life and lower efficiency than the teethed one.

[nemo]

For nemo's TARN motor:
The SUN is the input.
The CARRIER is stationary.
The RING is the output.

Talked with a good friend of mine who is in mechanical engineeing/profession yesterday.
He commented that the teethless planetary gear has shorter life and lower efficiency than the teethed one.

I suspected that the teethless planetary gear has shorter life and lower efficiency..and now you got it conformed from your friend.

I'll see what happens with mine TARN in a couple of months. I ride my folder nearly every day for about 5miles.
What I love about it is the noise or rather silence....

I also found that MC33035 3 phase IC driver, common in many controllers, has max voltage of 40V. That's max rating. Not recomended which is 10-30V.
So I just might get away with dewalt battery (36V absolute max)
Not good with 36V nicd or nimh !
Also there might be some controllers with different design that uses MC33035 and will be ok with higher voltage.
Not mine I think. Interesting is that the mosfets on mine are up to 80V(datasheet)

[bobmcree]

]
I also found that MC33035 3 phase IC driver, common in many controllers, has max voltage of 40V. That's max rating. Not recomended which is 10-30V.

i don't know where you got the 40v spec but it is incorrect. the absolute max rating according to the datasheets i have for the original motorola part used in the kollmorgen controllers i have been using for years is 30v and i know for a fact that several people have blown them at 36v.

do you have a data sheet showing a 40v rating?

[nemo]

]
I also found that MC33035 3 phase IC driver, common in many controllers, has max voltage of 40V. That's max rating. Not recomended which is 10-30V.

i don't know where you got the 40v spec but it is incorrect. the absolute max rating according to the datasheets i have for the original motorola part used in the kollmorgen controllers i have been using for years is 30v and i know for a fact that several people have blown them at 36v.

do you have a data sheet showing a 40v rating?

here:
on page 3
http://www.onsemi.com/pub/Collateral/MC33035-D.PDF

Vc30,Vcc40V...can you explain? Thank you

[bobmcree]

]
I also found that MC33035 3 phase IC driver, common in many controllers, has max voltage of 40V. That's max rating. Not recomended which is 10-30V.

i don't know where you got the 40v spec but it is incorrect. the absolute max rating according to the datasheets i have for the original motorola part used in the kollmorgen controllers i have been using for years is 30v and i know for a fact that several people have blown them at 36v.

do you have a data sheet showing a 40v rating?

here:
on page 3
http://www.onsemi.com/pub/Collateral/MC33035-D.PDF

Vc30,Vcc40V...can you explain? Thank you

thanks for the data sheet. it appears that the ON Semiconductor parts will tolerate a higher Vcc (supply voltage) than the original motorola parts. this is good to know, but i would not take it to mean that existing controllers using the older parts can handle the higher voltage. The Vc spec is the maximum voltage the chip can output to drive the low side fets in an h bridge.

i did not mean to come on so strongly about the 30v spec or sound like i was doubting your word, but i have been reversing and selling the kollmorgens for quite awhile and i don't want people to think they can run them at the higher voltage and then complain to me when they blow. the a123s run at 33v after a slight discharge, and their internal impedance is high enough that at the 30A + that these motors draw they will be well below 30v, so they might hold up, but i do not warrantee the motors i sell above 24v.

the kollmorgen motors using the motorola mc33035p have repeatedly blown when people run them at 36v. they are of course a 10 year old fab, so it's good to see ON has improved the parts, probably by refining the fabrication process. too bad most controllers using these parts are potted, so it would be difficult to swap in the new parts.