Using RC motors on E-bikes [Archive]

[recumbent]

Can RC motors operate reliably for 1-2 hours on a daily basis, on an bike?

I'm curious, because you guys speak like they can, I've never seen electric RC motors operate before. :|

 

[recumpence]

I have nearly 100 miles on my bike with this RC motor so far without any problems.

Longevity is not an issue unless the motor is being abused.

These little RC controllers are awesome too. They are very reliable.

Matt

 

[recumbent]

These little RC controllers are awesome too. They are very reliable.
Matt

Amazing, are you sayin the bigger RC controlers can be used on ebikes also?

Sorry for the questions, just thought they were too small, however I did see some large RC planes before.

 

[recumpence]

Yes, I use a Castle Creations HV110 on my 4,000 watt bike. It weighs 5.4 ounces and is the size of a couple match boxes stacked together.

It is reliable, USB programable, and easy to get serviced if you even had a problem with it. Admittedly, high powered RC planes are harder on these controllers for longer periods of time than a bike is. A big RC plane can ask 7,000 watts for 10 minutes straight with one of these controllers.

My controller never even gets warm.

Matt

 

[safe]

I have nearly 100 miles on my bike with this RC motor so far without any problems.

I've gone through various stages of development on my bike and have seen things that worked well for a few hundred miles need to be replaced. That's all part of R&D that you need to do the longevity testing on everything to see how long it really lasts. At some point things stop breaking and they hit a sort of steady stage that goes for a long time, but then on the long end (thousands of miles) you start to get things wearing out that you don't normally think about. Like I now have a rear hub bearing that is slowly going away. I'm having to tighten it regularly because the cones are literally wearing out. An upgrade to a better hub (better quality) will fix this, but it's just an example. Over time (and after breaking a lot of parts in the process) the RC motor on the ebike could be refined to a "high art" that will be light weight and last a long time.

Sometimes "change" means "work"... which is how people used to do things in the old days. (all the kids these days seem to want "change" to happen instantly... this is just not how things really happen, you need patience and persistence)

 

[recumpence]

Absolutey.

These motors are good almost indefinately except under two circumstances;

#1 High heat. Keep the motor under about 160 dergees and it is fine.

#2 Too much load on the bearings. I went from a very tight 9mm belt to a much looser 15mm belt partly to make sure the motor bearings do not ear out. Plus I have a shaft load bearing on teh end of the shaft to drastically reduce the load on the motor bearings.

I have a smaller AXI motor on my CNC. It originally ran in a twin rotor helicopter, then in a large scale RC truck, now it is in my CNC running the spindle. That motor has about 300 hours or run time on it (always with a bearing side load from running belt drives in all 3 applications) without any problems at all.

That is one reason I was willing to trust this motor for my bike project.

There are any number of problems that could arise, though. So, yes, I think long term testing is needed.

Hmm, lots of miles? Oh, man, I guess I am willing to make the sacrifice for the betterment of the hobby! :wink:

Matt

 

[Miles]

#1 High heat. Keep the motor under about 160 dergees and it is fine.

160 degrees what?

 

[safe]

Hmm, lots of miles? Oh, man, I guess I am willing to make the sacrifice for the betterment of the hobby! :wink:

Isn't it great to have such a valid rationalization for enjoying yourself.

 

[safe]

160 degrees what?

I suspect the next "trick" will be cooling.

Options:

1. Air (1/25 of water)
2. Water (1 cal/g/C)
3. Ice Melting(80 cal/g/C)
4. Vaporization of Water (540 cal/g/C)

 

[recumpence]

I am looking into a couple different RC motors for my bike.

I will keep you guys post on my findings.

Matt

 

[recumpence]

Dirty_D,

How's your bike coming along? I noticed your build thread sort of died.

Matt

 

[dirty_d]

well its pretty much done other than paint. the only thing it really needs is a properly machined adapter for the go cart sprocket, the one i made is a little off, and the motor sprocket wears too fast because i had to make it myself and the welding screwed up the heat treatment on it.

 

[Miles]

Another large outrunner: http://www.bphobbies.com/view.asp?id=V450327&pid=B3675243

 

[dirty_d]

hmm no shaft protrusion on the mount end, but i think you could make your own shaft, the shafts on these motors shouldn't be press fit into anything, it looks like its secured to he propeller end with a set screw, and on the other end its probably kept from sliding out with an E clip or something.

 

[Miles]

They seem to be made by this company:
http://www.suppomodel.com/

Click on A7050

See also 200A HV (6800 Watts) controller......

 

[TylerDurden]

Fortunately, their webmaster does not always rescale the images before uploading... 8)

 

[Miles]

 

[TylerDurden]

Factory store pics are interesting too.

http://www.suppomodel.com/store.html

 

[dirty_d]

i wonder what the cost is if you buy direct from them, can you?

 

[recumpence]

That is an RC boat controller. It has liquid cooling tubes on each side and no heat sink.

I would have no problem buying a motor from them, but controllers are another story.

Matt

 

[briansrapier]

Unfortunately, I don't have a camera to take some pics and show you examples...

As far as cooling goes (I've been noodling this out, too) you could use 1/4" or 3/8" soft copper tubing and wind it around the motor a few times, similar to the attached picture. You could then use a lightweight (aluminum) condenser, such as an old automotive a/c condenser. Connect the two items using rubber heater hose to allow for vibration. Fill the closed loop with water/anti-freeze.

Place the condenser where it will receive good airflow and sits slightly higher than the motor. Convection will take care of the rest. As the motor heats up, the coolant will also be warmed and will begin rising up the higher line to the condenser where it will be cooled. The coolant will drop to the bottom of the condenser, and will travel down the lower line back to the motor.

I have a tractor that works on a similar principal - no pump to circulate the coolant. The only time it gets hot is when the radiator gets plugged up with grass seed.

I guess I'll have to eventually put my money where my mouth is a produce something...

 

[Miles]

Nice idea, but the problem is that the majority of RC motors are outrunners so:

1. Most of the motor casing is turning.

2. Cooling the outside of the case is pretty ineffective anyway because the magnets are between the case and the windings. That's why outrunners need to be vented.

 

[recumpence]

Heat has not been a problem, so far. If my bike was geared for 50mph or higher, it may become an issue. But, I am running a fan and my motor runs around 100F pretty much all the time.

Matt

 

[docnjoj]

I've been considering a similar system, but without recirc (use a drip). This is for a MY1018z, and it would at least lower the temp of the magnets! Will it work? Gotta work on the noise of the gears first!
otherDoc
Edit: Definately wont work on outrunners!

 

[John in CR]

For cooling an outrunner wouldn't it be easiest to just put an appropriate turbine on the drive shaft to force lots of air through the already wide open air ventilation pathways? I've seen this on some smaller outrunners. I'd think that these larger ones would already have a layout that naturally stimulates air flow as they turn, making cooling a non-issue unless we seal them up inside a housing to protect them from dirt and the elements.