Range extender system???

[Whiplash]

Has anyone ever tried to make a simple gas/elec hybrid using small R/C motor driven by a small 4 cycle R/C engine? It would seem this would work OK and be able to generate an easy 700-1000 watts NO? That would be enough to power a bike almost indefinitely and you could mount it nearly anywhere on the bike like behind the seat on the seat tube with a rack holding the engine, motor and fuel enough to easily double most bikes ranges.... Am I missing something or could this work? I know the 4 cycle engines can be made pretty quiet too with a properly designed muffler... Even another 350-400 watts would give ME basically as much range as I wanted to drive! I am trying to figure out how to greatly extend the range of my bikes so we can go outside our town if we wanted....

 

[wineboyrider]

OLAF lampe had a thread about one that he built somewhere in this forum???

 

[fechter]

You mean like this?:

Honda GX-31 mated to a 350W brushed motor used as a generator. I never tried it, but in theory it should work. Those little gas engines don't have a very long lifespan, so it would wear out fairly fast. Using a brushed motor as a generator would also allow for electric start and some kind of voltage controlled auto on/off circuit. You'd want some kind of safety to prevent overcharging the batteries, and you could have it automatically start when the voltage sagged too low. A manual start would be OK too, but you should still have some kind of overvoltage safety.

 

[neptronix]

Or maybe just skip the electrical generation phase and run the gas power to a LH sprocket? hit the electric power when the torque starts to die etc..

As for the hobby motors, aren't they all 2 stroke, noisy as hell, stinky as hell, end not very efficient?
You'd be doing the air quality around you a favor by just converting to 4 stroke gas if that is the case.

 

[stanz]

Just toss one of these in a trailer and you're good to go for a couple hours :

http://www.harborfreight.com/800-rated-watts-900-max-watts-portable-generator-66619.html

 

[Lyen]

Whiplash, how far do you actually wanna to go?

I have actually bought one below:


But I then sold it because of the noise and the smell of the gas.

My typical round trip is less than 200 miles. I managed to get around with 2 48v 40Ah batteries.

 

[recumpence]

Hey mentioned in the first post "4 cycle RC engine". They do make 4 stroke tiny RC engines.

Yes, it would work.

Matt

 

[Whiplash]

Cool! I might have to try it?!!

 

[AussieJester]

Seen it done on motorbicyling but not using rc motor using IIRC a curry motor? it was actually very stealth, he used a clone honda motor i think, 4 stroke anywayz, was all mounted within the bikes triangle and covered with cloth-like
material, was extremely stealthy except for the sound of the muffled motor. Soz i forget the members name a search in the stink
bike site would likely turn it up wasn t too long ago.

You should be concentrating on :: cough :: my new reduction drive anywayz Whiplash not some hybrid stink bike contraption

KiM

 

[Whiplash]

Lol! You know how it is, you can't let the mind rest! I just did 20ish miles with the old setup with the wifey on her frock bike with baby in tow... fun stuff! But I can't wait to. Try a full 2500-3000 watts through the gears on the trails! I should be able to make a bit of headway tomorrows...

 

[StudEbiker]

It looks like the image monster ate all the pics, but this was a very cool hybrid build from awhile back. Looks like there is still an active link to the build on MB.com though.

http://endless-sphere.com/forums/viewtopic.php?f=6&t=6429

 

[Whiplash]

Still throwing this around, but would a say, 700 watt motor if spun to its peak rpm actually produce 700 watts? Or if I did this, should I get a motor rated for more watts INPUT so I can get less output due to losses?? How does this work? A brushless motor would work right??

 

[vax]

I've been thinking this over some time now - I want to build a special range extender for my electric scooter.
And, I want to use 2-stroke pocket bike engine as a base. Here I can hear you say, 2-strokes suck, 2-strokes pollute and have poor economy.
No.
2-stroke engine can be much more efficient than 4-stroke. All you need to do, is run it on constant rpm-s and tune exhaust pipe length accordingly.
For that I'm gonna remove butterfly valve from carburator, so it's allways at full throttle. What keeps constant speed is generator output voltage, that drives PWM load circuit, electrically braking the generator. Of course, there has to be destination, where to put that load, otherwise it will just over-rev. So, there has to be some circuit, that stops the engine when battery is full and starts (using generator itsself as a starter motor), when battery level is low.
So far I think I'm gonna use 60V brushed DC scooter engine as generator - it starts the engine without controller and is much cheaper.
But, If there's some better generators, let me know. It would be cool to have whole piece at very compact form, like outrunner sitting directly on motor output shaft without any pullies or belts.

 

[heathyoung]

There are small 2 stroke motors for 'choppers' with a 12V starter mounted on the rear - these my be very handy for what you want.

 

[dogman dan]

Personally, I'd just slip a couple 6s lipo packs in the pockets of my baggy pants.

 

[vax]

Some update.
I got Bafang geared hub now for experimenting; I'm gonna ditch the planetary reduction and couple the rotor directly to motor output.
The stator will be mounted onto aluminium adapter, and bolted to crankcase.
Since it has hall sensors, I thought just buying Kelly 20A mini controller and use it on regen mode.
Also, I think I can start the motor directly with e-motor/generator. All this could be automated, the research has already begun, I'm using Arduino Uno.

 

[Whiplash]

Cool ideas, that engine looks to be water cooled NO? If it is, don't bother with it, the water system will weigh as much as the whole generator!