The power trailer...

deacon

minor bike philosopher
Jan 15, 2008
8,117
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north carolina
I have an idea... I know I'm full of them and most are pretty stupid. So here is another one. I know someone is going to ask why in the name all that is holy would I want to do what I have in mind. Purely because I'm evil I guess.

Okay first of all I have built a dozen or so bike trailers, and I have built bikes using weed whackers. I am now running ebikes. One friction and one small hub motor. They both require some real work and as everyone says the range is poor.

I'm wondering what would happen with say the smallest WW possible mounted on a trailer turning over a 350watt brushed scooter motor. Now I know the the motor would become a generator. How efficient I have no idea. I suppose I would leave batteries in the circuit. Change and discharge them at the same time.

Any thoughts?
 
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svc

New Member
Jan 10, 2009
43
0
0
sydney australia
'Brushless motors are typically 85-90% efficient, whereas DC motors with brushgear are typically 75-80% efficient.' from wiki... Electric motor - Wikipedia, the free encyclopedia

In a system like what you are talking each of these inefficiencys will compound. (generator, charging system, wiring and drive motor) leaving you with not much of what you started with. I'm not saying don't do it. But something to think about especialy when you are towing the weight also. If you have regenerative braking already you would lose alot of it i think while your generator was running . I believe regen braking is limited mostly by the charge rate of the battery/s.

Do you make regular trips somewhere without power? How about a covert charging station somewhere with spare battery pack? You could put a solar charging system or wind generator (stick a prop on a motor) to trickle charge. If you needed a faster charge you could have a weedwacker powered generator there also.

Probably a crazy idea for most people. But if you had a spot and the parts it could work.
 

jasonh

New Member
Jun 23, 2008
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Longmont, CO
It surely won't be terribly efficient, but I'm willing to bet it'd increase your range by at least something. If you've already got everything, I'd say it's worth a shot :)
 

toytime

New Member
Mar 20, 2008
550
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Ontario
Would it not be just as easy , or easier to use a 110 volt motor along with a sewing machine "throttle" to go with your generator?
 

lordoflightaz

New Member
Jan 23, 2009
296
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Phoenix, AZ
Deacon with all this free time you have I think you should consider as Emeril says "Kick it up a Notch" Have you thought about Stirling Engines and Fresnel Lens. I am afraid this will cut into your story writing time although documenting the build will be a true opus. Mounting a stirling engine on a trailer will surely charge a battery and could even run the bike (electrically or just produce horespower for belts, chain, gears,etc).

When the bike trailer is parked you point the fresnel lens at the sun. A lens the size of a small direct tv or dish networks satellite dish would be needed, I think. You may need to come up with a gyro compass to get the lens pointed in the direction of the sun if you want to generate power while the trailer is in motion but this is probably doable.

Mounting a Stirling engine on a trailer also allows for other alternative energy sources. In a pinch you can build a wood fire to make the engine run.

I do have a couple links somewhere if you are interested.

I just got this in my inbox YouTube - PARABOLIC DISH MIRROR PARABOLOID DIY REFLECTOR DIRECT TV SAVE ENERGY Solar Reflective Film It was even 5 minutes after I posted my reply.
 
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jasonh

New Member
Jun 23, 2008
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Longmont, CO
No he wants to run a scooter motor with a weed wacker motor to generate power to recharge his batteries I think.
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
3
0
north carolina
Okay how about an old car alternator fitted to a weed eater on the trailer...

Rig it to each battery independently of the other. That should charge them up since the engine won't be running anything else.

I have absolutely no use for such a thing I just wonder if it could be done. What fun is a bike if you can't ruin it as you go along.
 

Roadkill

New Member
Feb 14, 2009
242
0
0
Roadkill, USA
I have an idea... I know I'm full of them and most are pretty stupid. So here is another one. I know someone is going to ask why in the name all that is holy would I want to do what I have in mind. Purely because I'm evil I guess.

Okay first of all I have built a dozen or so bike trailers, and I have built bikes using weed whackers. I am now running ebikes. One friction and one small hub motor. They both require some real work and as everyone says the range is poor.

I'm wondering what would happen with say the smallest WW possible mounted on a trailer turning over a 350watt brushed scooter motor. Now I know the the motor would become a generator. How efficient I have no idea. I suppose I would leave batteries in the circuit. Change and discharge them at the same time.

Any thoughts?
I made one last year with dual 500 watt I THINK scooter motors. I forget the wattage.. They were the same and I used two and the wheels that came with the scooters.. I chopped these things in half and welded them as one and hooked them up with like new deep cycle batteries. I was getting 2-3 miles maybe 5-7 using pedal assist in a big way using 2 batteries. These motors are from the stand up chinese types with the plastic fairings. I will post images. I also had the scooters running on solar panels in the sun with no load on a stand for display when selling them.

The flat tires on scooter wheels are the worst especially when towing a load on top of them..
I will post pictures sooner or later. It is a sight for sure when I do.. Later all.
 

Roadkill

New Member
Feb 14, 2009
242
0
0
Roadkill, USA
I would love to see the THING
I just migrated to a better PC. I will probably post a bunch in the introduce yourself section as I have yet to make one. That might be my blog sort of.. I don't know.. I have little time for blogs as do we all here I think.