Advice on building a trike please.

[Heynow999]

Hi

I'm new here, and I have been thinking about building and electric trike, and would like some advice. What I want it for is I have to take my son to school every morning and I would rather take him by bike than start-up the diesel car every morning for such a short distance. It is about 3 miles round trip.

Now I am a bit of a tinkerer (and cheap) so I want to try and electrify a pedal trike. The idea is to get a used trike and then power it with the motor and battery from a Black and Decker cordless lawnmower. I have the mower and I am not very happy with it, so I am happy to cut it up for parts. It is maybe 50 LBS?

Mower
http://www.blackanddecker.com/productguide/product-details.aspx?productid=2500&toolview=2#details

Bike?
http://cgi.ebay.com/PINK-FREE-SHIPPINGF-ADULT-TRIKE-BIKE-TRICYCLE-BICYCLE_W0QQitemZ180177821809QQihZ008QQcategoryZ2904QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

My son is only four so the idea is he will sit on the back part where I will make some sort of seat. It is an easy drive on quiet suburban streets.


So I guess there are a few issues. I would have to have gears and a chain to the bike for the motor. I would need a variable speed control as the mower is only on/off.

Any other thoughts?

Thanks

Peter

 

[lawsonuw]

Can you pop the lid on your mower and post some pictures? Depending on how it's built inside it may be poorly suited to re-purposing. Anywho, the motor is most likely powered by a geared DC motor with an output in the 2000-3000rpm range. A good ball-park for the speed the motor needs to be slowed down to is about 200rpm. That comes out to a reduction of 10:1 to 15:1.

My 2 cents
Marty

 

[Heynow999]

I don't have any pictures right now, but I have taken the mower apart and I have a good idea of whats in it. The motor is about the size of a large can of tomatoes, it has brushes and is direct drive. The blade is just bolted to the shaft of the motor. It has two 12v AGM battery's wired in series for 24V. I understand that I would have to gear the motor down probably 10:1, I saw a homemade Ebike where the guy had a nice setup with pulleys and belts to gear it down, then a chain drive to the wheel. ( I can't seem to find the link anymore)

I took it apart because the charger never worked very well so I wired up some posts on the cover of the motor so I can charge the batteries individually with my car battery charger. I would use the same setup to charge the bike if I build it.

Anyone have an opinion on these Schwinn trikes from Walmart?

http://www.walmart.com/catalog/product.do?product_id=5679542#Features+%26+Specifications

I live in Canada, and with the American dollar dropping like a stone, I can order one of these for about $200 Canadian!

Thanks

Peter

 

[TylerDurden]

I have the same mower.

If I were gonna use the motor to power a trike, I'd probably just hack together a friction drive for the front wheel and slap a 40A brushed controller on it. I'd have junior riding on the batteries hidden in a seat in the back.

The Schwinn appears to already have some kind of a jackshaft in the back, so it may be possible to tap-in there and put some geared drivetrain together, if friction-drive is too kludgey.

 

[Drunkskunk]

From the look of the pictures between the Ebay bike, and the Schwinn, the Schwinn looks to be a sturdier bike.

As for the motor, if its a direct drive, its going to either be a very high wattage motor or a lower RPM motor. Probably both. Lower RPMs mean it will be easier to build a drive system for it. But high wattage means it will eat up batteries fast. to haul you and a kid around may take something bigger than the batteries in the mower.

 

[fechter]

Friction roller drive would be the easiest. You'd want it on the front wheel if you go that route.

If you have access to junk parts, you could do a jackshaft and figure out a way to drive the chain. It's generally bad to have a setup where the motor forces to the pedals to move. Some kind of freewheel is good.

You definitely will want some kind of speed controller and throttle.
Check out TNC scooters.

 

[Desertprep]

Friction drive may be the easiest but it is costly and time consuming in the long run. Front wheels wear faster on a friction drive so they need to be changed more often. Also, as the tire wears the friction drive becomes less efficient.