confused about engine, do i need a freewheel?

HEADDS · #1 (**permalink**) 10-01-2008, 07:20 PM

I have 2 Homelite engines, one from a weed wacker and the other from a leaf blower, but I just cant figure this out. Say I make a friction drive bike, when the bike is at a stop, wont the engine keep turning? I would prefer to somehow mount some kind of sprocket and run a chain assembly, can someone please put up some pictures of home-made engines? Or give me some info on how to mount a freewheel of some sort? Sorry if I am dumb.

deacon · #2 (**permalink**) 10-01-2008, 10:07 PM

I only do friction drive because it is simple. You just need a design that allows you to lift the engine from the tire. It's called a gravity clutch. At least thats how I do it. Others do it differently.

comfortableshoes · #3 (**permalink**) 10-01-2008, 10:27 PM

I like deacon like the friction drive because of how simple it is to do. The clutch system is more of a way to lift the engine off the tire at a stop than a true clutch...

I put some pictures up of my drive system- I built a simple frame out of aluminum, and used the engine housing to hang it off the side of that and attached a BMX peg to the shaft.

Goes like a bat outta heck- 'cept when it's wet out.

What size is your homelite? And what shaft set up is there? If it's got a threaded shaft you should be able to get a BMX peg on their no problem but if not... THen you'll have to figure out another way.

AS for the leaf blower- those have some nice power! But attachment will be hard- most use bolts to attach the blower directly to the flywheel, you will need to figure out someway to attach a sprocket to that, perhaps a belt drive? Just thinking "outloud" Also there is no cooling fan once you remove the blower and the shroud... So Id worry about heat damage. The good thing about the leaf blowers is that the motors are pretty narrow, lending themselves well to a bike frame build as well as a jack shaft!

So many possibilities....

comfortableshoes · #4 (**permalink**) 10-01-2008, 10:40 PM

I read your post more closely.. and I was thinking what if you created a belt driven ghetto clutch- you could put two belt pulleys- one on the end of your shaft and one on the end of a jack shaft, then put a tensioner pulley on a lever with a spring that you move in and out with a brake lever to give tension and engage the drive, then on the other end of your jack shaft you have a sprocket like normal that runs to a regular 44tooth gear attached like a regular engine kit...
Any thoughts on why this wouldn't work?

I put a paint diagram below to pictorially represent my crazy idea. maybe I'll try it on my homelite....

Spikedfox · #5 (**permalink**) 10-01-2008, 11:07 PM

nice design shoes.

deacon · #6 (**permalink**) 10-01-2008, 11:14 PM

No reason it wont work. Once you figure out how to attach the pulley to the engine, what size pulley you need for the wheel, and how to attach it, you should be good to go.

HEADDS · #7 (**permalink**) 10-01-2008, 11:56 PM

Rebuilt the engine tonight, still have to fgure out what to use as a drive roller.. heres some pictures, this is the leafblower....

Egor · #8 (**permalink**) 10-02-2008, 12:16 AM

A clutch like this, you pull in the handle and it pulls the roller off the belt. Have fun Dave
An engine I found under the bench, It started first pull. I cant get anything done the bench is a mess. LOL

PS: A friend of mine has a Hodaka engine to put in the Bonanza, what so you think. Should I!

comfortableshoes · #9 (**permalink**) 10-02-2008, 05:38 AM

that leaf blower looks perfect for a BMX peg.

That shaft looks like what is on my craftsman. Should do great for you no matter how you build it.

deacon · #10 (**permalink**) 10-02-2008, 06:32 AM

I built one just like it. Get yourself a bmx axle plug about an inch or less in diameter. It will slide all the way down to your flywheel. Then fill in with washers and lock washers then put your nut back on tight and you will have your drive wheel.