Friction drive with the clutch

S

sojudave

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I've seached. I swear I have. I got three weed wacker motors, and I'm going to make friction drives out of them, but I want to keep the clutches on them. Is this possible? I know most folks take the clutches off.

thanks

sojudave
 
From the weed wacker clutches I've seen, they're a little light to hold up to the torque required. Doesn't take very much to cut grass.
 
What size weedwhackers do you have? There are a lot of small size whackers of 25-31ccs out there. There are also some larger models, sometimes called brushcutters, that use the larger engines popular with MBers as well.

From what i've seen there are two common size clutches on small motors, 78mm and I believe 56mm on the common smaller weedwhackers and chainsaws.

The commercially made friction drives use the larger clutch because they usually suggest motors larger than 31ccs where the 78mm clutch is used.

One problem in engineering occurs after the clutch though. How will you mount the drive spindle so it aligns with the clutch and how will you support it with bearings? I think that's why many diy friction drives simply hang the motor over a wheel, bypass the clutch and direct drive the spindle off the motor shaft.
 
One other aspect of weed wacker engines is the 1/2 crank design. As a w/w has almost no radial loading on the crankshaft, many use only one crank bearing. If the crank is radially loaded with drive roller tension, it will fail.

In addition to clutch diameter, rotor/drum width also is an issue.
 
I'm running a 24cc weedeater engine on my bike with the clutch. I only have about 20 miles on it so far but, I like how it works. I am trying to figure out how to make a bearing mount on the other side for even pressure though.
 
I was going to do the same thing on my first bike but bought a Staton friction drive instead, glad I did. The unit has two bearings on the roller so the engine and clutch are not radially loaded. The 43CC - 2.2 HP TLE43 has plenty of torque and good top end, also very quiet.
 
I was going to do the same thing on my first bike but bought a Staton friction drive instead, glad I did. The unit has two bearings on the roller so the engine and clutch are not radially loaded. The 43CC - 2.2 HP TLE43 has plenty of torque and good top end, also very quiet.

Agreed the kit is really good and removes any need for backyard engineering. If you have around $450-500 and a bike this is the way to go with friction drive. If you don't have much money, lots of tools, several spare engines and other assorted hardware laying around and a bike to put it on a homebuilt would be the cheaper but not necessarily better way to go. I've heard the only things that "go" on a staton friction drive are the tires, spindels and engines, all after many hours on the road.

If you're going to make your own please post pics. It's always cool to see how people converted old scrap metal into something cool.
 
i third motion the above two guys, i just fitted a slightly used staton model to one of my bikes and i was very impressed, boy is that 43cc mits quiet compared to my 33cc tanaka its like a mouse but with plenty of power,

have you looked into these kits

http://www.motoredbikes.com/showthread.php?t=15024

at least you should be able to get some good ideas.

good luck !!!!
 
i just fitted a slightly used staton model to one of my bikes and i was very impressed, boy is that 43cc mits quiet compared to my 33cc tanaka its like a mouse but with plenty of power
Interesting... I was curious how the 43cc Mitsu would sound compared to the 33cc Tanaka.

So, in terms of sound dB... it goes:
Mitsu << Subaru < Tanaka ?? (where the Subaru & Tanaka have nearly the same volume, but the Sub wins because of the lower pitch)
 
So, in terms of sound dB... it goes:
Mitsu << Subaru < Tanaka ?? (where the Subaru & Tanaka have nearly the same volume, but the Sub wins because of the lower pitch)

Not in my experience. Can't speak about the Tanaka but I have a Robin and a Mitsu and there is no comparison, the Robin is the quieter of the two.
 
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