Yet another new guy

[Metalshaper]

Hello to all and thank you for all the informative posts I have seen here today. I am starting a low-budget build very soon and I will likely be posting a lot of questions since there are so many experienced builders here.

 

[Blazkowiez]

Awesome to have you here, take tons of pictures as you're building!

 

[Metalshaper]

Taking pictures

I plan to take a lot of pictures as the build progresses. I have an old 3.8 hp vertical shaft engine from a lawnmower, took a few pictures of that tonight as I'm planning on using it if I can convert it to run horizontal. So far my plans are to build a reverse trike with two 20" front wheels and a 24" rear, using a centrifugal clutch and running #35 chain.

 

[Russ2251]

3.8 hp with a c-clutch is asking a lot for a 24" diameter tire...unless a monster size driven sprocket (or jackshaft) is involved with your design.

 

[Metalshaper]

Currently planning on a 5:1 gear ratio with a 50 or 60 tooth sprocket on the rear wheel, depending on whether I go with a 10 or 12 tooth sprocket on the clutch. I may have to use a jackshaft to route the chain, but I read here on the forums that a c-clutch should not have a gear ratio lower than 4.2:1.

 

[Russ2251]

but I read here on the forums that a c-clutch should not have a gear ratio lower than 4.2:1.

That's assuming a gokart size tire, say something like a 10" or 11" (±) diameter tire. Not 24".

 

[jace]

yeah, you shouldn't use a c-clutch with any tires bigger than about 15"

 

[Metalshaper]

I think I will use a jackshaft to further improve the gear ratio beyond the 6:1 I can get with a 10 tooth drive and 60 tooth final gear. The question is, how much more do I need to reduce the gear ratio to use a centrifugal clutch with a 24" tire? If I put a 30T sprocket on the jackshaft input and another 10T on the output, will the 9:1 overall gear ratio keep the clutch from burning up?

 

[Bluethunder3320]

its all trial and error. i have 6:1 on my kart with 18" tires, but its a super light machine, so it doesnt have much of a problem,

and on my mini bike i have it 10:1 with 19" tires, the clutch is fully engaged and not slipping almost instantly...