Doing a search on mini mudmotors.....

Shawn,

I've got the same question. They have clutchs and transmissions listed on the same page so I sent an email asking if this is actually a gear reducer and some specs. I'm thinking since it's an off-set center line design it's probably a gear reducer. The ouput shaft has a 8 spline shaft. It's been a few days and I haven't heard. I'll give them a call if I don't hear anything in a couple of days.

Ed
 
Ed,
Let me know what you find out. I thought the same thing when I saw the offset design. Could be a cheap way to make a nice little rig. Shawn
 
Ed

I don't know what cvt stands for but those are variable speed pulleys with what looks like a 1422V belt. I've rebuilt about 1/2 dozen of those working on old wood working machines. A lot of people call them Reeves drives after the original brand. They are also made by Gerbing, Speed Selector, Reliance, Maury, Hi-Lo, etc., etc. They make countless variations of them but all are generally very stout and built to take years of use. I drill press I bought was over 40 years old and used heavily and it had the factory original belt on it. I could have kept using it but made it a spare as a matter of course. The speed ratios you can get from VS pulleys can be quite impressive. My Powermatic 1150 DP is around 10:1. Not sure how you plan to incorporate them in your design but I have no doubt they are up to the task. Just be sure to keep them dry.

Eric
 
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Tom -

You have to remember that there are some good old southern boys on this site - they may not know what a snowmobile is.

Mark W
 
Mark,
You are right I have never ridden on a snowmobile (I think it would be a blast though). But I think I know what you are talking about. One of the pulleys has a centrifugal clutch built into it so the faster it spins it tightens up and away you go. I have mostly seen those on low r.p.m. 4 cycles though. Shawn
 
Eric,

CVT stands for Constant Variable Transmission or as Tom mentioned Constant Velocity Transmission. Same principle just different terminology I believe. If you look up the regenerative system on the Hybrid cars they refer to it as Constant Variable Transmission. Anyway same thing as your belt setup on a drill press. In school we called them Reeves drives.

http://www.staton-inc.com/Details.asp?ProductID=2651

Shawn and Mark, The answer I got was clutch not a gear box. The CVT isn't the best idea but I thnk I found another. This is a 3.11:1 gear box that fits the Honda GX35cc, Honda GHX50-49cc, Robin-Subaru EHO35cc, Mitsubishi TLE43cc and the Tanaka Pure Fire 40cc and I beleive the Tanaka 47cc race engine but I need to check on that. Rickshaw is using a 3.75:1 gearbox design. Do the math...the difference in rpm/torque won't be noticable with a small engine running at 7,000 rpm max.

It has a 10mm (10mm divided by 25.4 = .398) threaded output shaft which using a .375 dia drive shaft could be put together with a threaded coupling and locknut easy enough. Motor mount/driveshaft housing is what I'm thinging though right now. I'm thinking machined aluminum bar stock. It's not rocket surgery but will take a little thought none the less.

Any more thoughts, questions, suggestions....I'm all ears!

31_gearbox.jpg
 
We always called them "torque converters". Rupp had them on their mini bikes. You guys keep this up and I'm gonna have to get or make a little boat.
 
Yep...same thing. A little red frame with a 5hp Briggs between your legs...Man that was power when your 8 or 9 years old!!....AND your first "chick Magnet"...what ever that means at that age!.....hehe

Gotta dink with something in the off months!
 
i was trying too explain this too a few guys at work a few of them are vietnam vets, they kept refering too long tail out boards used in the rivers over their just curious its kinda off subject but has anyone seen these and know about what they used for power? they recall v 8s and hot rod 4cyl as well as all manner of small moters ?
 
You fellas keep this up and get a how to\plan solidified for non mechanical guys like me and you could sell them, perhaps as a site fundraiser. I know I'd spring for them, I was looking at a rickshaw to push my kayak for giggles and grins but I'd much rather build something myself. Or something to push the Kara I'm gonna build one these days soon. I'm pretty inexperienced at mechanical type stuff so It'd have to be pretty step by step.
 
I recall seeing some of the pictures from Veitnam. I had a freind who thought he'd join the coast guard thinking he'd be stationed state side. They shipped him to the Mekoing Delta as a gunner on a PT boat.

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Ed, Isn't that just how things go, I enlisted Navy to be a gunner on a river boat and they sent me to Ga. instead. Lucky me but I sure didn't know it then. SE U.S. instead of SE Asia. Luck beats skill.
 
Seriuosly?...That's a hoot. I'll have to email by buddy Dennis and tell him that. When he first got there he was assigned to a PT that was actually plywood! Like the one JFK was assigned to. He said they shot that one out from under him the first month he was there. He told me they patched that boat 6 times and the bilge ran 24/7 until they finally got a metal boat. He'd tell me about running the river at night, very peaceful, listening to the jungle sounds when all of a sudden the'd round a bend in the river and tracers would be coming from both sides of the river across the deck! Everyone would hit the deck as the pilot got her up on plane. Then as soon as they'd get a little up river everything would return to normal. They said in the beginning the'd try to return fire but lost to many gunners that way. Not my kind of fun.
 
I've seen pics of SanPans with V-8 longtails on them. Old Mr.Potter was a gunner on a PBY and had some stories. One of my contractors sat offshore on the barge that put them back together. Had to be the most dangerous job in Nam at the time....the gunner not the fixer...although they patrolled the barge with grenades that they tossed in if they saw bubbles....
 
As we discussed Ed, I have my engineering buddy at Toro looking into this. He is thinking that and ice auger tpye of gear reduction might be the trick. They get these babies down to less than 300 rp I think but he says that changing out gears to get any rpm output desired should not be a problem. Can you imagine the torque on an ice auger or a powered post hole digger. That would be some serious torque.

One thing to keep in mind Ed, the Ricksahw is using the honda 4 stroke with a max output of 7,000 rpms. The little 2-smokers have a much higher rpm limit (12-15,000 rpm) I believe.

Mark W
 
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