honda gx 240 6-1 gear reduction kart

[Doc Sprocket]

No clutch on my engine I'm afraid, it's straight from an old cement mixer lol only had about 10 hours use from new

I see. Okay- it makes a bit more sense now why you'd go to the extra trouble. You of course need a clutch, that's why I asked. While these redux units often do have a built-in clutch, they sometimes don't.

 

[mymumisaman]

Yeah would be nice if It had a clutch, iv taken the drive off to have a look and it's a cog on the crank linking to another cog to the output shaft , id have to swap the crank and side of engine casing to put a clutch on it and that would cost over £160 .......but saying that, I like a challenge and it gives me chance to try something new

 

[Doc Sprocket]

but saying that, I like a challenge and it gives me chance to try something new

Ain't no thang wrong with that my friend, this IS DIY after all!

 

[mymumisaman]

update

Well I've been playing and finally sorted out the lever system that engages the whole thing here's some pics,

It's not quite finished, still got to sort out the keyway and little bits and bobs .

 

[Doc Sprocket]

Looks pretty good. I'd be interested to hear how much of a problem slippage may (or may not) be.

 

[mymumisaman]

Well when I get it together with the shaft I'll post a video , I still need to make some hubs for the wheels before I can test it under load, might get that done next week.

 

[itsid]

cool idea a belt clutch,
that all looks very nice indeed.
It should be mounted the other way around
- small rotor on PTO, large rotor on jackshaft -
otherwise you will have (eyballing) three times the rpm on the small rotor, and a hard job of gearing that down on the actual kart.

Still: I don't think that is the right material for this.
Wood is dissipating heat at a very low rate, wich makes it a good heat insulator, but in this case that is not a wanted feature
especially not with this exact setup (large on pto) since the small rotor is turning really fast and will build up a huge amount of heat.

Anyways, good idea, turn it around and give it a try (not without making sand molds before) that way you can cast it in aluminum afterwards

'sid

 

[OzFab]

Don't forget, the engine still has a 6:1 reduction box...

 

[itsid]

Ah true...
I really forgot about that.

'sid

 

[mymumisaman]

Well it works ..........just a little too well lol. Iv overlooked how the small pulley is connected to the shaft, and yes I am using threaded bar for the time being, but its 20mm high tensile stuff till I can get more funds lol, basically I need to make a keyway as the pulley is just spinning round the shaft, but it works!

 

[chris_the_poser]

Lets see a video

 

[mymumisaman]

Il post a video tonight , iv been putting a keyway in the shaft for the small pulley,

 

[mymumisaman]

Well here are a couple of videos ......enjoy! ........(hope I put them on right)

http://static.photobucket.com/playe...yy218/my_mum_is_a_man/VID_20130816_201133.mp4

http://static.photobucket.com/playe...yy218/my_mum_is_a_man/VID_20130816_201918.mp4

Hope this works.

 

[mymumisaman]

I still need to make the hubs for the wheels that I plan to use but at least it works, just got to figure out what I want to turn it into...trike? Or kart?

 

[OzFab]

I think I see a problem with that setup; the static position is disengaged & you need to actuate it to engage which means you'd need to hold the clutch in to drive & release it to stop

Other than that, great work... until the wood wears prematurely...

 

[mymumisaman]

I think I see a problem with that setup; the static position is disengaged & you need to actuate it to engage which means you'd need to hold the clutch in to drive & release it to stop

Other than that, great work... until the wood wears prematurely...

I wouldn't consider that a problem, more of a safety feature not sure how I'm going to set it up , either a handbrake lever kinda setup or hook it up to the throttle , so foot down engages clutch then throttle. I'm not having any gears so don't need a clutch pedal as such.

 

[philip metzner]

I realy like your work, my hats off to you! The trouble as I see it is your gear reduction is wrong You already have 6:1 on the engine which is close as it is. All you need is a axle pulley slightly larger than the engine pulley with a idler pulley to clutch it. Your system has defeated the gear reduction box on your engine and your wheel speed is to fast.

 

[mymumisaman]

I haven't negated the reduction drive just increased the gear ratio from a 6 to 1. To a 3 to 1
The engine is 8hp so should do the trick if not then I can always adjust the pulley sizes. it's. A case of trial and error as I'm still unsure of what I want to build and how heavy it's going to be. I've. Built a little kart before with a 5 hp 160 clone, it had a 5 to 1 reduction with a centrifugal clutch and pulled quite Well, so I figured bigger engine should be able to cope with less of a reduction. Dependant on weight of coarse. If not then it's an easy fix.

 

[itsid]

I guess there'd be no need to adjust pulley sizes, the driven pully sits on a jackshaft anyways, doesn't it?
Therefore you can simply adjust gear ratio with stock sprockets on shaft and axle, or am I missing something (again )

'sid

 

[mymumisaman]

At the moment the engine is connected directly to the axle but if it don't work out then I'll put a Jack shaft on no problem