2 Speed Belt Tensioner Build

[huttronics0001]

this would really help with my ratio problem, the idea of two belts is great

but the shaft on my transmission is only long enough for one pulley, what would be the best way to fit a second pulley on there?

 

[redsox985]

Get two thinner pullies so that the belt doesn't have to jump very far making shifting quicker with less over rev and less distance means less possible stuff that can go wrong.

 

[huttronics0001]

well i thought i could have two belts then have the tension go from one to the other for the different speeds. i just want to know a strong way to extend that shaft so it will comfortably fit two pulleys

 

[devino246]

well i thought i could have two belts then have the tension go from one to the other for the different speeds. i just want to know a strong way to extend that shaft so it will comfortably fit two pulleys

If a clutch can fit on the shaft, then so can 2 pulleys.

 

[Kenny_McCormic]

Out of curiosity, what are your gear ratios?

 

[devino246]

Out of curiosity, what are your gear ratios?

7.4:1 in first, 2.5 in second. Its quite a jump, but i did all the math and theres quite a bit of overlap in the gears. I can switch the second gear pulleys around too if i need more overlap.

 

[Hendersonjk]

pulley ideas

waterpump pulleys come doubled up. If 2 normal pulleys wont fit I`d put them both on a shaft or tube with the right ID so you can keep them straight and weldem up.

 

[huttronics0001]

the engine shaft is fine, but the one on the transmission is not

 

[devino246]

the engine shaft is fine, but the one on the transmission is not

What do you mean your transmission? What kind of engine is it?

 

[fowler]

or does he mean the shaft with the other pully on it as in jack shaft

 

[devino246]

or does he mean the shaft with the other pully on it as in jack shaft

Well ive never heard of a jackshaft thats too short for 2 pulleys.

 

[fowler]

nor have i
its not a lawnmower tranny

 

[devino246]

Regarding progress on the build: Ive decided to take a break from the kart for a few weeks. Temps in the upper 90's with high humidity dont make for a good work environment. I also need to focus on some new/unfinished home improvement projects.

 

[huttronics0001]

are you using cables or rods to tension the idler pulleys? i'm doing the same configuration except 3 speed. I would also like to know what sort of set up you have to move tension from one to the other and if you have any ideas on how to make it for 3 speeds as opposed to two

 

[devino246]

are you using cables or rods to tension the idler pulleys? i'm doing the same configuration except 3 speed. I would also like to know what sort of set up you have to move tension from one to the other and if you have any ideas on how to make it for 3 speeds as opposed to two

If your using 3 pulleys, your gonna need 2 jackshafts. 3 pulleys cant fit on the engine shaft. Im using cables for everything. Refer to the link in post one for how everything works.

 

[Orange Krate]

Update please?

 

[modelengineer]

If your using 3 pulleys, your gonna need 2 jackshafts. 3 pulleys cant fit on the engine shaft. Im using cables for everything. Refer to the link in post one for how everything works.

You wouldn't need 2 jackshafts. You have your primary reduction in chain from the engine to the jackshaft, then you have 3 pulleys on the jackshaft, and 3 on the axle.

On my kart I used trampoline springs to tension the belt and a rod linkage to the clutch pedal to disengage it. It worked really well.

 

[devino246]

You wouldn't need 2 jackshafts. You have your primary reduction in chain from the engine to the jackshaft, then you have 3 pulleys on the jackshaft, and 3 on the axle.

On my kart I used trampoline springs to tension the belt and a rod linkage to the clutch pedal to disengage it. It worked really well.

That makes sense, why didnt i think of that?

Update please?

I was having problems with an air leak around the intake, so im taking a good long break. Ive got more important stuff to worry about right now. I also have stuff id rather be spending my money on. it'll restart this fall when its a little cooler.

 

[huttronics0001]

i am able to get 3 pulleys on my engine shaft, before i had a tractor tranny but now i have a jackshaft. I built a tensioning mechanism and a stickshift in the process of attaching them together. but taking a few days to clear my head, 3, 8 hour days in a row was too much.

 

[devino246]

You should start your own build thread. Be sure to post pics