Hoglet one way clutch

[tornitore45]

The plans locate the one way clutch on the chain sprocket connected to the pedal.
The sprocket on the crankshaft is locked on it.
This means that when the engine fires the chain and both sprockets turn at engine speed. That seems to me a lot of motion for nothing.

I am considering locating the one way clutch on the crankshaft, in that way when the engine fires the chain and both sprockets stand still.

Naturally it will be a different size one way clutch, also grabbing a 3/8" shaft will be better able to transfer the torque than grabbing a 1/4" shaft.

Any thought?

 

[BaronJ]

Hello Mauro,

Whilst I have never seen a "Hoglet" ! Based on your description you need to drive the chain at some point so it seems logical that even if you put your one way clutch on the crankshaft you are going to need some additional way to provide drive to the chain unless the engine is reversible.

 

[tornitore45]

Baron, the Hoglet is set up to look like a Harley Davinson motorcicle.
The chain is part of the kick start mechanism, it connects the pedal with the crankshaft and rotates only a couple of turns when starting the engine. After that the one way clutch stop the motion of everything down stream of it; in this case just the pedal keeping the chain and sprockets turning according to the original design.
According to my proposed modification, with the clutch on the crankshaft, both sprocket and chain should loose motion after the engine catches.

 

[BaronJ]

Hi Mauro,

Thank you for your concise explanation of the Hoglet. Not knowing what a Hoglet was, I didn't understand the reason for the one way clutch. Now that you have explained it I agree with your reasoning.

Good luck with your build and when you are able a picture would be nice.

 

[tomrux]

Mauro
What about a one way bearing?

Tom R

 

[tornitore45]

Tom R,
that is exactly what I think of using.
One of those cup needle bearing that look much like regular bearing but are one way.
I am considering to use an 1/2" ID jacking up the diameter of the crankshaft journal from 1/4" because torque requirement is halved and a larger bearing is rated at higher max torque.

 

[Walsheng]

We use one way bearings on RC helicopters so we can auto-rotate them down. Some of the larger ones have very powerful motors. The only down side is I have only seen them in metric sizes.

John

 

[tornitore45]

McMaster has them in Imperial size. On new project bastardizing is pretty common I have just about both set of tools.