On 6/17/2013 2:33 PM, wrote:
On Monday, June 17, 2013 1:56:54 PM UTC-4, John Doe wrote:
This is my most recent push stick for inline skating. It works OK but

it is still being improved.



http://farm9.staticflickr.com/8524/8...3e921320_z.jpg



In the bottom right, there is a yellow gearbox.



Between that gearbox and the crankshaft inside of the orange body,

there is a 1/4 inch aluminum rod connecting the two.



Being a two cycle engine, there is some sputtering. The wheel bounces

back and forth as it turns and the gears get banged around a lot. I'm

afraid that's going to eventually break stuff.



The 1/4 inch aluminum drive rod is about 8 inches long. I would like

to replace it with something flexible, or put a clutch in there.

Anything that would absorb some shock. I suppose a clutch would have

to be at the gearbox output, since the motor spins the rod at

thousands of RPMs.



Any easy possibilities?



How about a smaller diameter 8 inch rod of spring steel? I don't know

if spring steel works that way, just asking.



Or perhaps the amount of stress when it's banging around at idle is

no greater than the more uniform stress when it's pushing me up a

hill. I could just wait and repair it as needed. I'm definitely going

to continue testing it as is.



Thanks.

On a motorcycle you'd be looking for a 'cush drive'.

http://www.pacificride.com/FileLibra...izerhubs01.jpg

Doesn't need to be anywhere near as fancy as that.

Easiest to incorporate in the wheel drive somehow.


Problem with a metal torsion spring driveshaft is if you hit a resonant frequency, things get worse instead of better.

BTW the 'sputtering' is typical 2-stroke 3-stroking, 4-stroking, 5-stroking, etc, at partial throttle settings the engine may only fire once every 3, 4, 5 etc strokes.
I agree with the sputtering cause, but it should not be that way.
Something is wrong with the carburetor or it's adjustment. I have had
several 2-cycle chain saws and if they are properly adjusted, there is
no difference in running from idle to full throttle. Could the wrong
gasoline/oil mixture be causing this?

Paul