Spinning a Piston Rod

[Mr. Ivey]

In a shifting gearbox, if the pnuematic piston that throws the dog gear from gear to gear were connected in such a way that it caused the piston rod to spin, wouldn't that cause serious issues if there was a slight amount of wobbel? The size would be something around a 1 to 2 inch throw with a 3/4 inch bore. I know even the small pistons are strong, as proved last year with Sparky 5, but can they take the abuse of having the piston rod spun at speeds of a gearbox throught an entire match?
Ivey

[sburro]

Originally Posted by Mr. Ivey

In a shifting gearbox, if the pnuematic piston that throws the dog gear from gear to gear were connected in such a way that it caused the piston rod to spin, wouldn't that cause serious issues if there was a slight amount of wobbel? The size would be something around a 1 to 2 inch throw with a 3/4 inch bore. I know even the small pistons are strong, as proved last year with Sparky 5, but can they take the abuse of having the piston rod spun at speeds of a gearbox throught an entire match?
Ivey

I AM not sure if I understand fully, but if you were to spin the rod of the piston, you could melt or even ruin the rubber seals inside. This would cause leakes and they are not a good thing to have.

[Max Lobovsky]

The proper way to do it would be to use bearings/bushings to couple the non-spinning piston shaft, to the spinning gearbox. I can't think of an exact design right now, but I'm sure someone on CD can .

[Mr. Ivey]

I thought it would either destroy the bushing on the piston or the rubber seals inside that prevent pressure leaks. I just wasn't quite sure if anyone had heard of the pistons taking such abuse and still working for long.
thanks
Ivey

[Peter Matteson]

Originally Posted by Max Lobovsky

The proper way to do it would be to use bearings/bushings to couple the non-spinning piston shaft, to the spinning gearbox. I can't think of an exact design right now, but I'm sure someone on CD can .

This is how we did it. I'll see if I can get a picture to post and show it.

We used a Technocat transmission but our shifting setup looks quite different. I don't know if there is a funtional difference between the setups.