Paul,
I absolutely loved your design at Nationals. I've been waiting to see your papers, so I'm excited to hear that you are going to publish them by IRI. Unfortunately, we won't be there. Is there any way we can get a CD? Will you be posting the info in the White papers section after the 19th?

Thanks for your help - and good work.

I was looking at the technokat tranny design and all I have to say is WOW! This is spectacular. I stared at it for about an hour before I could fully visualize how it all worked together. If I'm not mistaken it's similar to the transmission of a stick shift car.
I noticed that you used only 40 psi in the cylinder for the shifter. Does that mean that you charged up that accumulater tank before every match or was it actually hooked up to a pump? What is the reason for using only 40 psi instead of 60? Does this cause the dog gears to get caught up on each other during a shift?
I don't think that I saw any synchros or anything of the sort. Did it shift at all speeds and while standing still? You didn't have to do any rpm matching or anything of the sort in the programming did you?
If it seems like I don't know what I'm talking about, please excuse me I'm just a student.

Some answers
 

Don,

Thanks for the interest.

The pneumatic system we used included one pressurized accumulator, with no pump. We had to pump up the accumulator before each match. The 40 psi set point on the regulator is only for air conservation. This thing works fine at 60, but that depletes the air in the accumulator quicker.

This thing shifts at all speeds and it is a very robust shifting mechanism. There is no rpm matching needed to shift. Since the ratio between the two sets of gears is 4:1, that means for every 1 revolution of the low gear set, the high gear set spins 4 times. So, every 4 times the high gear spins, the dogs line up and a shift is possible.

So, if a shift is called for, the dog gear gets pushed horizontally unto the other gear set. Since the pneumatic cylinder is constantly trying to push it into position and since the air cylinder acts like a spring, the dog gear will settle into its mate after the gear rotates around enough to allow for the mesh. It really is a sweet, simple thing to watch.

Andy B.

Woohoo!!
 

It's out early!! Great job Andy! It looks awesome....

Brings back many memories :D

If anyone wants to see any pictures that arent in that White Paper, talk to me on AIM @ the screen name "twinattack"..

:)