pneumatics for featherweight

[Liftoff]

Well yes, well spotted... the ram is a sort of hybrid one, started off as a standard 63x20mm ram off ebay, and then machined the outer cylinder and piston rod to my requirements. You'll find compact ones at reasonable prices off ebay (generally from Hong Kong or China) The main issue I find with them is the reduced port dia which does not help flow. Their advantage is that you can disassemble them, so you could drill the orifices to a more suitable size, clean and reassemble.

Something similar to this is what I started with, should be compact enough if used as is and have the ports taken care of.

http://www.ebay.co.uk/itm/CQ2B63-50-...item4850088561

[Rahulvyas]

What bore and length do i need the pneumatic cylinder of?

[maddox10]

Depends what you want to do.
Just lift over a good height . That you can do with a low pressure ram 40mm bore 100mm @6bar stroke ram.

Good flips or launches requires other stuff.

[Rahulvyas]

Thanks all guys.

I will go to the local store which sells big pneumatic stuff.
so does the 5 way valve have internal solenoid, or i need separate?

[maddox10]

I guess, if it's a shop that sells new stuff, that it will be a dissappointing trip.

[Liftoff]

If you go for a valve similar to the one I linked it includes the solenoid, 12v dc.
No need for "big" pneumatic stuff shop, actually most of the parts you need are small. Ebay is the best place in my opinion for the best prices

Do you know of a good double acting system that is this tight?

You could use the same set up I use for a double acting cylinder...all you need is to split the supply to the buffer. So from the 5way valve connect to the QEV on the buffer and the retract side of the ram. You could add a QEV at the retract side to avoid back pressure when the ram extends...

[Rahulvyas]

ebay usa shipping to india is costly, i can only buy from china
i will double check once from the local shop and take some advice and if they dont have small sized stuff, i will order from ebay

other than that, what is the cheapest way to drive 4 motors wirelessly without buying a sabertooth controller or some other motor driver( which is costly) ?
till now i used wires ( but didnt take part in any competition)xD

[Eventorizon]

If you wanted to up the power of the system without increasing the pressure what options do you have?

Smoothing the flow of air, increasing the buffer tank size and increasing the bore are the main ones I can think of.

Regarding the motor drivers, look up TZ85A hacked brushless controllers.

[Liftoff]

There's not much else you can do... large fittings and short pipework from buffer to ram is the most you can do, QEVs also help, but other than that I can't think of what else to do. I also tried increasing the pressure, up to 12bar the system works fine.

[Walmsley2012]

I just wanted to say thankyou for all of the information in this thread. I am also looking into Pneumatics but have been searching now for a while for a thread like this i.e part lists etc. I most certainly will be keeping my eye on this. If a building diagram does come about ill be sure to take a look.

Many thanks