Pneumatic Cylinders on ebay - any good?

[limpet]

http://www.ebay.co.uk/itm/25mm-Bore-...item43aa4aa7a7

Are these any good? I`m thinking of running two together.

[Mouldy]

There ok, I used one yeaaaars ago. Looks like it's the kind with screw in endcaps.... Best thing to do as an upgrade is remove the endcaps.. Then inside the port for the fitting there will be a hole around 2mm dia... Drill that out as large as possible as it's a major flow restriction.

You won't get the best flipper around with them, but it will work.

[mattsdragons]

they will work but from what i know about flipper, you ideally want something around 40mm bore

[Mouldy]

Not really if using two.

Basic equation for working out cylinder force; (pie x radius squared) x the pressure your running in bar.... So you'll be looking at around 30kg of force per cylinder... So overall 60kg before losses due to mechanical advantage. ...so pivot the cylinder on the flipper arm close to the tip... Further away from the arm pivot the better.

[calumco]

yeah davindras right, you want the rams pivot more towards the very front of your flippers arm but at the same time you want to try get a 3:1 ratio with the 1 part at the pivot side of the flipper arm for the most effective weapon.

my flippers got a more 2:1 ratio so its good but it could have been better

[limpet]

Thanks for your help and advice etc. I have now bought a 100 stroke x 40 bore Festo, it weighs over 1kg but looks fairly substantial.

[maddox10]

A usable size. Don't expect world shattering achievements tough.

[limpet]

no but if the weight is ok (and the system actually works!) I`ll probably add another.
Its all new tech to me.

[calumco]

you'll have something that turns robots over at least so it'll be alright, nothing more confusing then usin pneumatics for the first time lol are you using a buffer aswell?

[limpet]

yes I`ve got a buffer tank, at the minute its a 1kg powder extinguisher unless something else come along before I`ve built it. What size cylinder is 'average' would you say?