pneumatics for featherweight

[Eventorizon]

it looks like a small copper circle sheet which fits inside this https://encrypted-tbn2.gstatic.com/i...1OA8jpcfFgo-9C

I know what a burst disc is. I think I have spotted where its mounted now in the pictures on the first page. The base of the ram is propped up against it which is what was confusing me.

Chris, where did you get your Burst Disc units from? Ebay and Google are only showing units that blow at a minimum of 1800psi, I need around 200-260psi for a low pressure system.

[Max]

You don't need a burst disk for the low pressure side of the system, you only need a pressure relief valve.
I believe what Chris is suggesting is you can remove the burst disk from the valve (presumably with the centres drilled out to increase flow) and replace it with an ordinary ball valve to act as your dump valve.

[Eventorizon]

Yeah, I reached the same conclusion about 20 minutes ago :-P

[Liftoff]

Yep thats right, spot on Max. I used the pin valve which came with the tank, drilled the centre away and took the burst disk off. That way there will be no restrictions from buffervto qev.

@Rahul, I don't do any FP systems, better someone with hands on experience to give you an answer

[Rahulvyas]

Ok, another thing what is the bore and stroke of the cylinder that you are using in your bot?

[Liftoff]

63mm bore 75mm stroke

[ChrisKazoo]

Using Chris' parts list and advice from many of you guys, I've finally got a pneumatic system that works Now to design a robot around it...

[Rahulvyas]

single acting, cool.
What are the specs of your pneumatic cylinder?

[Eventorizon]

It look like a 40 Bore 75 Stroke. Nothing amazing but it can put a robot out of our arena if attached to the right robot.

[ChrisKazoo]

It's this one from eBay, 50mm bore 45 mm stroke. Modified like Chris suggests by drilling port holes bigger and had to drill and tap an exhaust port at the bottom to vent it after it's fired.
http://m.ebay.co.uk/itm?itemId=190837115480

[Eventorizon]

It's this one from eBay, 50mm bore 45 mm stroke. Modified like Chris suggests by drilling port holes bigger and had to drill and tap an exhaust port at the bottom to vent it after it's fired.
http://m.ebay.co.uk/itm?itemId=190837115480

Why not use a QEV? (Quick Exhaust Valve)

[ChrisKazoo]

Why not use a QEV? (Quick Exhaust Valve)

I have a QEV on the inlet and have pondered whether having a QEV on the exhaust would be worthwhile but I would still have to drill and tap a port for it as it's a double acting ram so normally would be vented by putting gas in the top port and exhausting through the bottom port back through the solenoid valve. Without a new port drilled the ram fires and then the gas has nowhere to go to vent.

[Rahulvyas]

is QEV necessary? I am using mine without it, no trouble till now

[Revsmin]

Not necessary no, but very helpful to increase the flowrate and thus the power

[Rahulvyas]

okay thanks