pnematics advice

[suvv]

evening
im currently piecing the parts together for a flipper system for an ant and having used pneumatics on model boats before i have a little experience however im used to not having a weight limit so could anyone with miniature pneumatics answer these

1) is this a good enough cylinder for an ant or is it overkill:http://www.hobbyking.com/hobbyking/s...r_6xL80mm.html

2) what size air tanks do people use as i saw a few on hobby kink

3) is there a micro solonoid or switch block that is very light weight but effective and the only ones i have seen are 3 way switches and i dont wana waste air or weight
thanks muchly

[Rhys]

The ram looks like it would be too long to be any use in an Antweight. And a bit heavy and narrow. Have a look on brick link for some Lego rams. They are much lighter and shorter and can handle 100psi.

Again, the ones on hobby king are a bit big and heavy. None of the ones I've seen would fit into the 4 inch cube. I think most people use custom tanks. Basically get an old aerosol container, make sure it's empty, then drill some hole in it. Then epoxy putty some copper tubes coming out of it. But that can be quite unreliable. Or you could buy a Lego air tank, but they're quite rare. And small.

As for the valve, the Parker x valve is supposedly quite good, but very expensive. I use an SMC v1000, which is cheap and has a good flow rate. But it needs to be activated by a servo, so the whole setup is quite heavy. Or again, Lego do cheap and light valves, but it's hard to adapt them to be fired by a servo.

Hope that helps. I'm sure other people will have different answers for you too.

[suvv]

thanks never heard of brick links will have to check that out does any one know what the max pressure is for one of the lego air tanks im guessing it wont be that high

[Rapidrory]

They'll most likely hold 100psi fine, however the fittings are not suitable for high pressure. I use one to store liquid butane on my ant flamethrower at around 40psi, and even having super glued the pipes on to the fittings it's about the limit the fittings'll handle. Same is true for the lego valves; the one's I used are modified and still regularly leak. An effective 100 psi antweight pneumatic set-up requires a lot of custom parts and work, which is why there's only about 2 active one's running atm. I'm planning to work on one in the near future, but that'll be a complete scratch build.

[suvv]

cool im guessing 40psi would be pritty weedy and not last to long in the arena

[Rapidrory]

Yeah, at that point you'd be better off using a servo flipper

[Rhys]

Lego rams will hold fine up to 100psi. They're pretty sturdy. I can't say the same of the lego valves though. The X-valve and V1000 will handle 100psi though.

And Rory is right about the tubing. It will only hold about 40psi before they blow off. But this is an easy fix, just replace it with this:
http://www.hobbyking.co.uk/hobbyking/st ... _Mtr_.html

That fit lego pneumatics perfectly and will hold to at least 100psi, sometimes more depending on the type of ram you are using (a longer inlet will mean it can handle higher pressure in my experience). It's not as flexible as the lego tubing, but it's much tougher.

And also as Rory mentioned it's very difficult to get right. Isn't Anticide the only active pneumatic ant at the moment? I know Scott's got one ready to go, but it's yet to have a fight isn't it? I know lots of people have tried and failed, me included. But don't let that put you off, buy some parts and have a play with them. You'll be astonished how much power you can get out of such a small ram.

This is about as good as my attempt at a pneumatic flipper ever got (Lego ram, V1000 valve & deodorant can tank). The next one is in the works...

https://www.youtube.com/watch?v=wnN5JAbW_TI

[Remote-Controlled Dave]

Anticide and Inertiant are both pneumatic. One much more successful than the other but both work and compete.
Scott's robot Flux did compete in an AWS and was pneumatic but didn't use the weapon as he was scared the robot would blow up.

[EpicentrE]

My one competed at the last AWS, as Dave said. However while I didn't use the weapon at first because I was expecting it to cause further damage to my already bodged-together chassis, when I did try to use it I found that I couldn't anyway. After a few fights, it was leaking so badly that I just stopped pumping it up, as it was empty by the time the fight started.

I wouldn't look into the X-valve that people have suggested; it has an incredibly low flow rate, which is one of the most important things in creating a powerful flipper. Where people might have seen it used (by Josh, in particular) was to power a larger air-piloted valve.

If you want a 100 psi setup, the easiest is definitely what Rhys suggested; modified Lego ram, VM1000 valve (and a servo to actuate it), a tank made from a modified aerosol can of some kind, and high pressure semi-rigid tubing. That's the easiest, but it still isn't easy.

[suvv]

that vm1000 looks great im guessing its really light aswell where is the best place to get it also are there any good sets of instructions on making an air tank out of a deodorant can??