FW pneuamtics on the cheap

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muchalucha
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FW pneuamtics on the cheap

Post by muchalucha » Thu Apr 23, 2009 7:09 pm

I have been thinking about a weapon for my fetaher and , after hearing there are no arenas rated for spinners in the uk , I was pretty much stuck with a flipper , i looked into mechnaical flippers , but i have found some old pneumatic rams i was given , they have a storke of about 1.5 - 2 inches , but have a very large surface area and after some tests with an air compressor , they look good .

My question is , what do i use as a valve , how to i trigger the valve (servos or such like) , is it ok for a FW to use refilled areosols or air dusters (so theres no flammable gases to asplode), and if so how do i hook a pipe lug up to an aerosol.
Fight or flight ... ?

...suicide

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teamocean
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Post by teamocean » Thu Apr 23, 2009 9:49 pm

you could use a compressor with the rams you have. Technobots have a couple of push fit valves which you could control with a servo which would operate the rams.

However, a system like this is not going to make a briiliant flipper, it will probably have a very low flow rate and will be more of a lifter than a flipper.

Also if you were to use an aerosol can or air duster as your main gas supply you would probably not pass a tech check.

In my opinion you should have a look around on ebay and get a cheap 5/2 or 3/2 solenoid valve and use the rams you currently have with a cheap car tyre compressor. You can also pick up low pressure pipe & fittings from ebay (there are a couple of good shops on there).

To try and make the most of a compressor system include a large coil of pipe after the compressor to act as a buffer, this will increase the flow of gas into the ram and improve the speed a bit.

Also to operate the solenoid valve I would recommend a very simple servo & microswitch set up, we have used it in Aftershock for ages and it works really well.

Anyway, hope this helps!
Will Thomas
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muchalucha
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Post by muchalucha » Fri Apr 24, 2009 3:53 pm

i had a feeling the tech checkers wouldn't like that ! is it ok to use the air canisters you buy from smc (not smc pneumatics , Sussex model center lol)for pneumatic landing carriage systems on model planes , the compressor system would be preferable but i don't think you are allowed on board compressors.
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Remote-Controlled Dave
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Post by Remote-Controlled Dave » Sat Apr 25, 2009 12:00 pm

You are allowed on board compressors aren't you? We even had one of those in an antweight.
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muchalucha
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Post by muchalucha » Sat Apr 25, 2009 9:05 pm

probably going to use a 12v compressor then , i have been filling empty deodorant bottles up from my air compressor and i can only get 3 - 4 full power flips .

can i use a tank instead of a coil for the buffer
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teamocean
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Post by teamocean » Sat Apr 25, 2009 9:47 pm

As Dave said compressors are allowed and you can fit a buffer tank as long as it can clearly take the pressure being supplied by the compressor.

A long coil of pipe can give similar results for a lower cost but a tank is still preferable.

Heres a couple of tips which I have found useful when trying to get the best flip.

!1. Use the largest bore pipe you can (to try to get the highest flow rate possible)
2. Use a large buffer tank (at least twice the volume of your ram)
3. Use the highest flow valve possible
4. Try to use the least amount of pipe possible when connecting the valve to the ram, this way you wont waste any gas filling pipework before your ram.
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petec
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Post by petec » Sun Apr 26, 2009 9:30 pm

Powder fire extinguishers are typically rated to 10 or 12 bar - pop the top and empty into a bin bag. Drill out the top opening to the correct size to take a normal threaded pneumatic connection. Once it's screwed in, use epoxy resin around it - not the quick dry - and once its started to go off, bake it in a slow oven to make it really strong.

Cheap, strong, safe....
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muchalucha
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Post by muchalucha » Mon Apr 27, 2009 5:15 pm

i think that might be over kill for what im doing , its only going to run at max 120 psi
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razerdave
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Post by razerdave » Mon Apr 27, 2009 5:39 pm

better to be overkill than under

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Post by Team Terror » Mon Apr 27, 2009 6:27 pm

I agree with DaveW, better to overdo something than underdo it :P
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BeligerAnt
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Post by BeligerAnt » Mon Apr 27, 2009 7:08 pm

120psi is about 8bar, so a tank rated at 10-12 bar is not overkill at all.

PLEASE make sure you use properly-rated parts. It is also a very good idea to do a hydraulic pressure test first (fill your pressure vessel with water and pressurise it) - a bit of water running out is far better than shrapnel flying everywhere.

Don't underestimate the potential dangers, 120psi is enough to make a big bang!
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Team Orr
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Post by Team Orr » Mon Apr 27, 2009 7:28 pm

if u want to be really low tech try the rex's robot challenge pneumatic system

jack
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muchalucha
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Post by muchalucha » Mon Apr 27, 2009 8:26 pm

i tried to build one of the "valves" and it well ... sucked. (no pun intended lol)

i know you can use engines on FW , so could you use a spud gun type device to geneate the pressure.
Fight or flight ... ?

...suicide

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Rhys
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Post by Rhys » Tue Apr 28, 2009 1:18 pm

just buy a compressor, they are much cheaper, easier and safer to use.

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