Leverage ratio dilemma

[Liftoff]

ok, I think I understand something now... had to find my old drawing board and loosen the rust off my engineering drawing - now I think I have a clearer picture of what's going on (I hope! ) What Leverage ratio would you go for?

My other question now is how large can I now go with the cylinder? The volume of the one I currently have is 0.23L with a 0.51L buffer tank (its a 12oz paintball bottle)
What's the recommended cylinder to buffer tank size ratio?

[maddox10]

My other question now is how large can I now go with the cylinder? The volume of the one I currently have is 0.23L with a 0.51L buffer tank (its a 12oz paintball bottle)
What's the recommended cylinder to buffer tank size ratio?

Industrial guideline is 5 times user volume. But I feel that a 3 times used volume is the lowest that yields enough advantage.

[Max]

You do know that a paintball bottle is way overrated for a low pressure system- you could save a lot of weight by using a more suitable bottle eg. A small powder fire extinguisher

[Liftoff]

Hmmm, so I'll have to get a larger buffer... I'm already off the x3 mark with the current set up - so increasing the size of the ram will only make things worse :|

I opted for paintball buffer thinking they were light and compact, the 12oz bottle weighs about 600g, a 20oz one weighs approx 850g... so how much would a similar sized powder extinguisher weigh?

[maddox10]

I opted for paintball buffer thinking they were light and compact, the 12oz bottle weighs about 600g, a 20oz one weighs approx 850g... so how much would a similar sized powder extinguisher weigh?

In theory less. But unfortunatly, 2 things are annoying.
1) most powder extinguishers are made from steel. Still cheaper to make.
2) with a volume of 1.5 liters , even a 1 kg model (from a car) is way to big.

[Liftoff]

1.5 Lt buffer wont fit for sure - too big. And if most are made from steel they wont come any lighter right?

The 20oz paintball bottle will fit in nicely though, with diameter of 8cm and height of 24cm and a volume of about 0.9Lt it should do. And then I can increase the ram volume up to 0.3Lt.
http://paintnomore.de/co2--hp/co2-flasc ... sche-1.php


Another option could be building my own buffer tank to the size I wish...but I know most of you here are against building pressure tanks without testing it might not be worth the hassle in the end if the weight lost is not much!

[plargen]

you can get a 900g extinguisher but you would have to find out what thread to add a valve

http://www.ebay.co.uk/itm/NEW-900G-POWD ... 2324d7acdd

you can also get 600g 1s as well and i think there aluminium

[Liftoff]

Think I'll stick to paintball buffers - the 1/2 thread is a good size and connects to regular air fittings, besides that I can increase pressure as much as I want to as well, and at 850g I believe its not too heavy.

Been thinking of some way to increase pressure, say up to 16-20bar, but I cant find any compact 5/2 way valves rated above 10bar! Might try to design my own and give it a test, but its much more convenient finding something off the shelf!