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why do you need a buffertank in an fp system because surley (due to the lack of a regulator) the pressure between the main tank and the buffertank would equalize meaning the co2 would condense in the buffer tank filling it up with liquid co2 and then it would just become a second main tank ? also, will the tank ice up/ freeze more or less in a fp system than a lp system and is there any way of reducing/stopping this?
You should not get much ...if any ..condensate from F.P. gas transfer.
The freezing is caused by the liquid co2 turning to gas.... it boils ...to do this it requires energy ...the energy to boil is taken either from the liquid itself ...making it colder and possibly even turning the liquid to ice ... and the surroundings such as the bottle and the atmosphere immediately around the bottle.
A fire extinguisher bottle doesn't freeze when used because a vast majority of the liquid expansion to gas occurs outside the bottle... the liquid is ejected and becomes gas / snow after exiting the nozzle and the atmosphere supplies all the heat energy for the liquid expansion to gas.
So it's heat transfer to the liquid...if you can improve it then you can derive some benefit.
Sorry but i still can't see the point in a buffertank in a hp system, I have a vague understanding of why you need one in a lp system (because it takes some time for the regulator to start and you want the ram to start extending instantly) but there is no regulator in a fp system so why bother with the buffertank?
I do.Quote:
Originally Posted by Max
The valve in a paintball botle has a 2mm² hole, a Burkert valve has a hole of 126mm².Quote:
but there is no regulator in a fp system so why bother with the buffertank?
A tiny wrong idea if you ask me. A regulator starts regulating from the moment the pressure drops below the set pressure.Quote:
I have a vague understanding of why you need one in a lp system (because it takes some time for the regulator to start and you want the ram to start extending instantly)
But has a certain capacity in let trough. (CV)
A small regulator has small holes to let the gas flow, you just can't fit a 16mm hole in a 15mm diameter body.
and often even smaller ....the internal hole that the tapered needle seats into on two of my paintball valves is around 1mm dia ( approx 0.8mm² ).... and this hole also takes the gas direction thru a right angle thus reducing the flow even further.Quote:
The valve in a paintball botle has a 2mm² hole
A different type then from mine, the ones I had (and leaked, therefor could be disassembled) used a teflon washer on a seat that is part of the burst disk assemby. And messuring that hole ain't easy. And the right angles don't help the flow.
I hope Max sees the reasoning for a buffertank now.
Ok, deffinitly going to use a buffertank! Are you allowed to make your own bottle to give it a bigger opening and also an internal and external heatsink to reduce freezing?
If your storage bottle has all the needed paperwork concerning pressure testing and such, you can.
Heatsink in the bottle. Can you give me a drawing or scetch about that?
External heatsink. Good plan,if you have the roomand weight to spare.
i just mean thin 'fins' (sheets) of aluminium welded to the inside of the bottleQuote:
Originally Posted by maddox10
what other paper work would be needed apart from pressure rating?
Interesting idea. But if I look at an ali CO2 bottle, I see something like a bottle neck.
A 20 oz bottle is about 75mm diameter, but the neck narrows down to 25mm or something like that. The tread in that bottleneck is about m18 *1.5. This means a 15mm hole. I'm not a bad welder, and have welded strange things in my life, but I fail to see how I can weld in fins in a commercial paintball CO2 bottle.
On the outside, I wouldn't weld them. No firm would be willing to recertify an ali CO2 bottle with fins welded on. I would solve it with a ribbed sleeve to slide the bottle in.
But never have build a machine that had the weight nor space left for such an add on.
If I made the internal heatsinks I would be making the whole bottle from scratch but I doubt I'll do that but if I have the spare weight I'll make an external heat sink.
How long is the 20oz paintball co2 bottle and does it need an adapter to fit onto the on/off valve ?
A tread about CO2 bottles.
In short, if you buy a CO2 paintball tank, you have 2 options. Pinvalve or On/off valve. If you use the pinvalve, you need an adaptor with pin-pusher, and between the pinpusher adaptor-pneumatic setup, another valve that isolates the bottle-what is opened automaticly- from the rest.
Making your own storage bottle. I hope you realise that it ain't that easy if you want to comply with the PED norm.
My advice, build your machine with an on/off valved paintball bottle ,and go for the custom bottle afterwards.
Where can I get an on/off valve go on a paintball bottle and what are the dimensions of the 20oz co2 bottle?
Do people build their own buffer tanks for LP flippers?
You would really want flow in at one end and flow out at the other but paintball tanks flow in/out is at the same end
What is a remote isolation valve? Will I need one as well as an on/off valve? If so, where can I get one and where can I get an on/off valve? And also can you make a fp buffertank and how would you do it? And finally what dimensions do paintball bottles come in?
You only need the remote isolation valve if you use the pin valve. But don't forget your dump valve!
you can make your own fp buffer tank or you could just use a commercially made co2 tank which would be far simpler/safer. i know kenny makes custom fp buffertanks but they'll be pricy. paintball tanks come in different dimensions dependent on capacity and manufacturer
Sorry Kane, just to clarify. The remote isolation valve is the on/off valve for a pin valve bottle. An on/off valve bottle does not need a separate one. You will need one of these valves to stop the bottle from leaking CO2.Quote:
Originally Posted by kane
You will also need a dump valve, to get the CO2 out the rest of the of the system at the end of the fight.
Ok, I can't edit my last post - apologies for the double post.
How on Earth does this clevis work? I can't quite fathom this pin.
In my previous post I gave a link to another tread, and that gives you 2 possibilities.Quote:
Originally Posted by Max
I buy mine at the local paintball store. (1.2km from my front door)
Otherwise, don't you have google in your favorites. Or can't you use the yellow pages and paintball shop in 1 sentance?
330mm long, 75mm diameter.Quote:
and what are the dimensions of the 20oz co2 bottle?
Yes, in a lot of cases it's an adapted 1 kg powder extinguisher from the car scrapyard.Quote:
Originally Posted by shakesc
Yes, the tread of the size in the bottleneck of a normal paintball bottle (in a fire extinguisher it's even bigger, M25*2 or 4/3 NPT) allows you a let trough of over 126mm², and that is the max you get from a Burkert 5404, so not much to worry about.Quote:
You would really want flow in at one end and flow out at the other but paintball tanks flow in/out is at the same end
How are those bottles adapted and can you use those bottles for a fp buffertank?
.Quote:
Originally Posted by Max
By adding in/outlets in the right kind of connectors.
No, testpressure 16 bar, workpressure max 5 bar.Quote:
and can you use those bottles for a fp buffertank?
If you would try, the plastic handle/trigger will pop off. If you replace that with something stronger, the bottom will pop out. If you weld that up, you'll have a grenade.
And, in the modern feathers, a car powder extinguisher would be a tad big
what should i use to make a buffertank? for my main tank would it be possible to get a painball bottle, cut 10cm out of the middle of it then weld the two bits together like this:
[attachment=0:3gcwa20h]painball bottle modification.png[/attachment:3gcwa20h]
also where can i get a dump valve? i have tried googling it but cant find any it comes up with something for cars
thanks.
It's nothing special - a ball valve will do.Quote:
Originally Posted by Max
OF THE CORRECT PRESSURE RATING.Quote:
It's nothing special - a ball valve will do.
Max... your questions show a lack of understanding / competence...don't even try to make your own F.P. Buffer Tank... in fact I'd recommend steering clear of F.P.
There are however various paintball bottle sizes ... if you want a shorter bottle.. try a 3.5 oz as a buffer.
http://i1.tinypic.com/82jkfi1.jpg
Cut a tank in half and reweld it, if you can weld ali as a professional , you could do it.
But to get it recertified, that will be another matter.
On dump valve, any manualy operated 2/2 valve of the correct pressure rating will do the job nicely. I even used adapted fire extinguiser valves for that job.
But simplest is a hydraulic 1/8 bsp ballvalve.
The dump vales you found for cars are more like the mandatory PRV we need. Pressure Relief Valves. In cars it's used to protect the turbo and inlet manifold from overpressure.
In the robots it's to have a safety feature in the pressurised parts. The PRV has to be set at the max working pressure of the lowest rated component, or at 1000psi, whatever is lowest.
sorry for my lack of understanding/competance,
i had tried to find smaller painball bottles but all the shops i looked at only stocked 20oz ones but cleary others are available.
i have been looking at the rules and think i understand what the rules require in a pneumatics system, i see that i will need my presure relief valve, my dump valve but i dont know if i will need a remote isolation valve if i use a standard paintball bottle?
If your paintball tank has an on/off valve.. as shown in my 3.5 oz pic.. then that will be your isolation valve ...Quote:
i dont know if i will need a remote isolation valve if i use a standard paintball bottle?
There's another sort of valve called a pin valve... this valve is normally opened and shut by screwing the whole bottle in or out ... not acceptable... this will need a seperate isolation valve.
You can see the pin in the centre that is depressed to release the gas.
http://ecx.images-amazon.com/images/I/41MP5YWu4dL.jpg
This would need an adaptor like this to push the pin and turn the bottle on/off...
http://hk2.image.pushauction.com/Vie...70&H=383&W=500
Just catch up.Quote:
Originally Posted by Max
Smallest is 3.5oz (135 grams, volume 180cc), biggest I have seen, and could be called paintball tank was 24 oz (760 grams, 1 liter of volume)Quote:
I had tried to find smaller painball bottles but all the shops I looked at only stocked 20oz ones but cleary others are available.
I repeat. Paintball bottles can come standard with an on/off valve, not a pin valve. It's just what you buy.Quote:
I have been looking at the rules and think I understand what the rules require in a pneumatics system, I see that I will need my presure relief valve, my dump valve but I dont know if I will need a remote isolation valve if I use a standard paintball bottle?
With a pin valve you need an isolation valve, with an on/off, you don't.
i have started finalizing some of the components for my pneumatic system and it looks like this:
[attachment=0:3q10759u]pneumatic system picture.jpg[/attachment:3q10759u]
i am not sure if the pressure relief valve and the dump valve is in the right place, apart from that does the rest of it look fine?
The dump and pressure relief don't go inline.
[attachment=0:30rxwtkz]pneumatic%20system%20picture.jpg[/attachment:30rxwtkz]
The ram you propose is not bad in size, develops 980 kg of force at room temperature.
But I think you'll like a slightly larger buffertank. The ram is 100 cc big, the buffer only 180 cc.
thanks for the reply (must have been hard to make the picture) i understand now.
i have made some simple cad drawings showing the positions of the major components and shape of the robot:
[attachment=2:2br8z8wz]flipper from side.jpg[/attachment:2br8z8wz]
[attachment=1:2br8z8wz]flipper with labels.jpg[/attachment:2br8z8wz]
[attachment=0:2br8z8wz]flipper from top.jpg[/attachment:2br8z8wz]
as you can see it should be very compact which is why i have been enquiring about custom made tanks(hard to find standard ones that will fit yet still hold enough gas) also it is not very high and invertable, thats why i can't have a very long ram. i know it doesn't need to be invertable because i can right it with the flipper and i can't use the flipper upside down but i would like to be able to move to the centre of the arena before righting my self to stop me flipping myself out of the arena! and also it won't matter if i get flipped but run out of gas.
also, i will try and find a larger buffertank but it is hard to find one that fits in the space i dedicated to it in my design but i think there is enough room if i can find a good fitting tank
http://img63.imageshack.us/img63/9494/co2tanks1copy.jpg
I'd double check with Mario on the minimum TOTAL bottle length with on/off valve and adaptor/pipe work.
Number 1 is a 50 ci HPA tank, and number 5 is a 20 oz CO2 tank
http://www.catalinacylinders.com/paintball.html
4 oz
http://static.zoovy.com/img/zephyrsp...e_co2_tank.jpg
hi,
what is a quick exaust valve and will i need one? also i've read that some antweights use deodrant cans for main tanks but how much pressure can they take, i cant beleive that something that thin can take liquid co2 but i thought it was worth checking.
A QEV exhausts the gas from the cylinder quicker...you don't need one on your F.P. design.
Deodorant cans!!!..NO NO NO
Don't faff around with making a F.P. buffer ...use an existing liquid co2 bottle with the appropriate neck fittings or BUY one from a reputable builder / source.
ok, i'll buy one or get one made by someone like kenny, i was just finding it hard to find a bottle which fits in the design and holds enough co2. what size are the ports on a burkert 5404 valve (can't open the pdf doc. with specs on it) and what size pipe can i use with it without an adapter?