Im sure youve guessed from the title, but the brass bit at the top wont come off. Any ideas anyone?
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Im sure youve guessed from the title, but the brass bit at the top wont come off. Any ideas anyone?
I dont have any problems removing that . And the tread below them is M18*1.5, standard metric fine.
I would not advise removing the top of a sodastream bottle.
Sodastream bottles are not intended to be refilled by the end user and you will also find it difficult to refill at events.
If you want to replace the pinvalve, its rather difficult. I never found a suitable valve to replace the pinvalve.
Paintball bottles have another kind of tread, so thats no option.
I would suggest not to use sodastream bottles for RW. But use a 12 oz paintball bottle.
http://www.fightingrobots.co.uk/discus/messages/9/209.html?1104518153http://www.fightingrobots.co.uk/disc...tml?1104518153
Scroll down .....
Note:-
The Continental SodaStream has a different bottle neck thread to the U.K........unless Mario is refering to the NEW Soda Club bottles.
New Sodaclub bottles.
Pics of both types on my site ......plus a NEW pneumatics page.
Mario is correct ....You may well find Paintball bottles easier.
So ...Rhys .....what are you up to?
I was just trying to get together bits for a LP compressor type flipper for my featherweight. I used to have a feather, but gave up after just the one event. I thought this would be the best way to go about getting a proper weapon.
As for the paintball bottles, can someone give me some advice? Where would I get them? how much are they? What size threads etc, Will they have dodgy valves that cant be removed either?
A paintball bottle over here, In Belgium, can be equipped with an on/off valve. Price around £31
The external tread is comparable to a 1/2 bsp.
I do not have any troubles removing any valve from any bottle.
So, if i buy a paintball bottle, can I just screw a 1/2 bsp connector onto it, or will I have to add/remove anything?
http://cgi.ebay.co.uk/Paintball-Brand-New-12oz-C02-Bottle_W0QQitemZ7219730185QQcategoryZ64674QQssPage NameZWDVWQQrdZ1QQcmdZViewItemhttp://cgi.ebay.co.uk/Paintball-Bran...Z7219730185QQc ategoryZ64674QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
I was looking at this. Would that be suitable, and easy to connect up?
Cheers
If you buy this paintball bottle you have one with a pin valve. And thats less handy. But yes, you can screw on a 1/2 bsp adaptor straight on.
Better is to use a paintball adaptor(or an adaptor made for it) then you can use the O-ring on the valve.
Please ensure that any gas storage vessel you use is supplied with suitable certification.
What certification would I need to make it legal? Im guessing most people selling stuff on ebay wouldnt have certification showing what pressure their items are rated to. Any ideas where I could obtain these? Or people who sell tanks with certification?
Cheers
A certified pressure vessel carries its own certification. Its stamped in the top of the pressure vessel, or another suitable spot.
@ Rhys
Questions.....
What is your present / intended pneumatic design?
Got any bits yet?
Is price a big issue?
Woody
(Message edited by woody on May 12, 2006)
My goal is to make a simple, but reasonably effective low pressure flipper. The current design/ideas is to have a compressor with a pressure switch for filling the tank on board.
Ive currently got a 40mm bore, 100mm stroke ram, and a soda stream bottle. I intend on using one of the 5 port low pressure valves from technobots. Like I said, nothing killer, but just something to get to grips with pneumatics. I dont want to go jumping in the deep end with CO2, this is just for experimenting, learning, and then hopefully adapting it into an ok weapon.
Price is always an issue isnt it :P Thats why I was hoping I could use the sodastream botle, rather than have to blow another £30 on a paintball bottle. I havent set a limit, so itll cost what it costs.
You can use a soft drink bottle for a low pressure buffer. These will survive at 100 psi and are very light. At what pressure will you set the pressure switch?
I started with compressed LP air before moving on to CO2.
Looking for 100psi. I wouldnt feel too comfortable with a drinks bottle. Will they really take 100psi? They seem a bit flimsy.
I just read the FRA build rules. They limit gas bottles to 50 psi without certification. You can always test these things. The biggest problem I had with coke bottles was the lids blowing off.
Quote from Giant Robo
I use epoxy in El Bravos` bottle caps.
Make the pipes going into the bottle about an inch or two long so the ends don`t get glue in them.
Sand the inside of the bottle neck so the glue will stick then completely fill the cap with epoxy and screw on the bottle from above. Hold the bottle upside down until the epoxy cures. You`ll feel the cap get nice and hot.
Your`e pipes will not leak or blow off and it strengthens the cap.
Make sure you mix, pour and screw on the bottle quickly before the epoxy starts to go off so it is still runny and will flow and seal the neck.
For El bravo I use two 1.25 litre PET bottles. They were fine at 100psi but to go higher with confidence I covered them in fiberglass and also the caps were filled with epoxy before being screwed on so they don`t leak and won`t blow off. I plan to give them another layer of glass; three all up and within the safety of the arena, pump them up to 200psi and then have another bot bash them around a bit. Then, if there`s no big bang! I`ll feel safe to put them up to 150 psi regularly.
Philip,
The FRA build rules are not negotiable, rule 8.3 clearly states that any pressure vessel that is not certified is limited to 50psi... end of story!
Therefor your idea of testing in an arena at 200psi or even running it at 100psi just aint going to happen as no event organiser would allow it.
Sorry philip, just realised that you are one of our friends from down under..Please disregard last post! :uhoh:
But Rhys, remember its certified or its 50psi!
I found camping gas bottles with a 1/8 bsp tread on the neck. Those are safe up to 20 bar (290 psi)
Sodastream or paintball bottles are overkill, as they can take 2000psi+. These are to heavy for this purpose
Yeah, Im planning to stay firmly within the rules. The sodastream bottle has lots of stuff embossed onto the actual bottle, so Im guessing that means its certified? I noticed 250 bar max on there, so as Im only running them at 10bar (at the absolute most) Im assuming I wont have a problem getting through tech check with this?
just took one of my old soda stream bottles apart and it apears to have a 3/8th bsp male thread on it underneath the brass adaptor. Unless 18*1.5 metric is a very close compairison to 3/8th bsp. Im sure you could get a 3/8th female fitting from technobots and put it on to use the bottle as a buffer tank.
If you want the bottle its urse, no cost.
Rhys .....Did you get my email?
RE:-Pnuematic Air Tank 2.5 Diameter - 4 Long?
It should be perfect for you .......being a purpose made commercial item for this sort of application.
I didnt, but I have got it now. They look pretty cool. Ill defo have one of them if you win. Let me know the full price when you get them and Ill send the payment over. Cheers Woody.
Dave, Ill still have that bottle off you as well. let me know the price for postage and Ill get the cheque sent over.
A 3/8bsp is close to a M18*1.5 the 3/8 bsp is 16.6mm diamter outside, and the M18*1.5 does tell enough.
But close doesnt mean a sigar. The closer , direct metric tread-alike- to a 3/8bsp is the M16*1.5