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coax barrel support help
Posted: Mon Feb 23, 2009 6:51 pm
by daniel323
Hey
I am planning on building a coax piston gun
the chamber will be 1" by 24" copper pipe
and the barrel will be 1/2" by 32"
would i need a barrel support inside the chamber?
thanks
Posted: Mon Feb 23, 2009 7:06 pm
by dudeman508
Ya you need a barrel suport to the barrel lies straits ad the piston has a flat sealing face. Ive seen a lot of people use cut up pieces of pipe
Posted: Mon Feb 23, 2009 8:46 pm
by daniel323
how do they cut them?
Posted: Mon Feb 23, 2009 10:16 pm
by MrCrowley
With a saw/dremel/hacksaw?
Posted: Mon Feb 23, 2009 10:45 pm
by daniel323
haha ok just wondering but how is it set up?
Posted: Mon Feb 23, 2009 10:59 pm
by dudeman508
You could cut pieces of the pipe into a U sort of shape and place them under, or all around you barrel. Im not sure but i think you still have to glue them in (ive never made a coax.)
Posted: Tue Feb 24, 2009 11:16 am
by mark.f
Or, depending on the space between the outside of the barrel and inside of the chamber, you could use short lengths of tubing with said outside diameter.
Posted: Tue Feb 24, 2009 11:56 am
by john bunsenburner
I like gettign electrical tape and wraping it around the barrel until i have the needed diameter, It is less messy than chppong things up and stuffing them into your chamber.
Posted: Tue Feb 24, 2009 12:10 pm
by Gippeto
john bunsenburner wrote:I like gettign electrical tape and wraping it around the barrel until i have the needed diameter, It is less messy than chppong things up and stuffing them into your chamber.
And hey,..It reduces chamber volume to squat in the process.
@ JB: Do you have any pictures of your builds to put up? I'm curious to see them.
daniel323, you do need a barrel support. Picture a radiation warning sign.
LIke this;
http://www.courier-journal.com/blogs/br ... 713541.jpg
Make your barrel support something like that. Place it 1/3 to 1/4 of the chamber length from the sealing end of the barrel.
Posted: Tue Feb 24, 2009 12:18 pm
by john bunsenburner
Now gippeto how hard would i have to wrap the tape?, i did it in current launcher and i have no problems...If you dont wrap it too tightly then the air can jsut rush by, f coarse it will give you a little loss but i doubt anyhtign major..Or if you have a small chaber put the tape at the end of it, which doesnt affect anythign at all...
Posted: Tue Feb 24, 2009 2:19 pm
by Gippeto
john bunsenburner wrote:Now gippeto how hard would i have to wrap the tape?, i did it in current launcher and i have no problems...If you dont wrap it too tightly then the air can jsut rush by, f coarse it will give you a little loss but i doubt anyhtign major..Or if you have a small chaber put the tape at the end of it, which doesnt affect anythign at all...
Post a pic or put up a video then. All I've seen you post a picture of was the blow gun you started to make.
I don't believe I've seen a picture of it completed yet.
If you do as you suggest, the barrel is not supported. If you actually support the barrel by wrapping it in tape as you suggested previously, you will at best reduce the chamber size.
Otherwise, all you're accomplishing is to install a major flow restriction in your chamber.
I will say, your typed english is improving, but you should really try and use the SpellCheck button.

Posted: Tue Feb 24, 2009 2:24 pm
by john bunsenburner
Sorry i was typing quickly, mostly typos in my post I think, only words i always mis-spell is whcih writing it without an h.

I changed plans about the blowgun valve gun changign its valves a bit, oh well you will see. I thought of what you said and i think oyu are right when it comes to larger chambers(my chamber is barely 3cm long). I used the tape to center the barrel and then poured a few cm of epoxy over, It works great for me, expect the gun in a mont or two depending when i get the stock done.