Page 1 of 1

How to build a straight golf ball barrel from bent SCH 80

Posted: Wed Jan 21, 2009 9:42 pm
by Combustion Monkey
This fix will also be handy if you have a foot of SCH 80 lying around and want to make a long barrel.

First get yourself some bent SCH80

Image

Then cut it into bushings that will completely fit into a female to female coupling

Image

Next cut some 2in SCH40 in to spacers, I cut mine at 2ft

Image

Repeat the above steps to make your barrel as long as you want. My external barrel is a bit over 4ft as it is being used in a good sized coax. This is the finished barrel wit coax adapter at the bottom.

Image

A shot of the sleaved layers.

Image

And one last pic of the barrel mounted to The Bettie.

Image

Any questions or comments would be very welcome!

Posted: Wed Jan 21, 2009 10:12 pm
by MrCrowley
Good idea, must weigh a fair amount though? :)

Posted: Wed Jan 21, 2009 10:20 pm
by Combustion Monkey
It's actually comparable or lighter than the full SCh 80 version. I may have stumbled on something very cool here.

Posted: Wed Jan 21, 2009 10:30 pm
by starman
Soooo, you're effectively not sleeving your barrel with sched 80, just using small pieces as stand-offs to get to a 2" coupler then down to 2" sched 40 pipe. This is a pretty good idea, albeit a parts intensive way to beef up your barrel. I don't think you'll have the overall strength of a fully sleeved sched 80 barrel....

It's reminding me a little of a mini-A1A Abrams barrel.... :wink:

Posted: Wed Jan 21, 2009 10:30 pm
by rp181
Nice! now give it a matching paint job =)

Posted: Wed Jan 21, 2009 10:36 pm
by Ragnarok
Combustion Monkey wrote:I may have stumbled on something very cool here.
I'll say - it's a very ingenious solution to your problem. And indeed, I'm impressed enough to be spending my 3,000th post on it.

Oh yeah, mustn't forget, always a necessity in these cases...
:wav:

Posted: Wed Jan 21, 2009 10:38 pm
by Combustion Monkey
starman wrote:Soooo, you're effectively not sleeving your barrel with sched 80, just using small pieces as stand-offs to get to a 2" coupler then down to 2" sched 40 pipe. This is a pretty good idea, albeit a parts intensive way to beef up your barrel. I don't think you'll have the overall strength of a fully sleeved sched 80 barrel....

It's reminding me a little of a mini-A1A Abrams barrel.... :wink:
True but when i priced it out it was cheaper by far than the length os SCH 80 i bought! After running the gun through HGDT the rating of the inner barrel should be more than fine, I was more concerned about flex than internal pressure.

And rp181 it should see paint tomorrow, i should be in bed already, got work in 5hrs :lol:
Ragnarok wrote:I'll say - it's a very ingenious solution to your problem. And indeed, I'm impressed enough to be spending my 3,000th post on it.
Thank you very much! Spending your 3,000th post on me feels like its a badge of honor!

Posted: Wed Jan 21, 2009 10:55 pm
by Lentamentalisk
Ya, if anything I would be much more concerned about your DWV chamber bursting than the barrel causing you any trouble, other than possible sag (and ruining of couplings due to the torque of that long, unsupported barrel.)

Posted: Wed Jan 21, 2009 10:57 pm
by starman
Combustion Monkey wrote:HGDT the rating of the inner barrel should be more than fine, I was more concerned about flex than internal pressure.
Oh, with a 1x combustion, you're more than fine pressure wise even if you used just plain SDR 21 1.5".

Posted: Wed Jan 21, 2009 11:03 pm
by Combustion Monkey
Lentamentalisk wrote:Ya, if anything I would be much more concerned about your DWV chamber bursting than the barrel causing you any trouble, other than possible sag (and ruining of couplings due to the torque of that long, unsupported barrel.)
The pic of the barrel on the cannon is an optical illusion. It's actually just a bit over 4 ft. The total length of the internal + external barrels is closer to 9 ft. So the couplings should bear the weight fine. And as for the DWV chamber i sealed it and ran it to 100psi on a compressor to leak and proof test it, it held fine. I picked through a few brands of Wye fittings before I chose the thickest.

Sorry for the excessive use of the word "fine" very tired and off to bed before the alarm goes off.

Posted: Fri Jan 23, 2009 6:09 pm
by psycix
Ah you fixed your problem!
How much space is there between the SDR-21 and the SCH40 2"?
If there's any notable volume, you could make an internal silencer/expanding chamber.

Posted: Fri Jan 23, 2009 6:24 pm
by Combustion Monkey
Its funny I had thought of that, but there just isn't the space. I would guess maybe a the air space is about the same as the thickness of the sdr-21.

And it works well. I have some damage pics here http://www.spudfiles.com/forums/an-inte ... 17162.html