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

[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



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



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



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.



A shot of the sleaved layers.



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



Any questions or comments would be very welcome!

[MrCrowley]

Good idea, must weigh a fair amount though?

[Combustion Monkey]

It's actually comparable or lighter than the full SCh 80 version. I may have stumbled on something very cool here.

[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....

[rp181]

Nice! now give it a matching paint job =)

[Ragnarok]

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:

[Combustion Monkey]

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....

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

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!

[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.)

[starman]

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".

[Combustion Monkey]

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.

[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.

[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