Performance beyond my expectations!

[rejeanboucher]

- Solid IPEX schedule 40 ABS pipe. wrapped with fiberglass tape
- 2 inch x 36 inch barrel
- 3 inch x 32 inch pressure chamber, 2 to 1 volume ratio
- 3/4 modified valve (partition was removed within the cavity on the exit side, anti-siphon valve was fixed)
- at 80 PSI the spuds are knocked out at well over a thousand feet and will go clean thru a 3/4 inch high density MDF furniture board from 30 feet.
[/img]

[shud_b_rite]

very impressive. very impressive indeed

[MrCrowley]

Whats with the fibre glass tape? Im not sure if thats the rare pressure rated ABS pipe you have but I wouldnt use it on a pneumatic.
And are you sure you shot at MDF not chipboard? MDF is very very hard to break. I only just get through chipboard at 700fps with a fishing sinker.
Oh an im pretty sure that bell reducer isnt rated either.
Other then that nice gun.

Edit:Care to change that title of yours? The rules say otherwise if you think it gets attention. Well it does get attention but its illegal attention jk

General posting guidelines:
When creating any new topic or post, please refrain from the use of ALL CAPS. It's annoying

[sjog]

come on man 1000 ft?
don't bullship a bullshipper

[Killjoy]

yeah that range seems only slightly exagerated.... other then that nice lookin cannon, the fiberglass tape is pretty cool, though if thats cellular core it won't provide any protection.

[noname]

I love how you were shooting at "high density MDF (medium density fiberboard) furniture board."
NEVER USE ABS IN PNEUMATICS! It WILL blow out eventually! It's not meant for pressure.
And over 300 yards with a crappy, lower than inline low flow sprinkler valves and a short barrel, you're good at judging distance.

[squeaks]

WARNING: DON'T USE ABS OR BELL REDUCERS!!!
You're going to kill yourself. Unless you got the extremely rare, pressure rated abs and even rarer, pressure rated abs bell reducers, than this cannon is going to blow apart in your face. Don't use it!

[SpudBlaster15]

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[noname]

It's not the worst, but it's definitely not the best, and shouldn't be used for pneumatics. I know it tears intead of fragging, but it isn't safe and even having it tear, in public or anywhere else, can give spudguns a bad name, and they may be illegalized. That's probably ot going to happen, but remember Murphy's Law.

[Matheusilla]

I can't find pressure rated pvc at any of the hardware stores around here. If I wanna do anything I have to use steel. I don't know what to do for a pressure tank for a pneumatic

BTW, I have used dwv abs sch 40 under pressure but I don't like it. I've seen aged pieces of it and it isn't good. It gets really brittle and it's color fades; scary stuff.

[Pete Zaria]

Look up plumbing supply or sprinkler supply stores from the phone book. You can almost always find a good selection of pressure rated pipe there. If all else fails, call contractors and house-building companies and ask where they get their PVC. They have to use pressure rated stuff for water lines....

I've pressure tested ABS cell core DWV sch40 pipe and fittings upto 4" to 125psi (remotely) for testing and it didn't blow. When I forced it to fail (dry ice and water in a sealed chamber... a long ways away...), it ripped open cleanly, the long way (end-to-end), along a wall of the 4" pipe. No shrapnel or missing bits. It depressurized pretty cleanly. For these reasons, I think it's an excellent material for combustions. NSF-PW SCH40 or better PVC is the best choice for pneumatics... but I think as long as you take good care of that gun (never store it in direct sunlight, try to avoid dropping it, never fill it over about 80psi....) it should be fine. Don't sue me if I'm wrong, though.

I don't think the fiberglass tape will actually do much, btw.

Cool design. Looks nice and clean.

Sorry, I have to agree with the others, 1,000 yards is nearly impossible for a gun with a 3/4" valve at 80psi. If you fired it from the top of a mountain, at a 45 degree angle, with the wind behind you, you might get 1000. My best gun can get a little over 350 with the right projectile...

Peace,
Pete Zaria.

[schmanman]

nice, is the barrel sch 80? I notice you have a separate spud cutter, why not just sharpen the end of your barrel?


I like it, though.

spudblaster, I think you've put the whole "abs will kill you" thing to death, and buried it in your back yard!

bows down *oh mighty abs god*

[MrCrowley]

Sorry, I have to agree with the others, 1,000 yards is nearly impossible for a gun with a 3/4" valve at 80psi. If you fired it from the top of a mountain, at a 45 degree angle, with the wind behind you, you might get 1000. My best gun can get a little over 350 with the right projectile...

Peace,
Pete Zaria.

*Cough* ah um he said 1000feet not yards *cough*

[rejeanboucher]

I forgot to follow up on my post, too many projects on the go.
Sorry if I offended some of you with my choice of wording & font style in the subject heading. To address some of your responses:
- it was very solid ¾ inch MDF board (not particle board);
- distances are estimated but I am sticking with well over 1000 ft. Will eventually confirm distances at our local RC flying field with a GPS reading. The barrel was angled at 45 degrees;
- I am so impress with its apparent muzzle velocity that I am tempted to build a simple ballistic pendulum to quantify some results; and
- Piping is solid core ABS schedule 40. I opted for ABS over PVC because for me the failure mode of splitting was a more desirable feature then having sharp pieces of PVC. Plus PVC is much more affected by the Canadian environment and to rough handling.
I have access to fighter jet tire inflation safety cage rooms and will eventually make up three test sample ABS chambers and pressurize them to failure.

[frankrede]

I tip my hat to you.
Well done.