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1.5"/17 (40mm) Spud Gun

Posted: Mon Oct 15, 2007 1:39 pm
by Flamex
Here is my first attempt at a spud gun. It uses a 3" Y pipe, 3" to 1.5" bushings and a 1.5" barrel. The barrel is suppressed, with a 2" pipe for the suppressor casing. The barrel is 28" long in all, but the effective length is 25" because of holes drilled in a 3" section of the pipe up front near the muzzle. A 1.5" ball valve is used for fuel entry, the use of which was inspired by utx's spud guns. A standard BBQ lighter is used for ignition, but there is room for future replacement with more reliable forms of igniter. I've purchased another 3' section of 2" pipe for a new suppressor casing, because the one I have installed now is too short for my liking, I had cut it too short. All piping and fittings are solid core ABS.

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Posted: Mon Oct 15, 2007 1:49 pm
by SpudUke5
not bad pretty nice for a first. I would have gone with a pvc bal valve only because its cheaper ane weighs less, and has the same flow. :D

Posted: Mon Oct 15, 2007 3:51 pm
by f.c
thats a nice basic combustion youve got there. :)

keep up the great work.

Posted: Mon Oct 22, 2007 9:02 pm
by Lentamentalisk
The one problem I have is that the sparker is in the endcap, which is not the safest of places for it, but then again putting a sparker anywhere inside the cannon is unsafe, and it is much better to drill 2 holes, bolt in some long bolts, and attach the sparker leads to those, so you dont blow your hand off.

Posted: Mon Oct 22, 2007 9:07 pm
by TwitchTheAussie
Shoulda made a handle but its all good. Nice work

Posted: Mon Oct 22, 2007 9:13 pm
by Novacastrian
Looks great, next step- chamber fan!!
I wouldn't be worried about the sparker.
Well done and welcome.

Posted: Mon Oct 29, 2007 12:05 pm
by Flamex
Lentamentalisk wrote:The one problem I have is that the sparker is in the endcap, which is not the safest of places for it, but then again putting a sparker anywhere inside the cannon is unsafe, and it is much better to drill 2 holes, bolt in some long bolts, and attach the sparker leads to those, so you dont blow your hand off.
The igniter should hold, as I used a high strength epoxy to secure it in place. I had a misfire with a new cannon I just built a few days ago using the same standard "igniter cap" and the cap and cannon were undamaged. The projectile didn't make it out of the barrel, and so the cooling exhaust gases contracted, sucking the projectile back into the chamber.

Posted: Mon Oct 29, 2007 11:10 pm
by BigGrib
definatley a handle or shoulder strap would be nice. also don't like the ignitor in the endcap, but that is personal prefence.