pneumatic pen gun v2 - added video

[rp181]

i agree with jook. A beveled edge helps.

[jackssmirkingrevenge]

I had explained how I cut the piston inthe other thread:

I've also changed the valve configuration, the piston is now solid rubber - cut from 1/4" neoprene sheet using a sharpened bit of chamber tube in a drill as an improvised hole saw

[jackssmirkingrevenge]

Thoughts of an automatic nailgun let me to do some testing with this launcher to determine the sort of performance obtainable with unstabilised nails. I used two lengths of 3mm wide hardened steel wall nails and fired three shots with each, respectively 1, 2 and 3 metres away from the target, which was a pellet tin backed by an acrylic box, starting with the shorter nail.

[youtube][/youtube]

As you can see, it was fine up to 2 metres but by 3 metres the nails were hitting the target sideways. The longer one did however appear more stable, given its greater inertia.

Here's the target and ammunition:

[Hotwired]

Nails are good midrange projectiles too if you give them a tail.

Fluffed out string packed tightly together, taped into a long fluffy brush about 1/2 to 1 times the length of the nail (best if it's no more than 2" long) with the taped end the same diameter as the beheaded nail and then further taped to the nail is excellent stuff.

Nails planks together from a distance and as an added bonus the fluffy brush tail bangs outwards when the nail hits the target giving a fuzzy string coloured circle as reference. Or whatever colour you dyed the string

But not so good in a loose magazine like this, although the tail is no thicker than the nail when stuffed into a barrel, when loose or when fired they fluff out somewhat. The poor little dartlets would get mangled as the tails get entangled.

[jackssmirkingrevenge]

Another solution would be to either slip the nail into a plastic tube like the sort pens carry ink in, or wrap it in tape, both could be made to work in a magazine - but again for an auto, too much work for individual projectiles.

edit: 3mm BB at 850 psi, after going through both sides of a soup tin it proceeded to punch through the 6mm thick glass of my window, NEVER underestimate the power of your creations