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Crayola the Marker Gun

Posted: Sat Sep 03, 2011 9:56 am
by pneumaticcannons
It all started about 2 years ago when I tried making something just like this but I completely failed :( . About a month ago I took apart a crappy check valve and found a rubber washer (that fit perfectly inside a marker). I realized this would work great for a marker gun so I decide to give o'l crayola another go.

Here it is:
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I now it's not exactly stealthy yet but I plan on hiding the barrel with the cap later.

Specs:

Barrel Length: about 12 cm
Barrel width: 4 mm
Main valve: piston (made out of hot glue)
Pilot: schrader valve
Primary projectiles: 4mm ball bearings
Firing Pressure: You guys are gonna laugh but: 150 psi :D

I think I was actually the first on this forum to use an actual marker for the chamber. Will somebody correct me if I'm wrong please

more pics:

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It kinda has like an outer barrel to increase to size of the main barrel so it fits in the gun. The outer doesn't run the entire length of the barrel in case some of you guys were wondering.

The Power is pretty good... For a marker gun. It can punch a hole in the side of a can which is very impressive to me considering how small it is.

Oh and btw jsr, I found a TON of precision made 2 mm ball bearings. I might have to try your nano vortex idea :)

here's the video:

[youtube][/youtube]

So I just solved the leaks and I didn't realize how much power I was loosing before. I think I just nearly doubled the fps.

Well, unfortunatly the barrel sealing washer, well, stopped sealing. When that problem started going out of control I scraped the gun.

When I built it I somehow new it wouldn't last long :D
I really learned a load about micro pneumatics from this build and plan to make a v2. The 4mm caliber worked out great at the 150-200 psi I was using. I got it to punch through 3 layers of coke can siding which is 1 1/2 cans. I shot this thing non stop in the three days I had it lol.

Here's a can I completely owned with the gun:
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Posted: Sat Sep 03, 2011 10:41 am
by nathanhd123
Nice design. As for being the first to do it I have no idea.

Posted: Sat Sep 03, 2011 10:43 am
by Gun Freak
150 psi :lol:

Posted: Sat Sep 03, 2011 10:44 am
by pneumaticcannons
Gun Freak wrote:150 psi :lol:
HELL YA lol

Posted: Sat Sep 03, 2011 10:48 am
by jackssmirkingrevenge
Dear god, we're putting feet in videos now :shock:

Nice little effort :) shame about the low pressure.
I think I was actually the first on this forum to use an actual marker for the chamber. Will somebody correct me if I'm wrong please


Wellmineused an actual marker body, but that alone would never have done for 850 psi so there was further internal tubing.

You probably shouldn't be trusting it even at 150 psi.
Oh and btw jsr, I found a TON of precision made 2 mm ball bearings. I might have to try your nano vortex idea
That gives you a lot more power potential than the 1mm balls I was using, but still, unless you're using 400 psi+ it probably won't be worth the effort.

Posted: Sat Sep 03, 2011 11:58 am
by pneumaticcannons
That gives you a lot more power potential than the 1mm balls I was using, but still, unless you're using 400 psi+ it probably won't be worth the effort.
That pump you saw in the video is good for 300 psi so That's pretty much my max pressure for everything now. I think you might have a point. :( I've worked with vortex's before and their just a pain in general.[/quote]

Posted: Tue Feb 14, 2012 7:04 am
by Packols
how do you make a piston out of a hot glue that fit perfectly in the marker plese tell me because i try putting the hot glue in the marker and end up cant get it out lol

Posted: Tue Feb 14, 2012 7:08 am
by Zeus
Spray WD40 in the marker, or use grease/vaseline. I use grease, my pistons never get stuck.

Posted: Tue Feb 14, 2012 7:55 am
by pneumaticcannons
I dremeled out the inside of the marker so that It was as close to a a straight cylinder as I could get it. Then I put some cooking spray in before I cast the hot glue piston. This was all really a big waste of time : /..... I would have used a plain copper tube if I had known where to get them at the time that I made this.... You should too. And don't use WD40, It messes up the rubber sealing face, trust me, I've done it :lol: