The Improved Pen Gun

[rcman50166]

I read and read and couldn't find the answer to my question.

How did you attach the schreader to the chamber? It's very clean and I can't see any solder points or welding marks...

It is a hot glue seal. The glue I use has an extra durability that most others don't. I've compared regular to mine and it turns out mine is much more flexible. It also has no degradablility. It can be used over and over. It's also multi temp which means I can use my low temp glue gun as well as a lighter. The reason I'm saying all this is because I know I'm going to get the "You should use epoxy or solder. Hot glue can't handle the pressure" speech. The lead to the valve is also longer than most. It has a one inch stem plenty for glue contact.

I made the seal by heating up the tube and then globbing a ring of glue on the end of the valve stem and inserting it while the tube is hot. This lowers any change for poor contact. I then strip any extra glue off. It works well because it is adjustable should a leak form and is removable if the internals crap out. All I have to do is heat up the connection with a lighter.


BTW: I think I found the pump I'm going to use in the future. It's a 12 gram CO2 tire inflator. It is smaller than any hand pump and it can provide pressures up to 1500PSIG. Click here to see what I'm talking about. It's pretty cheap too.

[Carlman]

c02 is not capable of 1500psi... it is stored at like 900psi

you cannot ajust what psi they put out if they are regulated or if they are not then its just dangerous for something of that size. so if you want to use them you will only get like 150psi.

[psycix]

An unregualted inflator? DONT!
With a gun this size, you will blow it up to burst pressure with one press.
Dangerous, I do NOT recommend to use that.

Unless you like to have nano-pipe-bombs (about the size of a pen) exploding in your face...

[rcman50166]

I know I know... The inflator I'm gonna try to get is flow regulated but not pressure regulated. But I figured that pressure would be a large problem. So I've been looking at very small pressure regulators designed for 12 gram CO2 systems. It has an input of up to 3000 PSI and is adjustable. I plan to take the pen gun up to 500 PSI at most.

[Sticky_Tape]

I was thinking about making such a pump. It would not be very easy. Creating those pressures requires a lot of force. I was thinking about making a 500PSIG stomp pump but then the bottom line came out to be too much, especially for a pen gun. It is also hard to make things seal at those pressures especially moving seals. That little piston in my pen gun took about 15 man hours to perfect.

Wrong about the takes alot of forse part it actually doesn't I made a shock pump with a 1/2'' bore and it can easily be pump up to not exact numbers but 300-400psi. Think psi pounds per square inch the smaller the bore of the pump the less forse it takes to get to high pressures.

And Pizlo it's sall good.

[jackssmirkingrevenge]

I would go with the shock pump as opposed to the inflator, air is free and doesn't have the temperature issues that CO₂ has.

[psycix]

I know I know... The inflator I'm gonna try to get is flow regulated but not pressure regulated. But I figured that pressure would be a large problem. So I've been looking at very small pressure regulators designed for 12 gram CO2 systems. It has an input of up to 3000 PSI and is adjustable. I plan to take the pen gun up to 500 PSI at most.

Thats what I meant, it may be flow regulated, but even on the lowest flow, your chamber gets to 800psi within a second....
I suggest building a mini-pump, and if not, well then spend your money on a small regulator.
Though a mini-pump can be smaller.

[rna_duelers]

A pump the size of a pen!A pengun with a Penpump For all those secret missions.

[psycix]

Yeah why not? if you can make a pen gun, you can also make a pen-pump.
And if you want a superconcealed gun, then you should also have a concealed pump right?

It wont take any force to pump it, since it got such a small surface.
Just 20-30 tiny strokes (can be done very fast) and your done!

Sorry to do so, but this emoticon really came into my mind when thinking of operating the mini pump, and I just have to post it:





I can imagine you in classroom pumping up ur pen gun under the table

[jackssmirkingrevenge]

I can imagine you in classroom pumping up ur pen gun under the table

Glad to see the double entendre on the forum lives on without my persistence

[Lentamentalisk]

Assuming your penpump would have approximately the same volume as your pengun, possibly larger, due to the lack of barrel down the center, it would take one pump per atmosphere that you wanted, as you would be putting exactly one atmosphere in there. ie: 1 pump=14.7psi, 2 pumps=29.4psi, 10 pumps=147psi

[rcman50166]

Alrighty then. I'll begin on the pen pump. I've been thinking about how to seal a piston that small though. An epoxied o-ring on the shaft is the only thing I can think of. This wouldn't be ideal when the o-ring wears out or breaks. I can't solder a small washer on it because the o-ring can't handle that kind of heat. However, I've got an idea of what the design will look like.

Another solution to the pump is using the inflator to fill a smaller volume "bullet" (a pipe 1/4 the volume of the pen) that then proceeds to fill the pen. This way you could take charged bullets with you rather than an inflator.

[Sticky_Tape]

I don't know but you may be getting into the charged cart Idea.

[lukcydog81]

Wow nice looking gun very clean I think it's a major accomplishment

bravo


:wav:

[rcman50166]

You signed up just to comment my pen gun? I'm flattered.