38 replies to this topic

[Shadow 92]

Here's a Nerf/ paintball design that I've been working on. It works by using the bolt as a piston. If you want more info on the evolution and background on the design see here. I'm building a prototype that will test the effectiveness of the piston bolt before I build the actual design which will strictly fire reballs. The prototype features the current design's bolt and and valve. A homemade pump is used to fill the chamber and will take the place of a remote airtank.







I know that most people don't like designs, but I have the full intention of building it. I already made an order list on Mcmaster. The only reason I will not build this is if someone can suggest and improvement to the design.

[keef]

Looks promising. Whats the trigger going to be?

[Prometheus]

Where's the magazine/clip?

[Shadowblade]

This looks pretty good, can't wait to see the finished product. So I guess there will be no clip/magazine and you'll single feed it?

[Peter]

This is just a really far off unfounded observation, but maybe that gigantic opening in the top is where the darts will go.

Edited by Peter, 26 March 2008 - 08:51 PM.

[Shadow 92]

Yeah, there won't be a magazine. Since the prototype isn't semi auto, I figured I would just put a small mega stefan in the breach to load it.

Here it is with the 3 way valve trigger. I was feeling a bit lazy so I didn't make the actual trigger or the tubing that connects the pump and the valve. But everything else is there.



Does everyone get how it works? I'm just asking because that's the only way I can get constructive criticism.

[CaptainSlug]

The barb connections on your valve look too restrictive to work. None of the passage ways should be below 1/4" ID (or equivalent area).
Unless of course your trigger valve is just a pilot valve for a larger valve.

Edited by CaptainSlug, 26 March 2008 - 11:09 PM.

[Shadow 92]

The barb connections on your valve look too restrictive to work. None of the passage ways should be below 1/4" ID (or equivalent area).
Unless of course your trigger valve is just a pilot valve for a larger valve.

I'm going to use 1/4" ID tube fittings. They just came out a little small because I made the trigger and the rest of the gun separately. The trigger valve is used to release the air in front of the bolt, causing the bolt to move back.

Here's a diagram I made for a while back. The prototype vents the air directly as opposed to piloting the QEV which vents the air in front of the bolt. The setup is also a little different, but it explains the general idea,

[CaptainSlug]

Unless you're using very hard o-rings that setup is going to have A TON of friction to overcome. I hope you get it to work though.

Edited by CaptainSlug, 28 March 2008 - 03:16 PM.

[Shrub]

Well I think you should make the breach bigger allowing clips and you could use a air regulator regulator like CS and his MS.

Edited by Longshot Wielder, 28 March 2008 - 07:47 PM.

[Shadow 92]

Unless you're using very hard o-rings that setup is going to have A TON of friction to overcome. I hope you get it to work though.

Thanks. I was thinking about using two o-rings with a medium seal if the single o-ring didn't have a sufficent seal. Hopefully, it will mean I won't have to use a tight fitting o-ring.

Well I think you should make the breach bigger allowing clips and you could use a air regulator regulator like CS and his MS.

I want to keep the breach small so when I go to build the final design (which will fire paintballs) there won't be any huge differences. I'm perfectly fine with manually loading each .75" long dart. I actually do plan on using a homemade regulator for the final design but I decided not to incorporate it into the prototype because it would mean that cost would go up with having to build both a regulator and a LPA tank. I don't want to use an air compressor because the gun would no longer be portable, but the valve is designed so it can accept a constant supply of regulated air.

[CaptainSlug]

This is the HPA setup I use with Nerf. I don't really use the LPA setup anymore.

http://nerfhaven.com...?showtopic=8632

Made entirely with off-the-shelf parts. Total part cost is around $135.

Edited by CaptainSlug, 28 March 2008 - 09:49 PM.

[Shadow 92]

This is the HPA setup I use with Nerf. I don't really use the LPA setup anymore.
Made entirely with off-the-shelf parts. Total part cost is around $135.

Really, its only 135? I remember reading the original topic but I thought the 135 was the price without an HPA tank. I'll definitely look into one. Is there any way you can make it so you fill the tank up with a regular bike pump so you don't have to go to a paintball shop every time it runs out?

[Thom]

No. No manual pump can even approach 2500 psi.

[Shadow 92]

I don't need it to go over 1,000 psi. I just want the option to fill it up at home it runs out. Anything over 120 psi would be great.

[CaptainSlug]

Is there any way you can make it so you fill the tank up with a regular bike pump so you don't have to go to a paintball shop every time it runs out?

You would have to own a compressor and have a fill kit for the paintball tank. But most compressors only output up to 300psi, which really won't give you very many shots from a 45ci tank.

The whole point of using a paintball tank is that it afford you around 2,000 shots per fill from a magstrike. One fill will last you a whole war.
The setup I have also allows you to swap out an empty tank for a full one.

If you have further questions they should go in the Paintball Tank thread: http://nerfhaven.com...?showtopic=8632

Edited by CaptainSlug, 29 March 2008 - 05:51 PM.

[Prometheus]

No. No manual pump can even approach 2500 psi.

That's wrong. PCP airgun pumps can pump up to 230 bar, which is over 3000 psi.

http://www.pilkguns....cessories.shtml

Scroll down the page a little.

Look at the price tage dumbass.

$205 is a lot of money to just drop on a low-volume hand-pump.

[CaptainSlug]

I think he was making a point just to make a point. With no stipulation on practicality or cost effectiveness.

[Quilan Fett]

I don't understand how you could pump that force. Am I missing something or would you have to exert a few thousand pounds to push the pump down?

[General Cole]

You can buy 30000 psi tanks with regulators pre filled at Target, Home Depot, Lowes, Walmart and others for 40 bucks. Refill at paintball shop or scuba store.

[CaptainSlug]

The tube is very very thin. Because of that, you fill up the tank really slowly, but it's possible.

Sorry but those kinds of pumps are only practical for the tiny volume tanks that they are designed to fill. Anything larger would take an ungodly long amount of time to fill.
Can we please stop thread-crapping Shadow 92's thread about this now?

Edited by CaptainSlug, 01 April 2008 - 12:18 AM.