12 replies to this topic

[the beast]

Im really mad now because ive been searching spudfiles and this site and google and im still completely puzzled how a pump works or how to make one. I really want to make one since my pump doesnt go to high pressuress and is extremely small. If someone could help me id be extremely happy and satisfied.



EDIT: Sorry, im kind of mad.

Edited by the beast, 01 October 2007 - 08:45 PM.

[keef]

Read the SNAP 1.2, it shows you how to make one. I made one, I'm not going to use it, so if you want I could sell it. I'm using a Airtank instead.

[the beast]

Sorry Keef couldnt find the snap 1.2 i searched and went to the homemade forums.

Edited by the beast, 01 October 2007 - 09:54 PM.

[Athune]

I looked into this myself but abandoned it after I found an old bike pump I had forgotten I had. Before I gave it up however, I managed to figure out the basic mechanism.
First, the basics. As I'm sure you know, the simplest type of pump is basically a plunger in a tube with a one-way valve at the tip of the plunger so that air can flow into the tube when the plunger is pulled, but is then compressed when the plunger is pushed back in. When I dissected my Buzz Bee Big Blast, I discovered a very simple one-way valve that could be reproduced out of PVC with a dremel like this:
1. Carve a channel for an o-ring in an end-cap that would be about the width of 2 o-rings to allow the o-ring to slide back and forth a bit. If you can, make the channel a little shallower toward the end where the shaft of the plunger would be.
2. Carve two channels perpendicular to and deeper than the first one that lead from the tip of the end-cap to the first channel plus the width of one o-ring.
This would cause a good seal when the plunger was pushed, and allow air into the chamber when it was pulled. If you need pics, let me know and I could email them to you; I don't have the time to post them right now.

[DX-Robert]

Here is a link with a short guide to making homemade pumps. The guide is intended for homemade water guns, but it works for homemade nerf guns equally well. Remember that you need to attach a check valve somewhere behind the pump shaft. This type of pump can generate enough pressure to force weakly glued PVC parts off and doesn't require any tools other than a hacksaw. The diameter of the shaft also matters; 1/2" PVC allows you to generate more pressure more quickly than 3/4", for example. Larger diameters allow you to move more air, but it takes longer to build real pressure.

Athune, your method works, but seems overly complicated...homemade pumps are really simple things.

Edited by DX, 01 October 2007 - 11:01 PM.

[Athune]

Athune, your method works, but seems overly complicated...homemade pumps are really simple things.

The "pump" you posted a link to is really just a piston. Pumps are simple, but they always require a check valve. Since check valves can be pretty expensive, and I couldn't even find one small enough to fit into a plunger, this was the simplest alternative.

Edited by Athune, 02 October 2007 - 07:13 AM.

[DX-Robert]

A 1/2" PVC check valve is $5.35 and a 3/4" is $5.85 at my Lowes. That's really not expensive, just think of what you'd pay in Europe or even just rural regions of the country where plumbing selections tend to be smaller. The valves don't have to be inside a plunger either, heck, they don't even have to be next to the pump proper. You can have a pump under an air chamber and have the corresponding check valve positioned around and above the chamber.

[the beast]

Thanks but i dont get how if you have a check valve how air even gets into the chamber of the pump to be pushed into the gun or tire valve. heres what i think if you push the handle down once the air will go out but how does air get back into the pump?

[frost vectron]

Good God.

http://en.wikipedia....iki/Check_valve

[the beast]

thanks.... i guess. Im just gonna go for it and if it doesnt work hopefully ill figure something out.

[Flaming Hilt]

[CaptainSlug]

Bike pump = $2 to $8
Supplies to make a comparable pump = more than $8 + time

[the beast]

thanks flaming hilt that really helped.

CaptainSlug Posted Today, 05:25 PM
Bike pump = $2 to $8
Supplies to make a comparable pump = more than $8 + time

Ya i know the only reason i want to make mine is because a 4 dollar bike pump will hold like 60 psi which i need to go over.