12 replies to this topic

[SirTofu]

With the magstrike coming out I immediatley thought that I would want to increase the air capacity so you could use 4 or more clips. I remembered tytus's rf20, and wondered if you could make a simple pvc airtank without a regulator and such to make it less complicated? I have looked, and nobody has really discussed this idea, have they?

So my questions:

Why haven't people made these? Are these really not such a good idea because they require tons of effort?

Is there a way to make a pvc tank and hook it up to a gun such as a pc, rf20, etc. without a regulator, and just a bike valve to hook up a bike pump to it?

How exactly would you make one and hook it up to the gun?

I have no real knowledge of this subject, so please help me out. Thanks.

[pat 1st Lt]

Well, I'm not entirley sure, because I rarley work with valves and regulators like this, but I don't think you'd want PVC for your tank. Mostly because that would let all the air out at once. A Bladder, like the ones on the RF20, PC, and MS, release air slowly and at a steady rate. An airtank with just a ball-valve will release all of it's air very quickly.

What you'd need is some kind of tubing that could hold a lot of air, and hold it at a high pressure safley. Also, it'd ahve to release that air slowly enough as to not over-clock the advancing mechanisms in the guns.




But, I'm sure it can be done. I just think that it can't be done with PVC alone. I'm pretty sure you need a bladder, not an airtank, for this one. OR you'd need a very high volume air-tank, and a bunch of complex valves and secondary tanks, etc.



Though if I were you, I wouldn't listen to me. I don't know a hell of a lot about auto-advancing mechanisms in Nerf guns.




Sincereley,
Pat

[SirTofu]

If you search for tytus's rf20, you see he has a pvc air tank. He used a regulator to regulate a pressure of the air.

To make a PVC reservoir. All you have to do is get a length of PVC. Cap one end put a union and a connector on the other and a hose barb on the end. Use it in place of your air bladder. Because if you don’t use the bladder the bladder can't burst. No they do not explode!!! They just go flat like a tire. I use a regulator and a pair of gauges not only because they're cool it lets you have some control over the ROF (rate of fire) of your gun and lets you know when to stop pumping. Although I doubt you could ever get enough pumps from a human into a PVC tank to make it break.

That's what Tytus said. Yet his explanation, has much to be desired.

Edited by SirTofu, 23 July 2006 - 11:27 AM.

[Carbon]

Is there a way to make a pvc tank and hook it up to a gun such as a pc, rf20, etc. without a regulator, and just a bike valve to hook up a bike pump to it?

Quick answer: no.

Long answer: It's definitely possible to make a PVC tank for an RF20, but you have to use some kind of regulator to make it work well, if at all. Elastic bladders are able to expand to hold more air at lower pressures. Rigid bladders can't expand, so to hold more air, it has to be at higher pressures. (If you run those tanks at lower pressures, you won't get a worthwhile number of shots out of them).

Much like an overpumped AT2k tank will crack, something will probably stress fracture if you try and run unregulated high pressure through an auto nerf gun. Even if it did work, the performance would drop off sharply as the tank emptied. Constant pressure is the trick...and that's why you need the regulator.

[SirTofu]

How the heck do you make a pvc air tank and use a regulator effectively? I'm wondering if this would be worthwile for a magstrike.

[Doom]

Having used both regulated air pressure and rubber bladders in homemade water guns, I can say with experience that both are viable options for this. Both are easy to assemble (unless threading pipe is hard). A rubber bladder however would be cheaper and still have more than enough power for this application. Compare something that is at most $3 a foot with a $20 regulator and air tank. The air tank, however, would easily get you more shots unless you use multiple rubber tubes connected in parallel.

I'm still surprised that no one other than myself has used latex tubes in Nerf or water guns after all these years. Go and buy 5 feet of part number 5234K83 from McMaster-Carr and have a great time.

Edited by Doom, 23 July 2006 - 04:28 PM.

[SirTofu]

How would I replace the bladder with a rubber bladder?

[Doom]

You would simply attach tubing to the barb where the original rubber tubing was and lead that to a backpack containing the other tubing. Not hard. To connect the rubber tubing to the vinyl tubing, you'll need two appropriately sized tubing barbs, one for the vinyl tubing and one for the rubber tubing. You'll also need a coupler to connect those, and tubing clamps to hold the tubing all on.

Edited by Doom, 23 July 2006 - 05:50 PM.

[SirTofu]

I think I get it. Do you mean kind of like this:



I wonder how much rubber tubing would be effective to use and how many pumps that would take?

[footemps]

For a solid air tank, my opinion is that you need to have the airtank have higher volume than the air chamber, and then it has to be at least double the pressure. Do you know why? That way you don't run out of effective shots. Having a higher pressure differential means that the air chamber in the gun will fill to full capacity and pressure instaed of having pressure drop with every shot.

Example:
40psi tank -> 20 psi chamber
Lets say the tank drops 5 psi every time the chamber fires 20 psi.
35psi -> 20psi shot
30psi -> 20psi shot
25psi -> 20psi shot
20psi -> ~20psi shot
15psi -> 15 or below
10psi -> 10 or below
Lets say with every 5 psi drop in the chamber, we lose an effective range of 10 to 15 feet in a skirmish. That means you'll be SOL if you don't have a high pressure tank.

Edited by footemps, 23 July 2006 - 07:38 PM.

[Doom]

The new rubber tubing should no affect the performance of the Powerclip or whatever is being upgraded. Only the capacity. I believe Hasbro uses similar tubing. If you want greater performance, but some bike tubes over the tube or buy a larger tube to stack over (or both).

As for the total number of pumps, it'll be a lot initially, but the idea is that you won't have to repump for a while. One foot of the new tubing can hold well over three liters when full. That older smaller bladder probably holds 500 mL. I don't know anything about the capacity of this pump however, so I can't tell you how many pumps it will take. I'd imagine it would be 6 times as many or more.

To answer questions sent to me via PM:

Your drawing looks correct. Just remember that you'll likely need two different barb sizes on each end of the coupler.

As for what to put at the other end of the rubber tubing, I usually put a barbed fitting threaded onto a cap or a bolt. Tubing clamps keep those on. So yes, you will need 4 tubing clamps. Thank you for asking this because I forget mentioning it often (when asked about it with water guns that is).

You may also want to create a container for this tubing because when full of air, it easily has a tendency to be affected by wind and such. Any container shouldn't be smaller than three inches in diameter with a single layer of tubing.

[SirTofu]

So for the end, a barb in it with a cap or bolt over it? Makes sense. Do you need to put anything like plumbers goob on the the barbs, or not necessary? I hope this discussion helps people as much as it has helped me. Sounds pretty simple. Now I need to acquire funds for two magstrikes.

Edited by SirTofu, 24 July 2006 - 01:27 PM.

[Doom]

You must have never used tubing barbs before. The idea is that the clamp keeps the tubing on the barb with a compression fit. Glues are unnecessary, would not make a better seal, and would not be a good idea. If this tubing pops because you overfilled it, you will want to replace it. Replacement is a little easier if you only have to remove the tube from the barb - if the tube is attached to the barb you just wasted a dollar.

If your tubing comes off due to excess force, you will need heavier duty tubing barbs or clamps. You're not even getting close to that point. If you're wondering, this is the kind of pressure system you'll need before you start worrying about these clamps: http://www.sscentral...ap/DSCN0262.JPG

Edited by Doom, 24 July 2006 - 01:50 PM.