APH: Pump alternative?

Build a homemade water gun or water balloon launcher and tell us about it.
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totokan
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APH: Pump alternative?

Post by totokan » Sun May 31, 2009 3:34 pm

So, my APH is coming out of the storage closet for the summer, and I had an idea that I'm sure someone else must've considered already. Instead of using a pump, would putting a schrader valve (like on a car or bike tire) be feasible? Then, instead of constructing a custom pump, one could simply connect a bike pump, or, for added speed and ease, an air compressor output. I'm not sure if it's been tried before, but i may consider this as a higher functionality alternative to an in-built pump.
EDIT: To clarify, i know the use of a schrader valve is common in large, cannon-type designs. I was wondering about prevalence in smaller versions.

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SSCBen
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Re: APH: Pump alternative?

Post by SSCBen » Sun May 31, 2009 4:15 pm

This depends on what sort of homemade water gun you have. The pump of a generic APH pumps water. Other pumps pump air. You can not swap a pump that pumps air in place of a pump that pumps water.

If you're simply pumping air, go for it. Most designs that pump air do use a schrader valve.

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C-A_99
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Re: APH: Pump alternative?

Post by C-A_99 » Sun May 31, 2009 5:24 pm

If your APH is a pressurized reservoir type gun, you should already be using a bike pump or air compressor to power it. So far, no one has made any pumps that pump air, only water. If you're looking to use a bicycle pump on an APH with seperate air chambers, you will need to convert the pump to work with water instead of air, and it will need to be connected to the homemade properly.

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Silence
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Re: APH: Pump alternative?

Post by Silence » Sun May 31, 2009 5:28 pm

C-A 99 wrote:So far, no one has made any pumps that pump air, only water
Just wanted to note, this is because nobody has bothered, not because it's particularly difficult.

One thing to watch out for, if you build an air pump, is to minimize the "dead space" between the piston and the two check valves. Air compresses, so if there's a lot of space there, it'll just sit there instead of being forced through to the pressure chambers. This is also why some pressurized reservoir guns' pumps become "bouncy" and ineffective at higher pressures.

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cantab
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Re: APH: Pump alternative?

Post by cantab » Sun May 31, 2009 5:36 pm

Silence wrote:Just wanted to note, this is because nobody has bothered, not because it's particularly difficult.
If you do need to pump air, it's probably simplest to use a bike pump.
I work on Windows. My toolbox is Linux.
Arsenal:
Super Soaker: XP215, 2xXP220, Liquidator, Aquashock Secret Strike M(odded), Arctic Blast M, CPS1200, CPS2100, SC Power Pak, 3l aquapack, 1.5l aquapack
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C-A_99
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Re: APH: Pump alternative?

Post by C-A_99 » Sun May 31, 2009 10:16 pm

I personally find that theres enough trouble building a regular pump for water, and for air, you have to adjust the groves more so that the O-ring can slide around, otherwise you need some kind of valve built into the rod that allows air to escape. IMO, its much more worth it to use a bike pump, one you know is reliable and will be able to build to higher pressures faster.

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cantab
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Re: APH: Pump alternative?

Post by cantab » Sun May 31, 2009 10:23 pm

An idea has just occured to me. For the APH's pump, use one of those syringe-type water guns! You've got a good seal, hopefully capable of decent pressures, and smooth motion right there. All one would need to do is securely seal the nozzle end of the donor gun to the APH (probably with a lot of epoxy putty).

You could probably use a medical or laboratory syringe instead, if you could find one big enough.
I work on Windows. My toolbox is Linux.
Arsenal:
Super Soaker: XP215, 2xXP220, Liquidator, Aquashock Secret Strike M(odded), Arctic Blast M, CPS1200, CPS2100, SC Power Pak, 3l aquapack, 1.5l aquapack
Water Warriors: Jet, Sting Ray M, Shark, Argon M, Tiger Shark, PulseMaster
Others: Waterbolt, The Blaster, Storm 500, Shield Blaster 2000, generic PR gun, generic backpack piston pumper (broken), 3l garden sprayer M, 10l water carrier:

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Silence
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Re: APH: Pump alternative?

Post by Silence » Mon Jun 01, 2009 3:12 am

A syringe is a really good idea. I suppose you could buy them fairly cheaply, although you'd have to go online unless you've got connections.

A piston water gun would look awkward, but there's no reason it wouldn't work. You may need to supply a valve or two yourself, though. River guns don't use any check valves, and some regular piston pumpers don't have a second check valve because the aperture is fairly small already.

Cannibalizing the pump from a broken or incomplete water gun should work, too.

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cantab
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Re: APH: Pump alternative?

Post by cantab » Mon Jun 01, 2009 2:18 pm

Yeah, I was thinking just leave the check valves that the APH normally has.

A friend of mine was actually using a syringe as a miniature water weapon in itself. Good for assassins-type stuff. I did point out how dodgy it looked with him having them though.
I work on Windows. My toolbox is Linux.
Arsenal:
Super Soaker: XP215, 2xXP220, Liquidator, Aquashock Secret Strike M(odded), Arctic Blast M, CPS1200, CPS2100, SC Power Pak, 3l aquapack, 1.5l aquapack
Water Warriors: Jet, Sting Ray M, Shark, Argon M, Tiger Shark, PulseMaster
Others: Waterbolt, The Blaster, Storm 500, Shield Blaster 2000, generic PR gun, generic backpack piston pumper (broken), 3l garden sprayer M, 10l water carrier:

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SSCBen
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Re: APH: Pump alternative?

Post by SSCBen » Wed Jun 03, 2009 2:51 am

I've thought about adapting some homemade high pressure pumps I've seen on Spudfiles. Here's an example: http://www.spudfiles.com/forums/easy-20 ... 13264.html

He notes it works up to several hundred psi of pressure. Should be adequate.

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Silence
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Re: APH: Pump alternative?

Post by Silence » Wed Jun 03, 2009 3:29 am

Promising link, Ben, but it took me a while to realize the actual instructions would be elsewhere. Linking it in case anybody else gets confused.

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