Homemade Gun help

Build a homemade water gun or water balloon launcher and tell us about it.
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Sharp
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Homemade Gun help

Post by Sharp » Sat May 20, 2006 12:41 am

Ok, I didn't know you could just edit the post... There is a check valve in between the pump and the PC. I originally had it all glued together. That's whenit didn't work. I broke it apart again to check the check valves. I did test those just by blowing in them, and found that I could blow air through the wrong way through the valve. Is that normal? thanks

p.s. I got pictures, just can't post them w/o a web page.

In response to joannaardway, I'm new, I didn't know where I started the thread. sorry. That and I can't post pictures, I can't post attachments. so no pics, not even those made in paint.
Last edited by Sharp on Sat May 20, 2006 10:56 pm, edited 1 time in total.

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DX
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Post by DX » Sat May 20, 2006 1:34 am

What did you use for the seal inside the pump? If your seal is not airtight, the pump will fail to draw water correctly.

Pictures of your gun would help, too, if possible.
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Silence
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Post by Silence » Sat May 20, 2006 1:45 am

Welcome to SSC--it's surprising to see a new contributor who has built a gun before joining ;) .

Yes, as Duxburian has stated, a picture would be the best help, mainly because I will look for one thing: Did you use check valves in your design? If you did, was there one between the pump and the reservoir? The check valve in that location would make sure that water could only come out of the reservoir (as opposed to the PC) and could only go into the PC (as opposed to the reservoir). It's possible that the lack of a check valve caused the water to move right back into the reservoir, and that's what I would check first.

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DX
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Post by DX » Sat May 20, 2006 1:49 am

As an add on, if you do have check valves, make sure they are both pointed the right way! More than one time I have caught myself about to glue a check valve with the < facing the wrong way. :rolleyes:
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Sharp
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Joined: Sat May 20, 2006 12:36 am

Post by Sharp » Sat May 20, 2006 1:55 am

yeah, the check valve is inbetween the pump and the resevoir. I've also tried it both ways. Neither works. I can't post pics as a result of my broken camera. sorry.

Sharp
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Post by Sharp » Sat May 20, 2006 1:56 am

Oh yeah, I used a rubber o-ring secured with electrical tape. It is air tight.

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Silence
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Post by Silence » Sat May 20, 2006 2:12 am

Well, if we can't see any pictures, then we'll just have to pound you with questions until we find the problem ;) ...

Do you also have a check valve between the pump and the PC? I'm assuming water was sucked out of the reservoir, but just in case it wasn't, air might have been taken directly from the PC. Also, if you didn't glue the weapon (otherwise you couldn't test the check valve in both directions), air might have come in through the seams.

By the way, on each of your posts, there's a button that says "Edit Post." While there are times when it's okay to create a new post after another of your own, you should use the edit feature for simple things like this. However, thank you for updating us about the seal in the pump :) .

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joannaardway
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Post by joannaardway » Sat May 20, 2006 4:42 pm

Why exactly is this in "pick of the best"? If no-one tells me, I'll move it.

I can't work without pictures. In a desperate situation, do a paint image...
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Silence
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Post by Silence » Sat May 20, 2006 10:49 pm

I always assumed that the threads Ben thought were good were placed in this forum...but I didn't know anybody could start a thread here.

No, a paint image probably wouldn't work. If it's a problem that is so subtle that Sharp can't see it, then he won't be able to put it in the diagram. We have a slight problem here, unless there is an obvious problem that he hasn't understood, in which case the diagram is worth a try...

EDIT: Maybe this subforum should be locked except for moderators who are moving threads there and for posts (but not new threads)...

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DX
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Post by DX » Sun May 21, 2006 1:54 am

This topic probably should not be here. Pick of the Best is only for the most quality discussions on SSC and topics should not be started in here. I'll move it.

EDIT: You don't wonder why I hate the way vBulletin does moderation? Moving a topic and not having a copy in the source forum used to be such a painless and simple process...
Last edited by DX on Sun May 21, 2006 2:01 am, edited 1 time in total.
Mess With the Best, Get Soaked Like the Rest!

2004 Red Sox - World Series Champions
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