Sac American River "syringe" type water gun built, pics coming..

[Silence]

Or more specifically: a 2" female threaded to male socket adapter, also known as a female adapter. I just pointed this out to prevent confusion with the APH article here at SSC, which uses a male adapter and female threaded endcaps--pretty much the opposite.

Perhaps he was asking what drill bit you used for the nozzle? I think I'd like to know, too... But anyway, the point of the selectable nozzles is so you can have a variety that can be screwed on.

[qckfrze]

Here's some ideas for the nozzle:

Use a male to femail adapter which has the threads on the outside, and then use a threaded cap. This replicates the smooth inside of the plain smooth 2" cap. If you use a plug which sits insie the adapter, you may experience turbulence which interferes with the stream.

As for the hole, I'm not exaclty sure what it's called. It looks like a cone about 1.5" in height, which cutting slits on either side. The cone has "levels" which allow you to control the size of the hole in "steps". When you start the bit, it eats through to the first size, and then to the second size, and then so on. Then I basically use a dremel to smooth out the hole to reduce turbulence. Any drill bit will work. I think the key here is to use your dremel to shape the hole to what you need.

[qckfrze]

FYI, The original piston with teh multiple grooves in it that you see where from an original seal design. We attempted to use lengths of vinyl tubing (air pumps for fish tanks use it) to seal the piston. There were a series of 3 seals, but the problem we faced was that they were not airtight.

If the seal on the piston is not airtight, you will pull air into the cylinder when you try to draw water. We ended up drawing maybe about 30% water and 70% air, which doesn't really make for an effective water gun. However, when we opened the nozzle and manually filled the piston, the gun works fine.

Moral of the story I guess is that even if hte piston is water-tight, it may not be air-tight, which is important to ensure that when you draw water you get ONLY water, and not air from the rear of the piston.

As for the o-rings, if the groove that holds the oring is cut too deep, you'll experience the same problem. However, on first try, I had one that was ok-deep, and I sealed it up by applying the dow33. Any oil-based grease that doesn't float away with the water will work to seal the oring against both the piston shaft cap and the outer cylinder.

Hope this helps!

[waterzooka]

I saw your posts and had to comment. I like the idea of being able to disassemble the unit. I built several similar water cannons almost 20 years ago and a few are still going strong. However, some have been damaged by sucking up sand or dirt.

Just recently I starting using set screws to hold the cap in place so I could disassemble the unit and clean it.

I have been using o-rings for the seal. They are perfect and create an airtight seal.

[qckfrze]

Thanks for the ups!

As it turns out, I did have to field service the cannon while I was out that day. One of the peeps in the boat pulled out the piston and the C-clip retainer, rendering hte gun totally useless. I carried extra c-clips in my lifevest pocket, as they were a cinch compared to trying to carry a tool with screws to boot. The c-clip slipped into the groove, a push of the piston to put lock it in the groove, and it was ready to go again!

I took a look at your website. Props on making it easy for everyone to make a Stream Machine on Steroids!