Super Soaker Central

I noticed that DR-3, the water gun that tried to be like a stock gun, worked ok, but had some problems that made it impractical. So I thought about making a gun that would also try to be a stock soaker. It would have a removable casing, made out of 4-inch cellular-core PVC sawed in half lengthwise. I may have to use larger pipe though. The configuration of the internals would be based on that of the CPS 2000. It would also have an actual trigger made out a homemade pull valve. Is it worth it to try it?

The general design of the CPS line (and indeed much of the XP line) is a good one. I'd certainly suggest you go with it.

Basically, at the rear is the reservoir. Immediately forward of that is the pressure chamber. Then the tee for the pump, then the firing valve, then the nozzle.

If you have a case, then you can use flexible vinyl tubing where appropriate. Probably for the reservoir to pump connection. I'd go with rigid from the PC through the firing valve and onto the nozzle, with a tee for the pump 'out' side.

One problem is that cylindrical isn't really the right shape. Most stock guns are rather taller than they are wide. 4 inches is a bit narrow anyway. If you can find 5 inch that would be good. 6 is too fat I reckon.
Possibly you could quarter the pipe, and then join two quarters with some flat plastic, to make each half. The whole gun then has a more oval cross-section. Getting the joins to be smooth and strong will be difficult though.

You can have triggers with ball valves; however, for large valves it gets more difficult. So you might be right to go with a pull valve. Of course there's making it.

Most stock guns use a rigid wire to connect the firing valve and trigger. However, you could probably use string or flexible wire if you wanted, provided you guided it well.

As for what you could use as another casing option, there's this stuff called Sintra, a.k.a expanded PVC. It's basically flat cellular-core PVC sheeting. Really cool. I used it in my robot as armor (not such a strong armor, but it worked fine for my purposes).

One thing I'd be wary about is the homemade pull valve; If it's going to be similar to the pre-Mad-D valves, then it's going to mess up lamination quite a bot, not to mention hard to manufacture. Yes, I'll be easier to operate than a triggered ball valve, but getting the most out of what you can fit in a small space is critical, lest you have too bulky a gun (of course, some would argue what bulky is). Just my thoughts on that.

Lamination isn't the only consideration. Ball valves tend to be harder to open than pull valves. For a large ball valve, the required trigger pull may be either too strong or too long.

Bear in mind that the best performing stock guns - the CPS line - used pull valves.

cantab wrote:Lamination isn't the only consideration. Ball valves tend to be harder to open than pull valves. For a large ball valve, the required trigger pull may be either too strong or too long.

Bear in mind that the best performing stock guns - the CPS line - used pull valves.

I was really just thinking about getting the most out of what you put into a gun; Yes, ball valves get harder to turn as size increases, but if you lubricate them correctly they might work better. Imagine if the CPS line had Max-D triggers (that didn't break a lot)...

...but yes, I do understand your point.

I've got the pull valve design figured out mostly. I think I'll make it so the pull valve can be switched with a ball valve.

I would also saw the casing in half lengthwise and bolt it together somehow, so it can be opened up. It sounds like this blaster would be the only other homemade water gun with actual internals besides the DR-3.

I should start building in a couple of months (need more money, doesn't sound like this one will be very cheap).