I had a CPS 2100 (mk.3) open yesterday and decided to experiment with this a bit. I took out its PC and started looking at various fittings that could be attached. Then I took out the thing that attaches it to the rest of the gun (some integration modders have done this) and replaced it with the male end of a 1/2 inch male adapter. I think that with a clamp this might be useful in trigger replacement.

Attaching PCs to PVC is easier with male ended PCs. I attached my CPS 2700's PC to the inside of a threaded 3/4" male adaptor with relative ease, and I could remove it as well. Attaching female ended PCs would be more of a challenge as demonstrated. Of course, if you wanted to, I am sure you could find an easy permanent way. The problem is finding an easy, non-permanent method of attachment.

Well, did it work? Was it better than the LRT from McMaster? I would much rather use something that can be bought easily than something no longer made from eBay that may not work at all.

I didn't test it yet, I need to find a hosing clamp that fits before it could work. However though, I think that LRT would work much, much better than a stock pc. I think it has about 5 more PSI. When I tried this I was mainly looking to see how easily a trigger could be replaced, an 11k seems to be likely to cause trigger trouble.

Actually, that was directed towards Doom, since he has apparently tried both, but the input is appreciated :P

Doom, did you use two different sizes of LRT layered on top of eachother?

Latex rubber tubing is definitely better than Super Soaker's CPS bladders. Two layers get twice as much power. You can put more bike tubes on top of that as well. I don't know why anyone would consider anything else in rubber CPS homemade water guns.

People have told me various "excuses" like using bike tubes gets more power or is cheaper, but in reality none of those claims are true. They claim that stuff because they want to make their water guns look better or "beat" me or something like that. Latex rubber tubing is cheaper and will get more power more easily.

When making the first rubber CPS homemade water gun around, I started off with a single 35 PSI tube. I got great performance with that alone! It was like a CPS 1000 with a far longer shot time and more power! I then tried sliding another larger ID tube over the first one, as well as adding bike tubes on top of that. I got over 60 feet of distance to the puddle (last drop was over 65). I don't brag about that either.

I could have kept pushing, but I cut my larger tubes up in an attempt to get more over them and only ruined them. I could easily buy more tubes, but I didn't mainly due to my lack of money at the time. Rubber CPS homemade water guns are pretty well established anyway.

Back at Aquatica, AquaTech (webmaster of the WBL website AquaLabs), bought some LRT and used it to modify his CPS 1200. This was before the K-mod, in fact it was such a different time that people referred to LRT as "surgical tubing," which is technically incorrect. He did it to increase the power of his CPS 1200, and he reported increased distance and power. Typical of the time, modifications and homemade water guns were shunned, so it goes as no surprise to me that he never wrote a guide. You can see that his CPS 1200 is definitely modified in the picture on his website. While he doesn't mention the modification specifically, note the lack of the top of the spherical PC.

Woah! those stats are cool. I'm going to have to order some of that stuff and build a homemade. Just wondering though, what order numbers do you find work best? I'm thinking of ordering 5234K83 (35 PSI, outer diameter: 3/4 inch, inner diameter: 3/8 inch) as an inner layer (attached by male adapter thin part stuck in and kept in place with a clamp), with an outer layer of 523K89 (25 PSI, outer diameter: 9/8 inches, inner diameter: 3/4 inch). That would total about 60 PSI.

Wow, I didn't know they were that good. Now I want to build one! What size LRT were you using? Also, can you attach LRT directly to PVC with a hose clamp? Come to think of it, you probably need a barb because 1/2" or 3/4" PVC would be too big (and what would be the point of buying a nother 10 feet)? Are barbed fittings easy to find at hardware stores?

Why is it that all my posts sound like I'm a hyperactive kid that never stops asking questions? :rolleyes:

Asking questions is the best way to gain knowedge. I strongly encourage it, and will now model it. :P Anyway, I had heard of that tubing before but had no idea it was so good. So how would you make a homemade with the tubing? Would you simply make an air-pressure gun but add the tubing instead of the PC's? Wouldn't you want a casing to protect the tubing?

One of Ben's
And... Here's a picture of his other one (the one in the front on the bench):


Can't find the topic...

As far as I know, no one else has made a CPS homemade with LRT (some have done it with balloons or bike inner tubes).

Edit:

That would be the school bus AWAY from school, right?

It indeed is, although I still prefer to learn by experience...more fun, and involve soaking people in the process...lol

That wouldn't be a good idea. That was one of my problems before. I tried the exact same combination I believe. You won't be able to slide the tubing on easily, and believe me on that. We had tried everything from stretching the tubing so it thins to lubricating it - you won't get it on. Right now the best combination to order appears to be 5234K83 (35 PSI) and 5234K92 (30 PSI). This will let you slide the larger tubing straight over the smaller one, very easily.

Use the sizes I mentioned earlier. As for tubing clamps and barbs, the best thing to do it to get a barb slightly larger than the ID of the tubing. The tubing will stretch, so you still will get the tubing to attach. Never use these without tubing clamps either. I can only see disaster with that. I've had one of these explode near me and I've had one of these explode by a friend who was being stupid... they will move around violently and could potentially cause a very bad cut.

I've also never been to a hardware store or larger chain store that didn't have tubing barbs of some sort. Ask an employee if you are having trouble finding them.

Look at the pictures on SoakerMedia in their gallery and you should see more than enough to make an duplicate of my CPS homemade water gun. And yes, you will want a casing to protect the tubing. The tubing can get cut, and if you are stupid, putting more water into it than it can handle will cause them to burst violently. Cases are definitely required. Notice how in the one picture m15399 there is an endcap. That was after a few accidents, and the cap wasn't in earlier pictures.

I could make a fairly detailed guide on this water gun, but I've been pretty busy. Too busy in fact. I should take off time from other things to get working on lots of other things...

Okay, thanks. Now comes the hard part, getting a bit of money, and convincing my mom to drive me to a hardware store.

They um... Don't exist anymore. They havn't been uploaded to v2 and they have been taken off the original site.

Why didn't you put a cap on your power pak? Just because it hadn't exploded yet, or because it needed to be able to expand more?

No cap was on the PowerPak-like homemade water gun for two reasons: the PC never burst once and I filled it beyond the PVC.

I'll also find all of the old CPS homemade water gun images on my hard drive. I hadn't realized they weren't online any longer.

That would be nice. I'd like to see those.

Why didn't it burst, but the first one did? Did it have something to do with the lack of friction between the LRT and the PVC?

I know this has been stated at least 20 times, but you attached the tubing to a barb with a hose clamp, then put an end cap over it, right? Was the end cap to keep the top layer of tubing from slipping off, or what?

Edit: Why doesn't the hose clamp cut through the LRT?

Edit 2: How has the LRT been holding up? Does it still work as well as it did when you made it?

I think that he wraps tape around the LRT before putting the clamp on so it doesn't cut. Not quite sure though.

Also, though, about how much did the homemade cost to make?

LRT is about $1 a foot, depending on size (the 1" ID is $7 a foot!). Doom ordered 5 ft. of it, so probably around 20-30 dollars not including primer and cement (PVC is cheap, ya know). But that all depends on how you measure it. I'm sure Doom already had the 3" and 1/2" piping from earlier homemades, so it could have cost him less than $10. If you're starting from scratch, probably ~$60-70. My PPP was about $40 including primer, cement, and a hack saw (my old one kind of sucked).

The PowerPak-like homemade water gun didn't burst for one reason: I never overpressurized it. The other CPS homemade water gun did burst for two reasons: the rubber was overpressurized several times (probably better to say overstreched), and my layering was very sloppy (in fact I won't even talk more about that, but I will let everyone know that it was sloppy because I used a second layer that was too small). The overstretching will burst most any rubber bladder. Most of the time the poor layering only caused the PC to shoot off like a rocket.

I also don't know why people think the rubber tubing expands until it hits a wall. The tubing gets about 3.5 times wider in diameter and stops expanding in that direction after that. Rather, the tubing gets longer (until it reaches the 850% enlongation point). That isn't a hard concept to understand, but I believe few understand it. In none of my rubber CPS homemades have I ever restricted the size of the rubber PC. That would only reduce my PC size and likely cause damage to the PC.

That is incorrect. One end (the end that is attached to the water gun) gets a single tubing barb and a single tubing clamp (preferably a larger one). The other end (the "open end") can either use a barb threaded into a female threaded endcap with a tubing clamp or a bolt with a tubing clamp. The bolt method is cheaper. I haven't seen much

I'll get a picture if this still confuses you. This is nothing out of the ordinary, so I would just follow your instincts if you are confused. I made this up as I went along. Most everything is obvious - remember that.

No one ever said it didn't. Depending on how tight you attach the clamp, the clamp will cut into the rubber tubing. Attaching too tight will cause more damage than good. It would be best to tighten until the clamp appears to start cutting. You can prevent cutting the important rubber by putting a layer or two of electrical tape over the rubber where the tubing clamp was as Some Guy said. The electrical tape will be cut into instead of the rubber tubing. I believe I mentioned that tip at SSC a while back. It's a really good idea if you do lots of work with your rubber (and if you're as interested as I was, you will).

You definitely understand my methods! I didn't buy a single thing for that project except for the rubber tubing and the ball valve. The larger pipe is 4" PVC (not 3") leftover from my first CPS cannon failure (which I stopped once I realize it wouldn't work). Everything should be recycled.

I also don't know if people realize it, but latex rubber tubing is actually a great deal. Sure, the smaller tube is about $1 a foot. What you don't consider is the expansion of the rubber - that turns into a 3 foot long tube that holds at least 3 liters (probably 5 if I remember correctly). That's a great deal as far as I am concerned.

Keep the questions coming. ;)

Yes, I understand that after reading it several times ;) I meant that once the LRT expands sideways until its touching the pipe, it must slide slightly along the walls to keep expanding, which causes the friction I was talking about. How long was the tube for the power pak?

Is it easy to tell when it's at its limit? Were you able to tell when it was full by just looking at it, or did you figure out about how big it would be at 850% elongation?

Would 3" be too small? It might restrict the expansion of the tubing slightly...

No prob ;)

I'm not sure if you caught my second edit (earlier post): How has the LRT been holding up? Does it still work as well as it did when you made it?

What about the ID (between chamber and nozzle)? Since CPS tubing can be used in a very laminar way, it should be able to support a larger ID (more output) without hurting the lamination too much, right?

Oh, I just remembered a question I had earlier: How do you fill the power pak homemade? Hose? If you used a hose, how did you get the water from the hose to go into the nozzle?

Edit:

I assume you mean an unthreaded bolt? I guess you could use a threaded one, though, if you put electrical tape around it.

I believe that you still are confused about one thing - in none of my rubber CPS homemades does the rubber ever touch the pipe. I didn't want to reduce it's capacity to hold water, and I suppose it also prevent friction problems, though I would be more worried that the pipe wasn't completely smooth and that it would cut the rubber.

You won't have that problem unless you are not paying attention. First, you can see the water in the rubber reach the end of the tube. That's when the rubber can't take much more water. Second, you can be like I was in my larger CPS homemade and put much more rubber in than you need - it's a "check valve" almost because if you keep pumping, nothing bad will happen because the rubber hasn't been stretched too much. Rather, you get a little more shot time. Of course, if you keep pumping, you will run into problems, but the idea is not to keep pumping...

If I remember correctly, 3" is too small really. You'll be loosing a couple fractions of an inch in space. As I said before, I don't want to restrict the expansion of the tubing at all.

Most of my tubing either broke when it tore or was stretched too much and too often. I don't think I even have any of it left. At the beginning I figured that since I could buy more any time I felt like, I shouldn't care too much about keeping it in good shape. The rubber will thin after repeated uses. I am assuming that Larami prevented some of the rubber thinning by restricting the size of the tubing's expansion, and you might be able to try something similar if you are cheap. Nonetheless, if you buy 5 feet and don't abuse it, you're set for life.

To get larger internal diameters, you will have to use a larger tube, sacrificing rubber thickness. Larger IDs are those greater than 1". That's out of the question here because tubing barbs don't typically get that large (unless you are willing to pay) and the tubing won't stretch that far.

A large internal diameter also will not cause turbulent flow! It just won't do anything to fix it. I should mention that in my guide. ;)

Yes, it was filled with a hose, and I had a picture of it being filled somewhere. I'll post more about it when I find the picture. I really only used a small gardening attachment to fill it.

Definitely threaded. Don't put any electrical tape over anything either - the threads keep the bolt from coming out! They won't cut into the tubing if that is what you were thinking. If they did, then the tubing barbs would also cut into the tubing.