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SEAL H3 - New Homemade

Posted: Sat Jul 30, 2011 11:00 pm
by SEAL
So, I wanted to make a CPH last fall, but something um, unexpected came up, and I forgot about it. I still have the concept drawing, and I'd like to share it with y'all.
Image

So yeah, that's my over-the-shoulder reservoir idea (My brother thinks it looks like a tuba.). Thing is though, I never was exactly sure if the whole design would work (My main concerns are with the PC area.). So that's where the finest from SSC come in.

To be honest though, I don't know how long it will be before I actually gather all the parts; could be 3 days, could be 3 years. Either way, I really do miss building homemades...

~SEAL

Re: SEAL H3 - New Homemade

Posted: Sat Jul 30, 2011 11:07 pm
by DX
I don't think you can pump water into the back of a CPS chamber. How would the rubber bladder expand and contract to fire water to the nozzle if it has to open to the rear as well? The pump is also either going to have a ton of deadspace, restricted draw, or sealing issues if you want to bring it through the second tee area. The connection to the reservoir might also snap off unless it's tapered down more gradually.

Re: SEAL H3 - New Homemade

Posted: Sun Jul 31, 2011 6:55 am
by atvan
I will magically fix all but the last of DX's complaints. Okay, this desgn will not work, but I can explain a way to fix it. Connecting a CPS on both sides is possible, but it needs lenghtwise epansion room. What I came up with in the past is to use a sliding pipe connected to one of the sides, with an o-ring on the end. This pipe is connected to the bladder, and slides over the main construction pipe. This also presents itself as an easy fill gauge.

You could also make or buy a snap on T for the support.

Re: SEAL H3 - New Homemade

Posted: Sun Jul 31, 2011 5:17 pm
by SEAL
atvan: Yeah, that's sort of what I was thinking, but I hadn't come up with an easy way to do it. I was thinking about using a flexible hose of some sort.

The handle will just slide over the pump shaft like on my APH.

And for the reservoir, I will probably use that really thin drainage pipe that isn't designed to hold pressure, therefore is much lighter than PVC. I don't know if it will be heavy enough to snap off though.

Re: SEAL H3 - New Homemade

Posted: Sun Jul 31, 2011 6:56 pm
by atvan
That stuff is still heavyish. You could make a support coming up from the nozzle area supporting the res.

Re: SEAL H3 - New Homemade

Posted: Sun Jul 31, 2011 7:11 pm
by C-A_99
You could also use air pressure with a large intake tube. It may not perform as well as traditional APH designs but it'll still work. You can also have the tube feed into the front of the PC, though that'll make things a bit more complicated to structure together.

Re: SEAL H3 - New Homemade

Posted: Sun Jul 31, 2011 7:43 pm
by atvan
That sounds like a good idea. Granted, he already has an APH, but he could try my idea.

Re: SEAL H3 - New Homemade

Posted: Wed Aug 03, 2011 7:42 pm
by SEAL
I don't really want another APH; one of the biggest problems that I have with mine is the huge stream dropoff.

I will try to think up an idea for the CPS chamber, and any suggestions are welcome. I prefer having the water go in one side of the PC and out the other (For ergonomic reasons.), but I need to think of something that will allow the LRT to expand lengthways.

Re: SEAL H3 - New Homemade

Posted: Wed Aug 10, 2011 5:53 am
by New Guy
Why does it need to expand length wise? Just use a narrowish tubing and run it from the inlet and in a couple circles or such and then to the outlet- size it so that you run out of room in the LRT housing before the LRT reaches its breaking point.

Re: SEAL H3 - New Homemade

Posted: Wed Aug 10, 2011 11:52 am
by wetmonkey442
^Because LRT expands lengthwise whether you like it or not. If you don't allow it room to expand in that direction, the bladder will experience stress from the forces of expansion and will break.

Relying upon only one direction of contraction would also severely limit the performance of your gun.

Re: SEAL H3 - New Homemade

Posted: Wed Aug 17, 2011 7:55 pm
by New Guy
I see... That makes sense. Could we maybe use a braided hose to go from one end of the LRT to the connection point headed toward the nozzle? That would give us flex and the ability to expand lengthwise without being too complex.

Re: SEAL H3 - New Homemade

Posted: Wed Aug 17, 2011 10:52 pm
by atvan
I would go with some rigid pipe sliding over each other with o-rings. A pain, yes, but a buikt in pressure gauge as well. Also, the hose may pudh the bladder weird.

Re: SEAL H3 - New Homemade

Posted: Thu Aug 18, 2011 6:01 am
by New Guy
Well, on my Geo (4x4 toy) I have some braided steel brake lines that are narrow and extremely flexible. I was just thinking you could maybe use that and just let it wiggle around inside the LRT chamber, allowing for lengthwise expansion but also making it easy to seal. I have a 3-ring seal on the pump of my APH and it still doesn't seal to well- I have it set up so I can also swap out caps on one of the pressure chambers so I can use the air compressor to boost it to high pressures.

I'm not saying your idea is impossible, it would just be exceptionally difficult to keep your pressure chamber from bleeding out.

Re: SEAL H3 - New Homemade

Posted: Thu Aug 18, 2011 11:24 am
by atvan
You could let the ball valve slide as well, so that the sliding area has the nozzle as an easier way out for the pressure.

Re: SEAL H3 - New Homemade

Posted: Thu Aug 18, 2011 4:38 pm
by SEAL
atvan wrote:I would go with some rigid pipe sliding over each other with o-rings. A pain, yes, but a buikt in pressure gauge as well. Also, the hose may pudh the bladder weird.
What do buikt and pudh mean? :p

Anyway, that's sort of what I was thinking, but I just don't know how I'd do it. I also wanted to have a spring or something that would compress when the LRT is full, and possibly give it more power when firing.