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Homemade QFD?

Posted: Thu Jul 06, 2006 5:39 pm
by Lucius Octavion
Hallo, I am new here. I really like all the scientific things on this site and I want to know if it is possible to make a regular homemade QFD that attatches to the hose and can be used to fill a gun like a splashzooka. Also, how do you make a portable QFD? Thanks, all help appreciated.

Posted: Thu Jul 06, 2006 6:38 pm
by joannaardway
In return for my answers I ask one thing - learn to use the "enter/return" key. Posts all on one line are not nice to read.

Homemade QFDs are possible.

Question 1: Do you mean for a homemade? - Really easy
Question 2: Or for a Splashzooka or similar? - Not so easy but possible.

Portable QFD - groan. The number of questions about this.

Getting hose pressure in the middle of nowhere is very hard. (oooh, magical tap tree!) And as silentguy has said:

Water lost at the tap is fine. Water that you have lugged several miles and then just lost in the middle of nowhere - not so good.

Sure there are ways - a pressurized container isn't hard, but moving it will be.

The closest thing I have to a portable QFD is a plastic bottle that can be used as a homemade, or can be clipped onto the port on either my modded 3200, or Vertigo (my homemade) for an instant fill.

EDIT: This belongs in homemades - not physics.

Posted: Sat Jul 08, 2006 1:34 pm
by SSCBen
I get a ton of questions about locating QFDs, and at this point I think we should make our own. A homebuilt QFD might be the first product of the probably necessary homemade water gun store.

The ID of my QFD - ~19.9 mm. The OD of the O-ring - ~20.1 mm. It appears that 20 mm ID pipe is what we need.

Checking online, 20 mm pipe does exist. Product #45435K91 at McMaster-Carr may be what we are looking for (though it's 8 feet long). My first thought though was to check for a correct sized brass pipe which would be available locally.

Other than finding the correct sized pipe for the coupler, the remainder of the building is easy. I myself would just buy a small ball valve, hose couplers, and a few pieces to hook it all together. Total cost would probably be high if you were buying all of the parts yourself, but reselling would be cheap.

Posted: Sat Jul 08, 2006 3:27 pm
by Silence
The closest thing to a portable QFD (please, just search for it using vBulletin's search feature--and sorry guests, but you can't do that) is an LRT-based system. However, it's best mounted in a car, in a base, or somewhere else that it can hold a ton of water but doesn't impede transportation too much.

You could also try setting up a large hose network, and you might even be able to convert it between a QFD water source and a sprinkler system.

But if you're doing the LRT method, why not just make your own backpack SC soaker?

@ joannaardway: Are the paragraphs short enough for you now? ;) Lucius Octavion's post wasn't that bad, although the second and third sentences could be separated with spaces. I agree, however, that it can be hard to read posts or even literature in which multiple ideas are in the same paragraph.

Posted: Sat Jul 08, 2006 3:46 pm
by SSCBen
I've built small air pressure portable QFDs before. Their use is very limited because as the pressure drops, so does the amount of water being put into the other water gun. Portable QFDs are by their nature less efficient than a hose. I think a larger portable QFD would be good for a few people.

The easiest thing to do would be making a LRT system with slightly more power than most water guns. That should work well. At that point though, you might as well just make a basic CPS homemade water gun as SilentGuy says. Same amount of work and instead of letting a worse water gun work in more places, you get a great water gun that works in all places.

Posted: Sat Jul 08, 2006 4:03 pm
by Silence
Actually, I was suggesting an actual SC homemade, as opposed to commercial SCs and all standard soakers. It shouldn't be that hard to do; but what I'm really thinking about is an application as a sidearm used to increase output or as a quick backup.

Basically, the light gun body straps onto the back of your left arm (or whatever arm you pump your primary soaker with), and a small handle perpendicular to the barrel transfers recoil to the thumb. (It sounds awkward now, but when you think about it, it's just like a regular soaker.) A small lever or trigger is near the handle, and while it might seem sacrilegious, I am even considering a modified sprinkler solenoid for this purpose.

With luck, this system won't be too cumbersome, and you'll actually be able to pump your primary soaker. That said, I don't think the design would see too much use--it isn't very useful, and I'm concerned about the pressure rating of some of the hosing and hose fittings.

Posted: Sat Jul 08, 2006 4:03 pm
by Lucius Octavion
How would it be possible to make a regular one that attatches directly to a hose?

Posted: Sat Jul 08, 2006 4:09 pm
by Drenchenator
How would it be possible to make a regular one that attatches directly to a hose?
That was exactly what Ben was talking about doing in the first place. Though you could build one that does not need to use the hose, the idea was to build a replacement hose-based quick fill device.