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Everything Nerf. => Homemades => Topic started by: Nerf Doctor on February 21, 2012, 06:56:15 pm



Title: EPVAT-Epic PVAT!
Post by: Nerf Doctor on February 21, 2012, 06:56:15 pm
Alright, time for the first homemade of the new year!
As you may remember, I took the SNAP, and I made it my size, also know as awesomely big. This turned out a little "eh". Well, this time I took the PVAT 2.0, also known as VenPVAT, and made it awesomely big, and dubbed it the "Epic PVAT", and this is the writeup.

First, the whole safety rant: Never use globbity plastic cements, always wear eye protection, protection is important, and wear a respirator when exposed to fumes. Always use a vice to hold your junk, not your or other people's hands. Now, onward!
First, stuff needed!
(http://i46.servimg.com/u/f46/15/46/29/71/p2170010.jpg) (http://www.servimg.com/image_preview.php?i=238&u=15462971)
Stuff you need from this pic is the 1/4" bolt(preferably carriage), 5/8L beveled faucet washer, 3/16" ID x 5/16" OD orings, 1/8" pipe nipple(needs to be hex), 1/2" to 1/8" bushing, 2" to 1/2" bushing x2, 2" coupler. Not pictured: 1/8" cap, strong spring, spacer.
(http://i46.servimg.com/u/f46/15/46/29/71/p2190010.jpg) (http://www.servimg.com/image_preview.php?i=244&u=15462971)
First, sand the smooth part of your bolt. I did this by placing it in the chuck of a drill and spinning it while holding sandpaper to it. Sand until the nipple slides easily along the bolt.
(http://i46.servimg.com/u/f46/15/46/29/71/p2190014.jpg) (http://www.servimg.com/image_preview.php?i=248&u=15462971)
Assemble the rear of your PVAT like so, using teflon tape between threaded connections, and PVC cement between slip joints.
(http://i46.servimg.com/u/f46/15/46/29/71/p2190019.jpg) (http://www.servimg.com/image_preview.php?i=253&u=15462971)
Drill out your 1/8" cap with a 1/4" bit.
(http://i46.servimg.com/u/f46/15/46/29/71/p2190021.jpg) (http://www.servimg.com/image_preview.php?i=255&u=15462971)
Drill a 7/16" hole in the side of the tank.
(http://i46.servimg.com/u/f46/15/46/29/71/p2190022.jpg) (http://www.servimg.com/image_preview.php?i=256&u=15462971)
Tap the hole with  a 1/4" NPT tap.
(http://i46.servimg.com/u/f46/15/46/29/71/p2190023.jpg) (http://www.servimg.com/image_preview.php?i=257&u=15462971)
Yeah, I tapped that!
(http://i46.servimg.com/u/f46/15/46/29/71/p2170012.jpg) (http://www.servimg.com/image_preview.php?i=240&u=15462971)
Assemble your pin setup.
(http://i46.servimg.com/u/f46/15/46/29/71/p2190026.jpg) (http://www.servimg.com/image_preview.php?i=260&u=15462971)
Assemble the tank with a 1/4" fitting in the tapped hole. Add a pump, and your good to go!

You now have an EPVAT!
Ranges are as of yet undetermined. I'm having sealing problems. First was the rear seal, due to the wrong sized orings, then was the front, due to wrong sized faucet washer, the front again, leaking between the bolt and nut holding the washer on, and now slightly around the edge of washer. I have found some interesting washer thingies in the faucet repair aisle of my hardware store, so might be looking in to stuff.

Also, lithium grease is the suggested lubrication method. I happen to have a can of liquid wrench lithium grease, so good to go.


Title: Re: EPVAT-Epic PVAT!
Post by: Exo on February 22, 2012, 04:19:11 pm
Obligatory praise.

Anyways, you may be able to get a much more reliable seal by making it a "push the pin in" trigger, say, a WNTS-esque thing, but using a small superlative head.


Title: Re: EPVAT-Epic PVAT!
Post by: Nerf Doctor on February 22, 2012, 04:52:33 pm
Well, I already did that, kinda, with my CVAB. The WNTS is pretty much a check valve with screw attached. I figured I'd try this, seeing as this has more internal-replacement potential with the location of the pin. For now, the seal is perfect everywhere(don't say it too loud, it might hear) and it shoots HARD. I haven't used stefans yet because I fear for my walls!


Also: Official unofficial range report-This shoots an absolver like nothing. With 3 pumps, shoots as hard as my Hydro Cannon with 5. Shoots regular darts from a short improvised barrel scary fast. The only problem is pulling the pin: It's kinda akward and slightly painful to pull. I'll be looking for something to put on it to help, maybe a drilled CPVC Tee.


Title: Re: EPVAT-Epic PVAT!
Post by: Exo on February 22, 2012, 06:51:11 pm
The FOMAS 2 (on NH) used a lever carved out of polycarb. I think it also used a Pvat. MAYBE.


Title: Re: EPVAT-Epic PVAT!
Post by: Nerf Doctor on February 22, 2012, 07:18:14 pm
It did. I know for a fact as me and Whisper on NRev corresponded for awhile on some stuff.


Title: Re: EPVAT-Epic PVAT!
Post by: arrizclark on March 13, 2012, 12:48:35 am
Thanks for the Info. it really helps ;)


Title: Re: EPVAT-Epic PVAT!
Post by: Nerf Doctor on March 17, 2012, 08:54:30 pm
No prob! I needed to add this info: I found a method to achieve a perfect(99.98%) seal:an o-ring glued into the front bushing. If you look here:
(http://i46.servimg.com/u/f46/15/46/29/71/p2170012.jpg)
You can see a kind of ridge within the front bushing. This is where the o-ring is glued in. I have no measurements on it right now, as I had to cut the o-ring to size.