Materials required:
Both Styles
1x 1/2" Copper threaded pipe coupler
1x 5/8" Copper, 1/2" pipe repair sleeve (1 foot section commonly carried by hardware stores that have copper pipe, and is essentially a long-ass 1/2" coupler)
1x 3/4" OD brass pipe from a towel bar (found two different units that work, one at goodwill and one at my local Habitat for Humanity ReStore)
PVC Adhesive
1x 5/8" long section of heavy wire of some type (I used 1/8" wide flat stainless steel from an old windshield wiper)
Version 1
1 foot 1/2" CPVC or 1/2" Polyester tubing
Version 2
1 foot of PETG barrel material
1 foot 1/2" copper pipe (can use less,down to 6" or so, if you don't mind the PETG being exposed)
Tools:
Pipe Cutter
Rotary tool with metal cutting, grinding, and sanding attachments.
Plumbing Solder and Flux
Torch
Step one: Dart Stop
Take your threaded adapter and strip of wire. You want this to be tight, so it doesn't come loose. Cut it slightly long, then round the corners a little and wedge it inside.
Step two: Cut Piping
You want to cut your CPVC section to whatever is best for the blaster you intend to use. In this case, it is intended for a +Bow, PAS, or BBB, so I chose one foot. On one end, round over the outside edge, so you don't draw blood on barrel taps. On the other end, chamfer the inside edge to help funnel the darts inside the barrel.
Cut the section of the towel bar tube to about an inch. The function of this piece is only as a couple between the threaded coupler and the repair sleeve, so it doesn't need to be very long.
The repair sleeve section needs to be about five inches long, depending upon your dart length. If you use 1.5" stefans, you might be able to get away with four inches, and be able to extract three breeches worth from one sleeve. I use a variety of lengths up to the stock 2.5", so I used five inches. I will still be able to get two breeches and a 2 inch coupler out of the one section.
Step three: Solder on, Soldier!
Prep all three copper and brass pieces for soldering, including smoothing down the sharp edges (I like the wire wheel on my bench grinder, but a file or grinding dremel bit work well too). Use your soldering flux on the top outside ridge of the threaded coupler, the whole inside surface of the towel bar section, and the bottom one inch of the repair sleeve section. Assemble the pieces as shown, with the towel bar section over the fluxed portions of the other two. I chose to solder them as two separate operations, but in hindsight, it would be better as one. When done, make sure you clean all of the flux off, as it doesn't led itself to a smoothly sliding barrel. If you get a good water soluble flux, it washes off easily with soap and water.
Step four: Cut your your loading port.
I forgot to take a picture of this step, but I will with version two. Basically, cut an opening in the piping with a dremel. Make sure it's at least 1/2" wide, enough for the darts to pop in easily. You want the slot to be long enough for your darts to slide in completely, so at least 1.5". You also need to take in to account the retention tab. The base of the barrel needs about 1/2" to seal within the coupler, but must open wide enough for the whole dart. So basically, cut the lower edge just about in line with the top of the coupler, and make it about 1.25" longer than your darts. Next, simply clean up the cuts with sand paper, a file, or grinding attachment. You don't want any burrs or bumps poking in to the inside, as this will tear up your hands, your darts, and fuck up your seal.
Step Five: Barrel fit and retention.
Insert your barrel in to the receiver section. Notice where you have resistance at the front end? You need to make the barrel slide more loosely to make loading easier. Use some fine sandpaper, preferably 400 grit or finer wet/dry and sand the area of the barrel that is in contact with the front section of the receiver. Don't mess with the back end too much or you will mess up the seal. After the whole thing slides nicely, wash and dry the barrel. Then seat the barrel completely in the receiver. Cut a small section of PVC from scrap pipe, or whatever. It should only be about 1/4" around. Now place the tab in the back of the loading slot on top of the CPVC pipe and mark the outline. Slide the barrel away from the base a bit, to give you a little more room. VERY CAREFULLY, dab a tiny amount of PVC primer on the outlined spot, and the back of the tab. Wait for the primer to dry a bit, and then, just as carefully, add a dab of adhesive to the back of the tab. Place the tab in the oulined space and hold it there for a few minutes while it dries.
Step Five, Version 2
The difference here is that I've used 1/2" copper pipe with PETG nested inside as the sliding barrel, rather than CPVC. The intent was to make a version that worked well for air powered blasters, but have common elements. Take your length of copper pipe (one foot in this case), and slide it inside the receiver. Seat the barrel in the coupler and mark the bottom edge on the barrel. Now slide the barrel back out until you can comfortably insert a dart, and mark the upper edge. Between these two marks is the area that you can solder on the retainer/handle. I used a tiny little compression fitting that I found in my garage (yay for buying the estate of an old mechanic). The soldering is a little delicate here, as you want to heat the area enough to melt the solder, but not melt your coupler connections at the other end. You also want to be careful to only flux the area you NEED on the barrel, which will keep the solder from leaking down in between the pipes and causing a problem.
Lastly, you need to seat the PETG inside the copper. Pretty basic, just slide the tube all the way down the pipe with a little adhesive of your choice. I used goop. I also flared the end a little to help feed the darts inside, and also to help keep it in place.
Finished Product:
So here you go... Both styles in finished form. The Copper/PETG unit is quite a bit heavier, but when mounted to say, a +Bow, it's no big deal.
Recently, I also realized that I should also be able to use the 1/2" ID Polyester tubing that CaptainSlug recommends for barrels. It should work nicely as a direct replacement for the CPVC, but with a slightly looser ID. I will build one whenever I get around to ordering some from McMaster-Carr.
Edited by Draconis, 16 January 2009 - 07:00 PM.