1 12” Length of 1 ½ in. PVC (can be shortened to 11” without any effects)
2 1 ½ in. by ½ in. PVC Bushings
2 1 ½ in. couplers
1 ½ in. PVC ball valve
2 ½ in. CPVC tees
1 ½ in. CPVC elbow
1 ½ in. PVC coupler
1 ½ in. PVC tee
1 ½ in. PVC endcap.
1 12 in. length of ¼ in. PEX pipe
1 +bow spring
1 clothespin, zipties, nail, all the stuff you need to make a clothespin trigger
1 1 ½ in. washer
1 rubber sheet
1 CPVC endcap
1 Belleville washer
½ in. PVC
½ in. CPVC
Part 1. RSCB stock. This is probably the easiest and in my opinion the most useful part of this gun, as it can be used in virtually any nerf gun with enough power.
To make one of these for darts that fit CPVC, I’ve found the best way is to use CPVC fittings for the T section of the RSCB (the elbow and tee). Then, I use a ½ in. PVC couplers lightly sanded/reamed out and shove the CPVC fittings tightly into PVC coupler. I’ve found that ½ in. CPVC fittings are only slightly larger in diameter than ½ in. PVC, and will usually fit into ½ in. PVC fittings with a little force. The CPVC tee is reamed out completely on the side facing the PVC, and the CPVC barrel I use on the other side is reamed out completely as well. See below:
I personally believe this is the most efficient RSCB setup in terms of dead space, and the smooth transitions due to the reaming have almost never given me a double fire on any setup I’ve used, including big blasts.
The rest of the RSCB stock is made of 2 sections of PVC with a ball valve in between. I made mine able to hold eight 1 ½ in. stefans, so about12 in. long each. You can make it as long or as short as you want, as long as the one closer to the air supply holds equal or more darts, or else the ball valve will eat your darts. The way it works is you fire all eight stefans with the ball valve closed, then open the ball valve and shake until the darts fall into the next section. Once you close the ball valve again, you can reload the back at any time.
The stock part is shown below:
I shoved a crayola marker barrel wrapped in tape into the pvc section. This allows for easy loading, as darts can be loaded in but won’t fall out because they fit snugly in the marker area. The PVC tee is cut down for comfort and a short section of PVC with an endcap was used for the stock. The whole setup is very stable and if you cut it to the right length, very comfortable.
Part 2. Plunger rod assembly
This is very similar to the setup Rork created in his last SNAP bow design, using ¼ in. PEX pipe for lightness and cheapness, and a similar plunger head to his superlative plunger head design.
I found the rubber sheet in the plumbing section of Lowes for about 2 bucks. It comes in 2 different thicknesses, so I chose the thicker one; I think it was like 1/8th in. or something. Basically, it allows you to cut custom rubber washers of any size and shape you need, which was great because I couldn’t find 1 ½ in. rubber washers anywhere.
I traced the inside of the 1 ½ in. PVC coupler and cut it out using scissors. This turned out to be a little too big, so I trimmed it down carefully using a utility knife until it fit snugly into 1 ½ in. PVC with a concave shape and was airtight. Patience is key here; you don’t want jagged edges, or for it to be too small or else it’ll be useless.
The order for the plunger head goes top to bottom from left to right. I ended up using a different bolt and wing nut, but basically it was the same. First I centered and drilled a hole in the CPVC cap for the bolt. Then, I roughed up the surface of the cap and superglued the flat washer to it. Make sure you carefully superglue the concave washer to the top of the flat washer, using superglue liberally around the seams. Then poke a hole through the rubber washer, and bolt everything together. The setup is shown below.
The next step is to make an epoxy putty ramp against the flat washer to allow the trigger to smoothly catch.
When you are finished, put a short stub of CPVC in the endcap and drill a tiny hole through the endcap, the CPVC and the PEX at the same time. I wrapped e tape around the PEX until it was snug in the CPVC. Now your plunger head is complete.
The pullback handle was made from a CPVC tee, CPVC, a short screw and gratuitous amounts of epoxy putty.
Part 3. Rest of SNAP and Carbon style wood grip
The main plunger tube in this gun was 12 in. long, but looking back you could definitely get away with 11 in. or maybe even 10, as the spring is only 11 in. long, and there is extra length from the coupler and bushing in the back.
Both the 1 ½ in. couplers in the front and back were cut down on one side about halfway from the edge to the middle. In the back coupler, this serves to allow room for the air hole on the bushing while saving space. The air hole in the bushing was cut using a ½ in. spade bit. For the front, the 1 ½ in. to ½ in. bushing was also cut down to reduce dead space. The part was cut to about where the flat section begins.
Fit the back coupler and the bushing together, then drill pilot holes for screws through both parts. I did three spaced equally around the part.
Now for the handle, this gets a little tricky. In Carbon’s original design, a section was cut out of the coupler to allow it to snap on, but because in this design the coupler is actually used as a coupler, I chose to leave it whole. Unfortunately, this meant drilling and screwing the handle on with screws at a slight angle.
I tried to counter sink the screws as much as possible, but they still stuck out and made fitting the bushing and plunger tube on impossible. I dremeled a small groove into the bushing and plunger tube for the screw head, which worked like a charm. This also helps align the screw holes when you disassemble and reassemble the gun.
Assemble the RSCBow and it is almost completed. Make sure to put the rear bushing and spring on the plunger rod before you screw on the plunger head. The next part is to add a clothespin trigger, which you can read about in Carbon’s guide to SNAP’s. The plastic clothespin I used was unfortunately pretty flimsy, and would nearly fly apart after being fired, so it is currently held together with rubber bands, which may be ugly, but work. In addition, to prevent said destruction, I put a block of wood behind the trigger to limit the trigger pull length, which prevents the pin from being pulled completely out and exploding.
Attach the RSCB stock to the RSCBow by forcing the CPVC elbow into the front bushing. This is the most efficient and compact way to attach it, and it is pretty sturdy due to the CPVC being slightly larger than ½ in. PVC. An optional reinforcement would be to take a metal strip and secure the ball valve to the rear coupler with screws, which I haven’t done but will in the near future.
Now you to can make your very own RSCBow. For those of you scared to make homemades, I have to say this was my first one, and it was a lot easier than I expected it to be. It’s very convenient to be able to make something exactly to your needs. I haven’t tested ranges, but I’d assume due to the extra plunger volume and increased deadspace from the RSCB stock, it gets similar ranges to SNAP bows and the like. Right now all I have is an 8 in. cpvc barrel on the end, but I may go longer.
Thanks for reading guys. QCF’s?
Edit-Pictures weren't right.
Edited by minsc, 04 April 2010 - 12:33 PM.