11 replies to this topic

[Ubermensch]

I originally posted this on Foam Universe for the Mother of All Mod Contests, but since that is over, I'll repost it here, where I think it'll be most helpful.

The Double Crossbow is a classic example of a “useless” older Nerf blaster. It fires missiles, is push-pull, and, to be honest, seems to lack potential. Last year, I purchased one through these forums and quickly modified it with CPVC barrels by wrapping duct tape around each stub where the former barrel used to be and then jamming the new barrel on. I was surprised to find that, when each barrel was loaded with four or five stefans, it could achieve respectable ranges of over 50’, with a shotgun spread of about 15’-20’. For a while, I relegated the blaster to use as a sidearm, or last resort, blaster. Recently, I received another of the relatively uncommon blasters. Placing it next to my older one, inspiration hit me. It was a small blaster to begin with—two of them would still be the same size as an Eagle Eye. Why not connect them together by their sides and handles to make a “quadruple crossbow”? A blaster that launches 20 one-inch stefans at a range of 60’ with a spread of 15’ would be undodgeable, and a definite force to reckon with! Soon enough, this is what I had. This write-up will teach the reader how to replicate what I did to make his or her own Quadruple Crossbow. The write up also gives instructions on how to modify a single Double Crossbow, if that is all that the reader wishes to do.

Materials Needed to modify a single Double Crossbow:
-1 NERF Double Crossbow
-1 ½” CPVC coupler
-Epoxy glue
-“Plumber’s Goop” adhesive
-10” of ½” CPVC

Materials Needed to make a Quadruple Crossbow:

-2 NERF Double Crossbows
-2 ½” CPVC couplers
-A tube of epoxy glue, with something to mix it and a mixing surface
-A tube of “Plumber’s Goop” adhesive
-1’ 9” of ½” CPVC (More if you want to make multiple clips)
-A length of PVC with an outer diameter of 1.5”, or an equivalent piece of tubing

Tools Needed:

-A Hacksaw
-A file or piece of sandpaper



Okay, to begin, place your hand on the soft plastic barrel of the stock blaster, like so.



Firmly grasp the tube, then twist and pull it out slowly at the same time, in order to remove the barrel.



Your blasters should now look like this.




Next, take your CPVC couplers.

Carefully cut the coupler in half, as close to the seam in the middle as possible.





You should now have four half-couplers. Soon, you will glue these half-couplers to the barrel stubs of the blaster. In order to make the bond stronger, use your file or sandpaper to roughen the lip around the stub. That’s this part. (The yellow area is where you should roughen the plastic.)





Take out your epoxy glue.



Mix the two parts of the glue together using a stick or brush.



Using this stick or brush, apply glue to the lip around the barrel stub, then place the half-coupler around the stub. Make sure that it is centered. Repeat this step with all four barrel stubs, then let it dry. Afterwards, the blasters should look like this.



In order to make the bond between the couplers and blasters stronger, coat the space between the blaster and coupler with Plumber’s Goop, like this.



Let the adhesive dry and cure for a day. Make sure to put the blasters in a room with the windows open, or a good ventilation system, as they dry. After drying, Plumber’s Goop is nearly invisible, so you can barely tell that it’s there.

At this point, each blaster could be used separately by simply putting 5” CPVC barrels into the couplers. If you only own one Double Crossbow, or do not wish to make a Quadruple Crossbow, stop reading now—you’re done. If you are going to make a Quadruple Crossbow, read on.

The next thing to do is to connect the two blasters. I used epoxy. However, other kinds of adhesives, such as Goop, could be used. If you are going to use epoxy, please use my previous instructions on how to prepare the glue.

The blasters will be connected by their sides, as shown in this picture.



Use your file or sandpaper to roughen the protruding areas on each “inside” side—the side that will touch the other blaster. This will allow the glue to have a stronger bond.



Place your adhesive on each of these protruding areas, as shown in this diagram.



The areas with drawing on them should have adhesive.

Press the two blasters together, making sure that each one lines up with the other, and let the glue dry. Your end result should look like this.

Edited by Ubermensch, 24 August 2009 - 03:13 PM.

[Ubermensch]

Now the handles must be connected. Push both handles all of the way in, to be sure that they are in the same position when glued. Cut a 1” long piece of CPVC and coat it with glue. Quickly slip it in between the two handles of the blaster.





Let the glue dry. Now both handles will be drawn back when only one handle is pulled. I’m right handed, so I pull on the right handle when firing. Your blaster should look like this now.



Once again, you could stop here by simply putting a barrel into each coupler, but I wanted to do more. Ramrodding each barrel separately to reload took too much time for my taste. Simply making “clips”, groups of four barrels, and loading in a new one after firing made reloading much faster. In the next part of the write-up, I will show how to make “clips” or “shells” for the blaster.

First, cut four 5” long segments of CPVC. These will be the barrels.



To make a clip, you need a piece of tubing with an outer diameter of 1½”. I used this.





A “Sink Tailpiece” purchased at ACE Hardware, measuring at 1½” by 12”.

Using your hacksaw, cut a 2”-3” long segment of your tubing.


(The length isn’t exact—it doesn’t have to be.)

For my first clip I used ~2”. I suggest 3” for greater structural integrity.

Now coat this segment of tubing with a large ring of Plumber’s Goop.



Put your four pieces of CPVC into each coupler on the blaster. Then shove the segment of tubing in-between the four pieces of CPVC. It should slide in pretty well, with a snug, but not tight, fit. Let the glue dry and cure for 24 hours. Optionally, reinforce the bond by putting glue in the gap between the tube and the barrels. Afterwards, you should have this.



Congratulations, you’ve made your first clip! Repeat the clip-making process as many times as you want, with four new barrels each time. I have made two so far. Here’s the final product, with one clip loaded into the blaster and one off to the side.



Plungers extended


Clips




It also fires Big Blast missiles (and apparently arrows, though I don’t own any) quite nicely if you don’t load in a clip.



The Quadruple Crossbow!

Video:



Ranges:

After firing one clip, the farthest dart went about 60’, while the shortest distance traveled by a dart was 45’. The spread, left to right, was 17’. The ranges should be the same with a single Double Crossbow, though the spread may be a bit smaller.

Thanks for reading!

[jackster57]

Cool. In the Mods and PJ thread didn't you post the same thing with like RSCB's on each barrel?

[CA13]

Great writeup. This is probably the most straightforward and satisfying mod one can do.

Great use of barrel material in construction (bracing, clips, etc.). Again, great mod.

[Bedhed117]

Nice mod dude. It looks great except for one thing, Isn't it hard to fire with the other handle in the way like it is? Other than that nice shotty.

[Echnalaid]

It looks like an NB-1 hyped up on steroids or some shit.
Nice work. Looks like it would be good indoors.

[Ubermensch]

Cool. In the Mods and PJ thread didn't you post the same thing with like RSCB's on each barrel?

Yeah, still haven't gotten that to work well yet.

[flamincows]

Nice mod dude. It looks great except for one thing, Isn't it hard to fire with the other handle in the way like it is? Other than that nice shotty.

I agree. It seems like it would be a more comfortable blaster to fire if you cut off both handles and epoxied one of them between the two stubs. A more comfortable grip could feasibly help ranges in this case as it might enable you to push the plungers forward with more force.

Of course having never held the blaster myself I may have no idea what I'm talking about.

Either way, I really like it. It seems like a damn useful thing to have while reloading; no one is going to rush that. Incidentally, how do you carry it in battle?

[white moonlight]

I really like the clip idea.

That is a very creative barrel idea, so instead of reloading one barrel flipping it 4 times, you can just reload all
4 and then flip it.

I also like how you connected the handles so you only have to prime it once.

You definetly did everything you could to make this gun have the best ROF possible.

You may want to sand down and file out the barrels though.

[Ubermensch]

Flamincows: You're right, having one handle would allow you to put equal force into both blasters. I considered doing so, but I didn't have any adhesive that I considered strong enough for the job. Anyway, I don't think the difference would be that noticeable.

[flamincows]

Why not drill a couple of holes and bolt everything together?

I think what I like best about this gun is how it seems like it would be almost impossible to break. And you are right, using adhesive on the handle (the only part of the blaster that takes any force) would take that away.

[Ubermensch]

That would definitely work. I would do itt, but firing is really comfortable for me already, so I feel no need to change the blaster.

Edited by Ubermensch, 25 August 2009 - 03:37 PM.