
Scrappy was an entirely unintentional project. After taking parts from my hornet for Tiny tim and the mirage I was left with 5 unused tanks, 2 release valves, and a bunch of other scrap. Not liking waste, the only option was to hook up several tanks to a single trigger for a kind of "shotgun" blast, and use up the parts sitting around gathering dust. The result was one of the most effective secondaries I own (yup, better than Tiny Tim). This is part 5 of my 7 part writeup of all the stuff I have done, and so in my opinion is the third most impressive / unconventional project I have worked on.
Welcome to the most image intensive of my posts so far. Read on from here (see? that wasn't too bad compared to my other long winded intros).
Here it is:

Ugly, but very functional. Imagine 4 Tiny Tim's strapped together. The whole thing is only about a foot long (with barrels), and is surprisingly comfortable to hold

The entire build consists of 4 major components:
-4 hornet tanks
-2 hornet blast valves
-1 cheap pump (the same type used in all of my builds, taken from a cheap water pistol, but the original hornet pump can also be used)
-1 hornet check valve (from where it is supposed to attach to the titan)
its function is simple, but the construction wasn't really so I'll try to explain this with pictures. Bear with me.
The pump output is split two ways in a homemade Vinyl T

one feeds directly into one of the blast valves

which then is connected to the bottom two air tanks, completing one of the blast systems:

while the other goes to the check valve, which has an output that is split two ways

one feeds to the blast valve

and the other to set of tanks on the bottom of the blaster

Although this may seem complicated at first, it is actually quite simple. The pump first pressurizes the whole system, priming all of the tanks. Then the first two tanks are fired with the blast valve that is on the non-return side of the check valve. Then the first set of tanks is not pressurized, but the second two remain pressurized because the check valve keeps air from escaping back into the de-pressurized tanks. The merit in this system is that you can keep the top two tanks primed and filled, and still be able to prime and fire the bottom two tanks multiple times.
In terms of actual loading, this works exactly the same way as Tiny Tim. Megas can be rammed down the acrylic coupler

or micros can be loaded into the barrels

The concept is simple, however this uses up much of the junk that people have left over from hornet mods or integrations, and is very effective as a secondary. also, besides the blasts of two darts, multiple darts can be loaded in each barrel to launch clouds of foam into the air (made all the cooler by the fact that you can do it again immediately afterwards).
The main difficulty in this build was down to materials for me. With proper tubing connectors, and perhaps some machined spacers this would be both much easier to make, and look at.
In my case, the whole thing is arranged and held together (quite solidly) with E-Tape. My greatest challenge however had to do with connecting the actual tubing. Using vinyl tube that could be forced inside the stock hornet tubing for an airtight seal, I fashioned multiple connectors by jamming these in place. For the T's and connections to the blast valves I drilled or cut holes in the tubing or valves, and epoxied everything in place. It was a lot of work, but well worth it for the result. When I have more time I may revisit this design and make it cleaner.
in terms of performance however there is little to be gained. Because of the dead space between the tanks of blast valves the ranges aren't as good as those of Tiny Tim, but the 80 foot ranges are certainly respectable for a shotgun type blaster of this size. It takes just 15 full pumps from the reinforced water pistol pump to bring this to pressure:


and the function of everything is very smooth. The handle of the pump is the actual grip meaning that you're hands don't have to move to prime the system. Although the location of the blast valves are unconventional for a trigger, using you're thumb to activate this blaster feels right, and the hornet tanks themselves make a great foregrip. The valves are even numbered. If I release them in order everything works fine. If I hit "2" everything goes off, because the check valve will let the pressure spill out of system "1".

Overall the whole thing is quite comfortable to hold:

And yes, of course there is a video; or two:
Micros (Oops! the barrel fell off. That one must have been made out of my thinwall barrel material

Megas
And the damage after the two videos:

I realize this is probably very confusing, so again, feel free to ask any questions, and please mention anything I can do better in these writeups, because the top two out of the 7 writeups are coming soon!
Edited by Boot, 31 October 2010 - 12:23 AM.