Monday, September 28, 2009
Sunday, September 27, 2009
There's a design flaw with the pump. Spring and everything installed, everything works. I need to see what's the problem with that O-Ring inside the pump and install a trigger system. The problem is that it compresses air, but leaks if the motion of the plunger stops -- problem.
After some mishaps with two springs that did not work as planned, I changed the spring design to accommodate a pulling spring nested in the middle of the firing plunger. I also doused all connections in cyanoacrylate and hot glue. :D
Saturday, September 26, 2009
Some more pics of what's been going on.
T-Joint and couple-inch section of 1/2" pipe. Will be used to cock the gun. Also pictured is a ring made from a PVC end cap that will be used as a stopper.
I had taken out the cracked pump to repair. To accommodate new designs, I shifted that pipe mount (that used to be a couple notches back) up. You can also see how I stuffed that 1/2" pipe into the pump -- by melting it. >=D
The firing anchor is temporarily mounted this way to provide the Gorilla glue with the "clamping" that it needs to set properly.
Formerly cracked pump. The crack was pumped full with Krazy glue (ethyl cyanoacrylate) and then electrical-taped for sturdiness. Once the Gorilla glue sets on the firing anchor I can put it back in.
Right now this looks mumble-jumbled but I do have a set plan. I'll upload it later. Handwriting is horrible on it, though.
Wednesday, September 23, 2009
New project: Homemade Nerf Gun.
This idea started with a toy pump used for pumping up an air-powered airplane. I attached a length of 1/2" PVC pipe to the end to accommodate Nerf darts, and rigged up a system to power the entire mechanism via bungee cord. It was a basic bow and arrow, and was operated in the same way.
General view of the gun. The black pump, white PVC barrel, steel reinforcement are clearly visible. As is the bungee cord, which hooks onto the bent metal thing on the end of the barrel.
Back view of gun -- reinforcement visible.
A bolt on the handle serves to stop the plunger from impacting the PVC barrel inside the pump, as doing so propels the barrel out from the frame like a bullet.
The connection between pump and barrel. Both were whittled and filed down to fit each other, as it is a dry fit.
Front view of gun -- barrel, reinforcement, and bungee anchor are visible.
The result of firing the gun with the bolt on the handle in place. It placed all the stress on the outer casing of the pump, and it cracked a few inches.
I'm currently working on a new design that will be considerably more complex and will be spring-powered.