Simple Lego Launcher
Using some basic Legos from a lego tecnic set, and the bricks I had laying around, I was able to build this launcher, which shoots a 3 1/2 long spike 3-4 feet at a selected lego target. This version is shot by pressing down the lever in the back (the trigger).
Supplies
Lego technic pieces and blocks
Rubber Bands
Building the Projectile
As shown in the pictures, I build a 13-stud long lego spike, with smooth plates covering the top. In these plates (look at the pictures) I made two notches for the trigger mechanism. Also, I made each end different, so I could put on 2 kinds of heads.(Pic #4)
Building the Inner Frame
This step is pretty self explanatory. Look at the pictures. You can see I made a base, added flat blocks fot the projectile to sit on, then build the sides. The clips sticking out each side are for the rubber bands.
Making the Trigger and Putting on Rubber Bands
In picture #1 you can see the trigger. That lip on the bottom grasps the projectile, under tension, and is lifted (which makes this contraption fire) when you push on the opposite end. Looking at the pictures, you can see I slid a pin through the middle of the trigger, attaching it to the frame. Follow what I did with the rubber bands, but different sizes and lengths of rubber bands will require different tensions. I also made and extended handle, using leverage to help equalize the heavy rubber band.
Wheels, Touchups, and the Start of the Shell
I added some wheels to my launcher to prop it up and give it stability. Very important, don't forget to add a piece like the one shown in picture #2... it helps the trigger mechanism fire.
The Outer Shell
I basically added blocks all around the roof, sides, and to part of the front. I could have made it a little spiffier with some more pieces, but I didn't due to my limited supply of Legos.
Testing It Out
To load it, press down on the trigger, sliding the projectile through the front. When the ammuntion is about halfway in, release the trigger, sliding the ammo back until it clicks. Fire by pushing down on the lever.
My shot pretty far, and I was pleased. If yours doesn't turn out so well, you might want to tension your rubber bands, and test the firing mechanism.
As always... don't shoot anyone. Its a pain... for everyone... including me (in the comments).
Questions? Criticism? Built it? Tell me in the comments!