Let me explain the basic concept behind Death Penalty. I am trying to get the MOST power with the LEAST amount of weight. This thing has to have a powerful axe and still be under 12 lbs. The pneumatic setup uses a 1.5" bore (or 1.75" bore) cylinder with a 3" stroke. It is mounted on a clevis, so it can swing about its axis in back of the cylinder. The piston head is attached to a lever on a 1/2" shaft. The shaft is in 2 sections of aluminum angle brackets (I will refer to them as jackstands). So, the 1.9" lever (it is 1.9" for a reason) is attached to the shaft. When the piston fires it turns the shaft 90 degrees. How though? Simple, remember that 1.9" long lever, the 180 degree circumference of it is 6", but the stroke only goes 3" so this means it cannot travel a full 180 degrees, just 90 degrees, got that? Good. But wait, how can the hammer swing a 180 degrees if the shaft only goes 90? This is also easy, notice in the picture that their is a pulley on the jackstand. And notice again that their is ANOTHER jackstand in front of it (this is the hammer pivot jackstand) with a pulley half its size. The bigger pulley drives the smaller one, only 90 degrees. Not exactly, the bigger one travels 90 degrees as the smaller one travels a full 180; since it is half the size, it travels twice the distance. The hammer arm is attached to the shaft that travels 180 degrees. Thus the hammer can travel its full swing as the cylinder only needs to go 90 degrees. Their is a catch though. Increasing the ratio of rotation 2:1 increases speed but DECREASES the force of the cylinder. Increases speed by 2, but decreases power by 2. Because you have a bigger pulley driving a smaller one. But it makes little difference since the cylinder has over 250 lbs of forward push (for a 12 lbs robot??!). Now their is a problem on retracting the hammer, we can't just leave it extended now can we? Most people that have axe bots use what is called a double acting cylinder. It can be pressurized in both directions, extend and retract. After thinking things over, I have decided to go with the double acting cylinder and hopefully I can find a valve small and light enough to fit in the bot. Wheew... That's about it for Death Penalty. I know the design will work but getting under 12 lbs will be a struggle. Cool eh?