The original idea of this project was to build life sized bullet proof pinball drop targets that could be shot at with a 9mm handgun. But after construction began, several problems were encountered that were going to prevent that from happening. So after a few modifications, a target was made that allowed us to shoot at the pinball targets with a .22 caliber handgun. The main problem that was encountered, was the weight of the targets themselves. In order to make them withstand the energy from a 9mm round, 1/2 inch thick steel was used for the target and 11ga. steel was used for the tubing of the entire project. This made the targets very heavy. Each target was 12.5 pounds, which doesn't sound like a lot. When you add 4 of these targets together, it adds up to 50 pounds that have must be lifted in order to reset the targets. So for this version of the targets, we used 1/4 inch steel plate with 11ga. tubing. Which cut the weight down to about 25 pounds that needed to be lifted. 16ga. tubing could have been used to eliminate even more weight, but none was one hand to use.
The targets are reset by 2 pneumatic actuators that we had on hand. Yes, it is more than likely possible that 2 actuators could have been found that would lift the 50 pounds required to reset the targets but that would have added extra cost to the project. Another possibility would have been to have only two targets instead of 4, but the frame was already built for 4 targets and starting over would have required more money and another trip to the steel supply store.
The pneumatics are controlled by a 555 timer circuit that when triggered, opens a relay for 1 second. There was no need for an Arduino and it was fun to do some old school electronics for a change. The original idea was to make the targets reset when all 4 of the individual targets had fallen. However, it was getting difficult to keep everything bulletproof and also survive the weight of the targets slamming down. So instead we used a bullet proof switch that was already constructed. The 555 circuit is triggered when the bullet proof switch is shot.
There is no bullet proofing on the front of the targets due to the cost of adding a sheet of steel to the front. The original idea was to have it cover the front and hang over the edges about 4 inches to block the actuators, air lines and wires from a direct hit. The problem is that none of the local steel suppliers stock that kind of sheet metal. We would have had to order a full sheet of steel (4ft x 8ft) which would have doubled the cost of the project. Splatter shielding was added to protect the wires and air lines. We know from doing these types of projects in the past that the bullet splatter can be more detrimental to the wires and tubes than a direct hit. The splatter shielding is made from 16ga sheet metal which is more than enough to stop the bullet splatter and was available from local steel suppliers.
* Here are the tools used to make this project.
Here is the BOM for this project: