someone entering your room when you dont want them to or do you just want to play a prank on a freind then rig up your door for a painful suprise. very easy and cheap and most people wont even have to go to the store.
Step 1: Step 1: Gathering Materials
for this instructable you will need:
fishing line $2.00-$10.00(depending on how good it is mine is 10lb line)
an airsoft gun and ammo $15.00-$105.00 (this depends on what kind of gun your using)
electric or duct tape (optional but helpful) $1.00-$3.00
a door (duh)-if you dont have one forget it
Maximum cost: $119.00 if the best possible supplies are used
Minimum cost: $21.00 if normal supplies are used. If your reading this you probably have an airsoft gun and most of the other supplies at home i spent nothing on this project
i am not responsible for any injuries or deaths inflicted using this method this is for fun purposes only and is not meant to seriously injure anyone
Step 2: Step 2: Mounting the Gun
There are a lot of options for this step, but the main objective of it is to get the gun securely fastend to the wall right next to the door. When i rigged my door i held the gun against the wall where i wanted it to sit and put thumbtacks under it to support it, however this didnt work because the gun would fall over the tacks, so i put some tacks over where i was going to put the gun and tied some fishing string from the bottom tacks to the top ones i also rapped some line around the gun for extra stability. I preffered this method because the wall i was mounting it on had a bend in it, and i couldnt quite duct tape it right to where it would stay up. For straight walls i highly recomend duct tape though, just make sure that you can easily reload and cock the gun. pistols are much easier to mount because you can use the handle to duct tape it to the wall, but i wanted mine to hurt a little more so i went ahead and used a rifle. The two pics below show the string and tacks used to mount my gun.
Step 3: Step 3: Making the Pulley System
Take a thumbtack and put it parralel to your door handle on the wall but make sure it is a good six inches or so behind where the guns trigger is. Placing the next tack depends on how you have the gun setup, if it is parralel to the door handle then u should put the next tack parralel to the trigger. If its pointed down like mine then u should put the tack above the trigger in line with the gun. If the gun is pointed upwards then you should put the tack below the trigger but in line with the gun. no matter what setup your using the second tack for the pulley sytem should be directly above the first tack however, it doesnt have to be perfect. The red dots are where i put my "pulleys" the rest of the tacks are to hold the gun
Step 4: Step 4: Putting in the Tripwire
Take your fishing line and tie one end to the trigger of the gun, i went ahead and put some electric tape around the trigger just to make sure the fishing line didnt slip off. When doing the rest of these steps be sure that the line is pulled pretty tightly, but dont over do it or youll pull something off. Wrap the line around the top pulley. This is very crucial for this to work, you have to put the string between the thumbtack and the wall, if you just put it on the thumbtack it will slip off. Also you shouldnt wrap it around the tack multiple times just drape it on the metal part of the tack so that it redirects the line downwards. When you pull downwards if you did it right it should pull the trigger. Now take the line and do the same thing with the bottom pulley making sure that it redirects the line towards the door handle. When you pull straight on the line it should pull the trigger (you do have to pull fairly hard or at least i did). Finally making sure the line is tight, cut the fishing line at the length you want and tie it around the door handle i went ahead and put some electric tape over it to make sure it didnt come off. Now your all done all you have to do is wait for someone to open the door.
P.S. since its hard to get fishing line on film the diagram below is how your rig should look i made three diagrams one for each setup i also included the pic of how to correctly rig the line behind the tack