The main goal of the balloon popping contraption is to perform an otherwise simple task in a more complicated fashion. The contraption uses mechanics to complete the task of popping a balloon through many smaller contraptions. Each contraption is set up to trigger the next in order to pop the balloon.
Step 1: The Frame
The frame is made up of Knex forming X shapes for strength. this will also allow support for the mechanisms that will pop the balloon. This is part of the first step of the process as it holds up the ramp which a ball rolls down to set the whole thing into play.
Step 2: Ball Ramp
The ramp is at the top of the frame at an angle so that the ball that is placed on it can roll down. This is the first step of the contraption and sets off the following steps.
Step 3: Swinging Arm
In this step, the arm is supported on a Knex beam on which it can swing freely. The top of the arm has a flat area connected to it so that the ball on the ramp can make full contact with it. The ball will run into the top if the arm and push the bottom in the other direction which triggers the next step.
Step 4: Train Ramp #1
This step the train is sitting on the tracks supported by the frame. As the ball on the ramp hits the arm of the swinging ball, arm is pushed into the train. This get the train moving down he track to the next step.
Step 5: Motorized Wheel
This is the most complicated part of the step because a switch needs to be turned on to get it to work properly. To set it off, the train car must hit with enough force to trigger the switch. A beam connected to the switch crosses the track perpendicular to where the train will cross, so that the train hits it directly. The train was also filled with two 50 g weights so that the train will have more momentum when it hits the beam. When the switch is turned on, it will rotate three wheels that will trigger the next step.
Step 6: Train Ramp #2 (Henry)
On top of Brio (wooden) train tracks sits Henry, (from Thomas the Tank Engine) ready for action. One of the rotating wheels will swing into him and cause him to roll down the track to trigger the final step of the procedure.
Step 7: Rotating Axis
A swinging axis is placed perpendicular to the Brio tracks so that Henry can run into it being. The other side of the swinging axis has a needle connected to it. The axis when run into will swing and push the needle into a balloon sitting next to the axis. Thus the balloon will be popped finishing to contraption with a bang.
Step 8: What You Wil Need
Knex: Trains: Other:
7" beams Electric straight train tracks Thumb tack
4.5" beams Brio (wooden) straight train tracks Duct tape
2.75" beams Brio ramp Kendama ball
1.5" beams Brio track elevator Golf ball
.75" pieces Any Brio train Balloon
.25" pieces Boxcar
360 degree connectors
180 degree connectors
90 degree connectors
45 degree connectors
Different forms of single connectors