This thing is a mouse trap car made by a laser cutter, the files below (odg, cst) are open office and roland cut studio files, each type has the same cuts needed to make the car. This car is not specifically made for speed or distance but more of a solid base for a mouse trap of any kind.ALSO! the way i was able to fit the pencils into the CD was the adapter made by MJCbull, http://www.thingiverse.com/thing:8300I made the car with a base for the trap, 2 sides to act as axel holders, and whatever you are able to use as the axels itself, i used a pencil and a small rod. for the wheels I used CDs and small toy car wheels, what you want is a very large difference in wheel size to make the pull of the mouse trap larger and in doing so, faster. after the car is assembled, you will need a larger arm to pull the string at a more fast, and drawn out pace. that is what i made the clamp for the arm for; it allows u to attach a pencil (very common to find and replace). and in doing so you have just finished a mouse trap car! wind that bad boy up and give it a spin. ( you may want to put some type of grips on wheels for more traction)