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String and Compass Method:

Illustration

1. Figure how much transition curve you want (in feet & inches) and how much vert, if any.

2. Tie one end of the string around the push-pin and stick it in the sheet as shown.

3. Holding the string taught, measure out exactly the amount of transition (see step one) and mark this on the string with an ink pen.

4. Tie the drafting compass to the other end of the string and tighten it so the slipknot is right on top of the mark you made.

5. Holding the string taut, swing the compass from the sheet's edge in a quarter-circle, marking the template with the chalk. You may need to move the contraption around to get the desired curve and best use of space!

6. Place sheet on sawhorses and cut out templates carefully.

7. If you want to make a ramp with a decreasing transition, you need to modify the above steps and instead of using a push-pin, use a round object that is 6 inches to 3 feet in diameter, such as a paint can or a round garbage can. Attach the string to the round object and somehow secure it to the wood in place of the push-pin in step 2. As the string winds around the round object, it will get shorter and your transition will become tighter. This is called a decreasing radius transition and it is very cool when making launch ramps and quarter pipes. Experiment and eyeball in a cool tranny.

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