# How to copy a curve?



## JPKnapp (May 27, 2009)

I want to build a new window blind that fits a large curved window above my family room windows. Any suggestions on how to copy the curve?


----------



## tooldad (Mar 24, 2008)

invest in a big copy machine???


----------



## tooldad (Mar 24, 2008)

more seriously though, I take it you are wanting the blind to follow the curve?

Grab some paper on a roll, like wrapping paper or construction paper and create a scribe using a stick with a dowel on one end and a pencil in the other. Tape the paper to the wall, and follow the curve with the dowel creating a concurrent radius or just trace the curve of the window for an exact copy. Then you can measure and do the math to figure radius. Finally transfer it to a sheet of 1/2" mdf or 1/4" hardboard for a pattern.

Remember the radius increases as you outward from the center point of the arc.

that is my suggestion


----------



## patron (Apr 2, 2009)

if its a half circle , just measure across the opening this is the diamiter , half that an you get the radius .
hope this helps .


----------



## a1Jim (Aug 9, 2008)

If it's round do as David suggest if it's oval make a pattern with paper ,cardboard or thin strips of wood hot glued together and use your pattern to make your window blind.


----------

