Repair 7

How to Make a Sine Plate

A sine plate allows parts manufacturers to precisely measure unusual angles. Composed of two parallel metal plates attached to a metal bar, the sine plate opens and closes at one end -- like a hinge -- allowing the user to set it at a particular angle. Sine plates are often used by do-it-yourself auto parts makers who do not have access to a commercial machine shop.

Instructions

1

Cut the 1-inch steel rod in half lengthwise. Weld this semicircular piece to the bottom of one of the metal plates, 6 inches from the hinge end.

2

Mill a shelf 1/4-inch deep by 1/2-inch wide into the hinge end of each plate. Cut the steel tubing into five segments, welding them alternately to each metal plate in the shelf at the hinge end. Insert the 3/8-inch steel rod to form the hinge holding the plates together.

3

Drill and tap 1/4-inch holes every inch on the sides of the plates, starting at the hinge and working outward.

4

Bolt the turnbuckles to the outer sides of the plates, then attach the gauge block between the semicircular rod and the hinge.

5

Drill holes into the top and bottom plates at appropriate places for mounting the sine plate bottom to your work table, and the top to the parts you will be working on.