1 of spring material
1 of sheet metal 3 1/16" x 3"
1 of 1/2" PVC nipple 6" length
2 of 1/2" PVC threaded caps
2 of #10-24 machine screws
2 of #10-24 hex nuts
2 of #10-24 wing nuts
4 of #10 washers
4 of pipe clamps
#10-24 Screw Tap
#10 sized screws were selected because they can fit crimpable ring terminals.
Step 1: Create Drilling Template
Using an index card and triangle tool:
1. Put the PVC cap onto the middle of the index card, don't worry about it being perfect.
2. Trace the cap around the index card.
3. Draw tangent lines perpendicular to one another around the traced cap circle.
4. Draw lines from corner to corner of the square formed by the tangent lines.
5. The intersection of these two lines is the center of the traced circle.
Step 2: Drill & Thread Cap
2. Center the template below the drill press bit.
3. Cover the cap with masking tape to prevent wandering.
4. Drill the cap with an appropriately sized bit at high speed, slowly push down.
5. With no power applied to the drill press, rotate the tap into the newly formed cap-hole.
Step 3: Cap Assembly
2. Use a screwdriver and wrench to attach the hex nut.
3. Slide on a washer.
4. Slide on the terminal ring / wire.
5. Slide on another washer.
6. Screw on a wingnut.