Step 5) Now cut the aluminum angle iron to the desired length of your swing arm. The swing arm used in the video was 10 inches (9 inches from center of the motor hole to the center of the swivel mounting bolt).
We used a 3/8 inch drill bit to drill partway thru the aluminum angle iron to form a bevel, and then used the smaller drill bit to finish the hole.
Drill the appropriate sized hole at the other end of the swing arm to match the bolt size you will use to build the assembly in Step 6).
Step 6) This spinning washer assembly is important to get right – the assembly must spin freely without binding. We used a 1/4″x3″ bolt as the main shaft with matched lock nuts and metal washers. At our local big box store we found a nylon nut that fits the 1/4″ bolt (look in the specialty fastener drawers) and that fits thru the inside of the large washer. Drill three holes in the washer as shown.
The assembly order for the bolt is as follows:
- Insert the bolt thru the swing arm
- Tighten the first lock nut all the way down to secure the bolt to the swing arm
- Lock nut 2
- Metal washer
- Nylon washer (nylon washers are optional but will reduce the chance of squeaking from the ghost)
- Nylon nut
- Nylon washer
- Metal washer
- Lock nut 3
Lock nut 2 and lock nut 3 should be snug against each other to minimize the chance that the spinning washer will bind, but make sure the spinning washer can rotate freely. After finishing the spinning washer, mount the swing arm to the wiper motor. The picture shows the final assembly.
At this point you need to plug in the power supply and verify that the swing arm rotates correctly and is aligned to give clearance all the way around. Make any adjustments needed then give the entire assembly a coat of flat black spray paint – go ahead and paint the spinning washer, just keep it a light coat so it doesn’t gum up.