How to Build a Spooky Working Drawbridge with Sounds and Light

Step 3 Install Chain Rings

In this step, we took two pieces of 5/16" rolled steel about 9.5" long and pounded them into circles around a 3" diameter pipe. Next we welded each ring at the joint to a 10" length (one per each ring) of 1/2" allthread (a 10" bolt could be used in place of the allthread). To install the rings into the top plate, we drilled 5/8" holes (one each side) through the top approximately 2" in from the corners and centered front to back. Then we inserted the threads through the holes in the top plate with the rings to the inside of the frame and secured them with nuts and washers.