Saw part duplication
[August 9, 2015]
This simple project involved the duplication of a missing part. An acquaintance recently purchased a radial arm saw, with unfortunately a couple of missing pieces. The missing piece was the small clamp shown to the left - the clamp on the left of the photo is an original, and the clamp on the right is the duplicate I built.
I couldn't find a long enough thumb screw at the local big box store, so I made one from a 5/16"-18 x 2-1/2" bolt. I heated up the bolt head with a MAPP torch, and then hammered it flat (followed by some grinding to shape the part). I turned the clamp pad on the lathe, and also turned the end of the bolt to fit the hole in the pad.
Initially I tried to turn the end of the bolt so that it would "snap fit" into the hole in the pad, but this did not work - when I tried to press it on it the pad just sheared off the "bulb" on the end. I finally ended up just turning a longer piece on the end of the bolt to fit the hole in the pad, and then after fitting the pad, peened the end to hold the pad in place.
I also purchased a 5/16"-18 square nut, but it didn't have the required flat profile I needed, so I just milled a piece of cold rolled steel to size and drill and tapped it for 5/15"-18.
[See photos below.] The clamp body was made from 18 gage steel sheet. The steel was heated with a MAPP torch and bent over a piece of steel milled to size as a forming tool. With some heating, hammering, and clamping in a vise, the basic U-shape was formed, and then cut to size by rough sawing followed by milling. The other required cut-outs were made by scribing the required cuts using the original clamp as a pattern, and then cutting out the pieces on the mill with a slitting saw. As a final step, the piece was cleaned, de-greased, and spray painted black.
Forming clamp body from 18 gage steel.
Milling slot for nut.
Finishign shape with slitting saw.
Below is a slide show of all photos of this project.