When dealing with castings, you have to remember that shrinkage, pattern mismatch, mis-located cores, and uneven surfaces can all contribute to making these parts hard to deal with. I was forewarned and ready to deal with the cored holes not being in the exact center of where the final holes needed to be, but when measuring the left base casting for my CAD model, I discovered that it was about 0.1″ short.
Quorn Parts 102/103, Bed Bars
The bed bars are very simple parts. I choose to make mine 1″ longer than Chaddock did. And in order to keep rusting to a minimum I made mine out of 440 stainless, which was heat treated to 35HRc before grinding to finished diameter.
Quorn Part 104, Wheelhead Column
I had a slight problem when making my wheelhead column. I couldn’t find any competent machine shop with a 4-axis CNC mill to run the spiral groove. So, I needed to come up with a way that I could do it myself with the manual machines I had at my disposal. My gearhead lathe couldn’t cut a 2TPI thread so I had to find a way to make this part on the mill.