I’ve been working on a Stuart twin oscillator for a while now and I think it’s time to start another build log.
Unfortunately, family issues have severely limited my shop time so this will not be a quick build. Anyway let’s get started. The first part is the standard casting. I flattened the bottom and drilled some mounting holes.
Then the standard was mounted to a tooling plate to act as a reference surface. The part was set back into the vise and the valve area and shaft bosses were skimmed, drilled and reamed.
Next the horizontal air passages were drilled with the part at 90 degrees from the vertical.
Then the vertical passages were drilled.
The part was placed on angle blocks and the sloped passages were drilled.
At this point I broke a drill bit in one of the passages. After stretching the boundaries of the English language trying to get the tip out, I gave up and ordered a new casting. The rest of this section will based on the new casting. After redoing everything I set up and drilled all of the ports for the cylinders and the valve.
Next I deviated from the drawing by drilling and tapping the casting to directly take the PMR intake and exhaust pipes. Then I plugged all of the necessary holes and filed the plugs flat.
I drilled a hole in the valve handle and painted the standard and handle. While those were drying I started working on the cylinder extrusions . First I squared up and flattened the valve area.
Then I turned each cylinder to length.
I was going to bore the cylinders on the lathe but I realized that it would be easier on the mill because of the flat valve area. So I set it up then step drilled and reamed the cylinders.
The cylinders were drilled for the center pivots and then placed on angle blocks to drill the valve holes.
Next I drilled the four holes to mount the cladding.
All of the holes were tapped which completes the cylinders. I’ll end this with the first family shot.
Till next time.
Tony
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