Alrighty - on to the valve stem assemblies. Both the valve slider and the valve crosshead are bronze, and were first milled to outer dimensions from a larger piece of rod. Both will be made in a group of three to make it easy to position/hold in the vise.
First shaping operation on the sliders was to mill the rectangular recess in the face side. This was done as a plunge cut with a center-cutting end mill, and the shape traced into the bronze.
Next, the piece was turned over and a slot run down the length with the mill. This will form the groove that the square adjusting nuts sit in.
With the piece sticking out the side of the vise, cross-slots were milled in to form the groove that the valve stem rod will sit in.
Then with the piece held at a 45 degree angle in the vise, the tops of the sliders were tapered back. Since the angles were all 45, it was possible to do both sides of each top with this one position, just had to raise the cutter for each side and run it back and forth.
Last shaping was to also taper the side faces.
With all the shaping done, the sliders were cut apart and trimmed to length with the mill. This photo shows the three sliders all complete.
With the sliders done, it was time to move on to the valve crossheads. On the Shay, the valve stems come down to a crosshead/guide assembly that the reversing gear connects to. This keeps the angular motion from the eccentric from being transfered to the valve stem. To start, another rectangular section of bronze was milled to size, then a step cut into each side. This step will allow the guide to hang onto the crosshead.
Next step was to drill the cross-hole in each of the three pieces (all three are gotten out of this one strip). This cross hole will be threaded for the pivot pin from the reversing gear linkage.
The piece was turned on its side, and notches cut into the edge to form the protruding post at the top of the crosshead.
Next photo shows the crossheads so far, with the major shaping and cross holes drilled. The three parts were then cut from this strip.
The cut ends were then trimmed to length with the end mill. The other part visible on the right was to keep the vise jaws from twisting.
Last step was to drill through the ends for the hole to hold the valve stem, plus a lock screw on the bottom that keeps the cross pin from un-threading itself.
Last two photos show the three valve stem assemblies complete - made up the valve stems (stainless rod threaded at each end) plus the square nuts. You can just see that the nuts have a short round section on the end. I did not have an end mill quite small enough to match the diameter of the stem rods, so this projection keeps the square nut centered on the slider.
With the sliders all done, next step is the valve crosshead guide, which bolts to the piston crosshead columns...
Nice work.
