Lots of pieces yet to be machined, but at this rate I estimate I should be finished in 2-3 weeks.
The last few build days were focused on the cylinder, one of the most complex parts of the process.
Both faces need to be parallel to each-other to a precise thickness, and 2 precise bores need to be made to fit the piston and valve.
Very boring job, both literally and figuratively. Took many passes to get the piston to the needed 1.5in bore size, but eventually it did clean up to-spec. Took a few hours, but much of that was driven by the CNC.
Tried using an ultra-length 1/2in end mill to machine the valve, but there was way too much chatter so I went back to the boring bar. I did accidentally overshot a bit (about 10 thou!), but luckily I have lots of spare steel stock onhand to machine the valve to fit the oversized hole.
After that and a few drilled+tapped holes, the cylinder was finally complete. Except for a bit of sanding on the edges to clean up the toolmarks.
Tomorrow I hope to get the piston and valve machined to fit the cylinder.
Hope you enjoyed🤠