were it me , Id copy a shoebox and double the cylinders ( 2 low side 2 high side ) .. Yes, still a slow compressor , but over the years the shoebox has proven to be the most reliable of designs.
after all if they weren't NASA would be using them.
If there is anyone that has a ShoeBox that can answer, it would be a great help to get a few dimensions. At least this will get me in the ballpark. What are the piston diameters (the rods)? What is the cylinder length? Is the cylinder aluminum? Not sure from the photos. If so, I was thinking about making a single block of aluminum for both cylinders. Saw that somewhere on GTA. Are the pistons steel? How do the pistons avoid getting galled on the aluminum? Are the pistons a sliding fit to the cylinder, or are they relying on o-rings for centering in the bore?For me, the difficult part will be the deep hole drilling. I asked about the dimensions to determine the length to diameter ratio. Been looking at gun drills and found them to be quite expensive. Thinking about making a D-bit drill. Depending on the L/D ratio, it might be adequate.
How do the pistons avoid getting galled on the aluminum? One part of the design I do remember is that the pistons don't actually touch the aluminum cylinders! But, like I said I'll get you the info this evening.