I still have no idea what you were doing

Some time ago I bought a 1937 Van Norman model 12 Universal Mill from a machinery dealer in London. It's in very good condition (1800 pound lumps of high-quality cast iron covered in oil don't wear out very fast), but uses an ancient collet system know as the Hardinge 5V to hold the cutting tools. The collets it came with were all imperial, and I have all-metric tooling, and 5V collets aren't available any more in any case.

So, I had to machine up an adaptor (using my 1963 Colchester Student Mk1.5 lathe - like I said, large lumps of cast iron, etc) to allow me to fit a new metric collet chuck that uses a number 2 morse taper (at least as old as the 5V taper, if not older, but still widely used) to the spindle of the milling machine. The trick is that the internal and external tapers have to be concentric and parallel, to a very high degree of accuracy. I managed to make it so that any non-concentricity is less than a thousandth of an inch, which I'm please about. Strictly speaking the thing should have been made from carbon steel, hardened, then ground to final size, but this is difficult and expensive. I was quoted about £200 for the job, so I made one myself.

I've upgraded the mill with a digital readout system, so now all I need to do is add the very big stepper motors and the PC and I can CNC convert it.

Anyway, I'm pleased with the results. Nice and shiny.

, but what the heck... will you marry me?

No.

pca