Martha II came with a generous selection of original three-jaw chucks, made by very, very reputable manufacturers. Unfortunately they all shared one commonality: They were at least 70 years old and hopelessly worn out.
To my big surprise Din800 M33 is still a pretty common standard on woodworking lathes. As cutting M33x3.5mm threads by hand is at the best of times "no fun", I was more than delighted to find out that cheap steel fixture plates are commonly available, but usually only up to around 125mm, with the odd one being available in 150mm/6".
So in fact only the center section with the actual thread was really
useful to me (for now) and a cheap 63mm (2 1/2") holesaw made relatively
short work of the mild steel plate.
Trying the same trick on some actual tool-steel finally killed the poor holesaw and left me now other chance than to first drill and then bore the center hole to size.
Bit of TIG-magic later and a hole for a C-spanner later:
The thing with proper tool-steel and the right inserts is, you end up with a really lovely finish.
As the whole "using-a-holesaw-to-drill-the-center-out"-thing really backfired, I decided to do something I had put off for ages. A long while ago, I found a Morse Taper 2 reamer made in the Soviet Republic of Ukraine, still in its original wax coating and wrapper. Based on the writing the outside, I assume it was manufactured in February 1986. So, the brown stuff is almost forty year old wax and not rust. Also it is sharp enough to immediately draw first blood...
The bore cleaned up absolutely beautifully, even though I might have to face the barrel off by a milimetre or two as all the tool sit in there quite a bit deeper than before.
So that's it and I have to admit, even a relatively inexpensive 160mm chuck is a massive improvement over a worn out top-of-the-shelf one from more than 70 years ago.
