Standard stuff here, nothing fancy. That leaves a single casting to be tackled: the workhead. The one with the dividing wheel! After far too much ummmmm and arrrr, I decided on using an ER20 straight shank collet fixture. I can, of course,still machine my own fixtures if needed, but that'll probably do for most stuff I want. I'm not sure ER series collets were even invented back when prof Chaddock was designing this thing!
Anyway, having ascertained that straight shank collet holders with a 25mm shank are readily available, I got to work:
It's a fussy little thing, this. As usual, the book assumes you only have a mini lathe and comes up with the usual bat**** crazy setups appropriate for models engineers of the era. I took the Joe Pie teachings to heart and dusted a few surfaces true on the top and bottom to give me solid registration. With this, order of ops is absolutely key! I wanted to do all the critical ops in a single setup, so setting it in the vice with the back facing up is the only way to go, allowing access to all three bores, relief, registration of for the backing plate and screws:
At this stage, it seemed prudent to machine tha backing plate itself. Holding thin plates is a pain, so I've taken to using Clickspring's "superglue arbor", except I weld the work to the arbor (awaiting welds):
The arbor allows machining of the bore, face and half the reverse face:
And on it goes:
Blue up the casting to finish the relief:
Bore the hole for the index pin:
I was having so much fun at this point that I forgot to take any photos.... They'll come later! Suffice to say, it's now assembled. I LOVE my Wohlhaupter boring head. I've made the pin out of some tool steel, which again I forgot to snap, but did for some reason take a pic of making the brass nobbly bit:
