Used a dividing-head fully (with the holey discs rather than in just rotary-table on its side mode) for the first time !
With grateful thanks to those on here who helped me sort why I could not make 50 go into 360º. The problem proved a mixture of my wonky arithmetic and a minor fault on the dividing-head itself, preventing the index-fingers closing that last little bit.
This was to engrave the lines on two hand-wheels, for a 'Stent' tool-&-cutter grinder I'd bought unfinished, second-hand oh, umm, quite a while ago and am slowly finishing alongside other projects.
To get 10, 5s and 1s lines of their equal lengths I improvised a simple stop on the milling machine, having removed the original stop so I could fit a DRO magnetic-strip in its T-slot. To answer the obvious question… for a repetition task like this it is far easier to work to a physical stop than trying to match numbers!
The cutter is a broken end-mill ground approximately to engraving-cutter form. It works so can't be that approximate!
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Even before that, I had successfully completed making the "Tool Holder Body" for the same machine.
This required turning a mild-steel cylinder to be a smooth sliding fit in the already made mounting-block, and boring it to a similar fit around a one-inch diameter holder. I used as bore-gauge a big milling-cutter's shank, having a ground finish far more accurate and smooth than anything I could have achieved.
Screw-cutting a non-standard Whitworth-form thread on the end, using an insert thread-form tool; and making a nut to fit by single-point steel tool, was also a bit more advanced than my previous turning experience.
The two threads were slightly rough with a tight spot, but careful mutual lapping, by hand, with fine-grade valve-grinding paste corrected that. Followed by thorough washing in white-spirit and an aerosol solvent cleaner, and temporary protective coat of WD-40.
The drawings call for knurling both components. Such a shame to rough up the beautiful lathe finish I succeeded in obtaining, using HSS tools, but anyway I think they might be too large for my knurling-tool, so I will have to flute them instead.
I have no idea what its grade is, but the "pre-loved" steel I used machined superbly on the elderly Harrison L5. The HSS tooling gave a lovely finish, better than that from the carbide tips I used for the bore and male thread. I will keep the off-cut, about 3/8" thick, as a one-inch ring-gauge.
How to protect the finished parts before assembly? Petroleum-jelly then e.g. bubble-wrap or the mesh bags sold wrapped around tangerines.
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After all those adventures with screw-cutting and rings of holes I felt the "Nineteenth Hole" calling, to celebrate and relax with one of my caving-club magazines and a very pleasant pint of Copper Brewery's Scramasax pale ale, a light, slightly dry session brew of 4.2ABV. Well, two pints to make sure I was right about the first. They also had Proper Job (St Austell's?) on the beer-engines, and I do like it; but the other was new to me so, like dividing-head arcanities, there to be tried.