Squaring the round for lock parts?

[ChrisPer]

Nearly everything you do in the workshop has a great way to do it found many years ago. Those of us doing a thing for the first time have a million ways to screw them up, and little likelihood of avoiding them all - unless we can get the word from someone who knows!

I am planning to make a wheellock. It needs a turned spindle with two different squared sections, a turned wheel with a square drive hole and a spanner with a square hole. My questions are

1) How do I make a square section from round that is actually centred on the axis of the round, using hand tools?

2) How do I make an internal square for the wheel that is centred on the axis of the wheel?

All tips gratefully received.

 

[ToddB]

File or grind one flat on the shaft. Then set the shaft on blocks on a flat surface and measure the height. Do the two adjacent sides and use a square to keep them at right angles. Then do the last sidekeeping it parralel to the first side.
As far as the square drill a slightly undersized hole and file it square. Do you already have the shaft?

 

[ChrisPer]

No, I plan to have it turned soon by a neighbour who has a lathe. His suggestion was starting from square stock.

You idea is good, and roughly what I imagined. Its just that there is likely to be a self-centering method if we only knew it.

One idea might be to set the turned spindle in a jig using bearing holes parallel to glass-hard file guides for the flats. Then detail fit the square hole in the wheel to the spindle as you suggest before chucking the spindle in the lathe to turn the outside of the wheel. That is the sort of setup I imagine a period lockmaker might have built.

 

[ToddB]

If the square stock is the size you need and its indicated in the four jaw chuck that would be the easiest.

 

[ChrisPer]

The part has two sizes of square, and neither is the largest diameter of the finished part. I think the idea was that the square stock gives the best start for filing and measuring.

Here is a pic: