Possibly started with oversize stock so it did not matter if ctr holes were a bit off as once mounted between ctrs and turned it would become true.

It would not surprise me to find that in a busy shop there was a dedicated role of drilling out centres for the turners. You could set up a drill with suitable kit just for this job and pay someone a lower rate than the fully trained turners. Keep the expensive workers doing the thing they are good at rather than the low skilled jobs of selecting and cutting off stock to size and centre drilling the ends close enough to the centre.

Martin C

Lathe Work for Beginners (Yates, 1922) shows a bell centre punch, and a centre drill with a tailstock (presumably Morse) taper.

After finding the centres (e.g., using calipers or a bell punch) and punching the centres at each end, the work would be supported on the headstock 'live' centre, and a centre drill mounted in the tailstock and drilled in the usual way, then reversed and the second hole drilled. I have seen this another book, which I can't locate at the moment.

I agree, Martin. My text suggests the earlier method of finding the centre by whatever means (calipes, odd-legs, bell centre) then using a centre punch, followed by centre drilling. The centre punch was the original method of producing the centre holes, hence the 60 degree angle often mentioned, whereas the prick punch was a finer angle to pick up scribed lines. The key point was that the centre drill was held by machine taper in the tailstock, and temprarily supported by the headstock centre whilst drilling.

My memory suggests (reliably?) that I saw a similar setup (in yet another old book) on a pedestal for centre drilling.

Older books mention "Slocombe" for centre drill, but I have only seen this name mentioned, no image of it. I suppose it was the original manufacturer.

Slocombe drill

Bill

DC31k, the question is regarding work holding for drilling when you don't have a scroll chuck not drill holding.

Martin C

Is it possible that this predates the slocombe drill and spade bits would have been used?

Dave, I think you (or they) have invented the independent (and often) 4 jaw chuck!

Bill

Has no-one ever turned up a new handle for a wood chisel?

You centre punch both ends of the handle. Then take the hitting end of the handle, locate that end in a dead centre held in the tailstock and with a drill bit in the headstock (which could be a centre drill bit on a Morse taper, as shown in Fig. 78 of the book above) drill the hole in the end for the tang. Your left hand holds the chisel handle and stops it rotating and your right hand winds the tailstock handwheel.

What works with wood will also work with metal. No chucks were used in the making of this post.

Hi Duncan, I have used one of those "bar square" items quite often, but a vastly better quality one than the one in your link.

As far as bell punches are concerned, I've only ever used one once, and that was in metalwork class at school, but can't remember what we were making for the need to use it.

Regards Nick.

The simple centre square **LINK**

https://www.toolbank.com/0/p/FAICSQUARE38

pre-dates the combination square with V stock like that linked to by Duncan. I imagine that would have been a common way for craftsmen to locate teh centre of a round bar for puching to make a drill starter hole. Back in the day a combination square set would have been seriously expensive. Few ordinary workers could have afforded their own.

I've had mine for 50 years and use it so rarely I've almost forgotten I have it. More likely to grab the Starrett combination set I scrimped & scraped up the price for second and 40 odd years back.

Clive