Centre drill extension

[olderdan]

I have a home made X Y table from part of a small mill on my bench drill which I use for coordinate drilling.
One problem is a limited quill travel of 50 mm and switching from a centre drill to a twist drill takes up nearly all the travel and moving the drill head loses the datums.
The answer is to make an extension for the centre drill to match the length of my edge finder and the length of the average twist drill. Made two for different sizes rather than a double ended one and rather than use grub screws I have simply used Threadlock which is easily removed with heat.

The bench drill has been modified to enable the head to be lowered on the column to within range of the job in hand.

[Rorschach]

That's a good idea. When I made my morse taper centre drill holders I really should have made them with a bit of an extension.

[LMMasterMariner]

Have the same problem even with 84 mm quill travel which I have at drill/mill. Nice idea. Thanks for sharing.

Cheers
LMMasterMariner

[PJs]

Thanks Olderdan for the rabbit hole on that fine old iron bench machine. Lathes.co.uk had quite a write up on them. Quite a good size table for your press and would think your X axis being made from plate would keep the profile low. Do square section slides work as good as dovetails?

Thanks again. PJ

[olderdan]

Do square section slides work as good as dovetails?

As you can see by this screenshot there are some high precision slides made this way and may in some circumstances are easier to make for the home workshop and many have been made by a built up construction and can be easier to refubish. L.C.Mason made a small screw cutting lathe by this method from gauge plate.
Its all down to what suits your application as which one you choose to use, dovetails are cheaper to manufacture as there are less parts but usually result in a taller assembly.

[PJs]

Thank you sir! Forgot all about Rulon, Turlon, etc...pricey stuff but impressive. Also forgot about L.C. Mason's contribution to model engineering. His books are like gold now. Thanks again for all of your contributions to HMT.

PJ

[12L14]

If we are talking about use of box ways in amateur constructions, lets not forget about A. D. Mayo "Midget lathe"(improved - box ways instead dove tail - version of earlier one made by W. R. Bell, funny thing is that Bell's tool rest for wood lathe used box ways).
And there is of course Dave Gingery(I prefer his description of making box ways over L.C. Mason's one - even if end result isn't as fine).

ps. at the moment I'm working at cheap substitutes of turcite(for low end devices like those chicom cross vices or extruded aluminium compound tables you can get for 20$ or so).
Self adhesive tapes(especially capton and glass reinforced teflon ones) seems to work fine(if there only was available linen or cotton - like in tufnol/micarta - reinforced teflon tape...).