The design in 3406 is by J A Radford and isn't the Norman pattern. Radford's design was similar to the current usual range of QCTP in that it consists of a block (more or less rectangular) mounted on the slide and then interchangeable tool holders that fit to that block. The design in 3406 uses a "T" shaped piston to draw the holder into contact and the alignment is by 2 circular dowels engaging in semicircular section grooves.

The Norman pattern is much earlier, Drummond had them on the "M" type lathe and possibly the "B" type precursor to that back around the 1930's.

I think there might be drawings of the Norman type tool post in the files section of the Drummond Yahoo group.

Keith

Edit – just checked and the design is on the Yahoo group, but a quick "google" search with "norman patent tool post" should bring up plenty of pictures and references to it. The design appears to be from 1925.

Edited By Keith Long on 16/02/2014 23:02:12

The drawings and information for that style of tool post are in the book "Building A Small Lathe" by L.C. Mason.

Phil

Gordon just beat me to it.

Edited By Phil P on 16/02/2014 23:21:05

Another version: (and quite an amusing story)

http://www.lathes.co.uk/hercusapron/steammachine.com/hercus/page6.html

That design is less bulky and as rigid as the usual aloris style and costs peanuts to make, I made mine without the offset angle, and with a fixed tightening handle. (tap threads in the block instead of a nut). I also made a version that holds 3 tool bits (Turning, Threading, Cutoff), which is mounted 90% of the time.

There was an article in Model Engineer magazine by L.C.Mason entitled "A Universal Toolholder" dated 2nd January 1970. The design is very similar to that already described.

I have made a couple of these for friends who use them as "quick set" toolposts, ie they retain a single block and adjust the height for each tool as required; sort of halfway between fiddling with shims and a full-blown QCTP.

My observations are that there is no need for a large diameter height adjuster, I think I used about 5mm diameter with a fine thread for precise adjustment, a small knurled knob on top makes fine adjustment a doddle. I would recommend though that a brass or copper tip be fitted to the bottom of the adjuster to prevent marking marking the upper surface of the top slide.

The dimensions given are not set in stone, they can all be adjusted to suit the lathe. IMHO the main considerations are are a robust central post and a toolblock to suit the size of tools in use.

Gordon.