From Frédéric Bornarel in France:High-resolution pictures--may be slow to open
I was always fascinated by the Quorn - which was so well designed by Prof. Chadock - but the price to get the castings was beyond my reach. So, after a long reflection, I decided to built one using the metal and materials already to hand in my workshop. I decided that I would try to retain the proportions of the Quorn, but using metric units, while also trying to improve it - but only from my point of view, I am not engineer - in two ways: firstly, when the entire wheelhead is moved, you are obliged to fix, each time, the correct angle of the column and, secondly, there is no attachment to mount larger-diameter twist drills.
I started with a 1/5 h.p. Chinese motor that I modified by separating the two coils to get clockwise and anticlockwise motion, the arrangement giving, via a round belt drive, two spindle speeds of 4500 and 8500 r.p.m. Then, for nearly two years, I started drill, turn, mill and weld. I made a rack cutter in module 1.5 to keep the angle of the head, and a worm and wheel to control the lift - one turn of the handwheel giving a travel of 3 mm. To help relieve some of the stress on the little worm and wheel gearing, I used a long extension spring to compensate for the considerable weight of the 5.1 kg head. The two bed bars I made 22 mm in diameter and 30 mm longer than those on the Quorn, this to compensate for the dust-exclusion covers I fitted - I have to say that I am not confident the ordinary gaskets used would protect the bars of the standard Quorn - though I may well be wrong.
The machine is not quite finished yet: the spiralling attachment is not done (but now illustrated towards the bottom of the page), nor the engraving of the degree marking of the column or the different cosmetic finishes I would like to apply. I also intend to make a neat box to hold all the various accessories.
My machine has no pretensions to be better than the Quorn, it was just made by an amateur and I did my best.