The mill complements the Sherline lathe and many accessories are interchangable. Like all my machine tools, it began with an identified need to do a particular job, or more specifically, to do a job I had been doing by hand more accurately, more quickly, and with a better finish. Once installed in the workshop, I quickly found more and more uses for it.
One feature I did not like was the way in which the y-axis leadscrew on the bed is exposed, and of course it very quickly collected swarf and dirt. My solution was to cover it with pieces of cloth that are taped down to suitable parts of the bed and carriage. They are a rather unsophisticated version of the bellows that one finds protecting industrial and toolroom mills.
Recently I have acquired a Sherline
rotary table with a proper worm drive, graduations, and various methods of workholding, and that has proved very useful for jobs like putting rounded ends on connecting rods. The other major piece of equipment is the
dividing head that I made for it, which allows me to make spoked wheel centres and all manner of fittings that have squares, hexagons, or circular bolt patterns.
The mill can be fitted with a drill chuck so that I can drill small holes accurately. A sensitive vertical feed for this would be useful, unfortunately Sherline do not make this as an accessory but I have an idea that one day I might develop.
Another tempting thought is to convert it to CNC. If I were ever to do that, I would retire the
pantograph mill.
I had standardized on 6 mm shank FC3 ("throwaway") cutters for the pantograph mill, and I wanted to be able to use the same cutters in the Sherline mill. Sherline sell several cutter holders, but not for this size, so I made my own. The basis is an MT1 blank arbor (not the Sherline one, though it could have been). This was mounted in the lathe, taper outwards, and the taper section was reduced to length, drilled and tapped for the clamp bolt. It was then removed, reversed, and clamped directly into the lathe headstock, so that all subsequent machining would be exactly concentric. The arbor was drilled and carefully reamed to exactly 6 mm diameter, and the outside was turned to shape. The body was then cross-drilled and tapped for a set screw that bears on the flat on the cutter shank and locks the cutter in place. Finally, a small hole was cross-drilled so that it broke through into end of the central hole, to allow the air to escape when inserting the cutter, which is a very fine fit in the holder.
This last photo shows two useful tools for setting up work in the mill. Both are made from 6 mm diameter silver steel and fit into the cutter holder. One is a centre finder. The end was turned to a point with about a 60° included angle (not critical), and can be used to pick up a punch mark in the work to be machined. The other is an edge finder, for which the end was reduced to exactly half thickness by milling, filing, and eventually finishing on an oilstone, and it is used to pick up an edge. Once I know the centre is exactly aligned with the punch mark or the edge, I can use the x- and y-axis traverses to offset the cutter to the correct amount in order to make the cut.