On Sat, 26 Jan 2019 at 16:16, Jon Elson <el...@pico-systems.com> wrote:
> The input pulley is coaxial to the > spindle, but does not run ON the spindle, it has its own set > of bearings in the headstock, so as to not impart any > vibration to the spindle. This was quite popular as an idea at one point, though seems to have fallen from favour later on http://www.lathes.co.uk/cromwell/ and http://www.lathes.co.uk/weiler/ are other examples. One oddity from Holbrook that I have not seen elsewhere (and isn't actually a feature of the H17 in the original advert) is a double dovetail on the cross slide. There is a part rather like a butterfly shape, fitting into a female dovetail in the saddle and another female dovetail in the cross slide. The cross slide nut is mounted in this dovetail, and normally it is rigidly bolted to the saddle by a conical bolt. But you can move that conical bolt to the taper-turning slide, and then you have completely independent taper and cross slide motion. (with typical taper-turning systems you have to use the compound slide to adjust the cut) http://www.lathes.co.uk/holbrook-B-13-71-21/ It is curious that the Sheldon R series is absent from lathes.co.uk, but then so is the Holbrook H series. -- atp "A motorcycle is a bicycle with a pandemonium attachment and is designed for the especial use of mechanical geniuses, daredevils and lunatics." — George Fitch, Atlanta Constitution Newspaper, 1916 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
