On Wed, 3 Oct 2018 at 11:10, Marius Liebenberg <mar...@mastercut.co.za> wrote:
> >Either one toothed belt and two sets of (carefully chosen) pulleys or > >two permanently-engaged toothed belts with a peg to engage the > >high-speed ratio and an over-running clutch on the low-speed one: > That sounds interesting Andy. Please elaborate so my older mind can get > the picture. Keyed to the motor shaft would be a toothed-belt pulley. Above that, running freely in a bearing (double row, probably) would be a rather larger pulley. On the spindle shaft there would be a pulley exactly the same size as the fixed motor pulley mounted on the over-running clutch and another pulley rather smaller. Both pairs of pulley have permanently-fitted belts. A means would be provided to lock the free-running ..... . . . This won't work for rigid tapping :-) Having two ratios is still an option, but the simple single-clutch and sprag won't work, it needs to be a method that actively engages and disengages both ratios. Air-conditioner clutches might be one way to do it: https://www.ebay.co.uk/itm/382495802219 -- 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
