On Fri, 10 Jul 2020 at 17:59, Chris Albertson <albertson.ch...@gmail.com> wrote:
> There is also a minimum amount number of degrees of contact required with > the small pulley. The pulley must be far enough away so the minimum number > of teeth are engaged. Or you can use idlers to modify the belt shape. This is done very frequently on car engine front-end accessory drives, for example. Sprockets for T2.5 belts are available with 10 teeth, so that would be a 2.3m table for the 300:1. Which is also probably too big. I suppose that the design criterion is that one stepper step should be less than the angular resolution of the telescope. So what is that, in this case? But I was coming at this from the opposite direction: If you have to rotate something that is large and circular (or potentially just a sector of a circle) how can you rotate it economically? This is one way. And in this case you probably would want to combine it with a geared motor to get the required ratio. -- 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, 1912 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
