How about just using some air cylinders to pull your counter balance cables.
----- Original Message ----- On 26 March 2013 00:48, Gregg Eshelman <g_ala...@yahoo.com> wrote: > Now I'm thinking it needs a semi-active tension system using a computer > controlled 3rd motor but with a spring so it doesn't have to be super precise You could just run a DC or brushless motor at a constant current on the third drum, and simply not worry about its position. But if you are going to have the third motor, and its controller, than making it an active part of the system is only software, so free. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto ------------------------------------------------------------------------------ Own the Future-Intel® Level Up Game Demo Contest 2013 Rise to greatness in Intel's independent game demo contest. Compete for recognition, cash, and the chance to get your game on Steam. $5K grand prize plus 10 genre and skill prizes. Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- ======================================== Todd Zuercher mailto:zuerc...@embarqmail.com ======================================== ------------------------------------------------------------------------------ Own the Future-Intel® Level Up Game Demo Contest 2013 Rise to greatness in Intel's independent game demo contest. Compete for recognition, cash, and the chance to get your game on Steam. $5K grand prize plus 10 genre and skill prizes. Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users