I cannot see anything positive with cable drives, for it to work, the cable must slip a little or you need a heavy "thread" cut in the drum, to allow it to lay in. The same bit of cable will always lie on the same thread.....the middle of the cable will need to be bolted to the drum at the middle point.
Strech will occur with usage....
I have used toothed belts (not for CNC I hasten to add) with computers to access cassettes in large silos, that worked well, the toothed belts can be a loop or a long piece (you can buy it in almost any length you wish.
I used T5, but for a large CNC I would say go to T10. Pulleys are available in many sizes, so you can add "gearing" if you wish quite easily. The parts are not really cheap, but have a very long life, low to no maintenance, as long as you oversize and do not stress (which is not needed, even quite loose there will be no backlash!)
Its a tried and trusted method of mechanically moving stuff and there are companies that sell the parts all over the world. Sometimes a few cheap parts come onto ebay...
Best of luck.
Der Fisherman.  |