Jim Fleig - CNC Services wrote: > Hi Ed, > > FWIW > > Many, if not most, of the ballscrews on the machines I service are coupled > to the motors by timing belts (various tooth types). I laser calibrate and > do lead screw compensation adjustment on these machines and am amazed at how > accurately they repeat. Different tooth types will provide varying levels > of repeatability. See link: > http://www.gates.com/brochure.cfm?brochure=7916&location_id=11536. Standard > disclaimer: I have no commercial interest in Gates. Properly tensioned, a > belt can be as rigid as a screw for the system it is driving especially when > the belt length is reasonably short. On the machines I calibrate I tension > the timing belt slightly more than contact to the pulley and get excellent > results that perform well for my customers for long periods of time. I have > never found it necessary to tighten timing belts like V belts but have often > found them that tight from the manufacturer or from other technicians. >
I _think_ (it's not entirely clear) that the machine in question doesn't have screws at all - either the carriage is clamped to a belt that runs between pulleys at the extremes of travel, or the belt is clamped at both ends and runs over a pulley on the carriage. Either way, the belt is quite long, and it doesn't benefit from the mechanical advantage of a screw. This is completely different than the traditional "belt and two pulleys" used to couple a motor to a screw. Using a long belt to replace a screw is significantly less rigid, but can be much faster and less expensive. It is usually done on large, fast, but non-precise machines like wood routers or plasma cutters. Regards, John Kasunich ------------------------------------------------------------------------------ Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM) software. With Adobe AIR, Ajax developers can use existing skills and code to build responsive, highly engaging applications that combine the power of local resources and data with the reach of the web. Download the Adobe AIR SDK and Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
