On Mon, Feb 14, 2011 at 09:31:31PM -0600, Igor Chudov wrote: > Right now I have at most 5 inches of Z axis travel. This is sufficient for > most parts, except when I have to use a short tool (little end mill) and a > long tool (drill bits in chucks). > > In this latter case, if I move the knee by hand, I lose the Z position and X > and Y offsets.
Why do you lose X and Y? > I have a DC servo motor (really just a DC motor with a shaft sticking out in > the back) with a 15:1 gear reduction. So, it will let me move the knee at a > reasonable speed. [random thoughts follow] Can you put a glass scale on the knee? I would at least measure the knee's acme screw before trusting it. You could use screw comp but you'd need to have a way to home it. If you get full servo control working, and make the knee W, you can have your long tools like your drill have tool lengths in W. This would be really handy: t(drill) m6 g43; g0 w0 (knee moves down) If you can't manage full servo control, a powered knee plus crank for fine tuning plus glass scale would be a pretty useful combination: when I had my knee mill, I'd sometimes set up some "short" tools and some "long" tools. When loading a long tool, I'd crank the knee down 1" or 2" or whatever (10 or 20 full turns of the crank). The value in the tool table would have this 1" or 2" taken into account. Then when switching back to short tools, I'd crank it back up. It's just as much of a pain as it sounds, but it does work. If it was motorized for 19.5 of those turns of the crank, it would have been much less trouble. ------------------------------------------------------------------------------ The ultimate all-in-one performance toolkit: Intel(R) Parallel Studio XE: Pinpoint memory and threading errors before they happen. Find and fix more than 250 security defects in the development cycle. Locate bottlenecks in serial and parallel code that limit performance. http://p.sf.net/sfu/intel-dev2devfeb _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
