On 11/02/2011 11:21 PM, Tom Easterday wrote: > On Nov 2, 2011, at 5:50 PM, Jon Elson wrote: > >> >> The way commercial machines like big gantry boring mills do it is they >> have a swivel joint in the gantry. So, each tower of the gantry can move >> independently without any binding. The beam across the gantry has a swivel >> at one end, and a slotted bearing at the other. They may have limit >> switches >> on the slotted bearing so if the machine gets seriously out of square, it >> trips the E-stop. In this manner, the two linear joints can move relatively >> together toward home, and then each homes to its own home switch >> and index pulse. Once homed, then the CNC program always keeps >> them parallel. >> > I would like to see a picture or video, that sounds interesting. But, let me > me rephrase my question… > > I spent some time poking around a huge vertical boring mill with a gantry tool carriage and that is how they did it. It appeared the gantry towers could be several inches out of line without causing any binding. They had obvious limit switches to e-stop the machine if it got farther out of square than that.
I only have a general idea of how this might be done in EMC, and I would assume some custom HAL component would be needed. Jon ------------------------------------------------------------------------------ RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
