Hi Andy > I think that truing up the axes can be seen as part of the > installation and commissioning procedure.
Well, it should be, but in this case the machine was delivered and used productively right away without any in-depth testing and up to now the errors were not noticed because the mill is usually used by students to mill simple parts for architectural model making. > Does the machine have a twin-drive X axis? No, it´s a single steeper motor on the y axis and it´s rotation is transmitted to the two y axis lead screw by a tooth belt. > It sounds like it is possible that the drives are out of synch, ... > If the drives are linked by a belt, then it might simply be a case of > releasing some shaft clamps and running the axis up and down my hand, > re-tightening and re-checking. I tried that, unfortunately I can only move one side by about 1 mm (about 3 mm would be required). > Z-axis alignment might also turn out to be relatively easy. A dial > indicator mounted on the spindle such that it describes a circle on > the machine table will give a very good measure of squareness, and > will also indicate how your adjustments are working. That´s how I measured the misalignment. I also have a coordinate measuring arm at hand; it might be useful when I deice to take apart larger parts of the machine to cure all misalignments. > It is not uncommon to find jacking screws built into the > linear rail mounting arrangement, for example (but this might > not be relevant to your machine) I don´t´ see any, unfortunately. > Given the machine type and the reported problem, I would be > concerned that the axes are twisted and "fighting" each other. It looks like the table is deformed from rectangular to a parallelogramlike shape. The table is just a bolted aluminum construction and it´s lacking a diagonal element to stabilize the rectangular shape. > Is the machine securely bolted to the floor absolutely flat > and level? Yes. > Even traditional cast iron machines can be twisted by uneven > floors, and it is more likely to be a problem with a fabricated > steel/aluminium frame. A good spirit level should show up > any twist (check it both ways on all 4 edges) I did when the machine was installed, even tough I didn´t have a high precision spirit level. The machine should be horizontal with a maximum deviation of 0.5 mm per meter. Good enough? See you Florian ------------------------------------------------------------------------------ Join us December 9, 2009 for the Red Hat Virtual Experience, a free event focused on virtualization and cloud computing. Attend in-depth sessions from your desk. Your couch. Anywhere. http://p.sf.net/sfu/redhat-sfdev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
