Thanks for the quick reply Glenn and Kirk, The scales are quadrature output - Mitutoyo brand.
I recall the list discussion on the difficulty of using the linear scales sometime last year or perhaps earlier. These are available close to me for a decent price so I thought this might be a way to go. Unfortunately the party tossed the DRO box so its just the scales, cabling and brackets. I hope to look closer at them tomorrow and maybe take a chance on them. Thanks again and I am open to any other thoughts. Brian On Sat, Feb 27, 2010 at 11:14 PM, Kirk Wallace <kwall...@wallacecompany.com>wrote: > On Sat, 2010-02-27 at 22:21 -0500, BRIAN GLACKIN wrote: > > I may pick up a set of linear scales which were part of a DRO for a > milling > > machine. > > > > The DRO box was fried but the scales are reportedly still working. If I > get > > these scales, will I be able to hook them up using one of the available > > boards (mesa or pico)? I have a 13.5X40 lathe I am considering using > these > > for. > > > > Any suggestions including what to look for with used scales are > appreciated. > > > > Brian > > If the scales have quadrature output, then you should be able use a > parallel port, Mesa or Pico. > http://zone.ni.com/devzone/cda/tut/p/id/4763 > http://en.wikipedia.org/wiki/Rotary_encoder > > Some scales don't use quadrature, so at best, you would need a > converter. > > Using a linear scale for the primary encoder is not recommended. Usually > there is a lot of feedback latency between the axis motor and the > encoder, which causes feedback loop instability. Some here have used > linear scales in combination with motor shaft encoders, but this is not > for novice integrators. > > Compared to a proper motor or ball screw rotary encoder, the most common > linear scales don't have very high resolution and rotary encoders can be > cheaper. Although this comment may be out of date, because a lot of the > newer scales have had pretty high resolutions, but still not like a > rotary. > > You may want to consider fixing the DRO display or selling the scales > separately and use the money to get rotary encoders (,or beer). > -- > Kirk Wallace > http://www.wallacecompany.com/machine_shop/ > http://www.wallacecompany.com/E45/index.html > California, USA > > > > ------------------------------------------------------------------------------ > Download Intel® Parallel Studio Eval > Try the new software tools for yourself. Speed compiling, find bugs > proactively, and fine-tune applications for parallel performance. > See why Intel Parallel Studio got high marks during beta. > http://p.sf.net/sfu/intel-sw-dev > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
