At 12:18 PM 3/25/2010, you wrote: >On 25 March 2010 14:49, Mark Wendt (Contractor) ><[email protected]> wrote: > > > I'm not sure at this point. I'm not sure if the errors > > showing up are cumulative or not. > >Not if they are due to backlash or microstepping nonlinearity.
I'll have to make sure one way or the other. We have yet to determine that it's truly backlash that's causing the problem. > > Actually, I am looking for + or - > > .001" accuracy on the strips I'm going to be cutting. That accuracy > > will be the height of the triangular cross section of the strip. > >But that accuracy is needed in the Z axis, which you have already >stated is spot-on. (I am guessing it is a ballscrew?) Yes and no. In order for the taper itself to be accurate, those flat to apex (Z axis) dimensions have to be met at darn near the spot-on length (X axis). Remember, there's going to be 6 of these strips glued up to make a rod section, and that rod section would look kinda funky if the flat to apex dimensions didn't quite line up. > > On > > the tips of some of the rods I make, I routinely hand plane down to a > > .025" flat to apex height, and can usually hit that measurement > > within a thou. If the machine can't do that in production, it ain't > > gonna work for me. So, I need to make it accurate. > >I don't think any rack-and-pinion system will be accurate to sub-thou >positional accuracy. However, as you are cutting a slow taper you need >far less X accuracy than Z accuracy. Don't need to be sub thou. Just + or - .001". If the X axis is consistently off .001" or .002" per inch, and it's cumulative, it'll end up being close to .050" by the end of the strip. I'm thinking that's a bit much. >-- >atp Mark ------------------------------------------------------------------------------ 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
