I am beginning to suspect that perhaps the screws that are used to tram the head are not tight. I will check.
Igor On Tue, Sep 25, 2012 at 10:28 PM, Gene Heskett <[email protected]> wrote: > On Tuesday 25 September 2012 23:23:36 Igor Chudov did opine: > > > I have a routine that lets me mill a deep circle in several passes, > > typically to cutout circles from plates. > > > > Something strange is going on and the resulting shape is not exactly > > round. It can be best described as a circle with humps. > > > > The routine is below. It is basically a while loop, milling > > progressively deeper until Z reaches the required depth. Every loop > > consists of two half circles milled helically, with the end mill going > > down along a spiral. > > > > Any idea why the shape may not end up being circular? > > > > Thanks > > > > Routine attached. > > > > (Copyright - Igor Chudov, released under GNU Public License V3) > > > > O<circulargroove> sub (circular groove, good for milling through holes > > too) #<xc> = #1 (X center) > > #<yc> = #2 (Y center) > > #<safez> = #3 (safe height) > > #<depth> = #4 (depth of milling) > > #<radius> = #5 (outside radius) > > #<milld> = #6 (end mill diameter) > > #<frate> = #7 (feed rate) > > #<zstep> = #8 (z step, per circle, optional) > > > > O<if> if [ #<frate> NE 0 ] > > F#<frate> > > O<if> endif > > > > O<if> if [ #<zstep> EQ 0 ] > > #<zstep> = [#<milld>/3] > > O<if> endif > > > > #<z> = #<safez> > > #<r> = [#<radius> - #<milld>/2] > > > > G0 Z#<safez> > > G4 P0 > > G0 X[#<xc> + #<r>] Y#<yc> > > > > O<loop> while [ 1 ] > > > > O<if> if [ #<z> - #<zstep> LT #<depth>] > > #<zstep> = [#<z> - #<depth>] > > O<if> endif > > > > G2 X[#<xc> - #<r>] Y#<yc> Z[#<z> - #<zstep>/2] R#<r> > > G2 X[#<xc> + #<r>] Y#<yc> Z[#<z> - #<zstep>] R#<r> > > > > #<z> = [#<z> - #<zstep>] > > > > O<if> if [ #<z> LE #<depth> ] > > O<loop> break > > O<if> endif > > > > O<loop> endwhile > > > > G2 X[#<xc> - #<r>] Y#<yc> R#<r> > > G2 X[#<xc> + #<r>] Y#<yc> R#<r> > > > > G0 Z#<safez> > > > > O<circulargroove> endsub > > > > M2 > > The first thing I'd check would be uncompensated backlash. Then it would > go to damaged screws, like a highly used area wobbled out. Third would be > scaling error on one axis, but thats fairly easy to check. > > Cheers, Gene > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! > A penny saved has not been spent. > > > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. Discussions > will include endpoint security, mobile security and the latest in malware > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ How fast is your code? 3 out of 4 devs don\\\'t know how their code performs in production. Find out how slow your code is with AppDynamics Lite. http://ad.doubleclick.net/clk;262219672;13503038;z? http://info.appdynamics.com/FreeJavaPerformanceDownload.html _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
