On Friday 04 July 2014 09:24:19 Stuart Stevenson did opine And Gene did reply: > Gene, > If you plan the scale to collect the data to compensate the ballscrew > then the .0004 scale is fine to obtain a pretty accurate positioning > and repeatable machine.
I just changed a boatload of -+ signs around in the math of that file so the slot cuts will be climb cuts, looks good exercising it in sim mode here on this machine. > I use climb milling for most everything except finish passes on steel. Any special reason why? I'd think mill wear would be the determining factor. > You will find the multitude of variables in the process will many > times require experimentation to find the best result. > Most of the time accuracy requires spring passes with 0 theoretical > material removal. Something this code doesn't do, although if my sacrificial backer is flat, it will cut thru the brass, then the scratch film cover, and into the wood with the last 3 or so passes each one a bit over a thou deeper. There is of course a limit to that as the flutes on this mill are only 1/16" long. > Tool makers rigidly refuse to finish the floor and walls in the same > pass. You may find this useful if your machine and setup is not solid. In this case, it is the walls that count, no floor as they are cut all the way through. Today I think, I spend some time getting the gibs just right, and measuring backlash. What I have done is do a fixed move of .005" back and forth, and adjust the backlash in the ini file until I get exactly .005" of motion using a .0001" dial. Does anyone have a better idea how to do that? These screws were blackened and most of that has been removed with a brass wire brush, bigger balls fitted, but I can visualize that its not likely to be as even now as it would be a year from now when the tighter spots have worn down. The nuts actually have some end float in the holders, but have disks of an old felt hat on each end, to serve as swarf wipers, and they are tight fitting enough that any dirt might serve as a polishing agent over a long period of time. The crush on the felt, and therefore the grip on the nut to prevent longitudinal movement is several hundred lbs, visibly bowing the retaining cover of 1/8" steel over a 1.4" span. I got those teeny little snap cap oiler gizmo's from McM-Carr by brown van the next day! So that also is on todays schedule, drilling the brass manifold to take one of them, and get some oil headed into the nut holders. They aren't dry but they are not well oiled either, all of which I expect are measurable effects. Now, if I can figure a way to do the same with the table ways. No wipers on them either. :( Thanks Stuart. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS ------------------------------------------------------------------------------ Open source business process management suite built on Java and Eclipse Turn processes into business applications with Bonita BPM Community Edition Quickly connect people, data, and systems into organized workflows Winner of BOSSIE, CODIE, OW2 and Gartner awards http://p.sf.net/sfu/Bonitasoft _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
