On Tuesday 14 April 2020 23:18:07 Reinhard wrote: > On Dienstag, 14. April 2020, 19:07:32 CEST Chris Morley wrote: > > On 2020-04-14 9:10 a.m., andy pugh wrote: > > > On Tue, 14 Apr 2020 at 03:58, Reinhard > > > <[email protected]> > > wrote: > > >>> Maybe G43.2 could be tweaked to take either a H number or axis > > >>> codes. > > >> > > >> That would be very nice indeed! > > > > > > Take a look at the andypugh/G43.2-direct branch and see if that > > > does what you expect. > > > > > > Looking through the code, it is clear that G43 / G43.1 and G43.2 > > > all completely ignore tool diameter. This means that G43.2 is not > > > actually useful for wear offsets on a milling machine (as far as I > > > can tell) but is useful for a lathe. > > > (Which is probably the intended use) > > > > Thats exactly what it was, a hack for lathe wear offsets.I think we > > should try harder to get out of the work around idea and do things > > properly. > > Doing things right is a good intention!
But in translating a design in wood that involved the huge box joints of a Green and Green design into something I could fit and glue up solidly as furniture, I was forced to hard code the diameter of the cutting tool into the gcode itself, using a tool diameter of about .247 for a 1/4" tool so that mating parts fit well but left a thou or so for a glue line. This was true even if the tool was fresh. The mahogany apparently had a "springback" that made the undersized fingers fit perfectly, or the surface of the wood grew as the glue wetted it. But most of my tool table entries are slightly smaller than the tool mic's at just to get room for a film of glue. Dry, they were still a rubber hammer fit. > But relative offsets are not a wear replacement. > It could be used in the same way, but the first goal is to fake a > toolsize for roughing. > I used that at lathe and stil use it on milling at work. If I remember > well, Siemens has cycles where you can add offset for roughing. > At work I need to create fake entries in tooltable, which is risky > when others work at the same machine too. > So having GCode that can apply a relative offset is safe and helpful. > > Another (big) challenge is all around wear offsets. This is completely > different and here I support the idea of first thinking/talking about > a good solution. If you want to implement support for wear offsets, > its fundamental having a timebase to count worktime of each tool. Then > a wear-offset becomes meaningful. Absolutely. The needed offset is not so much that of needing a glue line, but how much the tool deflects as it dulls, as well as a way to comp for backlash. Mahogany seems to be a faster tool wearing wood than cherry for instance. I suspect thats because most Mahogany today, is recovered from sunken logs that have been in the water in a Honduras river for 100+ years and have taken on some of the waters minerals over time. Good Mahogany is scarce, and getting scarcer by the year as we use it up. Much of it today is kiln dried, as opposed to air dried which means any warpage is baked in forever, and for furniture is worthless. Been there, done that. > > At work they run performance tests for all tools, so the cutting > volume, lifetime and price of each tool are calculated. Result is > standard tools for every machine and the knowledge about lifetime of a > tool. > So if you know, that a certain tool has a lifetime of i.e. 100h it > would be nice to know, how much time it already has been used for > cutting. > > Reinhard > > > > > _______________________________________________ > Emc-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-developers 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) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
