Reinhard, I agree that it's logical to use positive offsets for tools in a spindle (since a negative physical size is nonsensical). However, what if you have an auxiliary spindle with a tool tip above the zero height of the main spindle? I'm not saying that's a wise choice, but it would be physically correct to have a negative length offset.
Best, Rob On Tue, Jul 14, 2020 at 10:28 AM Reinhard <[email protected]> wrote: > On Dienstag, 14. Juli 2020, 06:09:38 CEST Chris Morley wrote: > > The problem seems to come from people thinking the contact with the > homing > > switch is where home is. which is not surprising, as when you ask > linuxcnc > > to home that's where it goes first. > > May be its caused by the wording, or linuxcnc people are already > accustomed to > crappy minds :/ > > The word "homing" does not reflect the importance of that issue. In german > we > talk about referencing an axis. So referencing is completely off to users > wishes or likes. The machine moves (assuming it does not have absolute > encoders that are battery buffered) toward the home switch until the > switch > signals contact. That's the axis origin - and I thought, this is what the > word > "home"-position means. > With any professional cnc I know about it is the case. > Obviously not with linuxcnc :( > > So if linuxcnc has different behaviour, it is far from being flexible. > It's just > crap! Crap from people that don't know machine behaviour. > > After referencing all axis (I use the german expression, which might > describe > more exact what happens) the machine knows its origin and can move. > No programmer will ever use machine-coordinates (G53) - only in case of > trouble or for maintenance. So if you use G54 ... you don't have to know > or > care about machine coordinates. The coordinates are as you like them to be. > And if you want the machine move to a different location after homing, > that's > what stored locations (i.e. G28) are for. > > And that a user needs to use negative tool offsets is bullshit. A machine > controller like linuxcnc should handle tool dimensions in any direction. A > tool length can never be negative and so you can't move an arc with > negative > radius. Well, I talk about tool dimensions, not wear level parameters, > which > of cause can be negative. > > Its very poor, that there are so many weird workarounds in linuxcnc caused > by > ignorance, lack of knowledge or misunderstanding :( > > I don't wonna support that crap, so may be, its better some other guy > cares > for translations ... > > > cheers Reinhard > > > > > > > _______________________________________________ > Emc-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-developers > _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
