ons 2022-12-21 klockan 06:08 -0600 skrev Stuart Stevenson: > A point and a vector fully describe a plane in 3D space. Yes there that's another option.
If three points are given to define an arc in a three dimensional space it will be in a "flat" plane. > > On Wed, Dec 21, 2022 at 2:40 AM Nicklas SB Karlsson <n...@nksb.eu> > wrote: > > > ons 2022-12-21 klockan 00:47 +0000 skrev andy pugh: > > > On Tue, 20 Dec 2022 at 21:27, Nicklas SB Karlsson <n...@nksb.eu> > > > wrote: > > > > > > > Three points with three in the (x,y,z) space will define an arc > > > > in > > > > three dimensions. Then there is three degrees of freedom for > > > > the > > > > tool > > > > direction at each point or two for a rotating/"round" tool if I > > > > think > > > > correct. > > > > > > We have been discussing this on the forum (At least, I think it > > > was > > > there) and someone had the idea of defining both an end point and > > > a > > > point part-way along the arc. This gives an unambiguous arc in > > > three > > > dimensions. If you define the centre point (in three dimensions) > > > then > > > with a start and an end you get two options. And you can't easily > > > define a clockwise and anticlockwise for an arbitrary plane... > > Maybe. Give three points then centre point need to be calculated by > > Linuxcnc but if this does not have accuracy problem for the path I > > guess it is a good option. > > > > > > > But this isn't what I was rambling about, I was discussing making > > > arcs > > > in XY and UV _simultaneously_ where the arcs have different radii > > > and > > > centre points. > > > The issue is not one of maths, but of G-code letters to use for > > > the > > > parameters. > > > An option might be a G2.1 and G3.1 to "queue up" an arc, to be > > > run > > > concurrently with the next feed move. > > Give all four coordinates (X,Y,U,V) at start point, middle point > > and > > end point? > > > > Then arc for path could be calculated from (X,Y) coordinates and > > arc > > for cutting direction by (U,V) with same mathematics will do the > > trick? > > Or thinking wrong a four dimensional arc need to be calculated? > > > > > > Nicklas Karlsson > > > > > > > > _______________________________________________ > > Emc-developers mailing list > > Emc-developers@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-developers > > > > _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
