When we first used our Haas machines we discovered they would cut a program of short linear moves very rapidly. A long shallow arc (imagine an 80 inch arc length of a 300 inch radius) roughed to leave .150 to finish was undercut past the finished dimension. We quickly learned to handle the limitations and have used the machines for a long time. Not very accurate but usable without much problem. On Apr 20, 2012 11:56 AM, "Jon Elson" <el...@pico-systems.com> wrote:
> andy pugh wrote: > > As I said earlier, I don't think this is a "Lookahead" problem, it is > > a "must be able to stop inside the next code block" problem. > > And I am not convinced that being able to stop the machine within the > > next code block is necessarily a sensible requirement. > > > Exactly! It is a safe scheme, but becomes a limitation. Total > lookahead is a boundless > problem, so I can see that is not sensible. What I can imagine is a > method of lookahead > where each vector is examined for acceleration, and it keeps running > ahead until a large > acceleration would be required. Some kind of mark is made for that > vector so the > traj planner knows a deceleration would be required coming up on that > point. Perhaps > this accel scanning could put the mark back the required number of > blocks so that when > the traj planner hits that mark it begins the decel then. This all is > complicated by the > feedrate override that is implemented at the moment. But, the scanning > could probably > just assume 100% speed (or whatever the max override allows). > > Jon > > > ------------------------------------------------------------------------------ > For Developers, A Lot Can Happen In A Second. > Boundary is the first to Know...and Tell You. > Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! > http://p.sf.net/sfu/Boundary-d2dvs2 > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
