On 8/16/2013 1:36 PM, John Kasunich wrote: > > > On Fri, Aug 16, 2013, at 02:28 PM, Charles Steinkuehler wrote: > > >> It sounds like this would work pretty well as a start, but unless I'm >> missing something it would still allow rapid moves on the extruder axis >> when the extruder wasn't at temperature. Ideally all extruder movement >> should be gated by the extruder-at-temperature signal. > > Does 3D printing g-code ever rapid the extruder? > > I can understand wanting it fail-safe, such that nothing bad happens > if the g-code ever does command a rapid, even though it normally > doesn't.
The g-code typically doesn't, but I do a lot of manual "jogs" and re-home to prime and clear the extruder before a print. In the reprap world, I'm not sure if these are g0 or g1 moves. In the LinuxCNC world I don't know if a jog qualifies as a rapid or a feed move, or if it's something else entirely. >> Is there a way to disable motion on an axis via HAL without causing >> joint following errors (or is that perhaps the best way to do it...just >> mask the motion, let a joint following error happen, and deal with the >> fallout)? > > Perhaps a combination of the two approaches? Use spindle-at-speed > to make it wait while the extruder heats up under normal circumstances > (without tripping on a following error). And block the motion command > to the extruder axis (and only the extruder), so if it tries to rapid the > extruder during warm-up you will get a following error instead of > busting something. > > Blocking the motion command can be done with a mux2. One input > connects to the source of the command (from motion). The other > input is connected to the output. That turns the mux into a track- > and-hold block. Put it in hold mode (select the looped-back input) > when spindle-at-speed is false. Yes, but that would generate a joint following error if motion was commanded while the mux was in hold mode, right? That was my question (perhaps not phrased well): Should I just accept the following error or is there a better way? -- Charles Steinkuehler char...@steinkuehler.net
signature.asc
Description: OpenPGP digital signature
------------------------------------------------------------------------------ Get 100% visibility into Java/.NET code with AppDynamics Lite! It's a free troubleshooting tool designed for production. Get down to code-level detail for bottlenecks, with <2% overhead. Download for free and get started troubleshooting in minutes. http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk
_______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
