I agree that the extruder is not an axis. And if the was inifinite time, and and infinite number of monkeys to write core, and extruder object would be cool.
In the meantime, if we are going to mash extruders into some existing "thing" that LinuxCNC supports, is it more reasonable to think of the extruder as a spindle? In particular, LCNC has spindle synchronized movement. Although that begs the question, should the extruder be slaved to the axes, or should the axes be slaved to the extruder? I suspect that the extruder has less inertia and can respond faster, so spindle synchronized motion is not the right answer. We want motion synchronized spindle speed. On that note: HAL has ddt blocks that can convert axis positions to axis velocities, and a hypot component that can convert the individual velicities to an overall velocity magnitude (2D or 3D, I suspect you only want 2D). Can that simply be multiplied by a scale factor and used to drive the extruder? On Fri, Aug 16, 2013, at 05:57 PM, Charles Steinkuehler wrote: > On 8/16/2013 4:24 PM, David Bagby wrote: > > The topic at hand is: How can one use LCNC to control a stepper motor; > > when the motor is NOT an axis motor? > > Sounds like a Hal level question to me - an extruder needs a pulse > > generator that you can control (that gets the motor movement), some IO > > (to turn the heater on/off and to get temp feedback). > > I'm thinking there must be ways to do that which don't require the > > involvement of the layers above hal that plan axis movements etc. (and > > hence use higher level concepts like an "axis"). > > > > If after you have this hooked up, you need to have an interface from the > > gcode level, think Mcodes and not Gcodes. > > I'm not against where you're headed, but the problem is you need > coordinated moves between the XYZ positioning and the extrusion "black box". > > So the choice is more like treat the extruder as an axis or use the > handy and well documented motion/trajectory-planner plug-in interface to > add a new modular coordinate system representing a proper model of the > "squirting plastic black box". > -- John Kasunich [email protected] ------------------------------------------------------------------------------ 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
