On Monday 01 September 2014 11:49:05 Marius Liebenberg did opine And Gene did reply: > What does LCNC do with the spindle at speed signal during execution of > gcode. Lets say the spindle speed goes below a required speed and the > spindle at speed signal goes low.
Marius; That would depend on what you do with that signal in your hal file. Some may use it for a feed hold, netted back into the correct motion input. On rubber framed machines like my 7x12, I suspect it would leave marks in the work, but I might try it anyway. I am not currently doing anything with it other than flipping the LED in the speed display from red to green, mainly because I don't know how to configure the near component that well. I suspect one would have to cobble up some sort of an automatic scaler so it worked on percentage of error, but have not gotten to that stage yet as I have to build a bigger spindle motor supply. ======== One thing is for sure, using a fixed setp to set that difference tolerance signal is a non-starter when the speed is varied for the job. As I sit here thinking about it, my first suggested avenue of approach would be to divide the PID.#.command value by a fixed amount that the output would then be a percentage of the commanded speed, say 5% of it, and use that to feed the near.#.difference pin. Use a mul2 as the divisor function by setting its other input to 0.05, but scale to your prefs of course, depending on how "stiff" the spindle control is. Make sure the mul2 is after the motion, and before the near in the addf list section of your hal as that will remove the lags if its out of order. OTOH, I purposely have some addf's in scrambled order just to stage a startup. ======== This time I'll be using a 2500 va dry transformer salvaged from a 30 yo stereo Phase Linear amp that should give me around 112 volts at 30 amps. The previously constructed one had a 70 volt, 7 amp secondary, 490 va, too small for a kilowatt+ motor and not only is the motor a bit lazy, but after an hour or so of trying to tune the PID yesterday, the tar in its potting could be sniffed. Todays project if the rain stays away, its a bit undecided between a slow drizzle and hazy sunshine. I gotta make the box its in too of course. Please post if my idea works. Or if it doesn't too. ;-) Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS ------------------------------------------------------------------------------ Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
