Greetings all; Since I will be useing this vfd, as opposed to a treadmill motor with one of Jon's excellent pwm-servo amps on this lathe, I'll have quite a number of options to get the spindle speed I'll need as there's the backgear to really slow it, and the 4 step pulley setup inside the door. Quite versatile.
I am not sure how much over speed this motor can do, but it does seem quite happy at 120 hertz, and doesn't heat excessively at 30 hertz. A 4/1 range. I have run it on the table as high as 200 hz, 5900+ rpms (can the fan blades tolerate that for long?) but the current draw is under an amp/phase (or my amprobes are lying to me as they are calibrated at 60 hz, so I'd imagine its inductance is killing both the max currents the vfd can push into it, but also the available torque is falling off a cliff. PEBKAC being what it is around me, I think I need some sort of a set of gladevcp or pyvcp leds to tell me if I ask for 1350 rpm and the belts are not in a position to achieve that, or the motor will be below 40 hz, the leds will tell me which way to move the belts in order to put the motor "in its comfort zone". I have some working button code on the mill I can use for the display, but might need, when I get to that stage, some help cobbling up the near modules settings to drive the "leds". ============= 2nd Q is only semi-related, but I can get, from gearbest, an arduino mega r3 with a pile of 10 bit analog inputs for a tenner. See: <http://www.gearbest.com/development-boards/pp_18651.html> Which, if it can talk to linuxcnc over the usb cable, might be able to warn me if the motor is being lugged excessively and getting too hot since its quite well out of sight and mind where its hung. Theres a lot more it could do, I just haven't conjured up the use scenario yet. :) But, mpja.com also has a $2.49 module #31588-MP, that could send an overheat alarm bit directly to a gpio pin on a 5i25 & that looks a lot simpler to do. Since these spindle bearings are bronze, an overtemp alarm on each because they've not been lubed recently could also be handy. Is such an effort worth it? Thanks guys. 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> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
