On Thursday 09 February 2017 13:11:56 dragon wrote: > I would sense the RPM directly at the spindle... not at the motor. > > Then use gearchange so that the system knows what range you are in to > send the VFD the correct signal for wanted speed. > > Sensing at the motor doesn't account for belt slip either, and that > would make rigid tapping iffy IMHO. > Sorry, I didn't make it clear, the tach is being fed from the spindle encoder, so the indicated revs are accurate.. I jut want a better idea of how fast the motor is spinning by having the tach at nearly full scale when the motor is up in the 3600+ rpm range. All I want to do is change the tachs scale, which is currently 1500 revs at the 270 degrees of the needle point. It cannot go that fast even with a 1 hp motor. Friction losses in the countershaft, and the bronze spindle bearings preclude even 1k rpms with only 1 hp. Regardless of the gear, the motors slip angle gets a lot worse above 800 revs.
Roller bearings in everything would probably raise that limit at least 1000 rpms. I can fix the countershaft, but I'm solidly stuck with the bronze bearings in the spindle. Best bearings ever made for a lathe spindle. Neither the bearings nor the shaft has enough wear to count. > just my thoughts > > On 02/09/2017 11:56 AM, Gene Heskett wrote: > > Greetings everybody, from the fringe of the snowstorm in the upper > > right coast; The storm is fini, now its getting cold. Even thats relative as I've seen -39F in the Black Hills of S.D., USA. So the present 19F is a heat wave. Not to my diabetic feet of course... > > One of the things I would like to do is to change the full scale > > range of the pyvcp tachometer, which is set in the panel-pyvcp.xml > > file at present. > > > > I can of course edit that and restart LCNC, but until such time as I > > get some sort of a photocel/ir-led setup to determine the belt > > position, I'd like to setup a pair of gui buttons to change that > > full scale range. > > > > That looks like an 8 step up-down button pair for control. > > Its not a problem to edit up 8 copies of the xml, or perhaps just 8 > > versions of the text changes needed. But how do I get pyvcp to > > re-execute and redraw the tach with the changed values? > > > > What do you folks recommend? > > > > The missus was walking, slowly and tenderly with a walker last > > night, so she will be ok in due time. > > > > Cheers, Gene Heskett 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
