On Thursday 16 March 2017 07:56:58 Erik Christiansen wrote: > On 16.03.17 06:57, Gene Heskett wrote: > > Maybe its ready for the next stage, which is installing a 4plex of > > IR belt detectors so linuxcnc can know what gear the belts are in, > > and if I ask for 1000 spindle rpms, it might suggest a better belt > > position to get the motor back into its prime power band. > > Gene, it's already bad enough changing belts on my mill, without belt > detectors getting in the way, so I can't help wondering how much of a > nuisance such gubbins will be on your machine. Would it perhaps be a > little more convenient to have an encoder at the motor, as well as the > one on the spindle, and let HAL compute the gear from the ratio? Or, > more directly, compare a requested speed with motor top/bottom speed x > current belt ratio, and squawk if it's out of range? > > > I already have those 3 leds setup in the postgui stuffs. However, > > I'd like to have some sort of a tach on the motor itself. > > Ah, if there's to be an encoder/tach anyway, then the job's half done, > without great fat opto-interrupters in the way, and less risk of them > being clobbered during belt changes, I imagine.
These are sold as obstacle detectors, MPJA catalog, page 11 left column toward the bottom of the page, $8, the IR source for each is beside the detector & works by reflectance, so its all outside the confines of the taught belt. And my Sheldon has overcenter toggle linkages, one lever gives enough slack to move the belt from sheeve groove to sheeve grove with ones fingers, and tightens it back up when you've moved it, 10 to 15 seconds, done. And if you had to, one hand above the sensor bar, and one below it, same as now. If I mount the sensors at 1" intervals on a bar, and mount the bar in the middle of the belt span, the distance from belt to sensor won't change much as the belt it moved, and the bar can be mounted straight across. My biggest problem is pulling up a stool of suitable height, getting me sat down on it, and back up when I'm done moving the belt. Bad back (two collapsed discs) and a bad knee doesn't help a bit. There is of course an encoder on the spindle as I consider rigid tapping one of the basic function requirements, not an optional extra. > Erik > (Who often tries to use the horizontal spindle for low speed work, > just to avoid wrestling great v-belts through a small gap at head > height for the vertical. Ugh!) Humm, would that not call for some sort of a custom tool to reach into that small gap? I'd surely be inventing one. Thanks Erik. 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
