The thing about home/limit switches is that you can actually mount them far from the engagement point, say two feet away. Use a hard, sprung rod to transfer the action. I've also come across switches that you can barely depress with your finger, so that any oil/gunk gets squeezed out the way before it trips.
On Thu, 11 Jul 2019 at 16:17, Gene Heskett <[email protected]> wrote: > On Thursday 11 July 2019 00:11:33 John Dammeyer wrote: > > > Well. Not the best in the world. And lots of false starts as much due > > to CAM management and G-Code generation. But the limit switch holders > > for the Y axis are done. LinuxCNCwith one parallel port, two HP_UHU > > Servo drives, one Gecko Knee Stepper drive. The HB04 Pendant made > > this a lot easier. > > > > Now to figure out how to mount a Knee Home Switch. > > > > And properly configure a tool table with the tool heights. > > > > John Dammeyer > > Those look pretty darned solid John, better than any I've done, but I am > usually more space constained too. My new 6040 gantry's y home is a jury > rig if there ever was one, and subject to whatever overtravel up to > about 1/16" before the gantry crashes. So I have the switch, a teeny > pushbutton mounted with about 10 thou of button travel, mounted on a > 1/16" thick 2.5" length of alu about 3/8" wide, bolted to the front face > of the bed so the switch hangs out past the bed facing to the rear, with > a 4-40 screw planted in the face of the gantry edge to push it. The > boltdown screws are a long inch away from the switch, allowing the alu > to flex about 1/8" without permanent deformation after the switch is > bottomed. With the 4-40 screw set for the length of stickout to keep it > from crashing, I can feel the mount flex as it homes, but cannot see it. > I've std roller micros in other places. With 5 dollars a bag of ten > switches, repeatability is well under a thou all around. I'm pleased, > which is what counts. Limits are set in the .ini file, about 50 thou > from crashing at the other end of the range. > > I may replace the z motor yet, all of them are very small nema 23's, and > with the weight of the spindle motor on the z sled, lift speed is > restricted to about 1/3 the maxvel of the x and y dirs, currently set at > about 190"/minute. > > No labels on the motors, and no data on the dip switch settings of the > tb6560 drivers I took out, so motor currents are set in the low 2's > based on motor heating. I replaced that whole control box since I was > unable to even get a full translation of the Chinese manual out of > googles translator. So it now has a quad of 2m542's that used to drive > my hf mill. and a clone 1.5 horse 120 volt vfd. Runs either direction. > But if I use tool contact to set tlo with a g38.2, I have to clip a > ground onto the tool. Too much of that grey epoxy paint to get a ground > anyplace. Even the motor to spindle doesn't reliably get thru the > spindles bearings. > > Thanks John. > > 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) > If we desire respect for the law, we must first make the law respectable. > - Louis D. Brandeis > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
