Greetings everybody; I found the reason for the hot bearings on the countershaft in this E-400 style spindle drive. The exploded view and parts list says the bearings, 4 of them, 2 on each end of the shaft, are supposed to be a torrington (now koyo) B-1412-OH, and a ten pack s/b here by tomorrow night.
So me and TLM will be busy making bearing pushers/pullers if the temps are fit for working in the shop building where TLM is located. When thats done, then the problem is that the shaft is worn and lightly scored where the shaft was slipping in the pulley that moves the spindle drive belts from below. The shaft is HARD so the scoring is not excessive, but the bore in the pulley is well buggered up. It only had one setscrew in it, and the last person to take it apart and reassemble it put the pulley on the shaft bass ackwards, so the pulley didn't cover the keyway at all and the setscrew was trying to do it all! And that slippage was at least 50% responsible for the 140+F temps measured there with an IR thermometer. I didn't grok the slippage until I cranked it up to north of 1300 spindle revs, and watched the rpms fade and come back up on the pycvp tach dial, by several hundred revs, at which point I changed the look angle of the thermometer and found the pulley body was as hot as the bearing housings! No wonder the belts could be smelled as if they were hot. This pulley now fits shloppy enough on this worn shaft that even a new pulley will also work loose in time. The pulley I can probably get from Browning yet, but the shaft, while simply a length of .875" diameter steel with 2 slots for woodruff keys, is said to be rockwell 60 or better, and would have to be made and hardened at ohmygawd per hour pricing. So, once I get the bronze bearings I found in it pushed out and the needle cartridges that were supposed to be in it, pushed in, the next step I am considering is, since the left face of the pulley is hollowed out, apparently by browning, to a depth of .375" and a diameter of around 2.1", thats plenty room enough for a taper lock flange, so I am considering boreing that end of the pulley for a thin sleeved taperlock hub and installing that as a means of immobilizing that side of the pulley on the shaft. I think it is more important that the pulley be immobilized on the shaft even if that means its a thou or two non-concentric than it would be if allowed that 2 thou or so wiggle room, which despite the key, will allow more and more wear over time. The set screw, driven tight enough, should hold the other end of the bore fairly solid, particularly if I give it a couple drops of green thread locker 90 degrees from the setscrew on each side. Where its at when assembled, I am considering boreing a 3/32 hole into the extended hub on the other side of the pulley so I can run some thread locker into the shaft/pulley wear gap. Does this sound like a good fix for a bad scene to you all? 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
