Quote: Date: Sun, 5 Mar 2017 13:21:05 -0000 From: "Ben Potter" <b...@bpuk.org> Subject: Re: [Emc-users] Bridgeport servo troubleshooting To: "'Enhanced Machine Controller \(EMC\)'" <emc-users@lists.sourceforge.net> Message-ID: <007401d295b3$58698280$093c8780$@bpuk.org> Content-Type: text/plain; charset="us-ascii"
>From: Jon Elson [mailto:el...@pico-systems.com] > > On 03/04/2017 11:37 AM, Ben Potter wrote: > > Yes, but the same drive connected to the X motor/tacho also runs at max speed. Have not tried the X drive connected to the Z motor. > Don't, until you have checked the motor for intermittent shorts to ground. (Since you put the drive back, and it doesn't blow fuses any more, but spins, this is a bit less likely, but you don't want to risk popping any more amplifiers. > > Most likely it was a transistor that failed to the shorted condition, that has now been blown open. Turning the motor by hand with the multimeter attached gives me either infinity, or 30-35 Mega Ohms between the power input and ground. Can't find a dead short - but I'm surprised that I'm getting _any_ path there. End Quote: My mid 80's Hurco manuals have a service chart which wants the motor and tach brushes checked and brush dust blown out with clean dry air every XXXX hours use. I have actually done this (more than once) because the servos were accessible. I suspect the 35Mega Ohm is a short at one brush holder caused by the brush dust. I admit that the monster FANUC yellow cap motors on my Hitachi Seiki Turning center have never been touched since the machine was delivered in 86. That machine was designed to run production, and God help you if you ever need to do service or repairs. Greg Out yonder in Yoder, CO ------------------------------------------------------------------------------ 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
