I have a republic lagun vertical machining center with a geared head. In the past I have experienced an alarm when the machine goes to do a spindle orient and tool change, the error was "spindle drive error, spindle did not orient". I did contribute this to not being warmed up because after getting warmed up it was normally fine. When I received this alarm the spindle would typically drift/coast down to a stop and I would be required to cycle the power.
Yesterday things got worse. I let the machine warm up for about 20 minutes at a low RPM and then began running a program, this was the first time that I received a spindle drive error during a program, this happened approximately 3 times (before every tool change) and was caused by an M5 (spindle stop) in the program. Shortly after running an entire tool and successfully changing tools the machine blew a 30amp fuse (one of the 3 fuses in the back where the power enters the machine). I changed this fuse hoping it was just an old fuse (the machine has been moved a couple time and is over 10 years old) I finished the part which required a few more tool changes, I did not receive any alarms, things ran great. I thought I should run a test of some sort to ensure the problem was the fuse so I began a long cut, single tool program and it blew the same fuse again.
Any suggestions of where to begin testing would be much appreciated.