Yesterday I made some parts and had a giant fan on the drive to see if it is a cooling problem. After about an hour or so the drive tripped out. I forgot to mention that the only thing moving during these faults is the Z axis and it is moving up ie the most loaded direction. Of course I can make it trip out with S6000 M3 so it does point to the infeed unit. I checked the internal cooling fan on the drives and they all are running. After the fault I reset the drive and continued to finish the last 5 parts without a fault. When it is about to fault out on a rapid Z up move I can hear a change in the tone of the Z servo and it starts to grunt for lack of a better word to describe the sound.
The 600vdc buss is well protected as well as all the parts of the drive system. By the time I could get it open on the bench any hot part would be cool. I'll check the AC ripple today when I make some parts. John On 6/3/2012 1:50 PM, Jon Elson wrote: > John Thornton wrote: >> Currently with the 10hp idler and the Samson lathe running as a second >> idler and the 611 in the BP 308 on I have the voltage balanced at 245 >> between all three phases give or take one volt. The VMC will make parts >> and run at 2k with full rapid speeds or ramp up with G code to 6k and >> run about an hour or so before the drive trips out. Turning off >> everything for a while and whatever caused the trip seems to mend >> itself. So now I'm thinking that there might be an actual problem in the >> infeed unit because once it starts to trip out if I reset the machine >> and start running again it trips out real fast. >> >> > Ah HA! Something is getting hot, most likely. So, it takes an hour to > heat up? > That suggests something massive, or possibly with a poor heat sink. > It is dangerous to work around inside the machine with 600 V DC in there. > Can you borrow a thermal camera? otherwise, you'll need to power down > and wait for the caps to drain, and then feel for anything getting hot. > One other possibility is if it takes an hour to heat up, a modest fan might > keep everything cool enough to make it run continuously. > > One other thought, you might have TWO different problems! One is in the > infeed module, the other might be something wrong with the spindle servo > drive. it may have a bad cooling fan or something. >> Monitoring the generated phase voltage while running and during rapid >> moves of Z I see no more than one volt variation. So that seems pretty >> stiff to me. >> >> The spindle and axes are all Siemens AC servos. If I changed to a VFD >> then I would loose my tool changer which would suck. I'd be more >> inclined to buy another VMC that didn't have a Siemens Simodrive 611 >> than try and mod this one, then sell the Discovery 308 on flea bay. The >> sad part is I have more $ invested in BT30 tooling than I care to think >> about so that clouds the issue of getting rid of the 308 for another VMC. >> >> I plan on calling Siemens back to see if there is anything I might do to >> reduce the sensitivity of the drive. The one thing that sticks in the >> back of my mind is how crappy the wave form was when I removed the >> commutating reactor from the circuit... anyway a lot to wonder about. >> > The waveform will be crappy due to the rectifiers connecting the cap > bank first to > this line, then to that one. There will be large current pulses. > > Have you measured the AC ripple of the DC bus? Put a DVM on AC and see what > numbers you get under loaded conditions. > > Jon > > Jon > > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. Discussions > will include endpoint security, mobile security and the latest in malware > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
