Recently had some time to devote to this WC41 I bought back in 2017, after fixing some electronics issues:
* bad 74HC14 inverting schmitt trigger that handles inputs E4;5;6;23;24;25, caused some of these to be low and some high regardless if I tried to manually pull inputs down/up - which caused PLC error messages that couldn't be cleared
* bad +15V voltage regulator (LM340-15) inside the Bosch TR15 servo drive power supply board - symptom - all red leds after power up, interestingly there is an error in the original Bosch circuit diagrams, the K1 relay is actually normally closed, so as to start up the TDA1060 generator via V11, when the T1 is getting energized, the circuit opens the K1 relay (and so does the external 24V supply, if PLC detects an error), if there is no external +24 applied and the TDA1060 circuit doesn't fire up, then it may lead to R5/R7 resistors heating up which I think Milacron saw happen when he posted about 038035 board problems in this old thread here -
deckel-fp4nc-troubles, those scanned schematics helped me a lot!
for diagnosis and testing I powered the board up on the bench via an autotransformer and full bridge rectifier + cap to get the desired 245V DC at P+ and P- inputs, you can see test point measurement notes under normal working conditions, TP3 3.4V is what the tester showed, in reality the signal there is short impulses at around 24kHz as far as I remember, and a sawtooth form on the TP4, the 1V is what a tester will show set on DC
There is a slight jitter on all 3 axis, +/- 0.003mm, I haven't yet checked the other boards for bad caps, nor have I did any maintenance on the servo motors and tachogenerators, so that is next on the list.
after these repairs, and supplying +24DC to inputs E85 and E87 (X5/2 and X6/12 on the addition I/O board) to clear tool changer (that I dismantled), I was finally able to reference the machine, as it turned out, the TNC is set up to read distance marks on the scales, so it doesn't need to travel to the axis reference switch, just to the next distance mark on the scale, which is nice
there was another curious thing, spindle gearbox is operated via small DC motors through reduction gearing, one of those motors had its inputs the wrong way around, meaning that if certain speeds were asked from the TNC, it would be unable to switch to them, since that one motor would want to spin in the wrong direction and the TNC would error after a certain timeout period, reversed the wiring and fixed that problem, one curious thing remains - during the gear change, the spindle motor is not energized, and there seems to be no other actuator to help the gears switch, but the link between the gear change motor and the "handle" in the gearbox is via a twist spring, so it seems that Micron engineers opted that the gear fork will be left under tension (because the gear didn't engage), and the next time the spindle motor is fired up, it will fall into place - not the best solution IMHO... if I wiggle the spindle when the gear changes are happening, it goes much smoother
there are few other issues yet to solve, like replacing way wipers that broke into pieces after getting the axis moving... the hand wheel pendant is causing some trouble - when it is connected, it is impossible to switch to hand wheel mode on the TNC, but there is some obviously bodged tumbler installed on the hand wheel case, that when switched, causes the TNC to enter the hand wheel mode, and the encoder itself will not work, I connected the hand wheel from the Fehlmann (same type of encoder and connector), and the axis moved with it
anyhow, weird combination of problems, that would make the machine unusable if only one of them was present... almost seems as if some of that was deliberate to make the machine unusable, or that someone was poking around in it without much clue and caused some additional damage, but it has been a great relief for me now that it to sprung back to life, waiting for DIN 2080 pull studs to arrive in couple days so as to be able to make some test cuts, right now don't have a single tool holder with that pull stud unfortunately
regarding the way wipers, some of them are moulded type - black rubber on steel are in good condition, the other ones (in the pictures), with the greenish rubber material seal in aluminum are basically falling apart, so far I found only one source for the stock material, but due to the current virus pandemic, will probably not be able to get them for at least a month
wiper stock source -
Way Wipers - EITEC
p.s. it seems that these machines are no longer supported by Mikron, I asked them for machine parameters (before I found out they have not been lost after it sitting without electricity for 3 year or more), and they said they are not able to help, so I'll soon scan both of the manuals I have (electrical and mechanical, which sadly doesn't contain detail drawings) for this particular machine and post them for anyone who might need them, along with the parameters list and the PLC program