[pkg]

I need help with the following problem on my "dinosaur" Roku Roku 1979 Vertical Milling machine with a Fanuc 5M control. The machine only moves positive in the Y and Z axis no matter what you do. The problem occurred overnight while it was switched off. I have already reloaded the parameters and this has not helped. I have checked all the limit switches and all are in order, none are stuck. The X axis works perfectly.

[beege]

Perhaps its in "overtravel" mode. I know on newer controls, you press "P" and "CAN" when powering up, and it clears ignores/clears overtravel conditions. On my Hardinge, I'd have to boot into IPL, and select the option about starting with overtravels cleared.

[Dan Fritz]

The 5M control never had software overtravel limits, so "P" and "CAN" will not do anything (sorry).

The fact that the X axis is normal while the Y and Z axes will only move in the + direction is very strange. Are you able to run Y and Z in either direction in MDI or in MEMORY mode? If it's just the jog function that's not working, it could be an I/O problem with the minus jog buttons. If you had an OT (OverTravel) alarm in the - direction, that would only let you jog in + to get off the limit switches, but you would certainly notice the OT alarms. Is the ALARM LED lit at all ? When you try to move Y or Z in the - direction, does the position display change? If the position display changes but the axes don't move, that could be an MLK (Machine lock) condition.

One thing I saw many years ago was perhaps the wierdest problem I ever encountered on a 5M. On the bottom edge of the "B" board (the bottom board) are 3 or 4 50-pin Honda connectors that have all the I/O signals on them. The connectors have pins that make a 90 degree bend, then solder to the circuit board. There are 3 rows of pins with all the signals from the limit switches, operator's panel buttons, etc., and these pins make a perfect "trap" for any chips that fly into the cabinet. On the machine I worked on, every time you pushed one of the buttons on the operator's panel, something wierd (like your problem) would happen. I forgot what the symptoms were, but the solution was pretty simple: An aluminum chip was wedged between two pins, so when one 24v signal came in, it put 24v on TWO pins, causing an unusual set of symptoms. The solution was to blow the chip out of there.

Another possible problem is a +15v or -15v power supply problem on the Y and Z servo boards. This is not very likely because all three boards are supplied by the little power supply on the X servo board. You may want to check those ribbon cables that go from the X servo board to the Y and Z boards. If one of the pins that carry + or - 15v is not making good contact, then the Y and Z boards might have +15v, but not -15v (or vice-versa). There should be +15v, and -15v check pins on each of the servo boards. Make sure that you see both voltages on ALL THREE boards. You can use checkpin CH3 as a ground reference for your voltmeter. A bad ribbon cable could do this, or just a poor connection where the ribbon plugs into the X board.

Hint: The X servo board has a black aluminum heat-sink on the top, and the power supply is housed underneith. The Y and Z boards will have a blank space where that power supply would be if it were an X servo board. All three servo boards have a Honda connector CN1 on the bottom edge.

[NZ_Jase]

Hi,

I had this issue on a 5T, X would move only towards the operator, Z was fine. It turned out to be a faulty A-PC03 IC on the A board.

Good luck, Jase.