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Hardinge with Fanuc 0iMD Multiple Stoppages Problem

Mickey_D

Stainless
Joined
Apr 18, 2006
Location
Austin, TX
I have a Hardinge GX480 APC mill that is driving everyone in the shop nuts. The machine has a Fanuc 0iMD control (horrible error trapping) that we try to run ten hours a day that is really fighting us. Back during the summer it would occasionally pause during operation (green operation button would go dark) and you would have to push the button again to make it start moving again. Now it is doing it A LOT and hurting productivity. This happens either before or after a tool or pallet change but never (yet) when it is in a cut. To restart it you have to push the green button.

Things we have done are clean the air filters (the one in the regulator is pretty rinky dink), go through the error logs (nothing showing up), sacrificed a bucket of chicken and some beer to it, and wiggled every contact and connection that I can find. Anyone have any ideas?
 
I think you are close with the cleaning of the air filters. We have one machine, that during tool changes, will stop. No alarm, just stop. We press go and it is happy. What we found was that the air pressure would drop below its desired wish and stop. Other machines would come up with an air alarm when they stop. Watch during a tool change or pallet change and see how much the air drops. Possibly turn up the regulator closer to the high limit so when it drops, it stays further from the low limit. Then see about improving air supply to it.
 
We did try turning up the air pressure but it did not have much if any effect. Cleaning the regulator air filter (one of the yellow plastic ones) did cut back the pressure drop when something wanted air quite a bit.
 
Fair enough. What else is unique to pallet and tool changes? Power requirement???? Maybe program a dwell after so it has time for a slow reacting thing-a-ma-bob??? You already tried the required sacrifices. The only thing I can think of is move it closer to the door. Worked for one of my machines. As soon as that thing was next to be replaced and was put buy the door, it never missed a beat.
 
We finally figured out what was going on. Seems that a 24volt lead going into the coolant pump contactor was loose (probably from the factory) and giving an flakey connection. Tightened it up and all is well.
 
Got two machines with the "O" control. One is an OiMB, the other is an OiMD. THe "B" model is, of course, several years older, and has this same problem. It is on a Chevalier(Falcon) machine, linear ways, Cat 40 spindle. It is the product of the first task I was given when I hired in here. I was tasked with finding a replacement for a decrepit old Bridgeport VMC that was on it's last legs. I researched comparable sized VMCs, all the way from DMG down the list. THis was the next to the last on my list. But it was sitting on the dock in California, and at the very least expensive end of the list, so the penny pincers selected it. Big mistake. It was fine long as we hadn't begun using an inserted side milling cutter in it to cut keyways in our main shafts. Never was able to get anywhere near the recommended 55 ipm feed at 855 rpm that Sandvik suggested for that cutter, and it sounded like the machine was beating itself to death. I suppose it was. It has developed the exact same symptoms the OP is describing. And I figured it is a bad connection somewhere. But it doesn't do it ALL the time. Get it warmed up and running, and it usually runs ok now. Long as I'm not doing something that imparts a great deal of vibration to it.
That shaft job was moved to a Toyoda FV 1680 VMC. Cat 50, box ways. Same cutter, some program, altered to the suggested feeds and speeds, just humms all day. Blue chips piling up.
Glad to hear that my opinion about a loose connection is the culprit. Now, just gotta find that SOB.
Seems to have something to do with the MPG, and possibly the main selector switch. On quite a few occasions, these two components have had a definite influence into instigating the condition, and sometimes in remedying it, for a while. But I'd say the problem is in the console, not in the control cabinet.
 








 
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