I have a Miyano BNE-51SY with a Fanuc 18i-T control. And I'm getting a reoccurring alarm 436 soft thermal (OVC). I've checked the amps and all have 0's or -'s so the alarm must be on the servo motor itself. I think it's the turret index motor (A axis) but it typically occurs during a boring cycle. Can anybody suggest what I should do next? Thanks.

Fadal 4020, Hardinge Cobra 42, Miyano BNE51-SY, Haas EC400, SolidWorks CAD and Esprit CAM

Quick Post

check all plugs!

electrical, can be related to this operation.

unbalanced tool, will lead to other problems.

just to start...

gday

Thanks TCA4570. I was able to figure out the problem. A service tech told me how to find the page in the control that shows the servo loads. So I just sat and watched A-axis until it alarmed out again. On this particular Miyano I have live tooling and the tools are driven by a helical bevel gear inside the turret. When the turret lifts to index the helical gear uncouples from the A-axis motor. During non-live tool operations the A-axis servo loading ran about 5%. But after an index to a turning tool I noticed the loading jumped to 84% and held constant. At the next index (a boring tool) the loading jumped to 125% and held constant. That told me something was causing the bevel gear to misalign with the A-axis motor during index and thus causing the overload when the turret re-seated after index. On this particular job I was running two live tools on this turret. So I pulled both of them and ran the machine with no stock. I noted that the A-axis loading never went above 0. So the solution seems to be to replace the bearings in the live tools. Bearings are on order now. If this doesn't fix the problem I'll report back whatever else I find. Thanks again.

emc

Fadal 4020, Hardinge Cobra 42, Miyano BNE51-SY, Haas EC400, SolidWorks CAD and Esprit CAM

This sounds like it might also have something to do with the alignment of the drive mechanism, if it is off a little the a-axis drive will try to hold the gear in the alignment position causing the higher load. Maybe while you are waiting on the bearings you might want to check the alignment.

Thanks for the suggestion cnctech. How should I check the alignment? I did sweep a center-cutting tool holder and the top plate was off by .011" TIR. But I've corrected that by loosening the top plate bolts and twisting the top plate into position.

-emc

Fadal 4020, Hardinge Cobra 42, Miyano BNE51-SY, Haas EC400, SolidWorks CAD and Esprit CAM

That ight fix it. did you try again to see if you still had a high load...

keyboard failing will post later....

I replaced the bearings in the live tool and as mentioned before I re-aligned the turret top plate and now there are no problems. Thanks for the suggestions!

-emc

Fadal 4020, Hardinge Cobra 42, Miyano BNE51-SY, Haas EC400, SolidWorks CAD and Esprit CAM