Centroid Community CNC Support Forum

Hello, I'm getting Y idling too high: Releasing power, now and then. Mainly on the y sometimes on the X. I ran my first program today after retrofitting my Republic Lagun 310 three axis mill to allin1dc. Everything went great but when it was sitting while not running the program it would come up with the idling issue once in a while. It has Baldor servos. I set the Kp to 1.000, Ki to 0.004 and the Kd to 3.00 as recommended then let the software do the auto tune. Motors are not hunting at stand still and are making very little noise. Is this something I should worry about? I attached pictures of my motor tags and the latest report. Thanks for any help!

Probably nothing to worry about.

Where is the Y axis sitting when this happens? Middle of working space, or out near home?

You should set Parameter 143 = 3 (or 11) so you can see the servo axis load meters on the DRO display. Then you can see at a glance whether any axis is carrying excessive current (e.g. due to being parked in a sticky spot or up against a springy obstacle).

You should also run the drag test on each axis: F1/Setup -> F3/Config -> F4/PID -> F6/Drag. That will give you a graphic map of the motor load throughout axis travel.

Marc
Can we suppress the idling msg ? Or increase the value of load to do idling.
I have problem in the x axis of a lathe (vertical x axis)around 35% they did loose the power.
I want at least on 50% they do idling and loose power
Thanks

First make sure your Kv1 and Ka values are realistic.

Then use the drag test to verify there is not excessive drag or resistance in some parts of the axis travel.

Then, if you are 100% confident your customer is not going to leave the axis parked up against a springy obstacle and smoke the motor, you can increase the multiplier in Parameter 63 to prevent the warning.

Note that "... idling too high, releasing power" only happens when the machine is idle: not running a program cycle, and not actively jogging. Therefore it would be a pretty unusual situation for it to cause any real hardship for the operator. It is not a Fault condition that has to be reset. The axis just gets enabled again when you go to jog it or run a program cycle.

I did the drag test on both the X and the Y. Both said, Excessive axis drag. I can tell by the load meters now, that the Y is moving a bit harder than the X. Especially out towards the limit switches the meter is about half way across. More so in the Y+. On a side note, with my old Dynapath controller, the machine would reference/home at X-,Y-, and Z+. Now it homes at X-, Y+, and Z+. The machine rarely ever went as far as it does now on the Y+ and it seems it does idle too high more often just after homing. Here's the pictures of the graphs from X and Y. Would loosening the gibbs make it have less drag? Or do I leave it alone since it sounds like when it's releasing power, it is just protecting the motors? Thanks again for the help.

If this is something that just started, I'd first check that your way lube is operating correctly. Loosening the gibs will of course reduce the drag at the expense of accuracy and increased chatter.

You could, of course, change your cncm.hom file and your software travel limits to that it homes Y- instead of Y+.

the y axis drag graph shows classic tightening of the axis at the end of the travel.

typical causes.
on an old machine: the machine wears in the middle of travel over its lifetime of machining, at some point the gibs are adjusted to work in this area, but are now too tight near the end of travel. quick work arounds, move the home switch and give up some travel so machine never tries to operate near the tight end of the travel. also.. i have seen chips and old lube turn into a wax like ball of junk that is crammed up against and in the axis at the end of travel and/or the way covers are jamming up in similar manner once cleaned up the idle too high goes away.

if you see this on a new machine often the cause is the ballscrew support bearing mount is not in line with the movement of the axis. old machines can have this problem too, it just never was a problem until other effects compounded it like described above.

Alright guys, thanks. All sound like great things to check into. It is an older machine..1989, so I'm sure she's looser in the middle. I'll definitely move the limit switches in on the Y a bit since I never come close to using all the travel. She ran good today, I sure am liking the Centroid better than the old controller!