Need Help!- Fanuc 0iMC Buzzing sound - Machine adjustment

[Leha_Blin]

Hi all!

Does anyone know which parameters should be adjusted for Fanuc 0iMC with alpha-i motors when there is buzzing sound by Z (vertical) axis in VMC?
The sound appears when running the program after G1 movement when axis is in position (when G0 or manual move - everything is OK). It even appears when there is no actual movement (Z-axis is locked). So there is some "misunderstanding" between motor-driver-control. Could anyone help with it?

[Al_The_Man]

Is there any counter balance system in place for the Z?
If so it may need attention.
Al.

[Leha_Blin]

Yes, there is a counter balance - weight type. Basically we 've clamped this weight and machined moved witout it. We even locked the Z axis (by special button on Operator Panel) so that it did not move (but the Z coordinates on the screen were changing like it was normal work). But the result is the same.

[Al_The_Man]

The machine position display will move because it is the Anticipated, or where it Should be position, not the feedback from the encoder.
Al.

[zavateandu]

HI

try to check the volyage of the brake of the z axis motor.

i had once some like this and when i start was ok but after a few moves i saw that my 24v from brake it dissaper.

try also to go on monitoring system and check if is an unsual load of the z motor.

normal with weight should be around 15-20% if it is higher it means is something wrong on the movement.

also check the guides if have oil on it.
check also the coupling between the motor of the Z and the ballscrew if it is corect tighten.

give us more details about what u do and what is not normal.

GOOD LUCK!

g

[ben_heinman]

Does the noise go away or hear different pitches if you change the feed rate with the feedrate overide switch?

[Leha_Blin]

The problem seems to be solved - the Load Inertia Ratio (2021) was adjusted and 2107 (LDINT during cutting G1). And I noted that it effects the parameters in SV.TUN screen - the Velocity Gain.
Thanks to everybody!