[shakoori]

Hello
Have a good day

I have a center milling machine okuma mc4va with yaskawa spindle drive and motor. It had faulty driver so we repaired that after the repair some abnormal sound come from machine gearbox ( unstable speed ) Machine has gearbox with 2 level : 0 to 998 RPM and 1000 to 4000 RPM.
The problem is exactly start from 1000 to 1900 rpm after and before of that there isn't any problem. Please help me

[Algirdas]

check where exactly sound comes out. Is it spindle bearings or gears. check if spindle agregates heat at the spindle nose ( final bearing health ).

[shakoori]

The gear sound come. it is exactly start at 1000 and end at 2000

[shakoori]

It doesn't have bearing problem because it turn with out any problems with hand

[Algirdas]

open the gear box and clean it. Maybe some damage there, maybe lubrication system fault

[joeavaerage]

Hi,
always cheapest and easiest to fix BEFORE it breaks, if you wait until it really craps out it will cost you a fortune.

Craig

[shakoori]

I have looked in the gearbox there isn't any problem bearing are ok and also the gears.

[Algirdas]

I would advice to sell the machine as soon as possible ...