The Delta "M" Series inverter is more modern and more advanced than the "S" Series inverters on Powermatics, Jets, and Lagunas. The "M" series does put off a little high pitched noise, [some call it "chirping" ]which seems to be mostly when the lathe is new. My G0766 was one of the first two or three shipped when the model first became available, and numerous others also noticed theirs made the same sound, so it is pretty much normal for this lathe, and my G0766 seems to have gotten quieter as the lathe was used over the months/years, and I hardly can hear that sound without putting my ear to the inverter box housing. I would not worry in the least, and you should just use the lathe and enjoy its fine performance. Seems new owners can be overly sensitive to the least little thing.
That being said, I recommend doing what I did before I ever put power to my G0766 for the first time. I went through the lathe, tightened every set screw, bolt, etc, and completely checked that everything was tight, and in its place. I learned that shipping across the oceans on a container ship induces a lot of vibration, and things can work themselves loose, and who knows if the factory workers took as much care as they should when they crated everything? A little problem seems to induce paranoia, and much apprehension.......everyone should go through their unit and carefully inspect and tighten every component. My G0766 has performed superbly since I got it in 2015.
Last edited by Roger Chandler; 04-01-2021 at 5:27 PM.
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