Lubricate / Oil locations ?

I’ve had my printer since December and use it most days. I noticed recently when it goes through it’s initial leveling procedure it has an unpleasant metal grating sound that things make when they need to be oiled. Can I use WD 40 on the printer? Where are the recommended spots? I did put a tiny drop on the z-axis bar which seemed to help but now the sound is back - somewhat intermittently. I know it needs to be oiled but I can’t figure out where and don’t want to damage the printer by accident.

I would not use WD40 on the printer, but the threaded rods are about the only thing that might need lithium grease on them. Most everything else is plastic bearings riding on steel rods which might need cleaned with IPA Alcohol every so often to remove dust and plastic that has stuck to them, and is causing noise like grating.

From the owners manual:

I was able to find the grease at Lowes.

4.3 Lead Screws
Periodically, you will want to wipe down the threaded rods with a lithiumbased
grease. Never use any petroleum based grease, which may compromise
the plastic parts. We utilize Lucas White Lithium Grease NLGI 2.
Apply the lithium grease both above and below the X ends on the lead
screws threading and wipe down the excess. Use your printer host software
to drive the Z axis up and down to help further distribute the lubricant.