I believe a bearings are fixing to go south..
https://www.routerforums.com/395455-post25.html
https://www.routerforums.com/1266810-post3.html
https://www.routerforums.com/395455-post25.html
https://www.routerforums.com/1266810-post3.html
I’m in the same boat . Purchased two 7512’s also , motor only . I have a 690 that’s been great,but probably not a lot of hours on it .Thanks for the replies gentlemen!
I have a brand new 7512 motor on the shelf that was slated to be set up on a second router (Kreg mobile platform) router table. I pulled the new one down a couple of days ago and plugged it in to compare the sound of both motors. My cabinet saw top mounted 7512 definitely sounds different ... and likely the shaft bearing(s) "going south" as Stick indicates. Probably a mistake to have invested in a second PC motor, but it's a done deal.
Its sad PC puts out such low level quality today and apparently takes advantage of yesteryear's reputation to keep selling older models. I will say that I have had two older 690's with no problems...and use them regularly for site work and along with the PC hinge butt door hanging template (template originally made by Rockwell, but bought out by PC, I believe). The 690 has proven to be a good size and weight for door work.
Based on Phil's input, I will see about about tearing my older 7512 motor apart and get better bearings-- once I get the 2nd table up and running. Sounds doable. Thanks Phil!