My Lathe doesnt have any of those issues. thanks Lee
Isn't it awesome how many people can help diagnose and cure your problem? LOL
The other night our smoke alarms went off in the house. We'd had the windows open all night and it's fire season out here. Must have been a fire in the area...
My wife posted it on facebook and at least 10 people wrote long involved posts about how "when your smoke alarm beeps it's telling you it's time to replace the battery" and how "the little sensor can get plugged with dust" and how "you should replace your smoke alarms every year for just this reason" and how "we hire a technician to come through every year and test our smoke alarms, replacing as necessary."
DUDE!!! It was a smoky night! So smoky our alarms went off!
For you;
No you won't get weirdness from setting on concrete. It's the standard of the industry. If you're really good then you can cast four pc of 3/4 allthread for the four corners of your lathe (at least mine took four pcs, one on each corner) and then spin down a NUT, a large flat WASHER and set the lathe. Now another washe and nut and you've got your adjustments.
NOW, you can twist your lathe up like a pretzel if you don't shoot the 4 points before dropping the lathe on! Level the washers, set the lathe and then level the lathe on top. My lathe has small projecting 'feet' at the corners I can level off of or shoot with the transit, it's easy to level the base. And then move to the top and get 'er where you want 'er.....
BTW my Grizzly has NONE of these problems either

Just last nite I spun 'er up to 1400 with a barreled action Gordied in (muzzle brake) and got just a touch of hum.... barreled action with trigger still in was loping about .200 out of center in the outboard spinnle....
hth
al