OK, here you go. These are the settings I used to make this 40-ish mm sphere. This list has a setting for metric then an equivalent imperial in size and appearance.
Sphere 1 only has the max edge length setting changed to 3mm. It is 800k.
Sphere 1 only has the max edge length setting changed to .05in. It is 806k.
Totally appropriate size for the M2
Sphere 2 only has the max edge length setting changed to 1mm. It is 2.3 megs.
Sphere 2 only has the max edge length setting changed to .025in. It is 3.3 megs.
This size would be good if there were details and texture on this sphere.
Sphere 3 only has the max edge length setting changed to .5mm. It is 13 megs.
Sphere 3 has the max AND min edge length setting changed to .005in. It is 18megs. You have to change both since you can't drop the max below the min.
You are probably at overkill for the M2, unless it contained exceedingly detailed and specific measurements.
Notice how #2 is starting to look a bit dark, but is not blacked out like #3? That is a good looking mesh that will give you a lot of detail for printing, probably a hair more than you need for a filament printer. It is something you have to get a feel for. #3 might be the perfect setting for a resin printer though.
I learned about these basic settings from tutorials at
http://www.infiniteskills.com/training/ ... ino-5.html You really need to sign up for a month and watch them all. Top notch vids!
Depending on your object, you may want to have the "Simple Planes" box picked. It builds planar surfaces with the minimal number of triangles it can, regardless of your settings.