Glass bed?

Would you ever just trust in the glass being close enough to the same thicknesses or would you only swap glass with a levelling sensor capable machine?

Sorry for the hijack François, hopefully this chatter is valuable info or you too.

You don’t really want to trust anything you change to the bed surface, it’s not only the thickness but also the flatness, and bilinear leveling accounts also for this. Even if you just move your bed a little bit or put your clamps in a different spot then there is a chance something will be slightly off. Probably not enough to completely mess your print, but you might end up with slight warping or elephant foot in some places. I prefer to run a bed leveling every time, it takes around one minute but it saves a lot of headaches.

I guess you can swap plates successfully even without a bed leveling sensor, but seriously I recommend you to take a bit of your time to add one if you didn’t already, it’s in my opinion one of the most important option if you want your printer to work reliably and with consistent results. With a bed sensor you’re almost guaranteed to have a perfect first layer every time.

On my printers that use glass, I just swap out the plate and just set the baby stepping for the first layer, since my glass printers don’t have bed level sensor, usually goes close enough. If you have a bl touch or something, it’s quick enough.