UM2 Build plate can "slide" or rotate

[Lemma 0]

Hello UM Community,

I recently printed a 30+ hour robot chasis and noticed that the top layers were ajar from the bottom by what seemed like a few degrees. I really scratched my head on this one until I realized the part had to have slid relative to the print-head for this to happen. Since I know this part had great bed adhesion, I knew the build plate had to have slipped.

So I checked, and sure enough I can twist the glass plate in place when clamped down.

Is this normal? How can it be prevented? Thanks.

[ahoeben 2,016]

I would start by removing the glass and bend the clips down a bit. You could try some gluestick on the bottom of the glass (in the corners?) to get more friction.