NEW Printrbot Metal PLUS

[3DPBuser]

My understanding is that aluminum will slowly warp over time, and that's one of the big reasons for glass.

[LambdaFF]

My understanding is that aluminum will slowly warp over time, and that's one of the big reasons for glass.

I think it's mainly a cost reason : glass is cheap (compared to machined aluminium), easily procurable and you can get several plates to swap between prints.

Cheap glass cracks easily if your temp changes too swiftly though.

The advantage I see to aluminium is that being screwed the positioning accuracy (and repeatability) is much better if you don't remove it between prints.

Both glass and aluminium can have flatness issues if bought from low quality material / provider, that has nothing to do with the soundness of the technical solution.