Thicker Boro-Silicate glass is almost non-existent in the UK. I found a single source but the price they wanted for a 300 x 300 piece left me in shock. Consequently, I am going to stick with my original plan of standard aluminium plate (what is the perceived advantage of MIC-6?).
I've been thinking about why an aluminium sheet should warp and the only reasons I can think of are:
- The sheet is too heavily constrained i.e. the fixings don't allow expansion
- The heating is uneven
- Uneven expansion is caused by the part being printed insulating one area of the plate
You can't do much about the last item. Silicon heating pads should prevent item 2 but I can see how people that use power resistors bolted to the plate would have problems. The first item can be relatively easily designed out by using oversized holes or slots for some of the fixing points.