Glass or aluminum heated bed?

#1
Looking to get the gmax 1.5xt with the heated bed. Can't decide if I should go with the glass bed or the aluminum bad. What one is going to be better?
 
#5
Aluminum is stupid. Its got high thermal expansion and conductivity. It bows. Its a massive heat sink (Takes a massive heater to heat up quickly). While Glass is flat. "BoroaFloat33" the way to go.

Now the real issue is Drive platen. Its Aluminum with big ass holes in it. Looking at that with FLIR camera. My god! Its a +30C higher temp at the holes shape. And, it's line for line pattern of the hole on the heat mat when thrown on top that drive platen. Aluminum is a terrible choice. Hell steel is far better as a drive platen than aluminum (1/4 of the effect). I like my choice. 1/4" Mid TEMP (534F. Work at 100-130C all day w/o issue) Carbon Fiber board with no holes (Thermal conductivity of 24. Where as aluminum was 438). Titanium Screws (For no heat corrosion). 120Vac Silicone Heater mat that is adhered to a PGS film that is adhered to the bottom of the Boroafloat33 glass. Ya!!!! Thermal dynamics. One way transfer of heat into that is spread into the glass. Rapid heat up. Low Heater cycling to keep it there. Reduced heater amp loads on you US wall sockets. And Easily controlled by a SSR and 5v from your controller card. Thus Marlin and software controls the heat profile as it listens to your thermistor on top the glass.