Heat bed Study for Scalar XL – Test 3

image_pdfimage_print

In this solution we are studying the use of 2mm insulation cork sheet, placed below the heating element.

The setup

Setup details:

  • Heat beds: 2
  • Bed 1: MK1a (with the thermistor) powered by PSU N°1 (360W)
  • Bed 2: MK2B powered by PSU N°2 (300W)
  • Initial Temperature: 24°C
  • Target Temperature: 110°C
  • Print Surface: 2x3mm thick mirrors (20x20cm)
  • Insulator: 2mm cork sheet

The temperature profiles:

The red curve is the heating profile, when we apply the 110°C target.
The blue curve is the cooling profile, when the target temperature is set to 0°C.Here the power supplies are OFF.

At the bottom of each graph you have the time in seconds

On the left of the graphs you have the temperature in °C

Conclusion

While heating we have:

  • 60°C in 3 min 12 (192 sec)
  • 110°C in 17 min 29s (1049 sec)

We must wait 9 min 11 sec (551 sec) to cool down from 110°C to 60°C

Comparison from the previous test:

Compared to  test 2 It’s globally worth , we are waiting 42 secondes more to reach 60°C and 2 minutes 35 (155 sec) more to reach 110°C.

Comparison with the Initial test:

It’s a little bit better:
We reduced by 4% the heating time compared with test 1
We reduced by 12% (141 seconds the cooling time of the bed
We can see that the heatbed inertia is very similar to the initial test, and the overall heatbed performance is worth than the  test 2.
It seems that we need to heat up the cork insulator before the heating surface can increase it’s temperature.
However the cork can keep up the heat a little longer in the cooling phase.