Heat bed Study for Scalar XL – Test 8

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In this test we are going to study how the system behaves when removing all insulators such as many reprap machines.

The goal here is to show if the insulation has a real impact on the heat bed performances.

The setup

Very similar to the previous setup, we remove the 2 insulating layers

From top to bottom:

  • Aluminum sheet
  • 2 heating plates
  • Wood plate

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: 21°C
  • Target Temperature: 110°C
  • Print Surface: 1x 3mm aluminum plate (435x320mm)
  • Insulator: none

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 5 min 07 (307 sec)
  • 94°C in 30 min 45s (1845 sec)

The whole system can barely reach 94°C max!

And we must wait 6 min 10 sec (370 sec) to cool down from 94°C to 60°C

Comparison with previous test:

Compared with test 7 the differences are very different:

  • the max temperature we can reach is 94°C! so 6°C less for a total duration of 30 minutes max
  • The heating time increases by 23% to reach 60°C
  • The heating time increases by 47% to reach 94°C MAX!
  1. This test shows how important the insulation is for a heatbed. Insulation allows to get extra 6°C on max temperature for the same heating period.
  2. Also, as we could have guessed, we have a performance decrase by 23% to 47% related to the lack of insulation below the heat element.