Archives de catégorie : Lit chauffant

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Heat bed Study for Scalar XL – Test 2

In this solution we are changing the insulator under both heat beds.
Before the insulator was a 2mm thick aluminum like sheet covered by kapton tape.
Here we are using the same material without the kapton tape.

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: 21°C
  • Target temperature: 110°C
  • Print surface: 2 x 3mm thick mirrors 20x20cm
  • Insulator: Thermal aluminum like insulator 2mm thick

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 2min 30 (150 sec)
  • 110°C in 14 min 54s (894 sec)

We must wait 8 min 21sec (501 sec) to cool down from 110°C to 60°C

Compared to test 1, it’s  50 seconds faster to reach 60°C 4 minutes 29 faster (269 sec) to reach 110°C.

We also reduce by 25% the heating time compared from Test 1

We reduce by 4% (20 seconds) the time needed to cool down the heat bed.

We can see that the heat bed inertia is smaller before we need less time to heat and less time to cool down.

Heat bed Study for Scalar XL – Test 1

Into this initial solution, we are using existing solutions with 2 standard 12V heat beds and 1 power supply for each heat bed.

The heat beds are driven using DC static relays.

The setup

Setup details:

  • Heat beds: 2
  • Bed 1: MK1a (the thermistor is under this one) powered by PSU N°1 (360W)
  • Bed 2: MK2B powered by PSU N°2 (300W)
  • Initial Temperature: 19°C
  • Target Temperature: 110°C
  • Bed print surface: 2 x 3mm thick mirrors 20x20cm
  • Insulation: silver 2mm thick insulator covered by Kapton tape

Temperature curves:

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 3min 20 (200 sec)
  • 110°C in 19 min 50s (1190 sec)

We must wait 8 min 41sec to cool down from 110°C to 60°C

Even if it’s seems a long time before we reach the 110°C (about 20 minutes), the time we need to reach 60°C is more reasonable.

This test is the reference test that we will use to compare the results of the others tests later on.