Chapter 4 – Heated Bed
Heater plates in the size 100x100mm are unfortunately not available in as many versions as their big brothers on the market. Due to the overall budget, we absolutely wanted to do without an expensive custom heating bed. Therefore a ready-to-use heated bed with 100x100x2mm is used which is actually designed for 12V operation.
In 24V operation the heating time is extremely short. In a test we reached a temperature increase from 40°C to 100°C in 29 seconds. The power consumption is then approx. 130W.
However, such a short heating up time leads to violent, no longer controllable overshoots.
The high power also fully exhausts the power supply. A limitation of the maximum power by means of fast PWM or PDM is therefore absolutely necessary.
Of course, it is not possible to print on the bare aluminium of the heating bed, so there are 2 variants to choose from:
Variant 1 – direct glued coating
Due to the excellent experience with Pertinax (FR2) in the P3 Steel, a Pertinax coating is again applied to the heated bed of the Tantillus. As usual, this is applied over the entire surface with 3M 468MP transfer adhesive.
Alternatively, instead of the glued Pertinax plate, any other functional coating can of course also be glued on. A nice possibility is also to use a magnetic quick-change system. More information is available below
Pertinax has a good insulating effect and warps slightly when heated. In order to achieve as little bimetal effect as possible and a good homogeneous heating, the Pertinax plate is only 0.5 mm thick.
Further information on the production of a Pertinax coated heating bed can be found here.
Elastic elements are required to level the heating bed. In the past, springs were used for this purpose. However, pressure beds mounted in springs often have to be leveled again. Furthermore, the heat dissipation into the pressure bed carrier is higher.
Shock absorbers cast from high-temperature-resistant silicone have meanwhile established themselves as an alternative. Structures equipped with these dampers remain levelled for considerably longer, in some cases for more than 1 year. Heat dissipation is also significantly lower.
Further information about the silicone dampers can be found here.
- pour the silicone shock absorber into the mould and allow to harden for 12-24 hours. You can find more information in the category silicone parts.
- cut the Pertinax plate to size
- degrease the back of the Pertinax plate with alcohol and apply the transfer adhesive over the entire surface
- degrease heating plate
- glue the Pertinax plate to the heating plate
- use a countersink to countersink the fixing holes to match the M3 fixing screws
- cover the hole for the thermistor with a strip of Kapton tape and make a cross-shaped cut in the adhesive tape (short-circuit protection)
- insert the thermistor into the hole and fix it with Kapton tape or JBWeld adhesive
- solder supply lines for heating bed supply voltage
- grind down the Pertinax plate as required
- fasten fastening screws to the heating plate with nuts
- slide the silicone dampers and washers onto the fixing screws.
Variant 2 – magnetic quick-change heated bed
Instead of gluing e.g. a Pertinax plate, PEI or similar directly onto the heated bed, a magnetic foil can also be glued on. The Pertinax plate is then glued to a 0.5 mm thick spring steel sheet (material: 1.4310).
At the end of printing, the spring steel sheet can simply be removed together with the printed part.
With large printers with slow heating beds, this technology can save a lot of time and energy, since a new print can be immediately started on another laminated spring steel sheet. However, the heated bed of the Tantillus is so dynamic that the advantage is virtually eliminated.
Another advantage is that it is easy to change the pressure bed coating. Due to the magnet system, PEI based films, Pertinax, FR4,… can be changed.
The magnetic foil must be temperature-resistant. Almost all foils available on the market demagnetize after prolonged exposure to heat >75°C.
The only film on the market that can permanently withstand even the highest heating bed temperatures is Graviflex 200 magnetic film from the company Schallenkammer. All commercial suppliers of magnetic exchange systems use this film, which is the only one available on the market that meets the required specifications.
You can take almost anything that is magnetic. However, it makes sense to use a spring steel sheet. This can also be bent slightly to remove a strongly sticking pressure without getting a permanent deformation as a reward.
Ferrofoil was also used for a while. However, this is very expensive and not dimensionally stable, therefore not recommended.
- Chapter 0 – Introduction
- Chapter 1 – Housing
- Chapter 2 – Z axis
- Chapter 3 – XY axis system
- Chapter 4 – Heated Bed
- Chapter 5 – Cooling
- Chapter 6 – Extruder
- Chapter 7 – Hotend
- Chapter 8 – Electronics
- Chapter 9 – Spool roller
- Chapter 10 – Silicone parts
- Chapter 11 – Option: Belt drive cover
- Chapter 12 – Option: Rasberry Pi Zero
- Chapter 13 – Option: UPS for the pi
- Chapter 14 – BOM / Downloads
- Chapter 15 – FAQ
- Chapter 16 – Samples
- Chapter 17 – Concluding remarks