How to drastically reduce your 3D printing energy bill
The average power consumed by a 3D printer varies from 120 to 300 watts per hour, mainly depending on the size of the heated bed. The remaining components, such as the motherboard, display, stepper motors, and fans, typically draw less than 50 watts per hour. The energy efficiency inherent in these components unfortunately leaves no room for improvement.
However, modifying the heated bed for greater efficiency has the potential to significantly reduce energy consumption. Here’s how you can reduce your 3D printer’s carbon footprint with a simple and inexpensive bed modification.
Why is your 3D printer terrible in terms of energy efficiency?
While 3D printing is undoubtedly sophisticated on a commercial level, consumer 3D printers are relatively simpler designs assembled with off-the-shelf components. Most of these components involve electronics and stepper motors that are inherently optimized for low power consumption. Nothing bad in that department.
Unfortunately, 3D printer beds are an entirely different matter. To save costs and reduce production complexity, almost all mainstream 3D printers lack thermal bed insulation. This is a bad idea because an uninsulated bed will radiate heat from the top as well as the lower surfaces. In other words, almost half of the radiated heat is wasted through the bottom of a heated bed.
The greater the amount of heat lost, the longer the bed heater must operate at the maximum power level to maintain the preset bed temperature. A typical 3D printer’s heated bed, such as the Creality Ender-3, draws over 250 watts of power at full tilt, so you should ideally insulate the bed to prevent the heater from firing often. Here’s how to do it the right way.
Thermally insulating a 3D printer bed consists of partially disassembling the printer to extract the bed. This isn’t a big concern because almost all consumer 3D printers come in knocked down kits full of user manuals and the tools needed to put everything together. The same tools can be reused for this purpose.
Choosing the right insulation material is our main concern. Heated beds in most consumer 3D printers are good up to 250°F. This is well below the ignition temperature of most materials, making most common insulation materials safe enough for our purpose.
However, such high temperatures still introduce problems with deformation, melting and gassing. Plastics such as acrylic and foam insulation materials will begin to deform at recommended bed temperatures for ABS printing. In fact, some foam materials can even emit potentially harmful gases. Check out our 3D printing food safety guide to learn more.
So the best materials are cork (rubberized cork also works) and silicone. Cork sheets are cheap and readily available, while being able to withstand temperatures well beyond what most consumer 3D printer beds can reach.
Silicone sheets are the better choice simply because of their significantly higher thermal threshold. Choose the option that fits your budget. What isn’t optional, however, are these tools:
- Appropriate cutting surface
- Utility knife or any other type of blade
- High Temperature RTV Silicone Sealant
- Punch tool or chisel
- Latex or nitrile rubber gloves (non-powdered)
Step 1: Delete the build platform
The exact steps will vary depending on the make and model of your 3D printer, but the process is much the same for Ender-3 or other variations of the Prusa i3 “bed-flinger” design. The first step is invariably to remove the build platform, also known as the printer bed.
Your 3D printer’s assembly manual will have detailed instructions, but it usually involves these steps:
- Power off the printer.
- Removing the power plug from the wall outlet.
- Disconnect the wires from the bed heater and the bed thermistor.
- Unscrew the bed adjustment knobs.
- And finally lift the bed from the 3D printer frame.
Keep the bed aside for now and move on to the next step.
Step 2: Cut insulation material to size
Lay your thermal insulation sheet on the cut surface and place the bed on top. Use a box cutter or an X-Acto knife to cut the sheet to the exact dimensions of the bed. A dull blade will make the task painfully slow and tedious, so be sure to use a fresh, sharp blade.
A thicker insulating layer retains heat better, but high density materials such as silicone add a considerable amount of weight. It is not advisable to go overboard with insulation thickness for printers such as Prusa i3 and Creality Ender-3 that use moving beds.
It is absolutely important that the thickness of the insulation sheet does not exceed the length of the box springs when compressed. For example, if your 20mm long bed springs are compressed to 10mm during adjustment, it is wiser to limit the insulation thickness to 6mm or less.
Step 3: Cut Holes for Bed Screws
Place the bed on the insulation sheet and mark the holes for the bed screws. You can either use a punch tool to cut out a circular hole of the appropriate diameter, or use a chisel and hammer to cut out neat squares.
Speaking of proper hole size, they should be large enough to accommodate the bed springs without touching or snagging them.
You can also resort to a box cutter or an X-Acto knife in a pinch, if you don’t have access to the aforementioned tools. However, the cuts will not be as clean or precise.
Step 4: Does your bed have a flat bottom?
The heated beds of virtually all 3D printers use PCB heaters. These beds tend to have flat bottoms. If this is the case with your 3D printer, you can skip this step.
However, those who have built their own DIY 3D printers, such as Voron (read more in our Voron beginner’s guide) or Rat Rig, have to deal with uneven bottom surfaces on their DIY beds, due to additional components such as thermal fuses, bed thermistors and wiring.
Using several thinner sheets of insulation with cutouts to accommodate these protruding components does the trick, followed by a final layer of insulation to cover the gaps.
Step 5: Prepare the Bed Surface
Before the insulating sheet can be glued to the underside of the bed, the contact surfaces must be thoroughly cleaned of oils and impurities for reliable adhesion. Warm distilled/filtered water and a drop of dish soap are sufficient to clean the bed, but isopropyl alcohol is a better choice.
We recommend wearing powder-free latex or nitrile rubber gloves, as your bare fingers and palms can leave oil and dirt on the cleaned surfaces. If you used water to clean the bed, be sure to wait at least 15-20 minutes for it to dry before proceeding to the next step.
The insulating material must also be cleaned. Avoid water if you have opted for a porous material, such as cork or foam, which can absorb or retain water. It is best to clean them with a brush to remove dust and contaminants. However, water resistant materials such as silicone can be cleaned with a cloth dampened with distilled/filtered water.
Once the surface of the bed is clean, you can optionally apply masking tape to prevent the silicone adhesive from migrating inside the perimeter.
Step 6: Glue it all together
Apply a thin but even layer of high temperature RTV silicone sealant to the underside of the bed. You can choose to apply the adhesive all over or just around the perimeter. The latter is perfectly fine because even if an air gap were to form in the center, this would only improve the thermal insulation.
Carefully align the heat insulation sheet and stick it on the bed. Silicone adhesive begins to harden immediately after exposure to air, but most formulations allow for 10-15 minutes to set. If you are using multiple sheets of insulation, repeat the process for all sheets.
Place some weight on the bed, while resting it on a flat surface where it can rest undisturbed. Most silicone adhesives take 24-48 hours to harden. However, it may take up to a week to achieve full adhesive strength depending on the formulation of the adhesive. Please refer to the manufacturer’s instructions for clarity. Ideally, avoid removing weight or disturbing the bed for at least two days.
Step 7: Reinstall the bed
With your bed properly insulated, you can now reassemble the bed screws and springs and reinstall the bed on the printer. Assembly is the reverse of the disassembly process you followed earlier.
Take advantage of energy savings
A well-insulated 3D printer bed not only heats up faster, but also significantly reduces energy consumption. This is most evident on longer prints, where heat loss tends to get worse over time.
The energy savings are even more pronounced on modern 3D printers that use the PWM (pulse width modulation) technique to control the power of the bed heater.
Why does upgrading to a direct-drive extruder often result in poor 3D print quality?
About the Author