3D prints shrink due to the its thermal properties while cooling. This puts a lot of stress on the print and with improper adhesion to the printbed it can detach partially or completely from it. There are many things you can do against warping.
Use an adhesive and/or heated bed
There are many types on the market like PrintaFix, glue stick, other wipe-on or spray-on adhesives or print surfaces like PEI, Buildtak or even unheated Bluetape.
It´s important to set the correct temperature of your heated bed for each material and adhesive.
For PrintaFix we recommend the following settings:
- PLA: first layer 210°C (410° Fahrenheit) no heated print surface
- ABS: first layer 235-245°C (455-473° Fahrenheit) with 5mm brim and a 100-105°C (212-221° Fahrenheit) heated bed.
- PET-G: first layer 225°C (437° Fahrenheit) and a 70-80°C (158-176° Fahrenheit) heated bed.
To adjust in your slicer, look at the picture below.
Adjust the first layer
You can also use your slicer’s settings to increase the extrusion width and height for the first layer only – this results in pumping out proportionally more material, which not only smooshes the plastic against the bed more extensively, but also makes the first layer more resistant to little adjustment errors – therefore, there is really no need to get the bed perfectly flat and bump-free down to the last 10µm.
Usually you take 120-140% of the layer height for the first layer.
Use a brim
A brim is a printed structure which is attached to your print and increases the surface area of the part to stabilize it or to increase the adhesion. Brims usually have 10-15 outlines and may be 1-2 layers tall.
Level the printbed
To level your printbed and to set the height of your nozzle properly, please follow the instruction of your 3D printer.
To set up the proper nozzle height or more accurately, set the correct zero position for the Z-axis helps reduce warping, getting rid of an elephant foot, but also helps to extrude the right amount at the first layer. Most 3D printers do not have a way of sensing when the nozzle touches your print surface, they just rely on an endstop or a separate sensor to probe the bed. For both cases, you usually need to manually set the zero position. The exact procedure differs from printer to printer, but the general idea is usually the same:
Make sure the nozzle is clean and ideally, heated up so that any boogers will get wiped away by the paper.
Use a thin piece of paper for stiffer beds (about 90g per m2 or 0.1mm thickness) and a thicker paper for springy beds (about 300g per m2 or 0.25mm thickness, e.g. a business card).
Adjust the endstop or sensor offset until you can feel a slight resistance from sliding the card around when the printer is at the zero position for the Z-axis. Most printers have a semi-automatic mode, by which the print head travels to several defined spots on the print surface and you must set up the nozzle height manually. If not, start in the centre of the bed for a first rough adjustment, make your way around the bed and repeat for each adjustment point. Move the print head as close as possible to the adjusters and tweak them until you get an even resistance with the calibration cards at each of them.
Calibration card (0.1mm or 0.25mm)
Use a enclosure
While the heated bed keeps the bottom layers of your part on temperature, it may struggle to keep the upper layers of the part from contracting once you start printing taller parts. In this situation, you may find it useful to place your printer inside of an enclosure that can help regulate the temperature of the entire build volume. Some machines may already include an external enclosure specifically for this reason.