15/10/2024
Tips for Advanced Filaments
By advanced materials we're generally referring to materials with a glass transition temperature higher than 70 degrees (ABS, PC, PA, PP, POM, etc).
Cooling:
One of the most important factors is slowing the cooling rate of the material as much as possible: no aux fan and set the part cooling fan to the lowest tolerable for a high-quality print. Slowing the cooling allows for more heat to conduct to layers below that currently printing, forming a better bond and also allowing the polymer chains which formula these thermoplastics to slide past each other. This sliding allows stress to be released, relaxing the force the print will apply to the bed when trying to warp.
Nozzle Size:
Similar to cooling, a larger nozzle extrudes a larger body of plastic, which carries more heat for the layers below, helping to relieve stress. If you can manage the quality of a 0.6 or 0.8mm nozzle, it'll improve your printing performance.
Chamber temperature:
The less the material has to cool down in general, the better. The higher the temperature, the more the polymer chains can slide past each other and release the stress caused by thermal contraction. Also, a higher chamber temperature means less cooling and therefore less thermal contraction on the whole. Preheat the chamber, run high bed temps and get those numbers up.
Go Slow:
Slower printing allows for more heat to pass into lower layers of the print, allowing for some stress relief as the molecular chains of the material can slide past one another.
Stress relief pause:
This one is theoretically possible, but we've never tried it in practice and would likely work better for materials with a medium-high glass transition temp (PETG, ABS, etc). It would include pausing the print after a certain number of layers are printed and allowing it to sit for a period of time, say 30 minutes (the longer the better). This would theoretically allow for the material to relax and take pressure off the bed. A couple of things to note with this, it could cause a layer line and also weaker layer adhesion at this layer since the material is allowed to cool to the chamber temperature.
Adhesion:
Don't be afraid of glue, it can be your friend. The more force the built plate can provide to resist warping, the better. If you find the print begins peeling the magnetic build plate from its seat, congratulations! You've successful beaten the magnets and now need to clip your bed down...
