Typically, you cannot print materials such as ABS (Acrylonitrile Butadiene Styrene) or ASA (Acrylonitrile Styrene Acrylate) on a non-enclosed 3D printer. This is because they have high thermal contraction rates. This means that as the extruded material cools it contacts and shrinks. This can cause issues such as warping, poor layer adhesion or complete print failures due to poor bed adhesion. These issues can be exacerbated by drafts as these can cause uneven and accelerated cooling of each layer.
Fully enclosed 3D printers avoid these issues by using an active chamber heater or a passively heated chamber. In this second case, the chamber is heated by the heat radiated from the print bed and toolhead. Ideally the chamber is 40-60 degrees Celsius. This slows down the rate of cooling significantly thereby increasing layer adhesion as interlayer bonding is increased. This also decreases warping as the part is given the time to slowly and more importantly evenly cool reducing the negative affects of the high thermal contraction rate. The final way a heated chamber benefits printing these materials is that it blocks drafts. Drafts can cause uneven cooling as they are not consistent and accelerate the cooling rate, the enclosure completely blocks all external drafts leaving only the controlled internal cooling fans.
Here are my recommendations for printing high thermal contraction materials on a non-enclosed 3D printer:
- Apply an even layer of glue to promote build plate adhesion.
- Turn up the bed temperature to increase build plate adhesion further.
- Try to stick to smaller parts as this minimises any effect uneven cooling may have.
- Turn the part cooling fans to a very low speed or completely off to reduce drafts.
- Keep the 3D printer away from areas with high drafts, such as doorways or windows. Ideally, put the printer in a room or closet and leave it.
- Print slowly. This gives the part the time it needs to properly and slowly cool.
- Use a slightly higher nozzle printing temperature to increase layer adhesion and reduce thermal shock. This when the hot material hits the cold surrounding air causing it to rapidly contract and immediate internal stress to build.
WRITTEN BY OLIVER ROTHNER
Award-winning product designer and engineer.
Currently working as Project Manager at Pro2Pro whilst obtaining further qualifications.