How do you account for shrinkage and warping when 3D printing a prototype?

1 Choose the right material

The first step to prevent shrinkage and warping is to choose the right material for your 3D printing project. Different materials have different thermal properties, such as melting point, heat capacity, and thermal expansion coefficient, that affect how much they shrink or warp when cooled. For example, ABS (acrylonitrile butadiene styrene) is a common 3D printing material that has a high shrinkage rate and tendency to warp, while PLA (polylactic acid) is a biodegradable material that has a lower shrinkage rate and less warping. You should also consider the compatibility of the material with your 3D printer, the cost, the durability, and the environmental impact of your choice.

2 Adjust the print settings

The second step to account for shrinkage and warping is to adjust the print settings of your 3D printer according to the material and the design of your prototype. Some of the print settings that can affect shrinkage and warping are the nozzle temperature, the bed temperature, the print speed, the layer height, the infill density, and the cooling fan speed. Generally, you want to use a high nozzle temperature and a low bed temperature to reduce the temperature difference between the layers and avoid thermal stress. You also want to use a slow print speed and a low layer height to improve the adhesion between the layers and reduce the risk of cracking. Additionally, you want to use a high infill density and a low cooling fan speed to increase the strength and stability of your model.

3 Use a brim or a raft

The third step to account for shrinkage and warping is to use a brim or a raft as an extra support for your prototype. A brim is a thin layer of material that extends from the edges of your model and attaches to the bed, creating a larger surface area and improving the grip of your model. A raft is a thicker layer of material that covers the entire base of your model and acts as a buffer between your model and the bed, reducing the thermal stress and the warping. Both a brim and a raft can be easily removed after printing, but they may leave some marks or residues on your model.

4 Use supports and orientation

The fourth step to account for shrinkage and warping is to use supports and orientation to optimize the geometry and the stability of your prototype. Supports are additional structures that help hold up overhanging parts or bridges of your model that may otherwise sag or collapse due to gravity or insufficient cooling. Orientation is the angle or direction of your model on the bed, which can affect the amount of supports needed, the surface quality, and the strength of your model. You should use supports and orientation to minimize the overhangs and the bridges, to avoid large flat surfaces that may warp, and to align the layers with the main stress direction of your model.

5 Use post-processing techniques

The fifth step to account for shrinkage and warping is to use post-processing techniques to refine and improve the appearance and the performance of your prototype. Post-processing techniques are methods that you can apply to your model after printing, such as sanding, polishing, painting, gluing, or annealing. Sanding and polishing can help smooth out the rough edges, the marks, or the residues left by the brim, the raft, or the supports. Painting and gluing can help cover up the cracks, the gaps, or the deformations caused by shrinkage and warping. Annealing is a process of heating and cooling your model in a controlled way to reduce the internal stress and the shrinkage and warping.

6 Test and iterate

The sixth and final step to account for shrinkage and warping is to test and iterate your prototype until you achieve the desired results. Testing and iterating your prototype means that you measure, evaluate, and compare your prototype with your original design, and make adjustments or modifications accordingly. You can use tools such as calipers, rulers, scales, or software to measure the dimensions, the weight, or the features of your prototype. You can also use methods such as stress testing, functional testing, or user testing to evaluate the performance, the functionality, or the usability of your prototype. By testing and iterating your prototype, you can identify and correct the errors or the issues caused by shrinkage and warping, and improve the quality and the accuracy of your 3D printing project.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?