How to Avoid Resin Prints Cracking: 8 Tips for Preventing Cracks

Many 3D printing enthusiasts are very interested in resin 3D printing, have their own desktop resin printers, and share the very interesting models they made. But there are often some troubles with prints, such as the quality of the model. Why are my resin prints cracking? This bothers a lot of people, as even successfully printed models can suddenly crack after a few months. What causes the 3D prints to crack? We will discuss the problem of cracking on the surface of the resin model, which involves the operation specifications of the steps of model slicing, resin use, and model post-processing. We will also give corresponding suggestions to avoid printing failure or cracking of resin prints.


Understanding Resin Prints Cracks: What Causes 3D Prints to Crack?

Resin is a substance that reacts to light and water molecule. Even after curing into a solid, ordinary resin cannot avoid being affected by the external environment., which may cause it to change. Therefore, proper post-processing is the method that can stabilize the model to the greatest extent and ensure the performance of the resin. Beginners of resin printing may try to wash and cure the printed model for the first time, and washing for too long may cause the model to crack. Some other common causes are: the wall thickness is too thin when slicing the model, or the exposure time is too short when printing. Below we conduct a more detailed analysis and a brief explanation about surface cracking.

Infill and drainage: FDM printing usually chooses the density of the internal filling, but for resin printing, extra attention is required. Full-density resin prints are prone to surface cracking, and too high a fill percentage can have the same problem. This is because the printing process, the interior may not be fully cured. Even after the printing is completed, there is still liquid resin inside, which will continuously generate and release heat, causing pressure inside the printed model, and eventually causing the printed product to crack. Having drainage on the model is a very effective solution. When printing large-scale hollowed-out models, in order to ensure the stability of the printed product, internal curing is even required.

Model slicing: Whether you use desktop LCD-based printer or DLP 3D printer, it involves very fine technology and high-precision printing process. Different 3D printers and materials usually have adapted printing parameters. During the slicing process, it is best to slice according to the best printing parameters, set the layer thickness, number of bottom layers, exposure time, etc., and then adjust according to the model. Hollow models require additional attention to the wall thickness of the print, which is also a cause of resin cracking. Generally, the recommended wall thickness is 1-1.5mm. If the wall thickness is too thin, it is more likely to cause cracking of the resin prints.


Post treatment: Curing and cleaning are both important steps after completing a resin print, and incorrect operation of this process can easily lead to cracking of resin printed parts. Some people said he soaked the print in the cleaning solution for ten minutes, ... that's too long! Prints may be penetrated by the solution, causing irreparable problems. At the same time, it is necessary to choose the correct solution when cleaning. Ethanol with a concentration of more than 95% is the choice of most people. During the cleaning process, it is necessary to ensure that the surface of the model is fully in contact with alcohol to avoid missing dead corners. In the model curing process, it is necessary to refer to the recommended curing time. Too short a time will not allow the model to cure adequately, while too long a curing time will make the model brittle and also prone to cracking of resin prints.

Highly efficient and safe operation is recommended: Anycubic Wash & Cure Plus Machine provides a powerful cleaning force that can fully clean the model without missing details; 360° automatic rotation curing platform that can stabilize the material properties of the resin.


Resin: Different resins have different properties, and the resin used is generally selected according to the need. Resin also behaves differently when it comes to model cracking. The water-washing resin requires additional attention to its hydrophilic nature. All types of resin have this characteristic, but water-washed resin is more susceptible to the influence of water vapor in the environment, it is less mechanical compared to other resins, and water molecules are more likely to damage the model. Of course, there are many advantages and conveniences to using washing resin. If you choose to use wash resin for printing, then proper post-processing is even more necessary. Applying a varnish to your prints after you’re done is also a way to reduce print cracking.

Anycubic UV Tough Resinwith higher toughness than standard resin, it can provide higher strength, good toughness, and certain crack resistance. Anycubic tough resin is able to ensure the accuracy of the 3D prints, it also can present a smooth and detailed surface, and has the advantage of low model shrinkage.


Preventing Resin Prints From Cracking: 8 Tips For Printing

  • The wall thickness of the print is set to at least 1-1.5 mm, which can be set according to the best parameters suggested by the resin and the printer.
  • For hollow prints, need to leave drainage holes.
  • When printing larger prints, it is best to hollow them out and leave drainage holes.
  • If high-density filling or solid is selected for printing, the curing time of each layer can be appropriately increased
  • During the cleaning process, the surface of the model may be damaged if it is immersed in the solution for too long. You should expose the surface of the print to alcohol as much as possible, 3-5 minutes is sufficient
  • During the curing process, take the correct curing time to avoid over-curing or under-curing
  • Store the resin correctly, avoid exposing the resin to sunlight or high temperature
  • If you are using washed resin for printing, it is best to keep the finished resin prints out of humid spaces

Resin Prints Repairs: How to Fix Cracked Resin Prints

It is a pity that the 3D printed parts have cracks. In order to avoid material waste or duplication of work, we can consider repairing these imperfect details. There are two types of repair materials that are usually recommended. Superglue is great for repairing small cracks and getting broken parts back together. The other material, epoxy, can also be used as an adhesive and is capable of replenishing larger gaps. Clean the cracks in the prints, then apply adhesive to repair and re-fix them. This is a common method that can fix some surface cracking. Of course, if you are looking for a more perfect work, referring to the cracking causes and suggestions in the above content can help you reprint resin prints with better quality.


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