Projector lens and mirror

How do the projector lens and mirror affect my print results?

The projector lens and mirror are essential components for the success of any DLP-based 3D printer. Their task is to project the UV light precisely onto the material tank in order to cure the liquid resin layer by layer. But what happens when dust or dirt builds up on these components? In this article, you will learn how impurities affect your printing results and how you can prevent these problems.

In DLP printers, the projector lens or mirror ensures that the light hits the resin exactly where it is needed to cure the planned layer of the object. A clean lens and a clean mirror are therefore crucial for the accuracy and sharpness of the printed products. Even the smallest amount of dirt can cause stray light and significantly impair the print quality.

How does soiling occur?

No 3D printer is designed in such a way that its housing completely keeps out dust. Dust will accumulate on the lens or mirror over time, even if the printer is placed in a clean environment. It is even worse if the printer is placed in a dusty or poorly ventilated location. Despite all precautions, such as covering the device, it is inevitable that dust and dirt will accumulate.

What are the effects of dirt?

Dust and dirt block the light that is necessary for the curing process of the resin. This leads to various problems.

Blurring: Even minor impurities can impair the sharpness of the projected image, causing the details of the object to become blurred. This impairs the realisation of print details.
Unclean surfaces / irregular layers: Dust or other dirt on the lens or mirror creates scattered light, which leads to unwanted exposures. As a result, the surface quality suffers.
Misprints: In the case of pronounced soiling, the light is blocked to such an extent that complete misprints occur.

How do I recognise soiling?

Regular inspection of the lens and mirror is crucial to prevent printing problems. Use the torch function on your smartphone to identify dust or dirt particles on the lens or mirror. Printers such as those from Rapidshape also offer the "Measure Straylight" function, where the light sensor included in the scope of delivery can be used to detect dirt using the light scattering wheel. How do I clean the lens or mirror? Cleaning these sensitive components requires care.

Here is a step-by-step guide:

1. remove the protective glass plate Firstly, carefully remove the protective glass plate that lies over the lens. Wear gloves to avoid fingerprints.
2. gentle cleaning Use a clean glasses cleaning cloth to remove dust or dirt from the lens or mirror. For heavier soiling, a little glass cleaner can be sprayed onto the cloth. However, avoid using too much liquid.
3. check After cleaning, you should check the lens or mirror again with a torch to ensure that no residue remains.

Conclusion: Small changes, big impact

The projector lens and the mirror of your 3D printer are of crucial importance for the print quality. Even the slightest impurities can interfere with the light projection and lead to poorer print results.

By regularly cleaning and carefully checking these components, you can ensure that your prints always achieve the desired quality.

Matthias Mohr