Projects

Printable lens caps

Summary

This is a design for a 3D printable cap for camera lenses. It is easy to print and lightweight. In this page there is information about how it was designed and made and there are also STL files for most of the common lens diameters.

Design

This design was made using Fusion360. Other commercial lens caps were measured and used as reference. Every geometry in the design was parametrized according to the lens diameter. That way, by changing only one parameter in Fusion360, lens caps of every diameter can be produced from the same assembly. The next images show lens caps that were produced by changing that one parameter:

The design was originally intended to be printed in place. Although the cap was successfully printed in place with the clips able to move freely in their track, there was one problem. There was no tension on the spring when the clips were in their furthest position from the center. This resulted in them not grabbing onto the lens firmly. In the final design, the clips and cover parts are to be printed separately. The clips are designed to have a natural position that is wider and should be compressed to fit in the cap part. That solves the tension problem and results in them having a good grip onto the lens.

The two parts are held together by the use of a dovetail geometry. In order to be assembled, the cap part should be bent so that its cavity opens up a bit. Afterwards, the clips can be fitted inside.

The thin cord linking the two clips acts like a spring, pushing the two of them apart.

3D printing

After 3D printing the lens cap parts, cleaning the parts' surfaces with some sanding and trimming corner imperfections with a knife will greatly help the parts perform and move as intended. Most 3D printers will not produce a result as detailed as this design requires to function.

Some actions that might help the prints perform better is making sure that the last layers direction is parallel to the movement of the mechanism:

The parts should be positioned as shown bellow for 3D printing.

When printing, 0.2mm layer height should be used. The STLs for most standard lens sizes can be downloaded bellow:

The only caps that were printed and tested were the 49mm and 52mm ones. If there are problems with other caps feel free to contact me via the site's contact form. You can also contact me if you need a special size lens cap - I will be happy to produce it for you.