Those who enjoy using vintage lenses will often acquire them in fine working order, but without lens caps. There are some creators who have made instructions to 3D print new ones, but they all have fatal flaw.
The benefit of using 3D printing to make lens caps is customization. Any size can be made and each can be custom engraved with either a photography company brand or to make it easier to distinguish the focal length and aperture of a lens without removing it from a bag. Generally speaking, 3D printing caps is also going to be cheaper than trying to hunt down a specific missing cap from a vintage lens as well.
Hack a Day spotted a handy tutorial made by DSLR CNC DIY that tackles a common problem with 3D printed lens caps. As great as it has been to use designs for 3D printed lens caps from other creators, DSLR CNC DIY found that they all have the same problem: they wear out quickly from use. The issue is in how the caps are printed. New lens caps made by lens manufacturers aren’t just a single material — either plastic or metal — but instead, use a main body material that is given the tension they need to stay affixed to the front of lenses by springs.
Prior to DSLR CNC DIY’s design, the designs that were commonly found online attempted to recreate the usability of standard lens caps without needing to add a spring, likely because finding one capable of doing the job is not particularly easy for everyone who might want to make the caps at home.
To get around this problem, DSLR CNC DIY created an entirely new design that integrates one-half of a common N1 (19mm or 3/4 inch) binder clip in order to provide the necessary tension. The result, he claims, is a lens cap that not only has the benefits of customization that comes with 3D printing custom caps, but also will not wear out over time.
The 3D printing designs are available for free and contain the plans for lens caps of 49mm, 52mm, 55mm, 58mm, 62mm, 67mm, 72mm, 77mm, and 82mm lenses as well as the designs for an EF-mount rear lens cap.
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