I am looking for some ideas, I am mounting an OV9281 camera sensor with an M12 lens in a waterproof box. I have designed a mount with snap-fit joints for the camera to fit too. This works successfully at one particular focus range but when I refocus the lens the height of the camera changes and it doesn’t fit in the box. I was hoping someone might have some ideas for a solution that will allow the camera to move up and down in relation to the lid when the camera is refocused and the box closed. I’ve thought of:

  • flexible tabs on the camera mount (I am using nylon currently and it seems there might be issues with creep?)
  • steel springs (hard to build into the model but should work)
  • Rubber washers (easy to build into the model but wouldn’t allow a lot of compression)

Does anyone have any other ideas?

  • $\begingroup$ It would help if we could see what the "waterproof box" looks like. $\endgroup$
    – agarza
    Sep 10 at 22:34
  • $\begingroup$ It’s a standard electronics enclosure if that helps? $\endgroup$ Sep 14 at 14:32

2 Answers 2


Printed planar 3D springs aren't that difficult to design for print and should work sufficiently well in your case - essentially make two frames, one within the other, "suspended on a labyrinth" - a snaking thread of material that provides a lot of flex. Add more loops for more flexibility, or stack a couple such frames to provide more yield.

enter image description here

  • $\begingroup$ This is a great idea, do you know if these frames suffer from creep if compressed for long times or does the amount of material in the planar spring negate this? Thanks again, this looks like a solid solution $\endgroup$ Sep 14 at 14:31
  • 1
    $\begingroup$ @tenniscelebrationparty I'm quite sure this is material-dependent and I have no idea how it depends on which material. I expect it can last at least a couple years and then you can print replacements. $\endgroup$
    – SF.
    Sep 14 at 15:05

spring actuated slider mounted

Your problem is basically, that the camera will stick out of the allowable space in some configurations. Such is usually due to the mounting point of the camera holder forcing a position of the components in relation to the backend of the camera.

This can be solved by mounting the components on some kind of sliding gantry and actuating it upwards with a spring. This will automatically align the camera position to the most lipside place the camera standout allows by pressing the lens protector against the lid. For adjustability of the spring pressure, absolute top position and easy swapping of springs (if needed), a grub screw could be used to adjust the position of the holder to the spring's maximum length - green in the image. By choosing a proper spring and having it at or even in the gantry, you can use somewhat standard parts, like the springs from pens, and don't need to work in as much space under the camera but instead can use the more likely more ample space outside of the camera's moving box. Also, the gantry base plate could mount all other components.

For maximum constrained movement and least strain on the parts, it would be advisable to use a pair of guide rails on two opposing sides of the camera plate, and place the springs either on the center of the gantry or use a pair on either side of it.

Dovetail Gantry with one compression spring

This can be simplified with the sensor chosen by mounting the whole board on small spring standoffs that allow them to be compressed by the maximum difference, but such a setup might tilt the camera if no guiding is included. That could be facilitated by adding an extension plate bottom or top of the sensor which constrains the tilt of the sensor board. It might be required to shorten springs quite a lot for this.

Simplified: Springs as Standoff

mounting point on the camera

Currently, you explain to us, that you hold the camera on the mounting plate of the optical sensor. However, you also could mount the camera by the lens holder. As an Upside, the camera will always be at the same position relative to the lid. As a downside, you will need to account for the whole board of the optical sensor to lift with the lid and if you fix the barrel even to turn the whole board of the optical sensor to adjust focus length. Both in turn will move the whole cabling too - you might need to unplug and re-plug it for some adjustments. Also, adding or removing filters will be more complicated.

A mounting on the Camera lens' barrel


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