Wyze Cam 3 Close Focus Lens System for Remote Monitoring 3D Printers (or Even Bird Houses)

Wyze Cam 3 Close Focus Lens System

https://www.thingiverse.com/thing:5264800

A few months ago, I bought three Wyze Cam 3 cameras, 2 for use as security cameras and the third one I wanted to install in my small workshop to keep tabs on my 3D printer if I go upstairs while it’s printing. I have been quite impressed with the Cam 3 with its high definition video and other cool features (my wife and kids love calling our cat Milo from a restaurant and make him look around, looking for where our voices are coming from. And no, this is not animal cruelty, he just ignores us and goes back to sleep).

However, I knew even before I tried, that it probably was going to have trouble focusing at a much closer distance (say 8 to 10 inches) from the side of my 300x300x300 CoreXY 3D printer to the center of the print bed. After all, they are made to be security cameras that focus on objects maybe at least tens of feet away. Indeed, after doing a Google, there were quite a few people who wanted the Cam 3 to focus at a closer distance. Some even wanted to use a Cam 3 to watch nesting birds in a birdhouse. This probably a worse case scenario, as most birdhouses are not exactly spacious mansions.

I found a Youtube video (https://www.youtube.com/watch?v=kkKAMMNlaf4) where the person dismantled his Cam 3, and after breaking free the lens by removing the glue that holds the lens’s focus so he could turn it further out, he was able to have his Cam 3 focus much closer. However, if at all possible, I wanted to find an alternate, less nerve-wracking method.

Because I was an amateur photographer for many years (remember 35mm?), I brainstormed the idea of using lenses in front of the Cam 3 to help it focus closer. My specialty was nature macro photography with a Pentax with lots of macro photography attachments, including a bellows adapter. And so, my thoughts immediately went to the head magnifier I use for close inspection when I do small parts for projects (it also helps me look like an authentic Nerd/Geek. At my age, people don’t see me as Geek – I need all the help I can get!). So, in effect, I was trying to put a macro lens on a wide angle lens. In ther end, I was quite pleased with the results.

I bought my head magnifier from a local electronics store: (https://www.mastervox.com/en/outils/equipement-datelier/loupe/mg9040c-loupe-frontale) for CA$9.99. The actual head magnifier itself is of really cheap quality. To make it usable at all, I had to make a head strap over the top of my head out of Velco strip so it wouldn’t slide down my forehead and another strap at the back to be able to tighten it around my head. The lenses are pretty good for the price, as long as you take care not to scratch them.

The head magnifier came with 4 plastic replaceable stereo lenses (1.6x, 2.0x, 2.5x and 3.5x). Because I was going to have to cut one of these stereo lenses in two, I had the idea to provide a holder/clamp/bracket that would hold a maximum of 2 lenses in front of the Cam 3 with the big advantage that absolutely no changes would be needed to the Cam 3. Also, it allows me to make a combination any of the lenses provided with the head magnifier (e.g. 2 of the 3.5x (maximum close focus), to any combination of the other lenses to get the close focus I wanted). It turned out that I only needed a single lens, the weakest one (1.6x), which worked well for me on my 3D printer (see the included photo with the text on it "the View is pretty good"). By the way, if you ever lose track of which lens is which magnification (because they are not marked in any way), all you have to do is measure the thickness of each lens. To avoid scratching the lenses, use a slip of paper on each side, to protect the surfaces from your calipers. The thickest lens is the highest power. When you have decided which lens you are going to use, cut them apart with a cutting disk on a Dremel.

I have documented the various combinations of lenses (though, not all of them). The closest I could focus with this method was about 2 or 3 inches, by combining 2 of the strongest (3.5x and 2.0x) I Googled a resolution test and found this one (http://www.eronn.net/camera/test-chart/resolutionChart.jpg). I printed it out (4 to a page), cut them apart and propped them up, one at a time in front of my cheap equivalent of an optical bench, using two long rulers and two (1x2x3) machinist blocks. I used the 2 rulers to show the distance and a label to show which lens combination I was using. I used the Wyze Cam Android app to verify the focusing and zoomed in to make sure the focus was correct. I also moved the resolution test sheet back and forward to see if I was able to monitor the equivalent area of the complete print bed, from the front to back of the printer. It was a bit hard to decide when the camera was at the best focus because the Cam 3 is a wide-angle camera and therefore has a wide depth of field.

When I went to design the clamp (I used MasterCAM 2021 because I have a teacher’s licence), I realized that I would never be able to print the whole assembly of the clamp for the Cam 3 and the lens support in one piece (I would have needed to 3D print it with lots of supports). So I decided to separate the two, so that no supports are necessary. I used super glue to attach the pieces together (I temporarily slipped 2 of the lenses between the 2 vertical supports to hold the proper distance – just don’t get super glue on the lenses). After I had decided the combination of lenses that I wanted, I then used a dab of hot glue to immobilize the lenses (though this might not be necessary). I have included a few file formats of the 3D drawing, so if you want to modify the geometry of any of the parts you should be able to import one of the included formats (File Formats: .STL (2 files), and 3 files each in IGES and STEP (Clamp & Support Geometry and the 2 Solid files)). The two Support Solids are exactly identical (print 2 copies and turn one around). If you want the IGES or STEP files, go to  https://www.thingiverse.com/thing:5264800

After I printed the clamp, I found it to be a little bit loose, so I thought I would need to modify the clamp and reprint, but instead I used some Gorilla white duct tape on the 4 sides of the Cam 3. This turned out to be better than just using the clamp alone, as the tape gave the clamp a more secure, cushioned grip on the Cam 3. Use a 6-32 nut and bolt to attach the clamp around the body of the Cam 3 (the nut goes in the hexagonal pocket as a captured nut). To attach the Cam 3 to my 3D printer, I used a T-nut and bolted it directly to the 3030 aluminum extruded frame.

 For anyone who wishes to try t he same measurements, here was my setup: see the photo

By looking at the above table, I think someone could very well use a combination of lenses for observing monitoring 3D printers or birds in a birdhouse.

Head Magnifier - we need the lenses from it (see photos & link) (we don't need the head magnifier)

3D Printer

Dremel tool with cutoff abrasive wheel

Super glue

Hot glue gun (optional)

Duct tape

6-32 nut & bolt

No Supports needed. I used PLA, any color. Infill 15 %

Temporarily slide 2 lenses into the slots to keep the supports squared up and at the correct distance and use Super glue to attach the 2 Supports to the clamp (there are some small notches to center everything). Don't get Super glue on the lenses (or your fingers!)

From the attached table (knowing the distance you want to focus at), choose the lens (or combination of maximum 2 lenses) and cut them apart (using the Dremel tool and cutoff abrasive wheel). Insert the selected lens(es) in the slots. Turn on your Cam 3 and verify that the distance focus is good. You may want to immobilize the lens(es) with a dab of hot glue at the end of one of the slots (just use the smallest amount possible - you may want to change the lens choice later)

I simply used a t-nut to attach it to the 3030 frame of my 3D printer. If you decide to monitor something outdoors, make the appropriate arrangement for 5V power and water-proofing the installation.

I really like the high definition video of the Cam 3 coming from the printer and I can also zoom in and even listen to the audio of my 3D printer working.