Years ago, I learned (the hard way) that coat hooks attached to drywall using standard cone-shaped anchors function more like a drywall zipper than a garment hanger. But as part my recent home renovation, I wanted a more artistically arranged sequence of floating hooks - too close together to use the studs - so I thought I’d try a more secure anchor. And I wondered if I could 3DP something to do the job.
On Printables, I found this excellent-looking anchor with mechanical wings. I particularly like that the designer wasn’t trying to copy the injection-molded designs you find in stores - he was designing something from scratch to take advantage of the strengths of 3DP fabrication.
I printed my first one in PETG and was a bit surprised to find that it didn’t fit through the ½" bore hole it was designed for. But rather than chop a bigger hole in the wall, I tried a quick hack, by intersecting the shaft and jaws of the original design with a hex-cylinder to shave the corners off. (See the orange version in the top image. It’s also the properly inserted one in the image below.)
As you can see, the serrated wings will now have a much narrower bite against the back of the wall, but that shouldn’t make a big difference to the strength of the hold.
Another tweak is the shaft length. This design requires a specific drywall thickness if the wings are going to engage securely, but I found that my drywall is thicker than the design expectation, so I needed to add some length to the spacer part of the shaft. I also want to try using it on ¼" drywall and on the ⅛" skin of a hollow core bathroom door. So to test the “plunge” depth of my other modified anchors, I printed the gray test plate you see here.