After years of sensors hanging off the ceiling on ugly brackets that never lined up with the hole, I finally went the 3D printed route. Cut a round hole in the plasterboard where you want coverage, then the mount just grips behind the board with sprung arms and pulls its flange tight against the surface. No screws, no glue, no patching the ceiling if you change your mind later. One thing I wish I'd known earlier: get the aiming sorted before you obsess over the finish. The design works like a spot gimbal, so the sensor ball tilts and swivels and stays put where you point it. Aim it at the doorway or the top of the stairs, not the middle of the room, and you stop getting false triggers from the dog. Battery changes are the part that sold me. The whole unit pulls straight down out of the hole, swap the cells, push it back in. The aim holds, so it's a two minute job instead of a re-alignment session. Print it in PETG if you've got an attic space above, heat up there kills PLA clips. Happy to share the details if anyone wants them.
Tips for getting motion sensors to sit flush in the ceiling without screws
Oct 27, 2026
Last reply: 10 hours ago
3 Replies
I tried this exact setup last week in my hallway, aiming it towards the stairs where I needed the coverage. It was a bit of a hassle getting the sensor ball positioned right initially. Since the gimbal doesn't have fixed housing like the official plug-ins, finding the sweet spot where it catches movement reliably without pinging when I walk past it took several adjustments. I settled on pointing it at the top landing, maybe eight feet up, which made a noticible difference.
Once it was aimed, the stability was impressive. I tested the battery swapping with a standard AA pack, and the unit stayed locked in its final position, even when the weight shifts during the pull down. The PETG material really held up well against the heat coming off the interior of the wall, which I hadn't considered when I initially started modeling the part. It feels much more solid than the cheap plastic brackets I used before.
One thing I'd add is that the sensor ball itself is surprisingly sensitive to direct sunlight leaking from a window. Even a small amount of reflected glare near the hallway entrance seems to give it false readings. I had to adjust the aim slightly away from that side to keep things quiet.
This sounds like what I need for my landing but the cutting a hole part is the bit that scares me. My ceiling has wires running through it somewhere, I can see a little bump where one passes. How do you check what's behind the board before you start sawing? I don't want to slice into something and have a much worse weekend than planned.
I had an issue with the initial fit because the flange was a bit thick, making it hard for the springs to properly engage the backing of the plasterboard. What fixed it for me was cutting the hole maybe half an inch larger than the main body diameter. That gives the internal mounting arms the necessary wiggle room to pull tight and distribute the weight evenly across the drywall. It’s much firmer that way. The battery access window is perfect for swapping cells without having to pull the whole unit out if you are short on space.
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