Smart Beehive Project

I designed the entrance section of the beehive in Fusion 360. This is where the cameras will be mounted to monitor bee activity going in and out of the hive.

Initially I planned to use a single camera, but after researching cameras compatible with the Raspberry Pi 5 and looking at their focal lengths, I realized I'll need two cameras to get adequate coverage of the entrance. The plan is to run them off a Raspberry Pi 5.

V1 — First Design

The first version established the overall shape and dimensions of the entrance piece. I printed it in two sections so it would fit on the build plate.

Smart Hive entrance V1 (half section) — designed in Fusion 360

V2 — Narrower Profile

After the first version, I decided to decrease the length of the part to make it narrower. This gives a tighter fit against the hive body and reduces wasted material.

Current Progress

I'm currently working on a version with an upper section to house the camera module. The goal is to have the camera securely mounted inside the entrance piece with a clear view of the landing board, all powered by a Raspberry Pi 5.

V1 — First Cut (Plywood Test)

Our lab uses a ShopBot Alpha CNC router. For the first version of the roof I used plywood to test the design before committing to the nice cedar. The roof uses dowel joints — the holes on the sloped gable sections are cut on the CNC, with 3 dowels per corner at a ¼" hole size.

V1 Test Fit

I test fit the roof on an empty hive that I have ready for this upcoming season and noticed that it's about ¼" too long — you can see the gap by looking at the bottom edge in the photo below.

After noticing the overhang, I decided to take actual measurements of the hive box I'm fitting to.

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Sourcing Cedar

After testing with plywood, it was time to move to the real material. I bought 6 cedar boards from Lowe's at $18.27 each. Usually, select cedar boards with no knots are very expensive, so instead of paying the premium I decided to go in person and inspect each board individually, only buying the ones with very little to no knots. Knots are weak points in the wood — they can crack, fall out over time, or create gaps that let moisture and pests into the hive.

I measured the thickness at about 0.85", and I only need 0.75" for standard hive wall thickness. This is good because when I join the boards I'll need to plane them, so the extra material gives me room to work with.

Joining the Boards — Tongue & Groove

I needed a way to join these boards into wider panels and I didn't want to go out and buy a very expensive joiner tool. Instead, I bought a router bit from Rockler — specifically the 1-7/8" D × 1/4" H × 1/4" Shank Rockler 3 Wing Slotting Cutters Bit for $54.99. Much better than a $260 joining tool. I used this bit to make tongue and groove joints — cutting a centered tongue on one board edge and a matching groove on the adjacent board so they interlock.

I attached the bit to my router table and cut the boards. It took lots of trial and error to get the fit right, but thankfully I didn't ruin any of the boards.

Glue-Up & Planing

The next step was to glue the boards up. I used Titebond III wood glue, which is waterproof and rated for outdoor use — important for a beehive that sits outside year-round. I could only do one board at a time since I didn't have a lot of clamps.

After they were all glued up, the boards had a small but noticeable bump where they were joined. I anticipated this — first I used a hand planer to remove the bulk of the material, also clearing off glue residue as I went. After getting it as good as I could by hand, the boards obviously weren't perfectly flat, so I brought them to the lab and used the thickness planer.

After a few passes and adjustments, running both sides of the boards through, I was able to get a very nice smooth flat surface.

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V2 — Design Changes & Second Cut

Based on the V1 test fit, I made several design changes for V2:

• Reduced the lengths of the rectangular side boards of the roof
• Decreased the height of the gable sides, which lessens the slope
• Made the ends not straight on purpose — this increases the amount the roof has to sit on, makes it easier to pick up, eliminates a 90-degree corner (which hides drilling error on the rectangular side boards), and I think it looks good

After the roof was cut out I sanded each part and was very happy with the result, then took everything back home.

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3D Printed Drill Jig & Side Board Problem

I 3D printed a jig to drill the dowel holes and align them up on the rectangular side boards. This is when I noticed the first problem — after getting the sides of the roof and a drill, I tried to place the jig on the wood and noticed that the side boards were cut too small. I think the CNC cut them on the inside of the vector instead of the outside.

I was determined to get this done, and being on spring break meant I wouldn't be able to get back to the lab for over a week. So I decided to re-cut the side boards using my table saw at home.

I slid on the 3D printed jig and it fitted perfectly. I pushed the dowels into the gable side of the roof (the holes were already drilled on the CNC), then measured the amount sticking out and put a piece of tape around my drill bit so I'd know the depth I needed to drill to.

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Finishing — Tung Oil

I finished all the parts using tung oil, which is what I use on my cedar bee hives that I don't paint. One important note: you have to use 100% pure tung oil and let it cure for around 30 days if you want to use it for bees. Most "tung oil" isn't really tung oil — anything labeled tung oil at your local hardware store is not likely even tung oil and is not food/bee safe (you need to read the label on the back of the package). I personally use Hope's 100% Pure Tung Oil ($29.99 on Amazon).

The best method I found for applying it:

1. Apply a generous amount to the wood
2. Leave it in the sun for 20 minutes
3. Wipe it down
4. Let it sit in the sun for around 2–3 hours

I repeated this process 3 times and was happy with the result. Note that you have to wait around 30 days for it to fully cure.

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Roof Assembly

After applying the 3 coats of tung oil finish, I bought a piece of ¼" lauan plywood from Lowe's to sit in the groove I made in the gable side of the roof. I cut the ply to the correct dimensions on the table saw, slid it in, and glued up all of the sides.

Interior Supports: One thing I should have done was add a groove for the plywood board in the rectangular sides of the roof. Since I hadn't done that, I decided to improvise — I used the previously too-narrow pieces of wood and cut a 15-degree slope on them using the table saw, which was about as close as I could get to match the slope of the roof. I glued them on the inside face and then used the nail gun to put nails from the bottom of the board up into the support. Since these pieces were also not long enough, I used some wedges to get the fit right, then glued up the faces and clamped them together.

Top Support: I also realized I would need to make a top support — something to add strength and also have something to nail the roof board into. I made the top support from some scrap pine I had laying around. I cut the slope of the roof at the peak, then offset it by the thickness of the roof ridge beams. I glued the supports to the opposing interior faces of the wood, clamped them, and used the nail gun to put nails from the bottom of the board up into the support. Then I nailed the two ridge beams to the angular parts of the support, ensuring they were flush with the CNC-cut slope of the gable sides.

After it dried I removed all the clamps and tested the fit on my bee hive box — and it fit perfectly.

Roof Board & Copper: After that I got some thicker plywood for the roof, which I hope to wrap with a thin sheet of copper to give it a nice look. The copper will also provide a bit of heat in the winter for the bees, and it looks really cool. More on this will be added here as I continue the build.

For the inner cover, I attempted dovetail key miter joints on each corner. All four corner pieces are cut at 45 degrees on the CNC, and each joint has a slot for a separately cut key that locks the miter together. The idea is that the key adds mechanical strength to what would otherwise be a weak glue-only miter joint.

This joint took a very long time to get working. I kept running into problems with the vectors exported from my Fusion file — the toolpaths wouldn't generate cleanly, and I had to go back and fix the geometry multiple times.

The finished result didn't turn out quite as good as I hoped. The joints came out a bit weak, and I think this type of joint requires extreme precision to pull off well on a CNC. For my final project, I think there are much better joint options I could use in place of this.

Camera Housing

3D-printed entrance piece designed in Fusion 360, houses the cameras at the hive entrance.

Roof & Inner Cover V1 — Plywood Test

First version of the CNC roof cut in plywood to test fit and joint alignment before using cedar. Also includes the inner cover board.

Roof V2 — Cedar Final

Updated roof design with corrected dimensions, reduced gable height, and angled ends. Cut in cedar on the ShopBot.

Drill Jig

3D-printed jig that clips onto the rectangular side boards to align dowel holes for the roof assembly.