12. Machine Design & Building
Enclosure Design & Manufacturing
This week my team and I built a 3-axis CNC engraver for drypoint printmaking. My specific contribution was in the enclosure design and manufacturing: from the structural aluminum tubing (cutting, drilling, painting) to the infinite-screw shafts and rod preparation, the laser-cut and table-saw machine bed, and the full fabrication and assembly of the plywood enclosure box.
The goal for this week was to design and build a machine with mechanism, actuation, automation, function, and a user interface.
My individual workflow focused on the enclosure and mechanical support parts:
- Understand the group machine concept and define what parts I would contribute.
- Prepare the structural material, including aluminum tubing, rods, shafts, and plywood panels.
- Fabricate the enclosure parts using CNC, laser cutting, table saw work, drilling, sanding, and assembly.
- Document how my enclosure work connected to the full group machine.
Process 01
Aluminum Square Tubing
The main structural frame uses square aluminum profiles that needed to be cut to precise lengths, deburred, drilled for fasteners, primed, and painted. Below is the full process from raw stock to finished painted pieces.
1. Tools & Measurement Setup
Each profile was measured and marked at 30 cm with a carpenter's square, and a metal scratcher. Once it was marked, the piece was fixed on the miter saw at 90 degrees, and lowered the disk without turning the machine on to ensure a clean cut.
2. Cutting the Profiles
The tube was secured against the fence and cut in a controlled pass to avoid deflection and keep a clean edge.
3. Deburring the Cut Edges
A file was used to remove burrs and smooth the cut face flush after every cut.
4. Drilling the Fastener Holes
The drill press helped making precise, perpendicular holes for the M4 fasteners that join the profiles to the 3D-printed corner joints.
5. Sanding & Priming
All profiles were lightly sanded with a 240 grit sandpaper to remove surface oxidation and improve paint adhesion. Then 3 coats of primer were applied.
5. Final Paint Finish
A metallic spray paint was applied over the primer for a clean, finish.
Learning Outcomes
- 9 mm Plywood Is Tricky Thin: Thin 9 mm plywood warps easily, especially after routing. Several panels bowed slightly, causing gaps during assembly. Clamping strategy and glue selection matter a lot at this thickness.
- Panel Separation During Assembly: Some panels separated after initial glue-up, requiring re-clamping. The combination of thin stock and pocketed joints meant the glue surface area was sometimes too small.
- Screw Length Mismatch on Hinges: The default piano hinge screws punched through the 9 mm plywood. Each screw had to be swapped for shorter ones, and exit holes required filling and sanding.
- Electronics Integration & Cable Management: Cable lengths and routing paths should be designed in parallel with the enclosure, not after. Cables from the PCBs were too short to route neatly.
- Discrete & Hidden Joinery: In a future version I would use pocket-hole screws covered by plugs, or dado/rabbet joints, so no fastener heads or filler patches are visible on the surface.
- Multi-Process Manufacturing: Managing one project across four fabrication processes (laser, CNC routing, table saw, drill press) taught me that tolerances stack, 0.5 mm cut error on the laser can cause misalignment downstream.
Recognising Opportunities
For improvements in the design, I identified a few areas that could make the machine safer, cleaner, and easier to adapt in future iterations.
- Soundproof Enclosure Materials: A future version of the enclosure could use materials that help reduce noise, such as acoustic foam, rubber seals around the door, denser panel layers, or a laminated wall structure. This would make the machine more comfortable to use indoors while still keeping visibility and access.
- Dedicated Electronics Housings: The electronics should have their own protective cases instead of being mounted openly inside the machine. Designing separate housings for the controller, drivers, power supply, and wiring would improve safety, reduce dust exposure, and make maintenance easier.
- Adaptable Work Table: The work surface could be redesigned as an adjustable table that supports different material sizes. A modular bed with slots, clamps, or removable panels would make it easier to secure plates of different dimensions without redesigning the whole machine.