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Modular desk lamp

Design Project 4 weeks Large build

A four-week build that combines three processes in one product. Students mill a hardwood base, vacuum form a shade over a mould they make themselves, and print the joint that connects the two.

A desk lamp with a milled maple base, a black printed pivot joint, and a glowing white formed shade, in a school workshop.

Overview

This is the biggest build in the course, and the first one where students have to make three processes agree with each other. The lamp is made of three parts: a hardwood base milled on the CNC router, a shade vacuum formed from PETG over a mould the student makes, and a printed pivot joint that connects them and lets the shade tilt.

Because the parts come from different machines, tolerances stack. A joint that is drawn to fit a milled pocket must survive the router’s actual accuracy, the filament’s shrink, and whatever the student did with sanding. Managing that is the point.

Students work in pairs for the mould and individually for everything else. Expect four weeks of about three lessons each. The first week is entirely design; nothing gets cut until the design review.

Skills needed

Assessment

Assessed against the rubric below at the design review (end of week 1) and at the final hand-in. The process record carries a third of the mark because the lamp on its own does not show what was learned.

Criterion Developing Proficient Exemplary
Design intent Parts modelled separately, dimensions typed in Shared parameters drive the joint and pocket A change to one parameter updates every part correctly
Manufacturing Toolpaths run but need supervision to fix Toolpaths simulate clean; setup sheet complete Student anticipates and adjusts for tool deflection or tabs
Forming Shade forms but webs or thins Clean form with correct draft, released without damage Mould designed for two-part or undercut-free release on first try
Fit and finish Parts assemble with force or shims Parts assemble as drawn with light hand pressure Fit tuned by measured tolerance, documented
Process record Photos only Photos with what changed and why Record could be followed by another student to repeat the build

Design review is pass/return. A returned design gets one more lesson before cutting is allowed.

Deliverables

  • Fusion design file with parameters, timeline intact, and one named configuration per part
  • CAM setup with a simulated toolpath and a completed setup sheet
  • The mould, with draft angles marked on a photo
  • The finished lamp, wired, standing, and switching on
  • A two-page process record with photos of each stage and what you changed and why

Materials

  • Hardwood offcut, 150 × 150 × 30 mm (maple or walnut)
  • 6 mm two-flute upcut end mill (shared)
  • MDF for the mould, 18 mm, two layers
  • PETG sheet 0.75 mm, 300 × 300 mm, translucent white
  • PLA or PETG filament, roughly 60 g
  • E14 lamp holder, inline switch, 12 V LED bulb, 12 V supply
  • M4 × 16 bolts and nyloc nuts, four of each

Steps

Week 1: Design everything before cutting anything

  1. Research three desk lamps you like and sketch how each one holds its shade. Note what stays fixed and what moves.
  2. Start a new Fusion design with user parameters for baseSize, pocketDepth, pivotDia, shadeDraft, and wall. Every dimension that two parts share must come from a parameter.
  3. Model the base as a single body with the pocket for the pivot joint and a channel for the cable. Keep every internal corner at a radius equal to or larger than the end mill radius.
  4. Model the pivot joint. It has to print without supports and take four M4 bolts. Run a section analysis to check wall thickness against wall.
  5. Model the mould for the shade, not the shade itself. Draft every vertical face by shadeDraft (start at 5°) and check the draw ratio stays under 1:1.
  6. Book a design review. Bring the timeline, the parameter table, and one question you are unsure about.

Week 2: Mill the base

  1. Set up a CAM job in Fusion: stock from the actual offcut you measured, WCS at the top-left corner, 6 mm end mill from the tool library.
  2. Add an adaptive clearing path for the pocket and a 2D contour for the outside with tabs. Simulate. Look for red.
  3. Fill in the setup sheet: material, tool, spindle speed, feed, stepdown, and where the clamps are. Have it checked before you touch the machine.
  4. Zero the machine, run an air cut above the stock, then run the job. Stay at the machine the entire time with a hand near the stop.
  5. Remove tabs with a flush-cut saw, sand to 220, and measure the pocket. Write the measured size next to the drawn size in your record.

Week 3: Form the shade and print the joint

A benchtop vacuum former drawing a translucent white sheet over a lamp shade mould
The shade mould under a softened sheet. Vent holes in every hollow let the vacuum pull the sheet all the way down.
  1. Cut the mould from two layers of 18 mm MDF on the laser or by hand, glue, and shape to the model. Drill vent holes in every corner and any low point.
  2. Seal the mould with two coats of sanding sealer and sand smooth. Texture on the mould becomes texture on the shade.
  3. Heat the PETG until it sags evenly, form, and hold vacuum until the sheet is cool to the touch. If it webs at a corner, add draft or a vent and try again.
  4. While the former is busy, print the pivot joint at 0.2 mm layers, 4 walls, 30 % infill, oriented so the bolt holes are vertical. Print one, test-fit in the pocket, adjust pivotDia if needed, then print the final.
  5. Trim the shade on the bandsaw, deburr, and drill the pivot holes using the printed joint as a jig.

Week 4: Assemble, wire, and document

  1. Test-fit every part dry. Nothing gets glued or bolted until all three fit together without force.
  2. Fit the lamp holder and route the cable through the base channel. Have the wiring checked before the switch is closed.
  3. Bolt the joint to the base, the shade to the joint, and set the tilt so the shade stays where you leave it.
  4. Photograph the finished lamp on and off, then finish the process record: one page of photos in order, one page of what you changed and why.
  5. Hand in the lamp, the files, and the record together.

Stretch options

For students who finish early or want a harder version:

  • Replace the milled base with a laser-cut stacked plywood base. This adds a kerf problem to the fit.
  • Make the shade a two-part form with a printed inner rib so it can be swapped.
  • Add a touch dimmer module and design the base to hide it.