Beacon - taekwondo lamp and bookend

A desk lamp and bookend designed for visual appeal, representing a black belt, and made with five different manufacturing processes

The finished lamp lit on a nightstand: a curved black arm rising from a wooden base into a lantern with a kicking figure on its panels, a flat spiral coil at the foot holding a row of books, and a strip of light along the base.

the problem

I needed a unqiue gift for someone that they could use daily. I settled on a belt-themed lamp and bookend to combine their interests in reading and taekwondo. The design needed to be visually appealing, represent a black belt, and be manufacturable with the tools I had available.

what I did

Sketched 30 ideas and settled on the book-themed lamp. Decided to use a waterjet for the key belt profiles, sand-casting for the complex coil shape, and a mill for the lantern and mounting points. The lantern was laser cut out of acrylic and the base was routed from wood.

what happened

This lamp has been in use ever since, with extreme amounts of visual appeal and a unique design. I learned a lot about the manufacturing processes I used, and about the importance of finishing techniques like powder coating and electronic assembly.

what I learned

One of the biggest issues with this design was that the draft angle from the waterjet created a visual seam between the two halves of the arm, and required extensive sanding to remove. It took me several tries to cast the coil successfully, and I learned about the importance of draft angle and sand quality.

what I would do next time

I would design the arm with draft in mind, and make sure to rigorously check the sand quality before attempting casting. Finally, I would have made the bookend out of steel instead of aluminum to increase its stability when holding books.

Five processes

Sand casting	the belt coil, using a FDM printed pattern
Waterjet	every profile, cut from 1 inch plate and stacked to reach 2 inch thickness
Milling	mounting points, holes, threads, the lantern cage, and the rounded edge on the arm
Laser cutting	the lantern panels, and the figurine lit on the bookend
Woodworking	Assembled the base, chamfered the edges, and used a CNC shopbot to route a light strip channel and electronics pockets

Idea

I sketched out nearly 30 concepts, settling on this one for its visual appeal, resemblence to a black belt, and bookend functionality.

Two notebook pages of sketches: four concepts on the first, and on the second a developed lamp with dimensions and base options. — **Fig 1** The sketch page the project came from.

A mock-up in foam, lit from inside, standing beside books on a bench. — **Fig 2** My first foam prototype, used to get the scale and proportions right.

Design

The assembly and the exploded view. For cost reasons, the arm was cut from 1 inch plate and stacked to reach 2 inch thickness. Screws run all the way through from the back into threaded holes on the sand-cast coil. The lantern is a pair of waterjet plates on standoffs with laser-cut panels between them that snap into grooves in the plates.

CAD of the whole assembly: arm, lantern, coil, bookend and base. — **Fig 3** The CAD model.

The same assembly exploded, showing the two arms, the coil, the lantern plates and standoffs, and the fasteners. — **Fig 4** The exploded assembly.

The arm and coil

The arm was cut on the waterjet, with each profile cut twice. The coil used a FDM printed mold, and was sand-cast in aluminum.

The casting pattern for the coil, in white, on a bench. — **Fig 6** The casting pattern.

The closed sand mould in its flask, the coil impression visible in the parting face. — **Fig 7** The mold, rammed up.

The pattern beside the raw casting, still rough from the sand. — **Fig 8** A prototype in bronze without enough central draft

Milling connection points

Most of the time on this project was spent carefully setting up the mill for each operation.Curved parts do not sit square in a vice, so nearly every operation needed its own set-up.

A coil backing clamped to the mill table under strap clamps, being drilled. — **Fig 9** Strap clamps, again.

A part held against angle blocks on the drill press table. — **Fig 10** Angle blocks, to drill flat holes on the 30 degree cut angle of the coil backing.

The curved arm on the machine part-way through the corner rounding operation, its edge half broken. — **Fig 11** The corner rounder, where it started to go off the edge.

A close-up of the finished arm, its rounded edge blending into the flat face. — **Fig 12** Final corner rounding with blending.

Lantern and base

The lantern is a pair of waterjet plates on standoffs with laser-cut panels between them. The figurine on the bookend is laser cut too, and lit from the base. The base hides the wiring.