Parametric Lamp

A fully parametric lamp using HEMMA-type fixtures. Tool provided to make your own diffuser design.

Print instructions

A fully parametric lamp shade for Ikea HEMMA-compatible fixtures (40 mm diameter fixture). I have included an example STL file, but you can design your own here and download STL files directly: https://alecperkins.net/parametric-lamp/

Design

Play with the parameters to get different shapes and profiles. You can adjust the "skew" of the perforations to also get more or less direct lighting.

The tool will generate a companion base as well, though that process is still a bit slow to do in real time so get the diffuser how you want it then enable the base. Also, the base mesh may not be printable (still working out some bugs) so I have included an STL file for an 88 mm diameter base.

Also, be mindful of how big your hands are and how big the intended bulb is. It’s possible to design a lamp you can’t actually assemble.

Printing

Use PETG or stronger if possible. Even LED bulbs can get quite warm.

Unless you expect the lamp to get rough treatment, you can dramatically speed up print time and reduce filament usage by setting 0% infill and disabling "Ensure vertical shell thickness". The corrugation from the diffuser perforations makes it quite rigid. The tradeoff will be an occasional gap in the slopes of the perforations depending on their angle. They are hard to see normally and all but disappear when the lamp is turned on.

For good results I do recommend adding a modifier to provide infill up to the first perforation. 15% cubic has worked well for me though use your discretion and experience. See the included .3mf file for an example.

Assembly

Requires a fixture similar to an Ikea HEMMA cord set, with a 40mm diameter screw neck and a screw-on fastener to secure the shade/diffuser.

For pendant-style lamps simply insert the fixture into the hole in the diffuser and screw on its fastener from the inside. For desk lamps, use the fixture and its fastener to bolt the base and diffuser together.