Halloween is only a few months away and if you want to 3D print any components for displays or other holiday projects, you better get busy! How about starting with these festive wall light switches which were de rigueur for all self-respecting mad scientists of the Victorian age.


When you need to illuminate the lab (to see what’s on the slab), you need some of these 3D printed knife throws. They replace the regular wall plate and adapt over a conventional wall light switch. Jeff Kerr, the Thingiverse user who created the original thing, printed his in PLA with 0.2mm layers, 3 perimeter shells, and 20% infill.


There are a number of remixes of this print on Thingiverse, some one-switch and some two-switch plates. There’s even a three-paddle switch plate now.


Several commenters have complained about the difficulty of this print. If you’re thinking about building it, check out the remixes (and read the comments) to see what improvements have been made.

Kerr does offer some tips for successful printing, like printing the plate part a little hotter than normal to insure good layer adhesion. And printing a raft if you have adhesion problems with the built-in support ribs (which people have apparently been having trouble with).

If you do print and install some of these knife switches and you don’t find yourself barking out the following command at least once while throwing them, the child in you may be in need of electrical reanimation.

“Igor, throw the switch!”

[With attendant thunder-clap sound effects, a shambling Igor, etc.]