Outfitting a D&D Beholder with LED Eyes

The Dungeon Workshop is an Instagram account run by gamer and dungeon crafter Bob Richens. On it, Bob shows off such electrified and actuated dungeon creations as flickering wall torches, glowing magic mushrooms, fountains that pump real water (and then turn to blood), and a wizard whose crystal ball staff lights up when her cat-familiar gets nearby.

And then there’s his most recent project. Behold the Beholder, the iconic D&D monster that’s a giant floating head, all slavering teeth, evil cyclopean eyeball, and wriggling, Medusa-like eye stalks.

Behold! My #tdw_beholder is finished. Beware of the magic death ray eye! Swipe for a few still shots. 👁 Awesome base made by BRO. Thanks man! #thedungeonworkshop #tdw_monsters #beholder #ralpartha #grenadier #reaperminis #gaming #dnd #dandd #adnd #adandd #led #dwarvenforge #pathfinder #gencon #tabletopgaming #rpg #osr #dungeonsanddragons #gencon #miniatureterrain #miniature #miniaturepainting #labyrinthlord #dwarvenite #coolminiornot #roleplaying #warhammer 9:00am 4/27/17

A post shared by The Dungeon Workshop (@thedungeonworkshop) on Apr 27, 2017 at 9:11am PDT

Bob brought his Beholder to life by installing a red 3 watt LED as the main eye and tiny surface-mount LEDs in the Beholder’s many eye stalks. We asked him to share some of the build details with us. Here’s what he sent.

Bill of Materials

(1) Reaper Miniatures “Eyebeast” model
(1) red, 3 watt LED for the main eye
various colored LEDs 0402-sized SMD
various resistor values, 0603-sized
various SMD capacitor values and sizes
thin, copper circuit board
magnet wire ~35 gauge
(2) CR2032 batteries
multiple MIC1557 timer chips
(1) micro on/off switch
(1) base to house all of the electronics
misc hardware (nuts, bolts, etc), glue, misc hand and power tools, paint and brushes

Build Notes

• Using a ridiculously small drill bit and a Dremel tool, I drilled tiny holes through the eye stalks and down into the main body.
• I also drilled a channel through one of the leg stalks and into the base. This is where I will run my wires to the circuit board and power.
• I then soldered the super-thin wires to the surface-mount LEDs and threaded their wires through the eye stalk channels I’d drilled, and into the base.
• Using my Dremel, I gouged out the main eye and installed a 3 watt LED (with wires attached). The wire was then fed through to the base via the hollow leg stalk I’d drilled out.
• Next, I cut out the circuit board material so that it could fit inside of the base. On the PCB, I installed the MIC1557 timer ICs. I then used the resistor/capacitor (R/C) components to build one flashing circuit for each LED. The different R/C component values are used to set the desired flash rate and flashing style. Finally, I soldered the wires from the LEDs to the timer circuits outputs (one per light).



• With the circuit built, I then built a small holder for the batteries on the circuit board and installed an on/off switch between the battery and circuits. Everything then got stowed inside of the base and epoxied in place to seal and protect the components.

• After that, it was only a matter of painting and detailing the model.