I maded it: TRex Solder 3rd Hand

TRex Solder 3rd Hand


(since Thingiverse’s markdown parser seems to be broken)


A weighted, non-slip, non-wobble soldering third hand.

Huge thanks to Modular Hose for giving me the Loc-Line samples I used to make this!

Why is it called TRex? It’s got really short arms …

Despite what Thingiverse might say, this is not a Customizer project. Opening that link will disappoint.

Parts required

  • at least 12× ¼” Loc-Line segments
  • 2× Loc-Line ¼” NPT threaded connectors
  • 2× Loc-Line ¼” nozzles
  • 2× alligator clips
  • 3× adhesive round non-slip feet (up to 16 mm diameter)
  • appx. 60 g steel BB shot (or available equivalent) as ballast
  • hot glue to secure ballast and seal port in place
  • Polycaprolactone (PCL; trade names include InstaMorph) warm-melt granules to secure clips into nozzles
  • (optional) PTFE plumber’s tape.

Note that Modular Hose promotional Loc-Line keyrings each have 3 segments plus a threaded connector and nozzle, so four keyrings provide enough parts.


  1. assemble the two Loc-Line arms with a threaded connector and at least six segments each
  2. secure the ends of the alligator clips in the nozzles using softened PCL or hot glue. Make sure that the ball joint connector surface is clear of material, as you’ll need this to fit the nozzle onto the arm
  3. fill the tool body with ballast, apply a plug of hot glue to stop it rattling and secure the end port in place
  4. Carefully thread the arms onto the tool body. NPT threads are tapered, so become gradually tighter as they go in. Use a little plumber’s tape if they’re too loose. Be careful not to overtighten, as this might crack the tool
  5. Apply the non-slip feet, applying appropriate pressure to activate the adhesive
  6. Get soldering!


Dan Kirshner’s Thread-drawing modules for OpenSCAD were used to make a nice ¼” NPT taper-profile thread. Thanks, Dan!

Foot and shot port
Side view

Data archive: TRexSolder3rdHand.tar.gz

Accessible Gaming buttons are done!

Accessible Gaming buttons are done!

Accessible Gaming buttons are done!

So in an attempt to avoid going completely shack-wacky, I made a bunch of Round Flexure Switches in my free time. I’m donating them to Makers Making Change, the charity I work for.

They are by no means in any form of corporate colour, except perhaps Lisa Frank. The tops are less tactile than I thought they’d be: the top couple of layers are gold PLA and are printed first, then the next layers are bridged above that. They’re almost imperceptible, especially after a thin layer of acrylic varnish.

The bodies are a mix of acrylic paint and ultrafine glitter, layered over with acrylic varnish to limit glitter shedding. The one that looks like a disco tree stump uses heavy gold mica flake medium. The iridescent green is unvarnished, unfinished translucent PET-G (from eSUN; perhaps my favourite material).

From a technical point of view:

  • The button nut is hot-glued in place. This keeps the top straight as a nice side effect.
  • The nuts are held in place with medium (blue) thread-lock. They won’t come apart unless you use appropriate force. Unlike red thread-lock, you will be able to take these apart for repair.
  • Digikey were out of stock on specified parts. These substitutes work directly, though you’ll have to remove a small lever from the microswitch:

I feel so seen … from 1814

So it seems my lifelong nickname is/was a Piedmontese word for noise, crash/clatter/bang or scream/shout/squawk:

[french/piedmnotese dictionary text]
Scruss s.; Bruit, fracas, cri.
La porta a la fait un scruss;
La porte a crié, a fait un cri.
from Capello, Luigi. Dictionnaire portatif piémontais-français suivu d’un vocabulaire français des termes usités dans les Arts et Métiers.. Impr. V. Bianco, 1814.

An early 19th century dictionary written by an Italian count had my number all along.