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Adam Savage's Miniature Vault Door Build! (Part 5)
2 min read6 May 2026Worth watching
TL;DR
Adam Savage returns to his 18-month-dormant miniature vault door project, tackling the intimidating combination lock mechanism. He machines a fully functional 3/4-inch combination lock from 25-thou brass sheet, complete with three rotating discs, a knurled brass dial, and engraved graduation marks — achieving a major mechanical milestone.
Key points
1
After 18 months away, Adam returns to his miniature steel vault door project, admitting he stalled because the combination lock mechanism felt too daunting.
2
He machines a working combination lock with three brass discs, each with tabs, slots, and a center spindle, cut from 25-thou (0.635mm) brass sheet using a milling machine and jeweler's lathe.
3
A knurled brass dial with 36 engraved graduation marks (every degree) is produced using a pantograph router with a rotary table setup — an operation Adam had never attempted before.
4
The three lock wheels successfully engage and disengage, confirming the core combination lock mechanism functions, though it still needs lapping and refinement for smooth operation.
5
The next steps involve setting a combination, cutting slots in the wheels, and designing a bell-crank linkage to translate the tiny lock movement into actuating all 12 locking pins in the vault door.
Actionable insights
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When picking up a dormant project, accept initial wheel-spinning as necessary — rebuilding mental context for all the sub-problems is part of the process, not wasted time.
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Break intimidating mechanisms into standalone sub-assemblies: Adam built and validated the lock body independently before worrying about how it interfaces with the vault.
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Use a watchmaker's lathe or similar precision equipment to correct off-center drill holes in small parts — a drill bit wandering in material is a solvable problem with the right tooling.
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For engraving small circular dials, mounting a rotary table on a pantograph mill allows consistent angular divisions — Adam used 36 divisions with tiered line lengths for major/minor marks.
Notable quotes
“It seems hilarious to use 3,000 plus pounds of equipment to make this tiny tiny little thing, but there it is.”
“It is not a millstone, although it has felt like a millstone around my neck at times.”
“In order for one little lever arm to move 12 posts, everything in here has to be at the just-so smooth. It has got to be so smooth.”
Worth watching?
✅
Worth watching the full video?
Watch if you enjoy hands-on precision machining content — seeing Adam work through real problem-solving at a jeweler's scale is compelling, but the key milestones and techniques are all captured here if you just want the highlights.
Saved you some time? The creator still deserves a like.
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