Make the tool that makes the part

The Dream Swing’s shade structure stood on eight steel support poles, and each pole needed a formed steel cap. No such part existed to buy, and no tool existed to form one. So the tools came first.

Sketch of a welder at work, sparks flying

The stuck thing

Eight support poles needed capped ends. The cap is a simple thing — a shallow steel dome, sized to the tube — but simple things with no part number are the ones that stop a build cold. Nothing off the shelf matched the profile or the pole.

The diagnosis

When the part doesn’t exist, look one step upstream: the real job is the tooling. A dome is just a disc that’s been convinced. What’s needed is a punch, a die, and enough pressure applied.

Made it go

I machined the punch and die on the lathe, cut disc blanks, and formed each cap on a 20-ton shop press, then welded them home on all eight poles. The tools outlived the job, and the practice continues: recent commissions include welded plinths for an architectural mailbox set by Architects Mosher Drew in South Park, San Diego.

Lathe-turned punch, die ring, and disc blanks laid out on the press plate — custom toolery, by lathe: punch, die, and blanks

A 20-ton hydraulic shop press — the 20-ton shop press

The punch and die loaded in the press — punch meets die

A freshly formed cap held above the die, with the punch alongside — a disc becomes a dome

The formed steel cap, held in hand — the formed cap, in hand

A support pole end capped and welded — welded home: a capped support pole

machining & die-making · metal forming · welding · one-off tooling

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