Pegboard
a wire-model jig you read by touch
A flat plate with a hole every 1/8 or 1/4 in, for rebar tie wire, that you build a wire model on. Push a wire into a hole and it stands; lay one in a groove and it stays on its line; count the holes with a finger and the model is as true as the plate. The holes sit on a square grid, a polar grid of rings and spokes, or both on one plate — a round barn on a square site — with the two grids sharing the plate under one rule: no wall between holes thinner than you allow. Braille rulers run along the bottom and left edges (a tick at every hole, a longer tick and a numeral at every inch), a raised triangle in the origin corner says which way is up, and raised inch lines or wire channels cross the field. Every dimension is a control, and every setting is spoken back: the grids, the hole count, the thinnest wall, the scale, the print. Export a watertight STL (one piece, or cut between the holes to your printer’s bed), a Rhino .3dm as editable surfaces or the print mesh, and a fit coupon — five numbered holes a step apart — to size the holes to your wire before you print the plate.
Nothing uploads. The mesh kernel runs in your browser when you export: a 1/4 in plate in about a second, a 1/8 in plate in three to five, grooves on a 1/8 in barn in about twenty — the line under the header says when it is done.
Loads a plate; your printer stays. Round barn is Fraser's 60 ft dairy barn, the Barn Jig demo, as a polar zone on a square site.
The tile is the board that was printed and approved — its ruler is cut in, not stood up. Its presets appear above when it is chosen.
Bed: 7.071 in square printable — the plate fits in one piece.
A hole every this far, across and up, the first at the origin corner. 1/8 in leaves walls just over a millimetre.
Rings near the centre keep every 2nd, 4th… spoke, the smallest divisor that clears the pitch, so no wall falls under it. Fraser's barn has 64 rafters.
Rings out as far as the field allows around the centre. Off: set the diameter — the zone may run past the plate's edge (a barn on the corner of its site); rings, spokes and channels stop at the field, holes outside are left off and counted.
Off: put the centre anywhere in the field — the corner of the site included. It snaps to the ruler's lattice either way, so it sits on a hole and reads as a clean fraction.
On: the polar zone is cleared of square holes and its edge is a raised ring (the round barn). Off: the grids overlay; a square hole gives way only where it would crowd a polar one.
Picking a wire sets the hole to the coupon's third rung over it. US steel wire gauge; measure your own spool.
Coupon rung 3 of 5 (0.016 in over the wire).
A floor under every hole, so each wire bottoms out at the same depth. Off: straight through, easier to clear.
A half-round channel — a pipe cut out of the surface — along every row and column (and every ring and spoke) from hole to hole. A wire laid in it sits half-buried in a round bed and stays on its line.
As wide as the hole, half the wire deep — a semicircle of the wire's fit: 0.079 in (1.99 mm) × 1/32 in (0.79 mm) now. Deeper than half the width becomes a round-bottomed slot.
UEB puts ⠼ before a number. Off saves a cell on a crowded ruler; the read-back says which.
A raised right triangle in the origin corner, so the plate cannot be turned the wrong way.
Embossed along the top edge in Grade 1, lowercase. Leave it empty for none.
A raised line along every major row and column of the square grid, cut by the holes it passes.
A plate wider than the bed square (less the clearance) is cut into pieces, between the holes.
16 facets: a 0.39 mm flat, an inscribed circle of 0.077 in (1.956 mm) for the 1/16 in (1.587 mm) wire · about 49,995 triangles, ~2 MB of STL.
Mesh density method: facets around each hole (a cylinder of n sides subtracted by the kernel); domes three quarters of it in fours; rings and a disc at 12.8 ÷ facets mm chords; triangles priced as holes × facets × 4 + domes × facets² × 0.6 + bars × 12 + ring chords × 4; the inscribed circle is the diameter × cos(π ÷ facets).
Read-back
- PEGBOARD JIG: a 7 in by 7 in RECTANGLE (177.8 × 177.8 mm), 1/4 in (6.3 mm) thick, with 650 holes of 0.079 in (1.99 mm) for 1/16 in (1.59 mm) wire, straight through. Printed full size, flat, no supports.
- A SQUARE grid: a hole every 1/4 in (6.3 mm) across and up, 650 in all, the first at the origin corner.
- The thinnest wall between two holes is 0.172 in (4.36 mm).
- THE SCALE: a raised tick at every hole along the bottom edge and the left edge, a longer tick every 1 in, and a Braille numeral (with the number sign) every 1 in — 7 along the bottom, 7 up the left edge, reading inches from the origin corner. The margins that carry them are 3/4 in on the left and 19/32 in along the bottom; a raised triangle sits in the origin corner so the plate cannot be turned the wrong way.
- RAISED LINES in the field: a raised line along every 1 in row and column of the square grid, interrupted by the holes it passes — 0.024 in (0.60 mm) tall (3 layers of 0.2 mm), narrower than a tick. A hole goes through a raised line as it goes through the plate, so a wire stands in it and the line reads as pieces between the holes.
- MESH: 16 facets around each hole (as designed; a 0.39 mm flat at this diameter, an inscribed circle of 0.077 in (1.956 mm) for the 1/16 in (1.587 mm) wire), 12 around each dome, 0.8 mm facets on rings and a disc — about 49,995 triangles, roughly 2 MB of STL.
- Braille dots are 1.6 mm domes 0.8 mm tall on a 2.5 mm dot pitch (BANA), 88 of them; at 0.2 mm layers a dome prints as 4 flat-topped steps.
- PRINTING: one piece — it fits the 7.071 in square the bed can print with the clearance kept. About 234.4 g of PLA at 100 % infill (189 cm³).
What prints, and how it is made
- Holes — 650
- Cylinders of 16 facets boolean-subtracted by the Manifold kernel at export. Laid out by the planner: square holes at whole pitches from the origin; polar holes on rings at the ring pitch, each ring keeping every d-th spoke for the smallest divisor d of the spoke count whose arc clears 95 % of the pitch; where the grids meet, a square hole gives way if it would sit closer than a diameter plus the thinnest wall to any polar hole (a grid hash, no O(n²)).
- Rulers — 51 ticks, 14 numerals
- Raised boxes: 0.08 in at every hole pitch, 0.16 in at every major, 0.60 mm tall. Numerals are the RAP Braille engine’s UEB Grade 1 (number sign optional), laid out at BANA’s figures — 1.6 mm domes 0.8 mm tall, 2.5 mm dot pitch, 6.2 mm cell pitch — every dome a sphere half-sunk in the top face. A numeral that would touch its neighbour is thinned to every second major; one that would hang past the plate is left off, and the read-back says so.
- Lines and grooves
- Raised lines are boxes and annuli unioned before the holes are cut (clipped to the field, so a ring of a zone that runs past the edge never floats), and a hole interrupts a line cleanly. Grooves are PIPES — a cylinder of the channel's width laid along each run, a torus for a ring, its axis depth less radius below the face — unioned first because rows cross columns, then subtracted; deeper than the radius adds a slot above the axis.
- Watertight, checked
- The export asks the kernel for its status, counts shells and enclosed voids by connectivity, and compares the genus (each through-hole is one handle) with the hole count — the status line says all four. Pieces are the same solid intersected with each bed box and moved to its own origin.
- Material
- Volume from the plan (plate − holes + raised work − grooves) × 1.24 g/cm³ for PLA at 100 % infill; the kernel’s exact volume prints at export.