Radius, Angle & Screw Gauge Cards – Wallet Size

Four workshop gauges in credit-card format (85.6 × 54 mm, ISO ID-1). They slip into a wallet, a toolbox lid or the small Gridfinity holder included in the set. Every marking is a colour inlay, so the numbers never wear off, and every card carries the same millimetre ruler along its bottom edge.

What's in the set

• RADIUS 1–10: concave radii 1 to 10 mm, cut as 90° notches with a rounded bottom. Slide a notch onto a rounded edge or corner: no light between them means you have the radius. Because the notches open at 90°, they work on parts of any size, not only small ones. The two top corners are convex gauges (R2 and R5) for inside fillets, marked with a thin red line.

• RADIUS 12–25: concave radii 12, 15, 20 and 25 mm (the middle 60° of each arc), plus convex corners R10 and R20.

• ANGLES: V-notches at 15, 30, 45, 60, 75, 90, 120 and 135°, and a sharp 90° corner (top left, marked with a square) to check inside corners.

• SCREWS & NUTS: through-holes for M2, M2.5, M3, M4, M5, M6 and M8, and hex holes sized to the ISO across-flats of the matching nuts (they fit ISO hex bolt heads of the same size too). A screw goes through the smallest hole it fits, a nut drops into the smallest hex it fits.

• The ruler: 1 mm ticks, longer ticks every 5 and 10 mm, zero on the left edge of every card. To measure a screw, lay it on the card and butt the underside of the head against the left edge.

• Gridfinity 3×1 holder: four slots on stepped rows, so the back cards stand higher and you can tell them apart by their notches. Standard Gridfinity feet, no magnets needed.

Convex radii on a flat card only work on its outer corners (anywhere else, the rest of the card hits the part). With the bottom corners reserved for the ruler, that leaves two convex radii per radius card.

Multicolour

• Cards: white body, red markings. The red is a 0.6 mm inlay, so only the last three layers swap colour: about three filament changes for a full plate.

• The 3MF files already assign the filaments for a Prusa MMU3: slot 1 red, slot 2 white. Load them and slice.

• Any two contrasting colours work. To colour-code the set, give each card its own body colour in the slicer; expect more filament changes, since the bodies then swap colour on every layer.

• One colour only: print the card STLs. The gauges work the same, the markings just disappear.

• The holder is a single part, printed in red in the 3MF (slot 1).

Print settings

• Printer used for the files: Prusa Core One with MMU3, 0.4 mm nozzle, 250 × 220 bed. Any printer with a 0.4 mm nozzle works for the single-colour version.

• PLA, 0.2 mm layers. The cards are 2.2 mm thick (11 layers).

• Cards flat, marked face up, no supports. 100 % infill (or 5 top and 4 bottom layers, which is nearly the same here) makes them stiff, about 12 g each.

• Keep elephant-foot compensation on (PrusaSlicer default). The gauges are edges, and a squashed first layer would make them read wrong.

• All four cards fit on one plate (cartes-x4.3mf).

• Holder: one colour, 15 % infill, 3 perimeters, no supports. It is 125.5 × 41.5 mm and 31 mm tall at the back.

Accuracy

These are printed gauges. They are good for identification and for checking, not for metrology.

• Radius and angle notches are exact in the model. A well-calibrated printer holds about ±0.1 to 0.15 mm on outlines. R1 and R2 are indicative: the nozzle rounds anything that small.

• The tip of each angle notch is rounded by about 0.2 to 0.4 mm. Judge the fit along the flanks, not at the very tip. Expect about ±1° on the larger angles.

• The holes are 0.3 mm over nominal, and so is the hex across-flats. Small holes usually print 0.1 to 0.2 mm under size, so the real clearance is about 0.1 to 0.2 mm. That is enough to tell an M3 from an M4, not to measure a thread. If a screw does not pass its own hole, check your printer's hole compensation.

• The ruler is as accurate as your printer in X and Y, typically ±0.2 mm over 80 mm (PLA shrinks a little). The 1 mm ticks are 0.5 mm wide, one extrusion line: crisp on a good printer, a little soft on a tired one. The 5 and 10 mm marks are the ones to trust.

• There is no thread pitch gauge. Metric pitches from 0.5 to 1.25 mm are finer than a 0.4 mm nozzle can draw cleanly in the card's plane, and a pitch gauge with rounded teeth would give wrong answers. I left it out.

Designed with AI assistance (parametric Python script, manifold3d).

En français

Quatre jauges d'atelier au format carte bancaire : rayons de 1 à 25 mm (encoches concaves, et coins convexes là où la géométrie le permet), angles de 15 à 135°, trous et empreintes hexagonales pour vis et écrous M2 à M8. Une règle graduée au millimètre sur chaque carte, zéro au bord gauche. Marquages incrustés en rouge sur fond blanc (0,6 mm, 3 couches), fichiers 3MF prêts pour la MMU3 (rouge en 1, blanc en 2), sans supports. Un support Gridfinity 3 × 1 à gradins range les quatre cartes debout. Ce sont des jauges imprimées : précises pour identifier et contrôler, pas pour mesurer au centième.