- Choose the head shape and intended finished hat size. Sweatband allowance starts at zero, matching the Online Workshop. Choose any extra circumference for your own materials and method. Legacy leather and measured-thickness options remain available for existing projects.
- Choose an overall crown-block height from 4½ to 8 inches (11.4 to 20.3 cm), then select one of the four open-crown profiles.
- Select a stand working height from 3 to 8 inches (76.2 to 203.2 mm), measured from the work surface to the bottom of the crown block, then generate the stand STL. Its 135 mm upper pad has a 2 mm rounded outside edge, leaving a 131 mm flat contact area around the BS-1.0 stud: Ø24.606 mm × 38.10 mm (1.50 in) overall height.
- Use Download Crown File to create the complete crown block with three Ø25.4 mm × 63.5 mm deep (2.50 in) sockets, an interrupted bottom centerline, and FRONT/BACK orientation marks. Printer Setup offers Bambu 3MF with settings for supported printer, nozzle and filament combinations, or a universal model-only STL.
- Open a Bambu 3MF as a project to load its settings. For STL, choose settings in your slicer. Keep scale at 100% and check the material and build plate before slicing.
The four profiles
1 Full dome · 2 Rounded open · 3 Classic open · 4 Shallow dome. Every profile holds the selected block size through the lower 31.75 mm, follows the selected inward wall taper, and begins its family-specific top curve 36.5 mm below the selected top.
Adjustable height
The selected value is the finished block height from the base plane to the top-center maximum. The 5½-inch setting is the governed workshop reference. Extended heights require enough usable printer Z travel and should be checked in the slicer at 100% scale before printing.
Print profile and material
PET-CF is the preferred working-tool candidate. Use 40% gyroid infill. With a 0.6 mm hardened nozzle, use 6 wall loops and at least 6 top/bottom shell layers. With a 0.4 mm hardened nozzle, use 8 wall loops and at least 8 top/bottom shell layers. For the stand, use a 100% infill modifier over the complete peg, root radius, and upper load pad.
The STL contains geometry only; it cannot force slicer settings. Verify every value in the sliced preview. PET-CF and these settings remain subject to physical workshop qualification and do not create a rated load.
PLA warning: PLA is not recommended for working Blocksmith tooling. Use it only for non-production training, prototype, fit-check, or display work at room temperature. Never expose PLA tooling to steam, an iron, a heat gun, hot water, or another workshop heat source; it can soften, creep, distort, or loosen before damage is obvious.
Smooth crown surface
Use random seam placement. It avoids one continuous raised ridge down the felt-contact surface. Inspect the cooled print in raking light and by touch, lightly remove isolated high spots, and keep fuzzy skin and ironing off on the crown, sockets, stand pad, and peg.
Variable/adaptive layer height is an optional surface trial. Keep the straight wall at the governed layer height and let the slicer refine and smoothly blend the upper 36.5 mm curve: approximately 0.18–0.24 mm with a 0.6 mm nozzle or 0.12–0.20 mm with a 0.4 mm nozzle, without going below the manufacturer’s supported range.
Print upright as generated and normally without supports. Inspect the socket-roof bridges, seam markers, layer-height map, wall count, and stand modifier in the sliced preview. After cooling, pass a felt witness trial with no grid, seam, or unintended texture transfer before shop qualification.
Blocksmith provides printable engineering geometry. It does not certify a material or print for steam, heat, load, or production use.
