Heads up: many models on this page are AI-generated or uploaded untested. They may be misconfigured for the intended application — check the dimensions and tolerances, and verify or edit the model before printing or relying on it.*
Rotating Gondola Line Arm
A 64 x 36 x 6 mm swivel arm from the 'NEMA17 Hanging Wall Polargraph Drawbot' kit (print two). Its 22.8 mm chamfered bore turns freely on the Ballast Gondola Pen Hub's 22.0 mm pen sleeve, so each drive line stays aimed at the pen axis at every hang angle. The line ties off through a 2.5 mm countersunk eyelet 40 mm from the axis, and a 1.5 mm knot groove on the top face seats the knot.
Ballast Trough Screw Lid
This is the 90 mm OD x 3 mm annular lid from the 'NEMA17 Hanging Wall Polargraph Drawbot' kit. It closes the Ballast Gondola Pen Hub's shot trough so the ballast can't fall out. Its 22.6 mm bore slides over the hub's 22.0 mm pen sleeve. A 30 mm OD thrust ring, 2 mm high, gives the two rotating line arms a smooth bearing face. Three M3x8 socket-head screws go through 3.4 mm holes on a 40 mm radius into the hub's M3 heat-set inserts, and six 1.6 mm radial ribs stiffen the plate.
Ballast Gondola Pen Hub
This is the main gondola body for the 'NEMA17 Hanging Wall Polargraph Drawbot' kit. It is a 90 mm dia x 46 mm hub with a 22 mm OD pen sleeve and a 14 mm through-bore that takes pens 8–13.5 mm across. The sleeve sits on the axis of an annular ballast trough, which holds about 120–150 g of shot or coins to give steady pen pressure. The trough is closed by the kit's screw lid, fixed with three M3x8 screws into M3 heat-set inserts (4.0 mm bores) at r = 40 mm. A 3.6 mm slot in the sleeve lets the collar's M3x16 screw clamp the pen, and a 1 mm chamfer on the base helps it glide over paper.
Chamfered Polargraph Line Spool
A 42 mm dia x 44 mm line spool from the 'NEMA17 Hanging Wall Polargraph Drawbot' kit (print two). It has a 30 mm drum that takes up 94.2 mm of line per turn, a 5.2 mm bore for the NEMA17's 5 mm shaft, and a radial 4.0 mm bore for an M3 heat-set insert and set screw. A 2 mm anchor hole in the outer flange holds the line. Both flanges are 45° cones, so it prints without supports, and a hollowed core keeps it to about 25 cm³.
Wall Backer Plate
A 110 x 70 x 8 mm wall anchor plate from the 'NEMA17 Hanging Wall Polargraph Drawbot' kit (print two). It fastens to the wall with four #8 wood screws in counterbored 4.8 mm holes on a 90 x 50 mm pattern. The spool standoff cage's four 12 mm posts drop into 12.4 mm square recesses on a 54 mm square and are held by M4x10 cap screws driven from the wall side. Those screw heads sit in 8 mm counterbores, below the flat wall face.