Sprocket pair

The prompt

Model two roller-chain sprockets for ISO 606 06B single-strand chain as two separate solids on a fixed centre distance; the chain itself is not modelled. Chain pitch p = 9.525, roller Ø6.35. Frame: both axes parallel to Z; sprocket A's axis passes through (20, -30), sprocket B's through (164, 78), so the line of centres from A to B points at 36.870° (centre distance 180). Both tooth plates occupy Z=0..5.3 (one chain line). Angles are measured in the XY plane from +X toward +Y about each sprocket's own axis. Tooth form, ISO 606 construction with these exact values: pitch diameter d = p / sin(180°/z). Around each roller centre on the pitch circle, a roller-seat arc of radius ri spans the seating angle, symmetric about the line from the roller centre to the sprocket centre. From each end of the seat arc a convex flank arc of radius re continues tangentially; its centre lies on the line from the roller centre through that seat-arc end, re beyond the end. The flanks are cut off by the tip circle da. Root diameter = d - 2ri. No tooth side chamfer. Sprocket A: 21 teeth, d = 63.908, ri = 3.30, seating angle 124°, re = 24, da = 68, root Ø57.308. Hub Ø32 from Z=5.3 to Z=25. Ø15 bore through Z=0..25 with a 5 wide keyway on the 90° side, floor 9.8 from the axis. A radial Ø5 set-screw hole at Z=15 runs from the hub surface into the bore on the 270° side. Phase: a TOOTH of A is centred on the 36.870° direction (pointing at B), so A's roller seats sit at 36.870° ± 8.571°. Sprocket B (plate type, no hub): 45 teeth, d = 136.546, ri = 3.30, seating angle 126°, re = 60, da = 141, root Ø129.946. Centre hole Ø60 through the plate; six Ø6.6 bolt holes through the plate on a Ø76 circle about B's axis at 0° + k·60°. Phase: a roller seat of B is centred on the 216.870° direction from B's axis (pointing at A).

Model facts

Overall size

248.2 × 212.2 × 25 mm

Bodies

2

Volume

84.3 cm³

Adjustable in the studio

2 dimensions