S5M (STD 5M) Pulley 20T & 100T, 1:5 Reduction – Printed & Tested

A 1:5 STD S5M reduction, printed and run on an S5M 690 belt: a 20-tooth pulley on a 100-tooth wheel with eight spokes. The wheel's top flange prints as a separate ring and glues on over 40 nubs; the 20-tooth pulley prints its flanges in place.

Printing

• Printed on an Anycubic Kobra 2 Max in PETG, 0.15 mm layer height.

• Pulley 1: print the "-w-supports" STL. Breakaway supports hold its top flange, which prints in place; snap them off after printing.

• The 100-tooth wheel: print the wheel and the separate flange ring, then glue the ring on over the 40 alignment nubs.

• Two M4 set screws per hub, in captured nuts.

• The STLs are exactly what was printed for the photos: pulley 1 with 0.2 mm of print compensation, pulley 2 with none. The STEP file is nominal size.

Files

• STEP at true size: one file with every part of the drive, the belt included.

• STL for printing:

  • STD-5M-20T.stl - pulley 1, 20 teeth, without supports

  • STD-5M-100T-P2-1flange.stl - pulley 2, 100 teeth

  • STD-5M-20T-w-supports.stl - pulley 1 with breakaway supports under its top flange: print this one

  • STD-5M-100T-P2-flange-only.stl - pulley 2's top flange, printed on its own

Need another size?

These were designed in the CheapCADTools Timing Pulley Generator. Open this exact design there and change the teeth, bore, hub, set screws, spokes or flanges, or switch to any of 34 belt profiles (GT2, HTD, T5, AT5, XL, MXL and more): https://cheapcadtools.com/samples/std-5m-20t-100t-printed-eight-spoke-reduction/?ref=printables

Belt length for your centre distance, free: https://cheapcadtools.com/belt-length-calculator/?profile=STD%7C5M&z1=20&z2=100&n=138&ref=printables

Paid, so you know: designing in the generator is free; downloading a new STL, STEP, DXF or SVG from it costs tokens (an STL is 3 tokens, about 15 cents). The files on this page are free.

All settings, as designed

Drive

• Family: STD; Pitch: 5M

• Belt Height (mm): 10; Clearance Height (mm): 2

• Centre Distance (mm): 183.86 (belt 138 teeth)

Pulley 1

• Num. Teeth: 20; Bore Diameter (mm): 5

• 3D Print Compensation (mm): 0.2; Tooth Clearance: Standard; Backlash: Standard

• Hub OD (mm): 25; Hub Height (mm): 10

• Retention Method: Set Screw (captured nut); Set Screw Size: M4; Number of Screws: 2

• Flanges, 3D Print: Flange Height (mm) 2; Flange Angle (°) 15; Rim Radius (mm) 4; Top flange as separate part: no

• Add Print Supports: Nozzle Dia. (mm) 0.4; Max Spacing (mm) 10; Air Gap (mm) 0.2

Pulley 2

• Num. Teeth: 100; Bore Diameter (mm): 5

• 3D Print Compensation (mm): 0; Tooth Clearance: Standard; Backlash: Standard

• Hub OD (mm): 25; Hub Height (mm): 10

• Retention Method: Set Screw (captured nut); Set Screw Size: M4; Number of Screws: 2

• Spokes: Spoke Count 8; Spoke Width (mm) 6.9; Hub OD (mm) 25; Rim Depth (mm) 8.4; Fillet Tip (mm) 10; Fillet Base (mm) 3; Spoke Height (mm) 6

• Flanges, 3D Print: Flange Height (mm) 3; Flange Angle (°) 15; Rim Radius (mm) 5; Top flange as separate part: yes

• Add Gluing Nubs: Number of Nubs 40; Nub Diameter (mm) 5; Nub Height (mm) 3; Socket Fit Allow. (mm) 0.2

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