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[Massimiliano]

I’m working on a small gear-driven mechanism for a camera panning rig and considering printing the 45° bevel gears in PETG (FDM). Tooth pitch is 1.5 mm, and the gears will be rotating slowly under low torque. My concern is whether layer lines and over-extrusion could cause poor meshing or increased backlash, especially since the gears need to run smoothly for accurate motion control. Would post-processing like sanding the teeth tips make a noticeable difference?

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[neil barnes]

FDM-printed PETG gears can work for low-torque applications, but layer lines and minor over-extrusion will likely affect meshing smoothness. Since your gears have a fine, even small imperfections could introduce slight backlash or tightness. Light sanding of the tooth tips and flanks could help, but it’s hard to achieve perfect uniformity by hand. Have you considered printing a test pair and dry-running them to check for binding or excessive play?

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[Massimiliano]

I haven’t printed a test set yet—wanted to get some advice first. Would printing at a higher resolution (e.g., 0.1 mm layer height) or using a smaller nozzle (0.2 mm) improve tooth definition enough to reduce backlash? Also, if backlash is an issue, maybe I’ll add a spring-loaded tensioner. Would lubricating the gears (e.g., with silicone grease) help with layer-line friction?

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[neil barnes]

layer-line friction entirely. PETG’s slight flexibility might also introduce minor deflection under load. If smooth motion is critical, you might want to explore SLS (nylon) or MJF printing—these processes produce near-isotropic parts with tighter tolerances and no layer lines. That said, for a prototype or light-duty use, FDM could suffice with some trial-and-error tuning.

In terms of lubricating, yes, light lubricant will reduce friction and noise from layer lines. Just avoid oils that might degrade PETG. A tensioner is a smart backup—let me know how the test goes! If you hit persistent issues, resin printing (for higher detail) or outsourcing to SLS could be next-step options. Good luck!

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