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I am making a gear/cog to attach to a high torque stepper motor.

I can realistically make it out of the following variety of materials:

  • 3D printer PLA/PLA+ etc.
  • layered PLA/PLA+ and fiberglass made with high strength epoxy
  • ply wood
  • ply wood with fiberglass coatings

The easiest cheapest gear for me to make with my tools is made with PLA, and perhaps I can sandwich some casting epoxy with fiber filings mixed in to increase the width + exterior surfaces coated with a layer of fiberglass.

But since this is going into the core of a thing I am making on top of a "high torque" (the Nema 23) stepper motor, I would want the structure of it to last at least a little while, and the teeth not to grind themselves to grit.

What is the ideal path forward? (Going for customizability, cheapness, ability for me to make, and ability to interface with more fragile cogs and components further out from the main driving gear without tearing them apart).

Chris
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    Why not purchase gears? There are numerous companies that service prototyping needs. Nothing you can print will match the performance and strength of a machined gear. – Eric S Jul 24 '21 at 20:12
  • torque = force×lever arm. If the gear is large enough, you'd mostly have to worry about the inner portion which should be pretty easy to reinforce with metal-collars or even just plates and bolts. If you truly need a custom shape and strength close to machined, pony up a bit for laser cut sheet metal. would put that CAD to good use and might even be cheaper than some quality metal ots gears – Abel Jul 24 '21 at 20:34

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What tools do you have available? 3D printed and layered PLA is your best choice if you only have a 3D printer.

For gears you usually want precision within .005" or less. You could CNC route material but I would not recommend wood (ply or lumber) as it would split easily when stressed along the grain. Fiberglass coating would help but then again you would need to very accurately control the layer thickness. If you were to CNC a part you may as well use a stronger base material.

jko
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