FR2 is the brownish material that many cheap circuit boards are made of. It’s a mixture of phenolic resin and paper. Apparently it’s quite useful to make gears out of:

Phenolic Gears exhibits superior shear force, help reduce machinery noise, absorbs destructive vibration unlike metal gears, phenolic is non-conductive, protects the mating metal gear train, and are known to outlast metal gears under severe continuous service. (source: https://www.knowbirs.com/phenolic-gears )

(Main pic stolen from here)

(Many more pics here)

Has anyone seen these used anywhere? I’ve read a hint regarding pool equipment, but I have never seen them there. I assume the fibres allow them to last longer than plastic/resin only gears.

  • Nerb@techhub.social
    1·
    17 hours ago

    @Gronk @WaterWaiver

    I printed 2 gears for my 7x12 lathe out of a filament from Igus.

    https://www.igus.com/product/20322?artNr=I190-PF-0175-0750

    Been in use for over 5 months and from inspection are in good shape. Quieter and unlike the originals durable. One is sacrificial and will shear if the lathe jams. When I jammed it it loaded the motor pretty heavily then let go so it did work. Some replace that gear with a metal one but I wanted the sacrificial feature so I do not blow the motor and speed control.

    You need a heated chamber and they recommend heat treating it before use which I did not do since I was not certain it would not change the dimensions.

    They have a few other filaments that are also useful. I went to this after multiple attempts to 3d print delrin. Even made a wood bed and finally gave up.

    It’s not cheap but I still have over 90% on the reel left after printing 3 gears.

    • Gronk@aussie.zoneEnglish
      1·
      25 minutes ago

      Thanks for expounding, I’ll definitely look into using that filament.

      My aim is to find a cost effective diy solution for robotic servos. I want to try to make something equivalent to the Dynamixel mid range.

      I think the cost of these motors make amateur robotics prohibitively expensive.

      I considered designing a gear hob / jig to make hobs for the open lathe 3d print, but I feel like that’s too far abstracted from my purpose and most people wouldn’t be willing to go that route. (But it’d still be pretty cool)

      So I’m considering multiple options, 3d printed gears, purchased metal gear sets, diy gears from the lathe

      I’m gonna do some more research on these gears and I’ll let you know if I find anything culpable