RESIN-PRINTED GEARS VERSUS PLA: WHICH IS TOUGHER?

When it concerns making gearboxes, 3D printing has the benefit that it lets you whip up whatever unusual gears you may requirement without a whole great deal of hunting around at obscure gear suppliers. This is especially great for those outside the restricted radius served by McMaster Carr. When it concerned 3D printed gears though, [Michael Rechtin] wondered whether PLA or resin-printed gears carried out better, as well as chose to investigate.

The subject of the test is a 3D-printed compound planetary gearbox, developed for a NEMA-17 motor with an 80:1 reduction. The FDM printer was a Creality CR10S, while the Creality LD02-H was on resin duty.

The put together gearboxes were evaluated by utilizing a 100 mm arm to press against a 20 kg tons cell to ensure that their performance might be determined accurately. By multiplying the force used to the tons cell by the  length of the arm, the torque output from the gearbox can be calculated. A rig was set up with each gearbox pushing on the tons cell in turn, with a closed-loop controller ensuring the gearbox is packed as much as the stall torque of the stepper motor before letting the other motor take over.

The resin gearbox failed fairly quickly, as well as dissection suggested a few of the interior gears had failed. A reprint with stronger resin was done, as well as the test begun again. This time, each gearbox lasted over 500 cycles without issues, however the resin gearbox failed soon after, wiggling about before jamming up for good. opening the gearbox led to damaged teeth as well as powdered resin falling out. Meanwhile, the PLA gearbox showed extremely bit wear in spite of the repetitive test.

Thus, if you’re wanting to put major tons with your 3D printed gearbox, you most likely want to choose PLA or one more FDM material rather than resin. This result is unsurprising, as a general guideline of thumb is that resin prints are much more brittle than their FDM counterparts. Of course, the precise plastic or resin you print with will vary this result however, so don’t take it as a hard-and-fast rule, much more of a general guide. video after the break.

[Thanks to Zane Atkins for the tip!]