MakerGear Forum

So far I have shredded 5 pinions, including 2 that were bought in Feb 2017. These shredded gears are not only a pain to replace, but they slowly degrade my print quality before I realize what's wrong.
Is it possible to buy a third-party pinion? All the other gears in the stepper gearbox are in good condition, so it would be nice if I could just get a pinion made out of the same material.

helix_3 wrote: ↑

Tue Aug 21, 2018 5:26 am

a pinion made out of the same material.

Which would disintegrate almost immediately, because it gets far more wear than the planetary gears around it:
https://softsolder.com/2014/07/31/maker ... tus-check/



The pinion has 11 teeth and the planets have 17 apiece. Each pinion tooth engages three planet teeth on each rotation, so it wears 3*17/11 = 4.6 times faster.

Which is why the planets consist of sintered metal and the pinion is (supposed to be) hardened steel.

Of course, we expect the motor distributor will sell quality motors. The distributor expects the motor manufacturer will use a hardened pinion. The manufacturer expects the gear factory will produces hardened gears. The gear factory must correctly harden the gear after cutting it. Every single transaction in that chain tends toward the lowest price with the fewest inspections.

If your extruders get that much wear, then you can:

• Regard the motors as consumables to be replaced on schedule
• Boost your spend for motors from a known-good (industrial-grade) supplier who's paying for more inspections and can guarantee their performance
• Contract a local machine shop to produce known-good pinions to your specification

Given the horror stories from the Chinese manufacturing and supply chain, you'll probably be better off regarding them as consumables.

I took my gear box off the other day for the first time and did notice it was rather DRY for a gear box.. I added a bit of white lithium grease to the gears and will inspect it again in a couple of months.

I must have a different version my pinons look different (J/K thats after four years of use.)

sthone wrote: ↑

Tue Aug 21, 2018 5:20 pm

after four years of use

The driving section on the end looks well-used: you're in line for a new motor, too!

Yeah it pretty much ran out of usable surface. I did end up buying a whole new motor already but also bought another pinion too just to use this one as a back up in a pinch if one of my other printers suffers the same fate.

Is the drive gear on the motor just a light press fit or does it need to be heated to remove and install?

They are suppose to be on there with a retaining compound so heat sould be need to remove them but I did have one come off on it's own once so ... I chock that one up to the Chinese manufacturing Ed was talking about though.