Stripped plastic gear, is this a standard part?

[mediaevalfishsandwich@zeroes.ca]

Stripped plastic gear, is this a standard part? Can I buy another? Thanks in advance!

Gear OD is 9mm
Gear/Teeth ID is ≈8mm
Gear Height is 10mm
Axle Diameter is 1.5mm
24 teeth

Output shaft on gearbox rusted and seized, consequently the motor stripped the first gear in the cluster.

Luckily if I invert the gear, the stripped part is no longer engaged, and the gearbox works again.

If it seizes again (I'm hoping a generous serve of fish oil and marine grease averts this), I would need new gear or new gearbox assembly ($350!!! 🤬)

Or is the gearbox a standard HVAC part that could be bought elsewhere?

#Maker #Gearbox #HVAC #Mending #FediHelp

[douglasvb@m.ai6yr.org]

@mediaevalfishsandwich I bet that exists in some catalog somewhere for purchase. Maybe with Misumi or McMaster?

[mediaevalfishsandwich@zeroes.ca]

@douglasvb Appreciate it! Yeah feels like it should be somewhere. I didn't know Misumi, one to remember for future.

Trying those, I fell down with the tooth width, 10mm gets me into a much bigger shaft diameter than I want.

🙏

[douglasvb@m.ai6yr.org]

@mediaevalfishsandwich hmm 🧐🧐

@ai6yr any ideas on a company that has a wide selection of small plastic gears?

[ai6yr@m.ai6yr.org]

@douglasvb @mediaevalfishsandwich

Paraphrasing Dr. McCoy

"Dammit Doug, I'm an electrical engineer/software developer, not a mechanical engineer! " 🤪

[mediaevalfishsandwich@zeroes.ca]

Digging around came across:
https://www.stlgears.com/generators/3dprint
You give it some parameters, and it makes an STL model you can print.

Module 0.344
Pressure Angle 20°
Teeth 24
Gear Length 10mm
Hole Radius 0.75mm

It looks pretty close to the real thing. I've no experience with 3D printed gears, might be another option? A whole other language I'm not familiar with.

It's not a highly loaded gear, at least ordinarily! Massive massive speed reduction/torque increase by the time it gets to the other end.

#Maker #Gear #3dPrinting #RCcar #Robotics #HVAC

[14mission@sfba.social]

@douglasvb @mediaevalfishsandwich @ai6yr Try: https://www.mcmaster.com
(Haven't actually used them, but I suspect this sort of thing is in my future).

[14mission@sfba.social]

@douglasvb @mediaevalfishsandwich @ai6yr But for a random mechanical project I've recently been roped into, we're looking at Temu, though that's for bigger gears.
Also, always worth looking in eBay.

[14mission@sfba.social]

@douglasvb @mediaevalfishsandwich @ai6yr Only seeing metal gears on McMaster, sorry.

[14mission@sfba.social]

@douglasvb @mediaevalfishsandwich @ai6yr Oh, found plastic ones, but they all seem to be too big for your purpose: https://www.mcmaster.com/products/gears/spur-gears-1~/number-of-teeth~24/system-of-measurement~metric/?s=plastic%20gears

[mediaevalfishsandwich@zeroes.ca]

@14mission thanks 🙏

I had not tried those, but I've had a look just now. I seem to have a very odd gear, the module (0.35), tooth width (10mm), and axle diameter (1.5mm) are evidently not common at all.

[mediaevalfishsandwich@zeroes.ca]

This gear seems to be a bit of an orphan, the smallest metric gear module anyone is selling is 0.5, so far as I can tell.

If I model a gear with 24 teeth and module 0.5, it comes out 13mm in diameter (as expected really), that's clearly not right, my measured module of around 0.35 gives an appropriately sized model.

🤔

[jwarlander@mastodon.nu]

@mediaevalfishsandwich If you know someone with a 3D printer "nearby", it's definitely worth trying.

Theoretically some materials may be more appropriate than others, but regular old PLA tends to work more often than not unless it's exposed to high temperatures.

[mediaevalfishsandwich@zeroes.ca]

@jwarlander thanks for the temperature tip. It's going to regularly see ≈60°C in summer, sealed box on Australian roof. Looking it up, might have to be another material. UV won't be a consideration, humidity might be.

I'm seeing references to dimensional variability in printing, guess can but try!