Mastodawn

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

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Dance the Manta Ray Mar 9

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

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Dance the Manta Ray Mar 9

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.

🤔

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Johan Wärlander 🦀Mar 9

@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.

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Dance the Manta Ray Mar 9

@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!