1
$\begingroup$

I spent the last days trying to make the best gears I could but they are not "smooth" nor good. I searched at thingverse with "gear" but I see no set of gears. I would like someone to point me a good set of gears (with 5, 10, 15... teeth for example) so I can use this STL file with Google Sketchup.

Do you guys know any good matching gears that I could print?

I will be using this gear in a fast spinning matching so it would be nice these gears to be well designed to support some fast moving.

Also, I think in my case I would like to use gears with this shape (the white gear). Any idea why is this gear design better than the usual? enter image description here

$\endgroup$
2
  • $\begingroup$ How is this about 3d printing? $\endgroup$ – marshal craft Mar 30 '17 at 22:44
  • 1
    $\begingroup$ Hi, Samul! In its current state, your question is very broad, and does not have any definite objective answer. For this reason I have to put your question on hold. I advice you to take a look at our help center for more information on how to ask here at 3D Printing SE. In general, 3D Printing SE is not a very good place to ask for specific STL files. Good luck! $\endgroup$ – Tormod Haugene Apr 4 '17 at 11:16
4
$\begingroup$

This type of gear is known as a "herringbone" gear. A traditional straight-cut gear is strong, but can cause more vibration as each tooth engages and disengages. A helical gear (slanted tooth) reduces that vibration as the tooth engagement is more uniform. However the angle of the teeth causes a sideways force that may be undesired. A herringbone tooth design effectively cancels the sideways forces but gets the uniform tooth engagement.

A search for "herringbone" on Thingiverse comes up with many gears of this type.

Regarding the quality, if you are not happy with the results of your own design, that's OK - gears are shockingly complex, and people make careers of gear design! However, if you have a good CAD model that just isn't printing well, it's not likely a bad STL.

An STL from a different source is likely to have similar quality with the same slicer/printer setup. You might be able to improve print quality of your design by changing settings on your slicer or adjusting your printer. I'd suggest asking a question with your current setup and specific print quality issues.

$\endgroup$
2
  • $\begingroup$ Thnks man, I didnt know that name, now I can google it and learn more about it! I am just sad that nobody still created a good set of gears :( That's amazing cause it's really important to have a good STL set of gears, despite slice programs, I know several configs can change it's quality but it would be nice to have some gear set to start with. $\endgroup$ – Samul Mar 29 '17 at 21:33
  • 1
    $\begingroup$ By lighting only flaw I can see as you really haven't described the problem with your results, is very noticeable z layers compared to the size of the part making them "pixelated". Other than that due to the different in color it is hard to see dimension issues. You might try smaller layer height coupled with a smaller diameter nozzle? $\endgroup$ – marshal craft Mar 30 '17 at 22:49
-1
$\begingroup$

As for high speed gear ideas why don't you design your own if there aren't any good ones. I will admit sometimes there will be surprising lack of content in some areas and I dont know what you expect, sometimes you do have to do some things your self to bridge the gaps. Maybe try looking into automobile transmission or even jet engines which use two shafts for high speed compressor and low speed fans. Jet engines spin pretty fast over 35k RPM. They may end up using a planetary gear I would think, the forces are well balanced. But you haven't said the purpose of this gear, is it power transmission on separate parallel axis? Speed reduction/change? In engineering, structurally things which use pointy edges can perform poorly under stress, the stress is highly focused geometrically. Instead if manufacturing constraints and design volume allows it, rounded, chamfered, or filleted edges reduce high stress points. Also adding material distributes loads where possible. Smaller teeth may increase vibration frequency but reduce amplitude. Ideally you would want to minimize the relative velocities of the contacting surfaces to reduce waisted force from friction converting to heat. Also heat can reduce strength and increase wear, decreasing life span of the gear.

$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.