Hello everyone. I want to share my invention with you.This is a gearbox in which a black 36-tooth gear acts as a switch.
I have not seen such a mechanism before, so I want to believe that I invented it

1st gear has a ratio of 12:20
2nd gear 20:12.
You can see how it works in the video.

 

Don't remember seeing this. So it could be pretty original. At least for lego build.

Cool, a very elegant solution!

Very nice! You could also use this:

 

in place of the 36T gear to make it slightly smaller. It would also allow using 8T gear for the output axle, if you wanted more speed without additional upgearing.

Edited December 12, 20213 yr by howitzer

12 hours ago, howitzer said:

It would also allow using 8T gear for the output axle

I don't think so, there is that 20T gear, which changes its position. In this case that 36T gear has really good use, so that You can estimate the space, which is needed for switching.

3 minutes ago, Jurss said:

I don't think so, there is that 20T gear, which changes its position. In this case that 36T gear has really good use, so that You can estimate the space, which is needed for switching.

Ah, true, there's no space for an axle to bypass the tan gear. Still, replacing the 36T gear with the aforementioned part would free some space that could be used for bracing or something in a vehicle or whatever.

I think the mechanism itself is conceptually really nice, just wonder how much stress this drivetrain could take. I mean it has quite a few weak spots; the two 8T gears themselves, and the whole moving assembly resting on a single axle that has the big gear with two more axles inside, and all those are impossible to brace from both sides because they have to be able to move. So something would skip for sure. What application did you have in mind @BB8, because I guess it would not fly for an RC offroader, but maybe useful for some mechanism that has to move light weight. Have you tested it in an actual build other than the demo?

17 minutes ago, gyenesvi said:

I think the mechanism itself is conceptually really nice, just wonder how much stress this drivetrain could take. I mean it has quite a few weak spots; the two 8T gears themselves, and the whole moving assembly resting on a single axle that has the big gear with two more axles inside, and all those are impossible to brace from both sides because they have to be able to move. So something would skip for sure. What application did you have in mind @BB8, because I guess it would not fly for an RC offroader, but maybe useful for some mechanism that has to move light weight. Have you tested it in an actual build other than the demo?

I think a bracing could be added, just put another 36T gear (or whatever) on the other side of the assembly, and then a longer axle through it to a static bracing. Still not enough for an RC offroader (unless you can find a way to replace the 8T gears with something bigger), but could be useful for something less demanding.

It would be also to do switching with some stepper, as it is not good to keep servo in on of positions (I suppose). It would be better to control it somehow trough wormgear. But that would be long switching again.

Could you use this instead of the 36 tooth gear, to allow use of something bigger than the 8 tooth gears?

https://rebrickable.com/parts/2711/technic-plate-1-x-5-with-toothed-ends-2-studs-and-center-axle-hole/

Not tried it, but seems like something should be possible even if the studs aren't ideal.

Even so, I think the real deal breaker will be when there's enough torque going through there, that the Servo can't hold it all steady.

Edited December 14, 20213 yr by amorti