Two-Speed Automatic Gearbox - inspired by TechnicBrickPower

[Zerobricks]

Watching @TechnicBrickPower's videos on youtube gave me an idea to try my own version of the Automatic gearbox.

The biggest change is that instead of using the inefficient differential to sense torque, the whole motor acts as torque sensing element. The motor is mounted in such way that it can be rotated and switch gears.

A more detailed description and demonstration can be found here:

 

For now this is just an unpolished idea, but it might be a gamechanger due to it's very high efficiency and simple construction.

Edited September 28, 2020 by Zerobricks

[JintaiZ]

Looks great!

[2GodBDGlory]

Wow! That is very original and interesting! The biggest disappointment for me is that one must find room to install a giant "flywheel" for proper shifting, but it is a fascinating idea, which could probably be extended to a four-speed, in exchange for its simplicity!

Good work!

[Zerobricks]

1 minute ago, 2GodBDGlory said:

Wow! That is very original and interesting! The biggest disappointment for me is that one must find room to install a giant "flywheel" for proper shifting, but it is a fascinating idea, which could probably be extended to a four-speed, in exchange for its simplicity!

Good work!

Yes, it could easily be expanded to 4 speed. I think using several motors to give us more shifting power and weight would allow to use a smaller maybe geared-up flyweight.

[2GodBDGlory]

Just now, Zerobricks said:

Yes, it could easily be expanded to 4 speed. I think using several motors to give us more shifting power and weight would allow to use a smaller maybe geared-up flyweight.

Neat! Using an XL motor would also add a lot more weight on the axle, working somewhat like the flywheel.

I just got some Control+ stuff, and I would love to try to make an electronically controlled 8-speed automatic gearbox, using the drive motors current draw as resistance sensors, and a separate motor for shifting. All I need to do is finish my current MOC, learn how to program, and build it... If the programming allows for it.

[Zerobricks]

Just now, 2GodBDGlory said:

Neat! Using an XL motor would also add a lot more weight on the axle, working somewhat like the flywheel.

I just got some Control+ stuff, and I would love to try to make an electronically controlled 8-speed automatic gearbox, using the drive motors current draw as resistance sensors, and a separate motor for shifting. All I need to do is finish my current MOC, learn how to program, and build it... If the programming allows for it.

That's also a very good idea. Remember to give your electronic gearbox some hysterises and delay time so it wont shift too often or oscilate.

[2GodBDGlory]

9 minutes ago, Zerobricks said:

That's also a very good idea. Remember to give your electronic gearbox some hysterises and delay time so it wont shift too often or oscilate.

Yeah, you don't want it getting halfway through a downshift, realizing that there is now no load, and then shifting up again!

8 minutes ago, 2GodBDGlory said:

 

The programming would likely be similar to what Sariel did here:

http://sariel.pl/2012/02/nxt-automated-gearbox/

8 minutes ago, 2GodBDGlory said:

 

 

Edited September 28, 2020 by 2GodBDGlory

[Zerobricks]

I managed to VASTLY improve the design so now the flywheels i no longer needed and the gearbox now works in both directions. Of course I built the gearbox from real bricks and it works much better than first evrsion.

If you look at the internals, the high gear is powered directly on the lower axle. The low gears take the longer route on the sides (bypass) and meet up at the yellow output shaft with a 1:3 gear ratio. Because I used 2 shafts for the low gear, the gerabox can switch regardless of the direction the motor is rotating.

By modfiyng the design, the gearbox can be upgraded to several options:

• a 3 speed bidirectional version by allowing the wave selector to turn additional 90 degrees and adding an even higher low gear above the selector
• a 3 or 4 speed monodirectional gearbox where each of the bypass axles allows for a different gear ratio

I will create a video of the real gearbox in action as soon as I find some time. I'm actually very proud of this baby, it's my best automatic gearbox as of yet!

[2GodBDGlory]

Looks great! I'll have to find some time to try building it soon!

[howitzer]

Now this is the kind of innovation that I'd love to see in official sets. A truly novel way to use the existing parts, allowing for functionality which has been impractical or even impossible previously. Kudos to you @Zerobricks!

[BusterHaus]

Very clever solution. Have you tried it with 2 axles? Since they're independent shifting might occur at different times. 

[Zerobricks]

5 minutes ago, BusterHaus said:

Very clever solution. Have you tried it with 2 axles? Since they're independent shifting might occur at different times. 

The independent axle don't shift at once, either of them shifts to low gear, depending on the motor direction.

[Zerobricks]

I recorded a quick video of the gearbox in action.

You can download the LDD files and photos here:

https://bricksafe.com/pages/Zblj/automatic-gearbox