[MOC] Outdoor RC LEGO with Gearbox and Clutch

[SimplyLegoTechnic]

Hey everyone!

I’d like to share the results of my latest creation: the Outdoor RC LEGO with Gearbox.

On one hand, it’s an evolutionary upgrade of my previous MOC (https://reb.li/m/190094) since it uses the same sequential 3-speed gearbox.

On the other hand, it’s a completely new model.

I’ve added a synchronized clutch mechanism and completely redesigned the gear-shifting system.

It now uses BuWizz 3.0 and a BuWizz motor instead of the standard LEGO hub and LEGO PU L-motors.

Surprisingly, the transmission works great, despite the glitches with BuWizz 3.0.

For those just interested in the presentation: YT.

For those who care about the build details, free instructions: https://reb.li/m/191991.

Edited August 27, 2024 by SimplyLegoTechnic

[gyenesvi]

That's a nice mechanism packaged in a neat body! I like the placement of the Buwizz motor, I always wondered whether such a placement is possible, looks cool and even somewhat realistic. Too bad it's only possible for RWD. The clutch system is interesting, though wonder if it's necessary. I have seen people change gears without clutch under the load of 2x Buwizz motors, so it seems the gearbox parts can take it. But for the challenge of making this clutch mechanism I completely understand why you went this way.

[2GodBDGlory]

Nice job! I really like the execution of the auto-clutch mechanism! I've always thought of that as being a cool mechanism that's impractical to implement, but your mechanism looks very reasonable!

[SimplyLegoTechnic]

11 hours ago, gyenesvi said:

That's a nice mechanism packaged in a neat body! I like the placement of the Buwizz motor, I always wondered whether such a placement is possible, looks cool and even somewhat realistic. Too bad it's only possible for RWD. The clutch system is interesting, though wonder if it's necessary. I have seen people change gears without clutch under the load of 2x Buwizz motors, so it seems the gearbox parts can take it. But for the challenge of making this clutch mechanism I completely understand why you went this way.

Thanks for the feedback!

About the clutch. If it wasn’t necessary, real cars wouldn’t have it either, right?)))

In my previous MOC (https://reb.li/m/190094), I showed in this video (https://youtu.be/8Zy2hgXiuh4) that shifting gears without a clutch isn’t exactly smooth. Since I build models to last for hundreds of hours with minimal wear, I need every bit of reliability I can get. Plus, moving the complexities of shifting from a complicated gearbox to a simple clutch mechanism just makes sense.

9 hours ago, 2GodBDGlory said:

Nice job! I really like the execution of the auto-clutch mechanism! I've always thought of that as being a cool mechanism that's impractical to implement, but your mechanism looks very reasonable!

Thanks! In this MOC, the BuWizz motor and the entire transmission have come together surprisingly well. I’ve never enjoyed playing so much before!

Edited August 17, 2024 by SimplyLegoTechnic

[Milan]

Great video presentation, and a nice model.

[SimplyLegoTechnic]

8 minutes ago, Milan said:

Great video presentation, and a nice model.

Thank you! I'm really glad you liked it :)

Of course, it’s a very challenging model to build, but it’s so interesting to see it in action!

 

[gyenesvi]

6 hours ago, SimplyLegoTechnic said:

About the clutch. If it wasn’t necessary, real cars wouldn’t have it either, right?)))

Of course, but RC cars can get away with it because they can just easily change gears while stopped. And indeed, I never thought it's a good idea to change gears while running a heavier model.

6 hours ago, SimplyLegoTechnic said:

In my previous MOC (https://reb.li/m/190094), I showed in this video (https://youtu.be/8Zy2hgXiuh4) that shifting gears without a clutch isn’t exactly smooth.

That's a very nice case study of the effect of weight on the change smoothness, and indeed, you have me convinced with this. One thing I'm curious about is whether the car keeps rolling when you switch gears while driving?

[SimplyLegoTechnic]

55 minutes ago, gyenesvi said:

Of course, but RC cars can get away with it because they can just easily change gears while stopped. And indeed, I never thought it's a good idea to change gears while running a heavier model.

That's a very nice case study of the effect of weight on the change smoothness, and indeed, you have me convinced with this. One thing I'm curious about is whether the car keeps rolling when you switch gears while driving?

Of course, the car continues to drive if there is enough inertia or on a flat surface, during the gear shift, like a real car)) The whole point of my latest MOCs is exactly this. And the video also tells and shows the game in motion with gear shifting. You probably just need to watch it :)

I hope I understood your question correctly.

[vascolp]

I really like this and the simple clutch mechanism!

In the video I also had a concern like gyenesvi, if the car would slowdown every time you switch gear. But it seems to work ok. The ideia of a 360º run instead of something like +90º, -90º is very interesting, and it uses directly the stepper.

Great work!

[thekoRngear]

On 8/17/2024 at 11:25 AM, SimplyLegoTechnic said:

Since I build models to last for hundreds of hours with minimal wear, I need every bit of reliability I can get. Plus, moving the complexities of shifting from a complicated gearbox to a simple clutch mechanism just makes sense.

 

You stand out than the most! I saw it on FB and immeditely liked it.

IMHO it already has entered in my most fave MOCs of 2024 list.

[Celeri]

Great MOC! Excellent concept of gearbox with cluch mechanism, and a really good video to present it... And the model is very nice-looking, too. Kudos!

[SimplyLegoTechnic]

4 hours ago, vascolp said:

I really like this and the simple clutch mechanism!

In the video I also had a concern like gyenesvi, if the car would slowdown every time you switch gear. But it seems to work ok. The ideia of a 360º run instead of something like +90º, -90º is very interesting, and it uses directly the stepper.

Great work!

 

3 hours ago, thekoRngear said:

You stand out than the most! I saw it on FB and immeditely liked it.

IMHO it already has entered in my most fave MOCs of 2024 list.

 

3 hours ago, Celeri said:

Great MOC! Excellent concept of gearbox with cluch mechanism, and a really good video to present it... And the model is very nice-looking, too. Kudos!

Thank you so much! I’m glad you liked it!
Right now, I’m waiting for a gamepad delivery so I can try controlling the model properly at higher speeds. Unfortunately, without an operator and a good camera, it’s hard to make a colorful video of these tests. The model drives out of the frame too fast, and the cheap action camera shakes way too much!

[LegoTT]

Hello, fantastic !

The rebrickable link is dead.

[Sokolov Edward]

On 8/16/2024 at 6:08 PM, SimplyLegoTechnic said:

LEGO PU L-motors

Is it possible to replace PU L-motors with PF servo motors? The question is not about the dimensions - this seems to be possible to solve, but about the required rotation angles. Will 2 options (+90 and -90 degrees) be enough to change the gearbox and steering wheel?

I watched the video - you need to rotate 360 degrees without returning. On PF, such a maneuver cannot be done with a servo motor. 

Edited August 19, 2024 by Sokolov Edward

[SimplyLegoTechnic]

18 hours ago, LegoTT said:

18 hours ago, LegoTT said:

Hello, fantastic !

The rebrickable link is dead.

Thank you!
If the YT link isn't opening, it might be because the video is blocked in certain regions due to copyright issues.

 

7 hours ago, Sokolov Edward said:

Is it possible to replace PU L-motors with PF servo motors? The question is not about the dimensions - this seems to be possible to solve, but about the required rotation angles. Will 2 options (+90 and -90 degrees) be enough to change the gearbox and steering wheel?

I watched the video - you need to rotate 360 degrees without returning. On PF, such a maneuver cannot be done with a servo motor. 

For the steering mechanism, it's possible. For shifting gears in this design, you need an additional mechanism that converts the 90-degree turns of the PF servo into 360-degree rotations.

 

[gyenesvi]

On 8/17/2024 at 3:05 PM, SimplyLegoTechnic said:

Of course, the car continues to drive if there is enough inertia or on a flat surface, during the gear shift, like a real car)) The whole point of my latest MOCs is exactly this. And the video also tells and shows the game in motion with gear shifting. You probably just need to watch it :)

I did watch the video, but did not catch the moment when you switch at first, but indeed it is visible. It does seem to slow down a bit, but keeps rolling.

On 8/18/2024 at 2:29 PM, SimplyLegoTechnic said:

Right now, I’m waiting for a gamepad delivery so I can try controlling the model properly at higher speeds. Unfortunately, without an operator and a good camera, it’s hard to make a colorful video of these tests. The model drives out of the frame too fast, and the cheap action camera shakes way too much!

One useful thing to have is a phone mount for the gamepad. I sometimes use that for filming while driving, and can follow my model that way :) The only problem is you need another phone to actually control the model, because both the control app and the camera app needs to be in the foreground.. :(

[SimplyLegoTechnic]

11 hours ago, gyenesvi said:

I did watch the video, but did not catch the moment when you switch at first, but indeed it is visible. It does seem to slow down a bit, but keeps rolling.

Sure! The model slows down when shifting gears, especially if there's more rolling resistance. Without rolling inertia, the transmission stops after the clutch, which is clear in bench tests where big wheels spin small rollers.

The solution will be a dual-clutch gearbox (DCG), but that'll come later, likely in 1:8 scale.

11 hours ago, gyenesvi said:

One useful thing to have is a phone mount for the gamepad. I sometimes use that for filming while driving, and can follow my model that way :) The only problem is you need another phone to actually control the model, because both the control app and the camera app needs to be in the foreground.. :(

This will be my first time using it, and I’ve realized that filming faster models (6-8 km/h and above) without an operator isn’t a good idea.