Lego 42209 full remote control with PoweredUp

[Appie]

Finished the mod I was working on of the Lego 42209 wheel loader to be fully remote control.

• 1x L-motor for drive
• 1x L-motor for steering
• 1x M-motor for bucket lift
• 1x M-motor for bucket tilt

And as you can see in the image, the pendular rear axle is still functional. The model also has my modified z-linkage from the other topic.

A video:

 

A few more images:

 

 

I tried my best to keep the looks as close to the original set as possible.

Easy access to the hub. Only need to remove 2 axles.

To easily turn on the model, I modded a small thing as well:

On the original model the "toiletpaper" panel hid the hole where you could (in real life) plug in the cable to charge the battery. I moved this slightly so I could turn on the hub by pressing the "toiletpaper" Technic panel.

 

Belly shot with the added wheelie wheel to prevent the wires or something else from being damaged while having fun with that.

If a moderator would rather see this in the mod and improvements topic for this set, that's fine. I figured such a big mod would warrant its own topic. From the original set bag 1, 2 and 8 are about 90% the same, the other bags are 50% or less as the original set, with bag 4 (I think that had the fake engine and stuff) being gutted the most).

Thanks for reading (and watching)!

[efferman]

It is impressive to fit these large motors and hub in this tiny model. How is the overall stability?

[Appie]

Thanks and it was quite the squeeze yes

As for the stability, it's fine. It can go pretty fast which can make it a little jumpy on the pendular axle (as you can see in the beginning of the video when it drives by the original set) and obviously it can do wheelies with the hub being at the back, but it really requires that you first drive in reverse and then instantly go forward to make it do a wheelie. In the Pybricks program I mapped throttle and reverse to the analog triggers. So precision controls are pretty easy. While I was operating the bucket in the video for example, that's at about 50% throttle and reverse. It's really planted. Quite surprised me actually, I expected that it being so rear heavy would be a big factor into how it handled. Steering is also very smooth.

[efferman]

Do you have used the motors as part of the Structure to keep the chassis rigid?

[Appie]

Yup. Since I wanted to keep the rear pendular axle, it became mandatory to have these motors be part of the structure to keep the rear rigid. Right above the diff at the rear is a liftarm contruction that functions as a thrid horizontal line to keep it rigid (M-motors being second and L-motors being the third). That liftarm construction at the bottom is interwoven with the M-motor structure through a #6 connector, since the M-motors at the rear do very little on their own (1 pin hole is connected to the liftarms at the rear of the motors).

Perhaps these pictures provide some better insights than just words:

 

That liftarm at the bottom is towards the left and middle only since on the right that diff gear needs space.

[efferman]

Im using an different approach to get all parts with stickers on the same place.

 

[Appie]

That looks great, but ya, quite a different approach than mine where I wanted to keep it 100% (current) Lego. Just a personal wish for my mod. Yours look well on its way to keep even more of the original look.

I actually haven't considered fitting all the original stickers, but yeah, some at the rear won't fit mine with parts used. Could maybe change it, but not going to apply them anyway. 

And your new boom looks nice. I wanted mine to stay as close as possible to the original boom while improving the geometry.

Edit: didn't even notice at first that you made the rear 2 studs wider. To keep those baby panels on the side of the battery box I guess? I was quite annoyed I had to sacrifice them for the Technic hub.

Since your rear fenders are wider too, going to expand the axle width as well? Or going to have the wheels slightly tucked in under the fenders instead of sticking out like the set? 

Edited Friday at 06:54 PM by Appie

[efferman]

Yes, the trackwidth is one stud wider to avoid a collision between the tires and the motors. Now it has the same width like the bucket. The wider fenders are to get it closer to the real thing. There the back and the mudguards have nearly the same width like the tires.

[Toastie]

Wow. Simply that.

You guys are crazy - in such an overwhelming, phantastic, positive way. I am in total awe. Another example that folks here on/in the Technic forum doing Technic are playing in the Champions League - and in this regard I am simply kicking cans down the street ...

Now, with that 4-port PUp hub, are you using the PUp remote to control that beauty? Or is control via cell phone?

All the best
Thorsten

 

[Appie]

15 minutes ago, efferman said:

the trackwidth is one stud wider to avoid a collision between the tires and the motors.

Yeah, it's tight on the original trackwidth. They "kiss" the M-motors a little bit. 

@Toastie

Thank you for the big compliment. Much appreciated. I don't think you're kicking cans down the street though 

As for the controls. I use Pybricks and a Xbox controller. With Pybricks you can save a control program on the hub (Pybricks firmware) and use a Xbox controller to control the model. Only need to turn on the hub and controller and it's ready to go. It only works with a Xbox controller because of the type of Bluetooth used by all Lego hubs (except the City hub, that one only works with the PUp remote on Pybricks).

And if you ever want to return to official Lego firmware, you only have to link the hub to the Lego app and it will overwrite it in a normal firmware update. 

[Toastie]

7 minutes ago, Appie said:

As for the controls. I use Pybricks and a Xbox controller.

Nice!!! That is the way to go.

I am more on the ESP route for signing-up BLE devices and controlling them (or entire programs) with the PUp remote - but that is just my preference.

For advanced control of machines as you are building, an XBox controller is so much better!

All the best
Thorsten

 

[Appie]

Yeah for these kind of controls it works better than the PUp remote imo since the PUp remote has no analogue buttons. You can set up Pybricks to do speed increments on the PUp remote with how many times you press the button or how long you hold the button (like each button press being 10% for steering or speed) to mimic analogue, but it's still not as good as real analogue controls I think. 

Edited Friday at 07:57 PM by Appie

[Teo LEGO Technic]

This is epic! The controls are so smooth and precise. Do you know if there is a PyBricks equivalent for use with BuWizz, do control it through a physical controller like the Xbox controller?

[Appie]

Thank you! 

Without a telephone to run an app between the hub/Buwizz and controller, I don't think there is. With a phone in between Brickcontroller 2 app might work or Buwizz's own app? Not sure of the latter, I don't have a Buwizz.  

[Teo LEGO Technic]

6 minutes ago, Appie said:

Thank you! 

Without a telephone to run an app between the hub/Buwizz and controller, I don't think there is. With a phone in between Brickcontroller 2 app might work or Buwizz's own app? Not sure of the latter, I don't have a Buwizz.  

Sounds good, I think I found some documentation that might help - https://buwizz.com/BuWizz_gamepad_instructions.pdf.

Again, awesome model!

[Jundis]

Both versions are superb!

As @Teo LEGO Technic already said, the movement is soo fluently and fits so well in this scale.

Outstanding job @Appie!

And actually I love the simple fact that Lego gives us a model to mod and to improve on. Hopefully we will get more heavy machinery in the years to come :-)

[Saruzeufel]

Very impressive RC conversion. That's a lot of motors for such a small set. 
I love the little detail of switching on the hub by using the charging port!

[Paul B Technic]

Nice work on these, I love how well they work.

[Appie]

Thanks everybody!

On 6/21/2025 at 1:00 AM, Jundis said:

And actually I love the simple fact that Lego gives us a model to mod and to improve on. Hopefully we will get more heavy machinery in the years to come :-)

It's a great little set as it is, but I love the options it gives to mod it. I hope we get more of this one in the future as well (and I really mean like this set for heavy machinery and not heavy machinery sets like the 42215, they can keep that 42215 set at a place where the sun doesn't shine imo).

[CK28]

Time to bookmark the thread for when i buy one. Just to add to what others already said, great work on the mods! I love to see these builds that squech out every last possible gap to make a very compact and detailed build staying true to the original dimensions!

[carver0510]

Awesome Build! Have you planed to publish an stud.io-File or instruction?