Lego 42172 Mclaren P1 RC Brushless motor

[Tup4n]

Hello!

I have motorized the original Lego set 42172 with the brushless system using mostly custom parts from Zene bricks. It took me 2-3 weeks to finish this project, since all technical solutions and parts have been tested on my previos 1:8 supercar - CADA AMG ONE. I managed to reach the top speed of 40.8 km/h on this set up using 12:20 gear ratio in the drive train. Since Mclaren P1 a little bit heavier then CADA AMG ONE (+400 g.) i expect only around 32-35 km/h. Here is the specs:

1) The motor - Surpass Hobby 2445 50000 rpm (3600 kV)

2) Cooling system - Surpass Hobby Rocket RC 20000 rpm

3) 3 geek servo motors for steering, fake engine and spoiler mechanism

4) The batttery - 11.1V 1800mah

5) RC differentinal, metal universal joints, metal shafts, ball bearings and etc.

6) Gear ratio from the motor - 12:20

6) Custom wheel hubs

7) Car weight - 3,7 kg (with the battery on board)

8) Expectation top speed - around 32-35 km/h

I have attached some video footage. All in all, i have so much fun driving this car. Hope you like it!

 

Edited November 5, 2024 by Tup4n

[2GodBDGlory]

Very fun! I love large-scale, detailed car models that actually have enough speed to make them fun to drive

[Tup4n]

3 hours ago, 2GodBDGlory said:

Very fun! I love large-scale, detailed car models that actually have enough speed to make them fun to drive

Agree! They look realistic and stunning, and in the same time, provide a challenge for the builders to make them fast. I spent 4 mounts on my previous project with motorization 1:8 super car with the brushless system, and there were so much issues/problems and bug fixings, until I managed to find a working solution for the drivetrain/motor cooling and the suspension. 
 After that, motorizing this McLaren was as easy task.  

[FriedlS]

Very great! 
So you didn’t use the planetary gearing from @ZENE? 
Is the cooling fan effective enough to keep the temperature of the motor in a good range? Because i have the problem with this motor that it becomes very hot in short time (and i use the planetary gearing and diff from @ZENE with just a 2s Lipo)

cheers, Friedl

[Tup4n]

2 hours ago, FriedlS said:

Very great! 
So you didn’t use the planetary gearing from @ZENE? 
Is the cooling fan effective enough to keep the temperature of the motor in a good range? Because i have the problem with this motor that it becomes very hot in short time (and i use the planetary gearing and diff from @ZENE with just a 2s Lipo)

cheers, Friedl

Hey!

Yes, the motor tends to overheat extremely fast. You should use the cooler fan in order to keep the motor safe. In the beginning I have experienced the overheating just after 5 minutes of driving. Now I can play with the car around 20-30 minutes (until the low battery) with out any problems and the motor stays cold. I will recommend Surpass Hobby Rocket RC cooler fun - it’s cheap, has high rpm and does the job. I can definitely say that you just can’t use the motor on such a heavy Lego cars (3kg) with out cooling system.

About reduction gears. The motor from the Zene has a build-in 4x planetary reduction. I am using additional 12:20 reduction gear ratio just for more torque and to reduce additional stress for the motor. I have tested my Cada Mercedes AMG ONE with gear ratio of 16:16 for more speed, but in this case at 30+ C outdoors the motor temperature was too close to the limits. That’s why I ended up with this setup - strong cooler fun and 12:20 gear ratio. It’s reliable and fast enough.

[Lixander]

You did a great job! I hope we will see more of these mods from you ;)

[JesseNight]

Better stock up on spare tires if you gonna keep drifting
Looks fun, and awesome that it has enough power to do that!

[wissamms]

could you show us some pictures of the motorisation set-up, and its integration into the car?

[Tup4n]

13 hours ago, Lixander said:

You did a great job! I hope we will see more of these mods from you ;)

Thank you! I have some plans on motorization of 42115 in the future. Since it is all-wheel drive car, it sounds like a new challenge!

3 hours ago, wissamms said:

could you show us some pictures of the motorisation set-up, and its integration into the car?

Sadly, I dont have a lot of photos of the motorization, since i completed the build quite fast. But i can share all that i have.

This is how the motor is attached to the chasis.

Rear axle with 1) RC differentinal, 2) 2 geek servos for spoiler and fake engine, 3) main pair of 12:20 gears

 

  Custom wheel hubs and positive caster angle (must have! It is impossible to drive the car with out these options)

I have to reinforce the rear suspension, as the weight of the car's back increased sugnificantly due to the battery and the motor. With the single spring on each side, it just stopped working.

 

Overall look of the engine bay

[ZENE]

It's been a while since I last came here, and I'm very happy to see your post because I was planning to post a 42172 modifiction too, haha.

Additionaly, you mentioned motors with higher torque, and we have designed a new planetary gearbox to meet the demand for greater torque, such as for off-road use or trucks

https://drive.google.com/file/d/1d32DTIV85e-GOYBNnh9HjATvvV0EPBeW/view?usp=sharing

https://drive.google.com/file/d/1Qn8abSusWCMVB5hVYug2V8e9_PGbTNra/view?usp=drive_link