Another mini Brushless Trophy Truck - The experimentation continues

[vergogneless]

Heyy everyone!

 

I'm back again with an update on the latest project, which is now mostly completed and awaiting the grand final video. 

 

Continuing my quest for perfection, I am still experimenting with mini Trophy Trucks.

The goals for this particular build are as follows:

• Increase the ground clearance by 1 stud, bringing it up to 3 studs at the front.
• Reduce the width and height of the model.
• Incorporate a ball bearing in addition to the existing ones on the motor shaft.
• Revamp the front section with a vertically positioned servo motor (to enhance robustness and improve the pivot point).
• Redesign the motor mount to accommodate the ball bearing components.
• Install a complete set of four shock absorbers.
• Naturally, aim to reduce the overall weight.

Now, let's delve into the specifications:

• A2212 1000kv Brushless Motor
• Bidirectional 30A ESC
• Gray Geek Servo 360
• Dumbo RC X6PM-350 + mini X6FG receiver (with an integrated gyro!)
• 3S 450mAh battery
• Carbon fiber rear axle
• Ball bearings on front and rear axle + motor
• Gear ratio: 1:2

 

It will be adorned in a dark gray and orange color scheme.

 

Without further ado, here are some initial photos.

 

 

 

Feel free to share your thoughts and feedback if necessary!

Edited June 22, 2023 by vergogneless

[vergogneless]

Here are a few photos showcasing the progress of the project.

What are your thoughts?

[vergogneless]

The construction is complete, and the initial tests have been conducted.

Aesthetically, I am quite satisfied with the outcome, and I have achieved the initial objectives:

Increase the ground clearance by 1 stud, bringing it up to 3 studs at the front.
Reduce the width and height of the model.
Incorporate a ball bearing in addition to the existing ones on the motor shaft.
Revamp the front section with a vertically positioned servo motor (to enhance robustness and improve the pivot point).
Redesign the motor mount to accommodate the ball bearing components.
Install a complete set of four shock absorbers.
Naturally, aim to reduce the overall weight (going from 470g to 412g).

 

For comparison with its larger counterpart:

 

That being said, the initial tests yield mixed results. The major issue, which I anticipated and is why I have been using only rubber bands from the start, is that the shock absorbers are too stiff. Even the "soft" ones used here. They don't perform their function properly on such a small, compact, and lightweight scale.

However, it's not all negative. It still remains fun and very responsive, as always.

Nevertheless, I believe I will change the ESC and replace it with a Surpass Hobby one. I still have an older bidirectional ESC, but once you've experienced the higher-end range, it's difficult to go back.

As usual, I won't make any modifications to this particular model. I prefer to rebuild one from scratch, as collecting models is primarily a pleasure for me. Regardless of the driving qualities and flaws, it will always be a beautiful object to display.

 

And, of course, I will create a big video for this one as well because it remains a pleasure for me, above all.

[Bluehose]

I don't understand what the gyro does on a car. Does dit make thé direction automaticaly counter-steer while drifting ?

[vergogneless]

@Bluehose 

Yes, you have more or less answered.

The gyro has several uses, especially in my situation (rear direct drive).

It is indispensable.

Firstly, it allows you to correct 95% of faulty trajectories, spins, slides, drifts, bad bounces that would otherwise lead to disastrous outcomes, and so on.
Moreover, once you exceed 25-30km/h, even the slightest gravel can cause a catastrophe without it.

Secondly, it helps maintain a straight course. It essentially eliminates any play in the LEGO steering systems.

[Bluehose]

It's impressive

[FriedlS]

Very great building! Again, i love these small cars 😊

One question, have you thought about a different way for your construction of the rear axels. You use these ballbearings, but your rear axels spins also in a normal Lego Liftarm without ballbearings. I would think about a construction where the rear axle spins only in ballbearings.

Greetings, Friedl

[vergogneless]

@FriedlS Hi bro! Thank you so much for supporting my passion for small scales :D

 

That's a great question/remark!

As you've seen, the motor mount is built in a quite peculiar way, not symmetric at all, but I don't have any other choice if I want to maintain a small scale.

Furthermore, the parts with 3x1 ball bearings are of mediocre quality, and they simply don't hold properly if they're not well fixed and secured.

And finally, by using a 1:2 ratio, it shifts the axis by 1 stud compared to the motor's axis, which makes the whole assembly even more complex.

 

However, I'll let you in on a secret, the axis won't stay resting on the arms without ball bearings for long! After a few tens of minutes without lubrication, it will rely solely on the ball bearings, if you catch my drift :D
The 1x5 arms ultimately serve the purpose of properly attaching the 3x1 ball bearing pieces.

[TechBricks]

That's an insane little buggy. What a cool project.
Good to see you are using RC and gyros.
Subscribed to your YouTube.

Edited June 21, 2023 by TechBricks

[vergogneless]

@TechBricks Thank you for your message, I appreciate it! I have also subscribed and discovered your enormous monster truck with the pneumatic system, especially the suspension. I left a comment because it particularly interests me for my previous model :D 

 

EDIT: I forgot to attach some current photos because I simply added a dark grey 9x1 beam hole on the roof (and replaced the 2x1 beams at the front), and I think it makes a huge difference. It was really missing before.

 

Edited June 22, 2023 by vergogneless