Tear-drop baja buggy

[Lixander]

I am worknig on a new project - a small off-roader.

Until now, the model has between 560 and 600 grams or about 19 - 21 ounces; 1x servo-motor and 1x buggy motor, 4x 6.5L hard shock absorbers for the independent front suspension and for the back hard axle type suspension; the front arms are packed tight, having just 1 stud between the left and right front suspension arms - this results in an enhanced suspension travel and look, resembling the real baja buggy`s. It can be fitted with 2x lighting sets.

It was hard to find a space for the batteries, as if a wider body was even uglier than the present one, which i still do not find so appealing. After I finished the body-work, I managed to find a spot for the batteries - BuWizz 2.0 and 3.0 and MouldKing battery hub. 

The next thing is test-building this thing until April or the start of March.

 

Edited July 3, 2023 by Lixander

[Jurss]

I'm afraid, it would hardly drive and steer, as front wheels would wobble etc.

It will be better, if You put wheels in front otherway.

[Jundis]

Before Jim or Milan will mention it:

Maximum image size is 1024x1024 pixels ;-)

[Lixander]

34 minutes ago, Jundis said:

Before Jim or Milan will mention it:

Maximum image size is 1024x1024 pixels ;-)

Even if they are from links?

3 hours ago, Jurss said:

I'm afraid, it would hardly drive and steer, as front wheels would wobble etc.

It will be better, if You put wheels in front otherway.

Got it; thanks. 

Now, let`s hope I will get those wheels 

[Milan]

6 hours ago, Lixander said:

Even if they are from links?

All the images posted on EB are linked, as we do not host them on site.
According to the rules, 1024 is max, as people do not have always fast internet, and multiple large images can slow loading the pages.

[Lixander]

7 hours ago, Milan said:

All the images posted on EB are linked, as we do not host them on site.
According to the rules, 1024 is max, as people do not have always fast internet, and multiple large images can slow loading the pages.

I understand. Thanks for the explanation.

[Jurss]

Another thing - front suspension will not hold together, those connection between halfbeams and suspension arms.

Those new 3L pins could help somehow.

[Lixander]

4 hours ago, Jurss said:

Another thing - front suspension will not hold together, those connection between halfbeams and suspension arms.

Those new 3L pins could help somehow.

I dont have any of those, but I am going to take them in consideration. Thanks.

I just finished test-building it; the suspension it is not so great and the front wheels are bent because of the gear rack or something like that.

Despite those errors, I made some modifications, especially in front - because of the wheel hub problems, I had to lower the suspension. I had to lower it any way, because it was too much stress at that angle for the shock absorbers and for the arms too.

Edited March 13, 2023 by Lixander

[Jurss]

15 hours ago, Lixander said:

and the front wheels are bent because of the gear rack or something like that.

Wheel centers are really far from steering center, so there is really significant lever which needs to be held by steering arm on that hub, and those connections on balls are pretty loosy, so You get everything really wobbly. That what I was talking before.

Situation can be imporved, if wheel rims will be put otherway (In fact, not sure, if this is possible with these rims and hubs, will check later), and other builders have also added steering linkage on the other side also - in Your case also on front.

[Lixander]

7 hours ago, Jurss said:

Wheel centers are really far from steering center, so there is really significant lever which needs to be held by steering arm on that hub, and those connections on balls are pretty loosy, so You get everything really wobbly. That what I was talking before.

Situation can be imporved, if wheel rims will be put otherway (In fact, not sure, if this is possible with these rims and hubs, will check later), and other builders have also added steering linkage on the other side also - in Your case also on front.

I tried it with the wheels otherway too - it seems that it is a little better; those wheels can be put both ways on that wheel hub.

I will try to add another steering linkage.

Thanks!

 

Edited March 14, 2023 by Lixander

[Lixander]

Quick update - finished the 1x motor variant and the 2x motors one still in tests, with a new body (I managed to make the body-works semi-removable, at least).

The second body wants to be a Ford Bronco Ultra4 (I know that some proportions are not as they should be; still thinking for a solution for this that can also accommodate a battery).

The first photo is just a concept, made after a reference (you can see it on Bricksafe); it can not be made in real life because most of those pieces do not exist on those colors. 

 

Edited March 26, 2023 by Milan
Removed 4K pictures. Max allowed image size is 1024x1024.

[Lixander]

PDF instructions will be made next days.

Until then, here are the renders in advance.

[vergogneless]

I love the design (especially on the very first image of your topic)! 

[Lixander]

36 minutes ago, vergogneless said:

I love the design (especially on the very first image of your topic)! 

Thanks a lot!

Unfortunately, I had to heavily modify the body-work and the chassis.

And by the way, I achieved 12km/h with it by using cheap Lego buggy motors and an alternative Lego hub. So this thing can achieve at least 20km/h with BuWizz electronics or even normal RC electronics.

 

Edited June 30, 2023 by Lixander

[vergogneless]

@Lixander  Yes, I saw that. You didn't really have much choice; it's the downside of electronic components designed for the Lego system: they are heavy and bulky, and they also lack in terms of performance and control.

I have personally experienced both options. It all depends on your preferences and expectations:

• Total and hassle-free compatibility, comfort, but at the expense of power and precision (Buwizz).
• Or, power and precision at the expense of facing various new constraints (brushless system).

In the first case, there's not much you can do to improve it. Moreover, combining a Buwizz unit with Buwizz buggy motors and an L PU motor for proportional steering can lead to unreasonable costs. Additionally, you would need a physical controller like a video game joystick to enhance control via a third-party application.

In the second case, there are always solutions to mitigate or completely eliminate the constraints. The purchase of basic elements does not exceed 70-80€, leaving a lot of room to invest in extras to optimize your models.

 

So, there's something for everyone; these are two quite different approaches, and each solution has its advantages and disadvantages. You need to align with your preferences and clearly define your expectations before investing to avoid disappointment.

[Lixander]

I see.

I want to equip my Lego RCs with normal RC electronics. I had gathered almost everything, I just need to modify the wires of the buggy motors.

In the future, I want to insert RC motors in the buggy Lego motors; I found out that 350-400 motors can (theoretically) fit the buggy Lego case.

 

[vergogneless]

Cool, I like the idea of modifying buggy motors. Do you have an example of a replacement motor?

 And what's your final setup (ESC, power supply, radio, etc.)?

[Lixander]

The ESC is a Hobby Wing Quick Run 60, the battery will be a 3s, the servo is a GeekServo and the remote and receiver are from AliExpress (but they seem ok).

The motors that I am keeping an eye on them for putting on the buggy case are ”Krick MAX Power 400” and ”Latrax 370”; I want to go for a brushless, but at least the Latrax is brushed.

Anyway, I have to see what I do with the wires and the first configuration first, then after some time, i will search deeper for replacing the motors.

Edited July 1, 2023 by Lixander

[vergogneless]

I see, small brushed motors like those, powered by 3S, will generate a lot of heat, won't they?

I agree more with your idea of directly finding a brushless motor! However, you'll need to change your ESC.

Regarding the remote, does it have a gyroscope?

[Lixander]

1 hour ago, vergogneless said:

I see, small brushed motors like those, powered by 3S, will generate a lot of heat, won't they?

Well, I don know; I think so, I have to research, but for now, I only want to put normal RC electronics without modifying the motors.

1 hour ago, vergogneless said:

I agree more with your idea of directly finding a brushless motor! However, you'll need to change your ESC.

Yup, that what I was thinking of.

1 hour ago, vergogneless said:

Regarding the remote, does it have a gyroscope?

No, it doesn`t have a gyroscope.

Edited July 2, 2023 by Lixander

[vergogneless]

Before switching to brushless, I used small Wltoys motors, brushed, and powered by 2S.

In the end, it wasn't sustainable because the motor would get so hot that it melted its support, lol. The issue with the LEGO system is the friction, especially on models over 400g, which forces the motor to work even harder.

But indeed, you can try using the original motor with a 3S battery and see how it performs. I'm curious to know!

 

As for the gyroscope, it's quite troublesome. Speaking from experience, on all my models, I can test with and without it. And to truly understand the importance of this parameter, I can clearly say that without it, I would have given up on building powerful LEGO RC vehicles altogether.

The servo motor alone NEVER puts the wheels back on a perfectly straight heading. The car always ends up going to the right or left, even with a positive caster angle. But in reality, the servo is not the issue, as it's a 2kg servo and works flawlessly. It always returns to position 0 without any failure.

The reason lies elsewhere: the inherent play in LEGO steering systems can only be corrected with a software solution, namely, the gyro. With the gyro, your car will maintain an absolutely straight heading and correct it in any circumstance.

Know that the best value for money on the market can be found at Dumbo RC, where you can get a remote (X6FG) + a receiver with an integrated gyro (also X6FG) for only 34€, fully adjustable.

[Lixander]

Now I see why a gyroscope is important.

 Thanks for the information!

[Lixander]

Pretty much finished. I hope to not find another mistakes in the PDF instructions.

https://rebrickable.com/mocs/MOC-152607/Lixander A./tear-drop-baja-buggy/#details