[MOC] RC Buggy by A_C

[A_C]

As inspired by pg5200's Buggy and Tamiya's Fighting Buggy, I've built this RC Buggy MOC. It's simple, fast and stable. 

Features:
- Total no. of pieces is less than 400
- Around 1/15 to 1/16 scale
- Requires a BuWizz 1.0/2.0 or CaDA or Mould King remote battery hub (SBrick should be possible by placing the hub on top of the battery box)
- PF Servo Motor for the steering
- RC Buggy Motor or BuWizz Motor for the rear driving
- Gear ratio is 1.4 : 1
- Transverse damper rear suspension similar to Fighting Buggy
- Rear camber angle is about +1 degree
- Optional 4 LED lights (instruction not included)

Instruction available at https://rebrickable.com/mocs/MOC-76795/

Have fun and enjoy!

It's not in Minifig scale, just give you an idea of its size.

It has a +1 degree of rear camber angle.

 

Edited May 17, 2021 by A_C
Added test run video

[SaperPL]

That's a really good looking buggy, at least it's properly hiding the motors inside the body, but I think you should make a video showing how it works - the gearing matters, so it may be either really slow or won't be able to climb at all etc.

[Andman]

3 minutes ago, SaperPL said:

That's a really good looking buggy, at least it's properly hiding the motors inside the body, but I think you should make a video showing how it works - the gearing matters, so it may be either really slow or won't be able to climb at all etc.

From what i can see it could/should be a 1,4:1 gearing. Could reach 2,5 to 4km/h. Not sure about the torque.

[amorti]

Am I missing something, or does "1° camber" actually mean "I didn't make a strong rear axle"?

2 hours ago, Andman said:

From what i can see it could/should be a 1,4:1 gearing. Could reach 2,5 to 4km/h. Not sure about the torque.

56mm tyres * pi for circumference * 1240rpm on a buggy motor at 9v * 20/28 reduction on the differential * 60 minutes in an hour / 1,000,000 mm in a km

=9.3km/h

With so few parts I'm betting it'll rip.

[Andman]

25 minutes ago, amorti said:

Am I missing something, or does "1° camber" actually mean "I didn't make a strong rear axle"?

It's feature, not a bug!

26 minutes ago, amorti said:

56mm tyres * pi for circumference * 1240rpm on a buggy motor at 9v * 20/28 reduction on the differential * 60 minutes in an hour / 1,000,000 mm in a km

=9.3km/h

I'm tempted to disagree. Looks like the slower output is used, thus 780rpm @9V (According to Philos homepage). That's nearly 6km/h... in theory. But i might be wrong.

[amorti]

@Andman you've come from 2.5-4 to nearly 6, but you're still wrong - one of us read Philo's page wrong (it was you).

I'd like to know how you get 1° of camber in Lego on purpose, unless it means 1° of slack either direction from square.

Edited May 15, 2021 by amorti

[Andman]

12 minutes ago, amorti said:

@Andman one of us read Philo's page wrong (it was you).

You are referring to the non-loaded characteristics, which is described here:

I was referring to the loaded characteristics.

5292	Torque	Rotation speed	Current	Mechanical power	Electrical power	Efficiency
4.5 V	5.7 N.cm	150 rpm	1.36 A	0.87 W	6.12 W	14 %
6 V	5.7 N.cm	380 rpm	1.38 A	2.27 W	8.28 W	27 %
7.5 V	5.7 N.cm	580 rpm	1.37 A	3.45 W	10.3 W	34 %
9 V	5.7 N.cm	780 rpm	1.40 A	4.61 W	12.6 W	37 %
10.5 V	5.7 N.cm	1030 rpm	1.46A	6.16 W	15.3 W	40 %

I'm again tempted to say that the values from table of loaded characteristics are closer to the real life conditions for this moc than the non-loaded characteristics of that motor.

Your turn :-)

Edited May 15, 2021 by Andman

[amorti]

Well, it runs on buwizz, so that's 11.2v which would give somewhere over 1030rpm.

I'll accept a mutual loss 

[Andman]

4 minutes ago, amorti said:

Well, it runs on buwizz, so that's 11.2v which would give somewhere over 1030rpm.

I'll accept a mutual loss 

:-D I didn't read that it is powered by a buwizz. That's a game changer. There is only one solution! @A_C, please make a video and show how fast it can go!

[A_C]

Thanks all for your feedback.

First of all, I don't have a BuWizz, and I'm using a compatible Buggy motor only. When the remote battery is fully charged, it has about 8.1V

And I've just uploaded a test run video but I cannot provide the actual speed in readings. But I think it's pretty fast, and it's definitely not a climber or crawler.

 

[LEGO Train 12 Volts]

Fantastic and really fast buggy!  

[A_C]

Just added another yellow version at here. It's not only another color version, but also replaced the expensive light reflector parts.