[MOD] Lego Technic BMW e30 MOD by Pawlo

[Pawlo]

Hi there everyone!
I would like to present to You my latest Lego Technic creation – a modification of Nico71 model: Small Black Sedan. My goal was to make it look more like iconic, late 80’ BMW e30 Coupe.

 

Modifications involved:
•    remodeling the body,
•    fitting bigger wheels (49,5x20),
•    improving steering system,
•    changing power source for 12,6V custom battery pack.

The most difficult and time consuming part was to design front grill – fitting too big front lights to it to look as most precise and neat as possible. I’m quiet satisfied with the outcome, I hope You will be to :)

Steering system had to be modified because of this drawback: steering from servo motor is passed by 20z and 12z gears working in 90 degree alignment. Because of that the wheels were always turned a little bit for one side. To overcome this I’ve asked Efferman to design a new 20z gear with tooth’s alignment made like this:

Part was printed by Shapeways and works really great. Thanks’ to that model always drives straight :)

My second most important goal  with this model was to check, if lego MOC is able to give fun on race track for RC models. To test it, I have used custom 10,8V Li-ION battery pack, which has maximum voltage of 12,6V at 100% charge. 

My Sbrick responded very well for this voltage, there were no burn’s or anything like that. Speed of the model is highly better compared to Lego 9V Li-ION battery pack. To maximize the effectiveness of the power unit, I’ve removed thermistor over-heating protection from Lego L-motor. With normal driving, temperature of the motor is on safe level. If You want to drive fast with Lego motors, I recommend to do this – it’s quiet easy operation :)

You can check how the model performed on the race track In the video below. For me driving it was a great fun, but also a big challenge. It’s not so easy as it looks ;) But after some practice and tuning of the steering sensitivity in Sbrick Profile Designer, it gave a lot of fun and thrill. I think it would be even more attractive if there were couple models racing on the track – surely I would like to try it!  So if You live in Warsaw  - PM me – we could do some serious racing ;)

 

 

 

[Aventador2004]

Nice mod!

[kbalage]

Nice performance with this battery pack, and of course a cool mod! :)

[mocbuild101]

Looks great, and performs even better! And it also looks like it's really fun to drive!

[Aventador2004]

Wait, is that a RC drift track you were at? I believe it is, nice driving.

[Pawlo]

Thanks for kind words, indeed model gives a lot of fun, I recommend to try it on Your own :) Battery pack is very easy to build, and for very small amount of money - I have dismantled old laptop battery, which is made with 14500 Li-Ion cells.

On 23.01.2018 at 6:03 PM, Aventador2004 said:

Wait, is that a RC drift track you were at? I believe it is, nice driving.

Track was a normal, non-drift track for RC models.

[HorcikDesigns]

Superb model, and even better performance!

Would it be please possible to share with us mode details about BB and connecting it to the extension wire? 

[Pawlo]

Sure, what would You like to know? ;)

[HorcikDesigns]

10 minutes ago, Pawlo said:

Sure, what would You like to know? ;)

Thanks :)

Which two cables did you connected with the battery? 
According to the Philo's site (and attached image), there are four wires (9V, 0V, and two for control signal) on the cable. You connected the 9V to "+" side of the bat. and 0V to the "-"? (if I understand it right) 
(some time ago I also tried to connect 3rd party BB to my S-brick and it did not ended well, because I probably had to connected wrong cables (S-brick luckily survived, but some PF connectors melted :D)




 

[Pawlo]

Connection from battery to Lego cable is made like this:

Edited January 29, 2018 by Pawlo

[HorcikDesigns]

Thank you. :)