What does a remote controlled and motorized Lego Technic Crane have to do with rally racing? Nothing – but it was a cool project so I thought I’ll post it.

Here is the Video:

For Christmas I received the LEGO 8053 Technic Mobile Crane which right out of the box is already awesome. It got all-wheel steering (8 wheels) and a really cool gear selection setup to control the crane arm to go up and down and extract, in addition to powering the hook winch.

During the building period between Christmas and NewYear (yes I actually took my sweet time rather than rushing through it) it became clear to me that this Lego model just beckons to be remotely controlled in some shape or form.

Of course it is easy to just go online and order a bunch of motors – Lego has some really awesome motors these days for their MIndstorm and Technic Models. But spending money felt like cheating. So I decided I will make due with whatever parts I have…

Thank goodness I held on to my old Futaba F14 radio from way back when. By the way I recently found out that rather then buying the super expensive MultiProp or MultiSwitch adapters and extensions you can simply use a 5K Ohm Potentiometer to control a channel. Which by the way if you open most rc radios is what you will find in there – cheap potentiometer.

I also held on to the grey little gear reduction motors that came with one of the first Lego Mindstorm kits. Unfortunately I have only 3 motors. But the functions I wanted required a bunch more. Time to get creative.

List of simultaneous functions for my Lego Technic Crane:
1) Drive Forward and Reverse
2) Steer Left and Right – 8 wheel steering
3) Turn the entire crane unit 360degrees
4) Arm Up and Down
5) Arm Extension In and Out
6) Hook UP and Down
7) Sidepods In and Out

Long story short I ended up rebuilding the entire crane from scratch.
I decided to keep the Crane unit and the Chassis completely separated to allow for 360 degree turns of the crane unit.

Problem was that I had three motors but only 2 ESC( Electronic speed controllers), what I decided was to use one servo to trigger a microswitch which in turn switches the output of my ESC between 2 motors.

A) Servo 1 – Steering
B) Servo 2 – Switching Gears between Arm Up and Down and Hook Up and Down
C) Servo 3 – Arm Extension In and Out
D) Servo 4 – Activates microswitch for ESC toggle
E) Motor 1 – Driving Forward and Reverse
F) Motor 2 – Rotate Crane unit
G) Motor 3 – Power Arm, Hook and Extension

I also had some small lightbulbs – I know these days we use LED’s which by the way 3mm LED’s and Lego’s are a match made in heaven.

But why not use up what you have. I also found an old blinking module, which I worked into using as my hazard lights. I further found an old Birthday card which had tiny flashing LED’s which turned out to fit perfectly into Lego’s clear yellow bricks for warning lights.

This was without a doubt the most complex Lego project of mine so far. Lego Technic RULES!