All-terrain crane full RC boom, 4 wheel steering and outriggers
About this creation
All-terrain crane (picker).
A very common piece of machinery on construction sites in Canada. I've decided to build one because of its versatility on sites and it seemed to be a good challenge to
build for my first complete large scale MOC. I've came out of my dark age about six months ago and only have a couple sets and tried to create something.
The frame was loosely inspired by 8297, starting with the rear propulsion/differential/suspension assembly. The chassis is powered by a PF-Medium only on the rear wheels (limited by parts and PF-motors). Both front and rear wheels are steered and connected together in opposite. All wheels have indenpendant suspension in the fashion of the 8297. I wished for a 4x4 chassis, but I was limited by parts (only one 3 stud-wide differential and one spare PF-medium). There is room in the chassis for 2 more PF-motors to power direction and outriggers.
The outriggers are all connected together so that they could be powered by a PF-medium with already the geared down connections in place. Through testing, I found out that the axle couldn't handle the torque and a lot of twisting occured.
The boom is fully RC and is completly independant of the chassis. 4 PF-medium, 2 IR receivers, 2 linear actuators and 1 battery box that acts both for power and counter weight.
Main boom is basically a two-section boom taken from 8292 and modified to fit on model, next time I will try to build a three section boom powered by chains. Rotation of structure is through a PF-M, geared down with a worm screw and 24:8 tooth gears. The result is a slow and smooth rotation of the entire assembly
Elevation of the boom was the most complicated to achieve. First, to get the right geometry and limited by the linear actuator's extension was a lot of trial and error. Also the elevation of the boom is achieved by two parallel L.A. with custom brackets and a no thrust gearing mechanism (inspired by J. Clarks' all-terrain crane). Positionning of the motor is akward because of poor planning on my part.
Cable is powered by PF-M directly, It was the last function added therefore was basically "snapped on" wherever it would fit. It is not geared down.
All in all, it was a nice project for the last 2-3 months and learned a great deal of different construction techniques. Like I said before, the crane is pretty "naked" but aestethics were not my primary goal on this.