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RC models by Robert Holsting

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  Outrigger controller .
There are four huge outriggers, and they must be controlled by RC.
At the same time, any improper operation / human error must be prevented, as the stability of the crane is on the line. If I by accident should retract an outrigger while standing 10ft away on the other side, the first sign of this could be the falling crane...

Two 3-position switches on the remote is all it takes to control the outriggers!
Switch A selects either "Next" or "Previous" outrigger. (No. 1, 2, 3 ,4, none .... and over)
Switch B selects either "Out" or "In" for the selected outrigger.

This circuit could be used for the crane booms as well, but for now this is out of scope, and will be addressed later.

  First we have to check if the boom is out of the stowed position. This is done by testing the switch in the boom resting bracket in the engine area.
Remember this guy? It sits right behind the cab, and in front of the engine compartment.



  The switch is hooked up like this.
When the boom is stowed: The output to the outrigger controller is grounded, thus enabling outrigger movement.
At the same time the switch acts as an end-stop for the boom actuators, and signals when the actuators should stop the downwards direction.

Download as pdf.

  This is the controller that I developed. It's based on an Amtega 8 processor.
Communication between receiver and my controller is done through two RC switches. (See more about them here:  Electronics )
Relays handle the rest, including one "reverser-relay" reversing the direction when the "In" direction is selected.

There are eight indicators: four for what it has in mind to do, and four showing any active legs.      Download as pdf.

  Problems!
The controller cycled through the outriggers at random when I first hooked it up. Very strange... until I got my oscilloscope out and looked at the "high" pulse from the Conrad RC-switch that delivers the signals from the switches on the remote, via the receiver.
Notice the short, low-going spike? That triggered the microprocessor to think "Oh ok, let's select the next / previous outrigger!" Noooot good.
A small change to the software was all it took. Now the microprocessor disregards very short inputs. 
Download software

  Schematic was converted to a PCD layout, PCB's ordered, and then I could fit the components!
Here the controller is shown in it's future home, towards the rear of the carrier.


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