October 2004



This model was modeled from a Bell 225A logger.

I added an electromagnet to the end of the arm to make it a scrapyard utility runner which I have once seen being used in a scrap metal yard.


The model is radio controlled and is run by 5 servos :

2 servos control the direction of the two front wheel drive motors.

1 servo turns the hydraulic pump on/off.

1 servo controls the hydraulic fluid direction lever.

1 servo turns the electromagnet on/off.


The boom is operated by an old action hobbies hydraulic ram.

The electromagnet is a Meccano electromagnet.

21 AA rechargeable batteries are built into the model to power everything.


Each front wheel has its own motor (MO with 19:1 gearbox).

To turn, each motor is run in different directions and the model swings around.

The rear wheel is a trolley wheel and has no act in steering.


The original in action!



A basic Schematic of the logger.



The 7 channel radio.



View of the hydraulic pump and reservoir.


View of the hydraulic flow direction controller.


View of the Meccano Electromagnet.


A micro servo acts on Double Pole, Double Throw (DPDT) or on/off sub micro switches.


View of one of the drive motors utilizing thrust bearings.