Full RC controlled Heavy wrecker. . Whilst obviously using many styling cues and indeed an entire 8285 in its build, in all reality this heavy wrecker is scratchbuilt and shares little in common with the factory 8285. . Weighing in at exactly 3.5kg and 65cm long, this truck took nearly 6 months to develop. I'm not 100% happy with it, I wish it looked less like 8285, but my parts stash precludes me building it in any other colour scheme.
All functions are controlled on seperate channels by one PF remote control, in total there are 4x RC receivers, 7x medium PF motors and an XL PF motor for the drive.
With 5 axles, the first two steer in unison, powered by a medium motor atop the front axle.
The third can be lifted or lowered at will, this is acomplished by a linear actuator and a medium motor.
The fourth and fifth axles are driven by a single XL motor. Depending on the surface the model stands on there is a small amount of gear jump as the truck starts to move forward. This stops very quickly and does not happen if the truck moves backwards.
The main boom rotates, extends and elevates, all powered by medium motors, also the cable can either be let out in syncronisation with the boom extension or independently. This change is based on the same mechanism used in 8421. Elevation of the boom is again by a linear actuator.
The rear vehicle lift both raises, fold and unfolds again all RC controlled using 2x medium motors. The arm also extends but this must be done manually, I cannot think of a way of powering this function without spoiling the aesthetics of the arm.
The biggest problems found during construction were fitting the sheer amount of parts needed for the various mechanisms in place within the vehicle structure, whilst keeping the aesthetics of the truck.
Many mechanisms initially were placed in positions that initially failed with the next mechanism so to counter this a great deal of time was spent doubling up on areas of the structure where a part or a few parts have bearing on not just one area or function, but more than one.
The second major issue was the constraints of the PF system. Fixed lengths of cable, pre attached to motors and receivers made the placement of such items critical. Also there is another mechanism built into the truck, the rear stabilisers, the basic design is lifted straight form 8285 however the drive is able to be actuated via a motor, and infact there is another medium motor and an RC receiver in place for this, however without a spare RC channel it remains redundant. Another reason why I have not given more thought to motorising the rear lift extension is the lack of an available RC channel.