RC Pneumatic Crane Truck

 


This model has something we don't see often: remote-controlled pneumatics. Some time ago I've seen a video of that and was impressed by how much smoother it is than manual operation. I wondered why it's not more common, and now I know: it requires a ridiculous amount of servo motors.

This is a hybrid model with a mix of pneumatic and mechanical functions:

  • Fully articulated crane & bucket through 5 motors.
  • Functional motorized outriggers that are able to lift the truck off the ground (albeit with difficulty near the end).
  • Liftable cabin to reveal motorized pump & driven V4.
  • Pressure control system to automatically turn the pump motor on & off.
  • 6-wheel HOG steering
  • Trailer attachment: compatible with Krone Emsland pneumatic tipper from Isenheim.

The frame is very compact, and very sturdy. It's also relatively heavy, as it has 6 motors and two battery boxes.
This is an advanced model - all the cabling & tubing and sub-model assembly, even if all shown, is still challenging. It took me about 6 months for the design & instructions.

I was heavily constrained when designing the cabin, by the remaining space & attachment points, so I did what I could. But again, to me Technic is first about the functions, second about the look, even if it's now generally the opposite.

I personally don't like the use of system parts in Technic sets, so it has the bare minimum, except printed tiles, because I like those.

This model does take some inspiration from various existing models (8109,42009,42024,42043,42070).

Required parts not listed in the inventory:

About pneumatic tubes:
I'm only using lengths corresponding to existing parts (all listed in the inventory).
However, the blue 27L/21.6cm tube has to be cut into 23L/18.4cm + 4L/3.2cm. Alternatively, you can buy '2mm ID x 4mm OD' silicon tubes and make all the tubes you need out of that.

About using parts from other manufacturers:
  1. MK pneumatic parts seem to not be as strong as the Lego ones. For most of the actuators used it's not a big deal, but the pressure control system has been designed to work properly with a Lego one. The MK pumps also feel weaker, but that I'm not so sure. Also the MK components seem to stick when not used for a few minutes, which leads to a strong hickup upon first use.
  2. Many servo motors from other manufacturers do not support progressive control, which would largely negate the whole point of RC pneumatics. The MK 'black furious' ones do support progressive control.
  3. most L motors from other manufacturers have different RPM specs. The gearing in this model was designed for the Lego RPM specs.
  4. For the M-motor it doesn't matter since it's only used to drive the pump.
  5. The trans-orange 1x3 tiles are not made by Lego yet, so if you want them, you do have to get them from another manufacturer (like GoBricks).

Video (1/2): outriggers operation:

Video (2/2): crane operation:

Comments

Post a Comment