Changes made since version 3 :

+ lattice boom structure like on crawler cranes
+ string (yes, string)
+ Ackermann-like steering (almost; still needs a little human intervention to achieve)
+ stronger superstructure

So I found time and a new camera. Here is the instructable. There's also some photos of a 300g balance. Yay! I didn't bother doing a maximum testt - I wanted to see if it could carry anything at all. Maybe you can test its maximum capacity? ;)

Inspirations to this model:

Supercar - steering and chassis
Picture of a crawler crane
Picture of a crawler crane
Crawler crane - booms
Lego Technic 8460/8431/8438 and 8421 - outriggers

Total number of pieces: 2046

Just like version 3, I made this "backward"; that is, I photographed it while I was taking it apart. Also, pay attention to the comments in the photos. Since there is no caption-option available (or I haven't found it), I have tagged almost every image. If there is anything that still looks confusing, feel free to leave a comment. As you can see, it's very lengthy, so make sure you have a lot of time.

It's kind of hybridized between a mobile truck crane and a crawler crane, since it uses the body of the truck but the crane of a crawler. Perhaps in the next version I'll try to make it more truck-like with whatever K'NEX hydraulic technique I can come up with.

Thanks!

Step 1: Pieces Needed

Photos 1 and 2: You will need at least all of those pieces.
Photo 3: Piece count.
Photo 4: Rods
- 394 Green rods
- 236 White rods
- 254 Blue rods
- 60 Yellow rods
- 6 Red rods
- 1 Grey rod & 3 Black rods
Photo 5: Connectors, small gears, spacers:
- 23 Tan
- 4 ???
- 231 Grey (1 port)
- 20 Light Grey (2 ports, 45 deg)
- 55 Orange (2 ports, 180 deg)
- 62 Red (3 ports, 45, 90 deg)
- 30 Green (4 ports, 45, 90, 135 deg)
- 118 Purple Adapter (4 ports, 45, 90, 135)
- 171 Yellow (5 ports, 45, 90, 135, 180)
- 101 Blue Adapter (7 ports)
- 64 White (8 ports)
- 11 small gears (one must have notch)
- 151 Blue spacers (51 can be substituted by 17 Grey spacers)
Photo 6: Bigger gears:
- 1 Big yellow bevel gear
- 8 small pulleys
- 1 Medium bevel gear
Photo 7: Wheels
- 12 Large pulleys + Large tires
- 1 small tire
- at least 442 cm (14'6") of string

Step 2: Begin With the Chassis! the Bottom.

Step 3: Chassis: Axles

Step 4: Chassis: Steering Column

This is the hard part.

Step 5: Chassis: After the Steering Column...

...we stabilize it (as best as possible)

Step 6: Outriggers: Part 1

We're going to make 4 of these, or two sets of these; I'll show you the first part here. These are for the front outriggers. The way they work come from Lego Technic 8460/8431/8438.

Step 7: Steering (and Other Miscellaneous Stuff)

Here we put on the steering stick. You can substitute the yellow rod for a longer one and attach a wheel if you like; I just never bothered with it since I was more concerned about creating a working crane. Also, the steering stick doesn't do quite an adequate job at turning the wheels (another thing to keep in mind for my next design...), even with the connectors holding it in place.

Step 8: The (base of The) Superstructure

Follow those pictures and captions!

Step 9: The (base of The) Superstructure: Part 2

Step 10: The Front.

...as in the part covering the front wheels.

Step 11: The Cab

...is where the driver sits.

Step 12: Outriggers: Part 2.

We made these before. The outriggers themselves are exactly the same as the front ones, but their connection points to the truck are slightly different.