It looks almost everything has been built with LEGO by now, so it is the case of Walking Excavators or Spider Diggers.
Swissbager is a LEGO fan and builder from Switzerland, who shown his Walking Excavator replica (Kaiser S2), at Legofest in Torino (Italy) back in 2006. Never too late to recall!...
And also some photos below. You will find a lot of them at swissbager BrickShelf gallery.
This is a tethered pneumatic remotely controlled digger which looks to operate very gently by the way.
Now, the feature set:
- Fully pneumatic excavator arm with 4 functions.
- Telescopic dipper
- Upper structure slew driven by two old style 9V motors.
- All functions above, served from a remote control with own compressor powered with four 9V electric motors.
- The under carriage is a "4-legged" structure with two rear large wheels and two frontal legs equipped with feet and small wheels, like the real thing.
- The four legs can be positioned vertically with pneumatic cylinders and positioned manually on their horizontal angle, so that the model can work on steep areas.
For those who didn't know this type of machines, walking excavators seem to be an extremely versatile class of small diggers, very useful to operate at very hard and space limited conditions, like difficult access, high slope terrains, etc...
Below a few self explanatory videos and photos that I found really amazing and illustrative of walking excavators capabilities.
Definitely a great challenge for any LEGO Technic builder!
It just reminds me to ask, when does LEGO give us another fully featured pneumatic model, like 8455.
As a closing note, there are a few manufacturers from these engineering wonders (Menzi Muck, Kaiser, Euromach) so it is easy to Google for them and find a lot more interesting videos, photographs and info.
There is even a facebook group dedicated to them, where the fans post the most incredible findings.