This here is The Cavator, a futuristic vision of your standard Evacuator and the 2nd place winner in Polish regional Solidworks Design competition organized by CNS Solutions (all winners can be seen here) Created by GrabCADr Mariusz Jablonski, it does away with the single arm and replaces it with two in order to create a machine capable of doing multiple actions in concert. After seeing this posted, I began talking to Mariusz about what his thinking was behind the concept.
My inspiration was the desire to create something new. Machines of this type usually possess one dipper stick and two caterpillars connected rigidly with a chassis. So I designed a machine that departs from this rule. The presented model has four independent caterpillar units and also two dipper sticks. I wanted to make this machine also had a unique design.
One question was raised by someone about whether or not the Cavator would be stable enough. Two arms with different implements on the end would create a slight imbalance. If positioned wrong (say, on an incline or on loose material), the Cavator could fall over if both arms were oriented to one side. Mariusz pointed out the design of the caterpillar tracks.
Most of the mass of the machinery is on the back because ther is the diesel engine driving the hydraulic pump. Therefore, when dipper sticks are loaded, machine can remain in balance. The caterpillar unit possesses three passive and one active wheel which are driven by the hydraulic engine. Additionally it has a slewing bearing which makes bigger the possibilities of the movement which is installed with the caterpillar bracket and the hydraulic cylinders. Thanks to this construction the caterpillars possess two degrees of freedom.
Right on - congrats to Mariusz on his prize (all the comments from the Community point out that he should have been first). This is some impressive work and we look forward to seeing more. If you like what you see, or have a question about the design, leave a comment. Mariusz left a STEP file for anyone to render - go for it!