This is a shovel made from Lego, and it has all the functions a regular shovel have. In it, it has all the motors of the Lego Bulldozer set, set 8275, and also the receivers, the battery box and the controller. To move the bucket and arms, I have designed a special mechanism with pneumatic.
First of all I'll show you the steering mechanism. It works like the real steering system of a real shovel.
This picture is made on the left hand of the shovel. The green gear cannot rotate because it's attached to the construction, so when the gray gear right to it rotates, the frontside turns over in the opposite direction.
This picture is made fron the other side of the shovel and here you can see much better the mechanism of steering.
This photo is made from the bottom and here you can see the gears and worms to drive the gray gear. In a small Power Function motor is an axle plugged and at the end of the axle is a gear with 8 teeth. Right to it is a slipping wheel on an axle. On the end of the axle is a worm wheel attached and that one drives the gray gear.
Now I'll show the driving mechanism:
On a Extra Large Power Funtion motor is a gear with 20 teeth attached and that gear drives another gear, with 8 teeth, which make an acceleration of 3 to 5. The gear with 8 teeth drives a differential with 24 teeth, that makes an total delay of 6 to 5. The wheels are attached to the differential. The differential makes it possible to not just drive straight, but also make turns.
Now it's time to show the real system in of this shovel. I have worked with pneumatic pistons and pumps, but because I wanted to do everything motorized I had to make a mechanism to make air pressure with pumps and motors. This is what I have designed for this problem.
Here you see the shovel's rear side and the special mechanism is marked with a purple line (it's better to look at the zoomed picture, which you can see if you left click on the photo) and it has a pump to make move the arms.
This is the special designed item and now I would describe how it's made: An Extra Large Power Function motor is attached to a beam. At the axle, which is plugged in the motor, is an gear with 24 teeth. This gear has 4 gaps in it and in these gaps fits an 3 long pin. The end of an pump is attached to the beam and the 3 long pin. So when the motor turns the pump makes air pressure.
When the pump unit is removed, under it there is one more pump unit. That pump unit belongs to the bucket, with that pump you can move the bucket. This unit is a little bit different than the other one because in this unit, the gear is replaced with a disc with 6 gaps. The motor is also different because this pump just has to one task: move the bucket, and the other unit has to do two different tasks.
This is the bucket with the pneumatic cylinder. The bucket is the bucket from the set 8283.
On this photo you can see the whole arm and the most important thing of this photo is the cilinder to move the upper arm where also the bucket on is jammed. This cilinder is attached to the upper pump unit.
This are two cylinders and these are used to move the both arms and the bucket. Because of it is a little bit heavy I have used two cylinders so it can be lift up very easily. Therefor I needed twice as much small tubes and some splitting parts.
Very well done, particularly for someone who ought to be in primary school still, just looking at your age. Also, i admire your detailed descriptions and explanations in a foreign language from your perspective.
Keep up the good work!