I Made an Excavator With a Working Arm to Scoop Things As Well As Working Motors That Make It Drive and Turn.

I made an excavator made for scooping and moving objects as well as driving. There is a fully functioning are which can extent at two joints as well as a scoop which can move independently from the rest of the arm.

I used a 3d printer using 1.75 mm filament. I also used 3mm thick particle board that was laser cut to build the chassis. I used the 3d printer to print several components including two arm sections, three servo motor holders, and the main base for the arm. I used AA batteries and an Arduino YF robot board. I used two mini motors for the wheels and a Bluetooth connector. Finally I needed an amazon android to control my robot.

The first thing I designed was the scoop which I did by sketching a shape I liked. I then extruded it to a proper thickness and used the shell feature to hollow out the formerly solid piece. I added teeth to make it a claw and a bracket on the top to connect the arm.

There were three main components to this section. The first was the main arm which would be supporting the claw as well as moving with help from a servo motor. It was on a pivot with the claw so the claw could move independently from the rest of the arm. At the end if this arm were two more consecutive joints used to control this main arm. It has a hole to hold the servo motor.

The second component was the movement arm which was designed to move the claw. It was connected to a a servo bracket which rotated this smaller arm, in turn moving the claw back and forth. This movement arm was connected to the same bracket as the main arm on the claw.

The final component was the servo bracket which was a 3d printed piece to hold the servo in a snug fit, ensuring a proper connection. This piece had a joint on the end for movement with other pieces.

Each part had holes and corresponding pegs to hold them all together.

The second arm section had three main components however on of them is the same servo bracket as the first arm section. The first main piece is the general movement arm. This arm controls the movement of the main arm in step one. It is connected at the base to the chassis attachment. This arm is bent so the the servo is strong enough to lift the entire arm rather than simply having a servo directly connected to the arm. It also has a hole to hold the servo motor similar to the main arm. This was designed by measuring the servo motor and creating a equally shaped hole. The hold also has a small section cut out to ensure the wires can fit through while still having a snug fit with the motor.

The second component is a mini arm which is attached to the servo built into the general movement arm. This piece is controlled by the servo and is responsible for controlling the main arm.

The final piece is the same servo bracket as the second step.

This section has three main components however one is the same servo bracket as the first arm section.

The first component is a block which is responsible for connecting the main arm to the cassis, moving the entire arm, and feeding the wires to the main electronics inside the chassis. This piece has an elevated section to hold the servo motor. It is higher to make sure the servo is strong enough to raise the arm using the bend in the general movement arm. It also has a cutout to hold the general movement on a pivot as well as a hole to run the wires through.

The second component is the smaller movement arm which is attached to a servo motor using the same servo bracket. It attaches to the bend the general movement arm and controls the vertical movement of the entire arm.