Full Design:

Our full robot design is seen in Fig. 1 and 2. The chassis will be made out of 2040 aluminium profiles from Prestech.

The center of gravity of the robot (full 3m height) when the spray is at it’s highest and the paint can is empty, is shown by the black and white dot (Fig. 3).

We will break it down into three parts to explain it in full detail.

Paint Delivery System:

We will be using a DPX3 airless paint pump (Fig. 4) for the paint delivery. This pump is an electrical piston pump which puts the paint under high pressure, spraying it out of a fine tip, in order to atomise the paint. The spray gun attached has a manual trigger, which simply releases the pressurised paint when pulled. In order to automise the pulling of the trigger, we will attach a linear actuator motor to pull the trigger (Fig. 5)

Vertical Movement Mechanism:

We will be using a timing belt pulley system for our vertical motion. A nema 34 stepper motor will be mounted at the base of our vertical aluminium profile track. A drive pulley will be attached onto the shaft, and will rotate, turning the aluminium drive pulley, which will in turn drive the attached timing belt. The timing belt will be attached to gantry plates, which will hold a horizontal bar where the spray gun will be casted onto. At the ends of the profile, idler pulleys will be placed.

Base:

The base will be a double layered base. Each layer will be 80x50cm.  The paint can and paint pump will be placed on the top layer. and the top layer sheet will be made out of aluminium.  The paint pump will be mounted into the aluminium sheet. The paint can will not be mounted to ensure ease of paint refill. Instead, gusset elements will be mounted onto the aluminium sheet, holding the paint can in place and preventing it from moving when the robot is in operation. The bottom layer sheet will be made of acrylic. The bottom layer will hold our Arduinos, motor drivers, power supply and RAMPS 1.4.

We will be using four DC motors of model number 550, four wheels of 22cm diameter and two 30A double DC motor drivers. These parts are typically used for children electric vehicles and hence would be able to withstand the weight of our robot. The wheels will be attached to our aluminium profiles through the use of steel rods and saddle clamps as seen in Fig. 7.