We learned water jet cutting and post processing of metal. In this assignment, we used waterjet cutting machine to produce two identical version in rhombus shape with pattern cut in the center.

The first step in this process involves designing the rhombus using adobe illustrator （5 in * 3 in） and import into ProtoMax layout. The design is translated into a digital file for the waterjet cutting machine to select the start point. This digital design specifies the dimensions, angles, and any intricate details of the pattern, and save into ProtoMax Make to start cutting. To ensure the cut went well, we selected the start point towards the center pattern because if we cut the outer shape first, the piece of rhombus would move while cutting in the center.

After cutting with water jet machine following the instructions, I found there are many scratches on the metal surface due to debris. So, we used sandblaster to removes any imperfections, such as burrs or irregularities, left behind by the waterjet cutting process. It creates a smooth, uniform surface for the next step because sandblasting can impart a unique texture or finish to the metal. This not only enhances the appearance but also improves the material’s adhesion properties for the powder coating.

We employed a vinyl cutter to create intricate shapes, specifically a star and a heart, from adhesive vinyl material. These vinyl cutouts are then delicately placed onto the right and left of metal surface of the rhombus as masks. Each heart and start and dimension of 1inch each side.

The metal pieces looked already smooth and clean, and we planned to provide the rhombus with its desired color and protective layer with powder coating. An electrostatic gun applies a fine, dry powder to the sandblasted surface of the rhombus after pumping to 10 psi. The positively charged powder particles are attracted to the grounded metal, ensuring even coverage. The coated metal piece is then baked in an oven at 400F degrees for 18 minutes. During this process, the powder melts, flows, and chemically reacts to create a hard, durable finish that’s resistant to chipping, cracking, and fading. I have two pieces of identical metal parts, we coated one piece with one layer, the other with two layers. After baking, I can see the differences with color. Apparently, the metal with two-layer coating looks darker and sturdy in color. Also, when I placed them into the oven, one sharp corner of metal pieces was accidently touched with the inner wall of oven, so it powder was faded a little and kind of invisible.

In general, I used waterjet cutting, sandblasting, vinyl cutting and powder coating techniques to finish my first experience of metal cutting and post processing.

Cost analysis table:

Cost Type	Cost	Price	Source	Quantity	Total
Materials	0.0179in stainless steel	$18.47	Home depot	1 piece	$18.47
Labor	waterjet operator sandblaster labor vinyl cutting labor powder coating labor	$17 $18 $16 $15	ZipRecuiter ZipRecuiter ZipRecuiter ZipRecuiter	1 h 10 min 30min 30min	$17 $3 $8 $7.5
	Prototyping Engineer (You!)	$38	ZipRecruiter	1 h	$38
Overhead	Facility Cost	$21/h	Techniwaterjet	1h	$21
	Quality Control	$41	ZipRecuiter	0.5h	$20.5
Design	Engineering and Development	$0	N/A	N/A	$0
	Iterations	N/A	N/A	N/A	$0
Misc.	Waste and Scrap	$1.64/piece	Verichek	0.5 piece	$0.82
Total					$134.29