For this assignment, I applied knowledge learned from class in 3D shapefiles and advanced manufacturing techniques to create a mold and cast object from my finger that can work as a wall hook.

To create a mold of my finger, I made a paste from 250 mL water and 33g of alginate powder in a cup. After stirring carefully and thoroughly, I placed my finger in the paste and waited six minutes for the alginate to set properly. Once I felt resistance in the paste, I knew it was time to remove my finger and prepare the cast material.

The cast was prepared using 30g of Plaster of Paris powder and 15 mL water. Once I mixed the caster powder with water, I realized that the mixture was slightly too runny. To avoid issues with increased set time, I added a tablespoon more of the plaster powder into the mixture. After I poured the mixture into the alginate mold, I positioned the wall hook screw into the paste, making sure to center it as much as possible to avoid stability issues. I then fastened the screw with a popsicle stick and tape over the cup. After about 14 hours, I removed the cast finger and after inspecting the alginate mold, I realized that I could not reuse it for another cast since it was oddly wet and breaking apart.

I repeated the steps above to create another mold and cast for my second finger wall hook. I made sure to avoid leaving the finger in the mold for more than 12 hours and it came out with fewer issues than the first finger.

After extracting both hooks, I decided to finish them by spray painting them black. After they dried, I removed all excess tape from the screw.

Very minimal waste was generated in this assignment and I am pleased with the fact that the finger wall hooks both only needed one iteration.

The entire project cost less than $10 for both finger wall hooks, including labor and development costs. Overall, the project was very cheap and easy to develop and execute. For next time, I will be more careful about the timing to remove the cast from the molds as longer definitely does not mean better.

Cost Model:

Cost Type	Cost	Price	Source	Quantity	Total
Materials	Alginate	$13.95	ScottsDental.com	~10%	$1.39
	Plaster of Paris	$22.98	Amazon.com	~10%	$2.29
Labor	Prototyping Engineer (You!)	$10/hr	Self	10 minutes	$1
Design	Engineering and Development	$5/hr	Self	1 hr	5
	Iterations	1			$0
Misc.	Waste and Scrap				$0
Total					$9.68