# Coin Chest Puzzle by OSKAR

Discussion in 'My Shapeways Order Arrived' started by Oskar_van_Deventer, May 8, 2016.

1. Oskar_van_Deventer Well-Known Member
Hi Shapeways fans,

Coin Chest Puzzle is a shape-mod suggested by David Tzur. The idea was to turn an Oskar's Treasure Chest into a piggy bank by making a slot in the center. The first prototype was a failure. It had only a slot in the center, but the slot was too small to pass even the smallest of coins. The second prototype had a big slot, big enough to pass a 2-euro coin. Unfortunately, such a big slot interferes with the inner mechanism that holds the puzzle together. The slot had to be extended into two of the corner pieces. As a consequence, a 2-euro coin can only be passed when those two corners are in place next to the center slot. Smaller coins pass without a problem.

So now people can get value into the puzzle without needing to solve it first. The question in my YouTube video is how much value you can push through the slot into the puzzle. I do not have an exact answer, but I guess it is over a billion dollar according to one calculation.

Buy the extra pieces puzzle at my Shapeways Shop.
Read more at the Twisty Puzzles Forum.
Check out the photos below.

Enjoy!

Oskar

2. drloris Well-Known Member
Hi OSKAR.

Going from the link you provide, the puzzle is a cube of 58mm across. I estimate that the spherical cavity is 50mm across at most (actually I'm sure it's rather less). Therefore the volume is around 65.5 cm^3.
The most expensive material shapeways supply is platinum.
The cost of shapeways platinum is 1750 per cm^3 (excluding per-part charge), so naively one could fill the puzzle with a sphere costing only about \$114,000. Now, athough this won't fit through the slot, one could divide it into small, flat objects which would. This can also increase the cost a little from the per-part charge. The smallest platinum part shapeways will print is 2.4 × 2.4 × 0.6 mm, so one could divide this sphere into 18938 pieces, for an additional cost of \$1893800, giving a total of approx \$2,008,000, or two meeellion dollars.

Now, I suspect that you're now considering the prospect of manufacturing such a puzzle, composed of 18938 tiny pieces, perhaps for multi-millionaires with plenty of time on their hands.
However, I'm sorry to say that this falls rather short of your target of one beellion dollars. 3D printing is clearly not suitable for this project.

Last edited: May 9, 2016
3. mkroeker Well-Known Member
Suspect the billion guy cheated by using banknotes, small diamonds (too lazy to check if tiny ones would even be expensive enough), the world supply of Blue Mauritius stamps or even a folded Vermeer to honor shapeways' origins.

4. Oskar_van_Deventer Well-Known Member
That is a funny idea, given that 3D-printed platinum is even more expensive (valuable) than the raw material, and that you can drive the cost up by making an order as inefficient as possible. Your way of thinking is quite out-of-the-box and opposite to how most people look at Shapeways. Thank you!

Oskar