Wednesday, November 18, 2020

Hiding Money in Puzzles - Unsafe Deposit

Unsafe Deposit by Alan Lunsford

It’s difficult to chastise my wife for “saving money” by buying things on sale when I’m “investing” in puzzles that come with money inside.  In my defense, Alan Lunsford specifically adds the amount of the coin to be released to the price of his puzzles to highlight the fact that you are explicitly paying for that coin.  The price of the puzzle is in the dollar’s field and the value of the coin to be released is easily identified in the cent’s field.  Unfortunately, this puzzle was only released in the US due to issues with mailing US currency to other countries.  I’m assuming that future puzzles will utilize some form of decorative non-currency token.

Quarter Trapped in Unsafe Deposit
Unsafe Deposit is Alan Lunsford’s latest coin release puzzle available on his layerbylayerpuzzles Etsy Shop.  Unlike the prior Cop Out puzzles, Unsafe Deposit is a cube with openings on 5 of the sides.  On the front, you can see George Washington’s head on a quarter through a square window.  On the left, there is a quarter sized slot that looks like it may be the exit point, but it is blocked on the inside.  There are also different sized slots on the top, front, back and right side.  Only the bottom of the puzzle is untouched.  Through the slots, you can also see that there are other objects within the cube.  The one visible from the top is blocked by an internal hex head socket screw bolt - or simply for this context, a screw with grabbable head.

Unsafe Deposit Card
The goal is to remove the quarter.  Given the name, Unsafe Deposit, you immediately assume that it is possible to remove the quarter that Alan has deposited in the puzzle.  Included with the puzzle is a card with the following rules:

  • The use of external tools is not permitted.  You should avoid the temptation to use your hammer.  Unless, of course, you have already solved it and want to see how the internal mechanisms work.  In that case, you may want to buy a spare.
  • No excessive force should be used in solving the puzzle.
  • The internal mechanisms are delicate so don’t hit it hard.  To be honest, you don’t need to hit it at all.  Hopefully your mail service doesn’t drop kick your package to the door.
  • Store below 40C/100F.  I’m not sure at what temperature puzzles made from PLA start to warp, but I’m assuming that it’s best not to store them in your car or garage in the summer.
  • Contains magnetic components.  Yes, the puzzle is attractive.
  • Have fun!  This reminder was added for those that get stuck and circle back to check the rules again for a clue.

The first thing you’re going to do is try the moves that you used for the Cop Out puzzles, but that’s not going to help you.  Of course, you’re going to do it anyway even though I just told you that it’s not going to work, but that’s OK - I would too.  Forget everything you learned with the Cop Outs.  Unsafe Deposit is a different kind of animal.  I knew that I was in for something different but I didn’t quite realize how much change to expect.  It is more of a sequential discovery puzzle than a coin release puzzle even though the ultimate goal is to release a coin.  Along the way, you will discover other tools that you will need to continue the journey.

Unsafe Deposit Solved
The solving sequence of Unsafe Deposit used very clever mechanisms but I found it very simple overall.  I solved it quicker than any of the Cop Out puzzles.  However, it makes an excellent introduction to sequential discovery puzzles.  What really impressed me was the construction of the puzzle.  The box looks like it has been seamlessly printed as a single object and not assembled from separate pieces.  This would require the printer to be paused while internal pieces such as magnets and sliding panels are added.  And of course, the filament needs to be changed to add the name of the puzzle in a contrasting color on the top of the box.  It really is very well made and I was immediately impressed when I unboxed it.  If anyone does take a hammer to theirs, please send me a photo so I can see what the internal structure looks like.  What is needed now is an Almost Safe Deposit follow-on.


  1. How an I contact you for a hint?

    1. Best place to get hints for Bolt Action is directly from Alan Lunsford at You can also find Alan, myself, and many others that can help you on the Mechanical Puzzles discord (

  2. I'm thinking of buying unsafe deposit but was wondering if this puzzle has any tools in it that have to found and used to solve

    1. Solved it today. Yes and it's a wonderful intro into SD puzzles!

    2. Both Unsafe Deposit and Bolt Action by Alan Lunsford are Sequential Discovery (SD as Tyler indicated) puzzles that have tools that need to be found, freed, and used in order to proceed and solve the puzzle. The new list of updated gateway puzzles for new puzzlers was just released today on the Mechanical Puzzles Discord and Unsafe Deposit was voted as the top SD puzzle to start with. It's well worth getting!