Bolts in a Bottle





Introduction: Bolts in a Bottle

About: My name is Troy. I'm a Mechatronics graduate studying Mechanical Engineering. I like to make things and spend time outdoors (especially SCUBA diving). I am a Community Manager for Instructables.

Puzzles are around us everyday. This simple bolt and dowel puzzle is part of a larger category of puzzles called impossible bottles. Impossible bottles are puzzles such as a deck of cards or ship in a bottle. There is often some work that is done before presenting the puzzle to others. These bolts and dowel will leave the observer scratching their head wondering how seemingly simple objects appear as they do.

If you would like to know how to make this very simple bolt and dowel impossible bottle, you will need a few items and a little time.

Step 1: Thoughts and Planning

Since this type of puzzle is about the bottle just as much as it is about the bolts through the dowel, each puzzle will be different.

When planning your puzzle, keep in mind that the sum of the width of the dowel (5/8 inch for me) and the length of the bolt (3/4 inch for me) must be less than the width of the inside of the bottle. I selected my dowel based on the opening of the bottle then selected the bolts based on that decision. This is extremely similar to the bottle I used.

Before you proceed, I would encourage you to either mentally think how you would do this, or go out and do it yourself. What would you use? Water, magnets, toothbrush or floss?

Once you have thought about it - or if you just want to know how to stump your friends - read on for the process I used.

Step 2: Prepare the Dowel

Cut the dowel as long as you'd like. Make sure it's just a little longer than the depth of your bottle. Doing this will ensure you can reach to the bottom of the bottle with the other end of the dowel.

Drill four holes in one end of the dowel. Be sure that the drill bit used is slightly larger than the bolts that will fit through them! I used 1/4 inch bolts. Drilling a 1/4 inch hole is a bad idea because this will not allow gravity to pull the bolt from the hole. This will lock the bolt in place and make it near impossible to remove the bolt from the dowel inside the bottle.

Sand the rough edges and finish the dowel. I applied a few coats of beeswax.

Step 3: Prepare to Solve

Get everything ready to assemble your bottle.

Other than the bottle, nuts, bolts, and dowel, you will need something like a straightened out paper clip, a tube from canned air/WD-40, or a stiff wire to manipulate the nuts while assembling. A broken bicycle spoke is pictured here.

Step 4: Insert All Nuts and Bolts

Dump all nuts and bolts in the bottle. Make sure they are not assembled in any way.

Step 5: Bolt One

Each bolt will have the same steps to get them attached to the dowel. Always start from the hole closest to the bottom of the bottle. Do this, because if you start from the hole closest to the neck of the bottle, each bolt will get in the way of the next.

Stand one of the bolts up by using the end of the dowel. Carefully nudge the bottle until the upright bolt is lined up with the bottom hole.

Carefully insert the dowel over the bolt.

Pull the dowel and bolt to the neck of the bottle. This will hold the bolt in place while you rotate the dowel so the threads are facing down.

Gently shake your bottle till a nut is under the bolt.

Lower the dowel and bolt till it touches the nut.

Drag the nut back to the neck of the bottle and rotate one more time.

Now that the nut is on top, carefully slide the dowel back into the bottle while keeping the head of the bolt as close to the edge as possible.

Insert whatever tool you are using and slowly rotate the nut clockwise until it is as tight as possible. This is done by tightly holding the bolt against the edge of the neck and allowing the nut to be free.

Step 6: Bolt Two

To insert the second bolt you will use the same steps from the first bolt.

Stand up the first bolt and insert it into the dowel.

Using the neck of the bottle, rotate the bolt, grab the nut, rotate again, and tighten the nut.

Step 7: Bolt Three

You have two options for the third bolt. You can insert it the same direction as the first, or you can rotate in 180 degrees. For the length of bolt that is allowed in this bottle/dowel combination it doesn't matter. It just depends on what you want it to look like. If the threads of your bolts are showing on the other side of the nut, you may need the nuts to be inserted in the same direction, or the threads from the first bolt will interfere with the third bolt.

Step 8: Bolt Four

If you've made it this far, only a little bit further to go. Following the same steps from the previous three bolts, insert your last bolt and tighten your last nut.

Step 9: How to Disassemble?

The disassembly of the bottle is much easier than it is to assemble. With the nut facing down, tap the end of the dowel against the bottom of the bottle. Gravity will slowly rotate the nut loose.

If you make one of these puzzle bottles, please share your results! I'd love to see what other puzzle bottle ideas you come up with!

2 People Made This Project!


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17 Discussions

Looks really cool. Maybe you could find some way to use a magnet to move the nuts and bolts inside the bottle to setup the puzzle

Hello. Love this idea. Something to consider using is a strong magnet to line up the bolts and nuts. I say a big one for the bottom to hold all the extras out of the way. Then a smaller one to move everything around with. Could help you get them buggers to the neck easer. I'll have to try it when I get time to make one.

1 reply

Whenever you try this let me know how it works out! I always thought that the magnetic fields would cause problems with the one you are trying to insert in the dowel. Share your result, I'd love to see it!

This is very cool!

That was interesting! Nice job.

Very interesting, another worthless piece of time wasting while on the job, I LOVE IT. Good job.

Using magnets would help

It looks like fun :) You should send one to Jason!

Never tried to put any thing into a bottle. I'm more of a bottle emptier (glug, glug!), but I really appreciate your art. Has anybody ever done a bottle inside a bottle? Or for that matter, a bottle inside a bottle, inside a bottle, inside a bottle...

And just how many times can you say bottle before it becomes just a weird noise you're making with your mouth?


1 year ago

I Like the inside work with the wires as tools... How about using longer bolts more believable with magnetized manipulating wire like tools? Then you can use larger bottles and make it more impossible to figure out like the expandable ships in a bottle. who would know without thinking outside the bottle to create inside...

1 reply

You can definitely use longer bolts! The only restriction to bolt length is the size of the bottle and the width of the dowel. I covered this in Step 1. If you have a larger bottle than I had, you can use these same steps with longer bolts.

Awesome idea!

Your ideas are awesome!!! Will definitely make this ☺☺

Woah! Cool. I don't know how hard it is to turn the nut, but I would imagine filing little notches in the coat hanger or whatever might make it a bit easier.

Cool. Are you guys having an impossible bottle competition?