Pencil Puzzler Revisited





Introduction: Pencil Puzzler Revisited

About: Formerly the owner of a company that designed software for avionics (EFIS, FMS, etc.) and video games (Tetris, Robocop, Predator, Michael Jordan in Flight, and a number of others), I'm now retired and finall...

Spoiler Alert! If you do not wish to know how this "magic trick" works, do not proceed (but I hope you do)!

I designed Pencil Puzzler a few years back as a 3D printable version of an old magic trick. I've seen this style of magic trick using rope, pencils and even nails, but they all operate in the same general matter. This version includes all parts, even the "pencil", so nothing else is required other than a 3D printer and filament.

I probably forgot a file or two or something, so if you have any questions, please feel free to ask.

Designed using Autodesk Fusion 360, sliced using Cura 2.3.1, and printed in PLA on an Ultimaker 2+ Extended and an Ultimaker 3 Extended.

Step 1: Print and Prepare the Parts.

I printed my parts on both an Ultimaker 2+ Extended and an Ultimaker 3 Extended using .1mm vertical resolution and 20% infill.

Prior to assembly, test fit and trim, file, sand, etc. all parts as necessary for smooth movement of moving surfaces, and tight fit for non moving surfaces. Depending on the colors you chose and your printer settings, more or less trimming, filing and/or sanding may be required. Carefully file all edges that contacted the build plate to make absolutely sure that all build plate "ooze" is removed and that all edges are smooth. I used a flat jewelers file and plenty of patience to perform this step.

Study "Assembly Exploded.stl" carefully noting the locations and positions of the various components as assembly proceeds.

You may also notice I applied black coloring to simulate pencil lead to the ends of all the pencil pieces using a black indelible ink pen.

Step 2: Join the Lower Case Parts.

Using "Case Lower Joiner.stl", join "Case Lower A.stl" to "Case Lower B.stl". Carefully note the orientation of "Case Lower Joiner.stl", particularly the recessed cross member.

Step 3: Assemble the Center Slide.

Start by positioning "Slide Bottom Outer.stl" under the case assembly as shown.

Position "Slide Bottom Inner.stl" onto "Slide Bottom Outer.stl" as shown. Thus "Slide Bottom Inner.stl" is on the top, followed by "Case Lower Joiner.stl", then "Slide Bottom Outer.stl" is on the bottom.

Position "Container Pencil.stl" into the assembly as shown.

Press "Case Upper B.stl" around "Container Pencil.stl" through "Slide Bottom Inner.stl" and into "Slide Bottom Outer.stl". This procedure finishes the center slide with "Case Upper B.stl" and "Slide Bottom Outer.stl" holding all the pieces together.

One complete, the center slide mechanism should operate. It may catch on the framework, but when the next step is finished, that should no longer occur.

Step 4: Final Assembly

Press "Case Upper A.stl" into the left side assembly.

Press "Case Upper B.stl" onto the right side of the assembly.

The center slide should now operate freely.

See the video on how the "magic" is performed.

Hope you like it!



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    30 Discussions

    I did it with a real pencil, the slide bottom outer sometimes fall but it is a nice.

    have you done others magic tricks ?

    1 reply


    No, I've done no other magic tricks as of yet, but I'm always looking.


    yes sir! thanks for the hard work!

    You are welcome, and I am very glad you like it!

    I really enjoy publishing things for people to download and print. Never in my wildest dreams did I expect an issue with this one.

    I am very impressed with your work in general. I sent you a thank you for your original version of this trick some time back. I went back and checked to see if it was you. We entertain with the pencil trick several times a year. It is a real crowd pleaser, but I am even more impressed that you worked on Tetris. You have no idea how many wasted hours I had playing that game until all hours of the night when I had to work the next morning. Keep up the good work. I am going to go cast a vote for your air driven car right now.

    Thank you so much for your kind words!

    But you'll have to get in line for those who have "cursed" me for the home version of Tetris, along with Robocop, Predator, Michael Jordan In Flight, and well, you get the picture! ;)

    Since retiring, I now design, print, test and publish things for people to 3D print, assemble and enjoy. And as always, I am honored by you taking the time to print and assemble something I have published, and am grateful that you took the time to comment about it.

    Many, many thanks again for your kind words, and I am truly sorry for your loss of sleep from my earlier designs!

    Thanks again.


    Thank you for sharing your version of the Zig Zag illusion, along with the instructions on how to make the "case" for it with a 3D printer. Maybe, thanks to you another great Magician will learn his first trick. When I was a child, my dad a variation of this. The case was made of Balsa Wood, and it used pieces of rope instead of the pencils used here. I had thought that it was part of the Magic kit he put together as a child in the 1940's.

    Upon investigating the history of this illusion's (trick's) concept, I found it was developed, and originally preformed by Ned Williams (stage name Robert Harbin) during the mid 1960's - Zig Zag Girl. A number of Magicians pirated his illusion, which frustrated "Mr. Harbin". Reference to the history I state can be found here:

    Tenyo, a company that sells props for magic tricks came out with a device similar to the one presented here, though it used cigarettes instead of the pencils suggested here. Their "designer" of their device was Hiroshi Kondo. They named the trick Tenyo T-110 Zig Zag Cig. Tenyo gives full credit to Robert Harbin for being the originator of the Zig Zag illusion, and states many magicians have copied it since originally preformed by Harbin. Reference to this can be found here:

    Again, I thank you for sharing this illusion, along with instructions on how to build the "props" to preform it. I hope I have cleared up any confusion about who created this illusion, when it was created, and the fact it has been copied many times, by many people, over the last 50 years. Peace

    1 reply

    Thank you for your thoughtful and detailed insight as to the published history of this illusion.

    My only intent was to design, print, test and publish a magic trick from my childhood (around 50 years ago) for the enjoyment of my kids, grandkids, and for anyone else that enjoys a good simple "magic" trick.

    Whether the subject object for this illusion is a pencil, a piece of rope, a nail, a cigarette or a rubber finger, they all operate the same as they have for at least 50 years, and they all delight, which is my sole purpose for designing, printing, testing and publishing anything.

    My license agreement here and on all other sites I publish is non-commercial, and as such, I profit only from the enjoyment of people who click the like button and/or actually print something I have published, and I do like both.

    Thanks again and I hope you liked it!

    No, mine was indeed a rope. I also had the option of purchasing the "finger" version but my mother would not allow me to (it was kind of gory).

    I don't know when or where the original idea came from, but I do know from Colorado, Kansas, Missouri, Arkansas and Oklahoma, I've seen this in various forms at craft shows and magic stores. As I mentioned on another site, I even built one of these using "laddie" pencils and a bass wood mechanism in my early high school days, which would put that one at around 44 years ago.

    Again, I truly apologize as I had no intention of "stealing" anyones design, offending magicians, or offending anyone. And while I do not know of the person that you mentioned how "created" the original, I do know a lot of others have indeed done so, some more than 50 years ago, I was there.

    A couple of minutes of research shows that the original design was a zig-zag girl, by Robert Harbin in 1965. All this 'inventor' did in 1981 is make it smaller and swapped the girl for a cigarette, not a pencil. Tenyo subsequently swapped the cigarette for a bunch of other novelty items, possibly including a pencil, but who cares. In any case, you don't use a pencil, you use a chunk of plastic with a black tip ;)

    If anything Robert Harbin owns the copyright to the design, which he published. But as pointed out below, there cannot be any patent infringement.

    Keep up the good work and sharing ideas...


    1 year ago

    Unless your the inventor of this and everyone in magic knows that would be Tenyo you are stealing someone else work and exposing it.

    6 replies

    If you don't have anything nice to say, don't say anything at all.

    All these simple illusions have been on the market for years as the author says. I don't think anyone from the Magic Circle is going to put a bullet in him for this.

    lighten up bro. this thing is ages old. Its modernized now. I 3d printed one for my friends son who is an aspiring magician and he loved it!

    I did not mean to offend anyone and I'll be happy to remove this model if advised as such by Instructables.

    I purchased a rope version of this thing, made by a local artisan at a craft show in Colorado near the Royal Gorge, over 50 years ago (showing my age I guess)! I've seen them at various stores and craft shows using pencils, nails and rope. The concept is my age or older, the implementation does vary though. I guess using a pencil as opposed to a nail or rope could be considered unique, but it was not the first.

    Guess I should have stuck with rope...

    Even if they did file a patent for it way back when, it would be expired long time ago. Someone further down mentioned buying this 50 years ago, patents last only 20 years. After that everything is in the public domain.

    Creator Alert!

    This effect and exact design were created by magical genius Hiroshi Kondo of Japan. He was working for the Tenyo Corporation at the time. They still own the world rights to this design.

    This comment: "I bought one of these at a local magic store over 50 years ago (at that time I wanted to grow up and become a magician) and always liked it for its simplicity and effectiveness." is impossible as this was created in 1981.

    Great to make and share, but also VERY important to respect the creations and original ideas of others.

    Make On!