Summary

This simple object does one thing - combine 4 pencils. With four of them you can make an open-bottom cube with room to expand upwards; with 8, a two-story building.

How I Designed This

Based strongly on a 4-way PVC joiner from the hardware store, inspired by a lifetime of exposure to tinker toys and Construx. Designed in FreeCAD using the Sketch->Part Design workbench, starting with a hexagon, then padding and slicing from there.

To the best of my knowledge this is an original work; I certainly started from scratch, anyway.

Project: Playing With Pencils

Scale 1: Preschool to Elementary

            <div><p>Any kid old enough not to try to eat their toys can enjoy this - just like big market toys, you stick the rods together with pretty plastic connectors.  Set goals appropriate for their grade level - maybe the fifth graders can have a competition to build the tallest building or the strongest bridge, working individually/in groups/as a class.</p></div>                <p class="detail-title"><strong>Scale 2: Junior High School and up</strong></p>            <div><p>Orthogonal building blocks are fun, but if you really want to make a structure you're going to need diagonals.  Using the attached files, make a 45° pencilgrabber that can slide anywhere along the middle of the pencil.  Whose design works the best?  Can the clips themselves be improved?  What if they bowed in the middle like a binder clip instead of flexing out like a paperclip?</p></div>                <p class="detail-title"><strong>Objectives</strong></p>            <div><p>Any student building a structure will gain valuable experience in what does and doesn't support; students working together learn teamwork, students working separately learn independence, and students reworking the model learn 3D modeling.</p></div>                <p class="detail-title"><strong>Audiences</strong></p>            <div><p>Any grades K-12 can use this, it is infinitely scalable; college students may be bored by the triviality of the tasks, depending on their background.</p></div>                <p class="detail-title"><strong>Preparation</strong></p>            <div><p>Have students save their pencils throughout the year, or bring in a fresh package from the dollar store or similar; a single twelve-pack can get you two feet off the ground, if the whole class is working together you may need a higher ceiling.</p></div>                <p class="detail-title"><strong>Steps</strong></p>            <div><ul><li>Print a series of these objects in advance</li><li>If editing, I recommend using the FCStd file when available - it has an Undo history stretching clear back to the first step, complete with the original geometries.</li><li>You may want to have diagonals and/or 6-sided variants available - Joiner5 allows construction beyond the simple tower, Joiner6 allows construction in all orthogonal directions.  (I tried doing the 45°s as well on a single box, with predictably disasterous results - but the whole point is to invent your own blocks, not for me to make you evetry possible block!)</li><li>I've never used the Customizer, but if that lets you delete items you could probably get away with just using Joiner6 for everything and cutting off the parts you don't want.</li><li>I don't actually own a 3D Printer, so if you have any feedback on Actually Using This I'll gladly integrate it into future updates.</li></ul></div>

Playing with Pencils