What You Missed: Subtraction Final

Yeah…so towards the end of last semester things got busy. As they do. And I neglected my blog for a bit. Now my summer trysts are over and I’m back at it. Starting with a series I’m calling What You Missed. This is (possibly) the first in a series of posts catching up on things/events that have transpired and deserve a blog post but don’t have one yet.

I’m starting with my final project from Ben Light’s Subtraction.

The Cryptex

So here’s the thing about the Cryptex…it’s sort of a made-up real object. Cylindrical coded objects safes have been around for a while. The Jefferson Disk is proof. But the neologism “cryptex” was coined by everyone’s favorite author of mysteries kicked into motion by shadowy ancient organizations, unbreakable codes, and the fate of the free world/religion: Dan Brown. A physical version was build for him and subsequently patented in 2004. Just for the hell of it I guess.

For my subtraction final I decided to make one using just the metal lathe. (The 4-axis mill came in handy too as an overpowered drill press as you’ll see later.)


A cryptex™ has 3 main components. An inner sleeve with pegs. An outer sleeve with a channel. And x-number of rings that form the locking mechanism, depending on how long your cryptex is. They go on the outer sleeve. Then The inner sleeve fits into the ring/outer sleeve assembly. Simple enough.

Except that the rings need to fit all these little pegs on the inner sleeve and they need to be able to rotate until the holes line up and the interior sleeve can slide out and there can’t be any gaps on the exterior. (Think bicycle lock.) So the rings are designed with a recess on the interior for the inner sleeve’s pegs to sit in and still allow the rings to rotate. If it isn’t clear yet, keep going. All will be illuminated.

(Was that an Illuminati reference? Is Cole part of the Illuminati? These are all good questions to be asking.)


I started with two stock materials. One was a length of .75″ aluminum rod for the inner sleeve. The other was a length of 1.25″ aluminum tube for the outer sleeve and rings. At this point all of my measurements were done so it was a matter of machining the parts to spec.

Milling the Sleeves

Milling the Rings

After I checked my tolerances, I started milling the rings. Each one needed to nest into the next, while leaving enough room for the pegs to sit inbetween each ring.

4-axis for 2-axis

I needed a few precise operations done that I a) couldn’t do on an unmodified drill press b) couldn’t rig up a modification on the drill press that was safe/satisfactory c) would have taken forever if I had trusted the 4-axis on it’s own. So I opted to take the literal wheel and control the 4-axis by hand. Essentially using it as a 2-axis, hand-cranked mill.

For each operation I set the spindle speed and, very carefully, moved the bit little by little.


Power Coating

Power coating uses the principles of static electricity to evenly and completely coat a metal object in a plastic-y paint-y type material. Then you bake it. The material melts together, sets, cools, and you’ve got a powered coated thing. As much as I liked the metal look of the raw aluminum I thought this would lend an air of “finishedness” to the project. It sort of did. The coat was even-ish on the sleeves. But I coated the rings twice which gave them a slightly different color.


The arrows and dots helped me keep track of the interior slots and where the pegs/channel were so that I could easily slide the assembly apart and back together.

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The finished* cryptex.



*After several failed experiments with electroplating and laser cutting, I still never arrived at a satisfactory solution for a code around each ring, so I just put on some stickers. Which, I know, defeats the whole point of it locking to being with.


Basic CAD Drawing

This week we had to recreate this object.  I’m more comfortable with Rhino, so that’s what I used for this assignment instead of the suggested VectorWorks.

Metal Lathe

Material Before & After

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The aluminum stock was surprisingly easy to turn. It’s definitely a more delicate process than the wooden lathe. Not because it’s unnecessary to to be delicate on the wooden lathe, but rather because on the metal lathe you are removed from the physical feeling of the material. Spinning a wheel to change the depth of the bit is a much different process that using your arms and hands to push into the material.

Finished Piece

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Lathe: Foosball Guy

Here I’m using a drill jig to create the hole for the crossbar on the blank.

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Rounding out the blank after both the crossbar hole and pin hole are drilled.

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Creating a rough shape.

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Semi-finished piece, before I sanded his legs flat on each side.

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Subtraction Midterm: Drafting Stand

Getting Bent out of Shape

This semester I’m taking an architectural drawing class in the Art History/Urban Design department. I’ve spent more than a few weekend nights awkwardly hunched over a small, low table sketching and drafting. If I felt like I was suffering for my art at first, after a few weeks of painfully unfolding myself after a drafting session, I’m now cured of that psychosis.

I needed a permanent solution. This midterm provided me with a perfect opportunity to avoid spending money I don’t have on a drafting table I may never use after this semester.


I didn’t have the material (or space in my apartment) for a fully upright drafting table design. Instead I decided to use what material I did have + my kitchen/crafts table to get the job done.

I designed a break-down-able stand that would fit on top of the kitchen table.

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The inset distance at the bottom (denoted with a 20″) is what sits on the top of the kitchen table. The tabs that drop below that rest on the folded down leaves of the table.


The design went through several iterations as I worked on building something robust enough for continued usage and…would fit onto the one sheet of plywood that I had at my disposal.

3D Modeling

Just for kicks I decided to 3D model the design in Rhino. These  aren’t strictly accurate. They were just to push myself to make the model and for a view of the object in digital space.

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I broke the CNC processes into individual parts (stands, struts, and holder) just in case something went wrong. I kept the origin point the same on all of the paths while creating them in MasterCam and when I set up the CNC machine. I had measured exactly how each cut would fit on the material, so I needed the CNC to be measuring from the same origin each time.

Finished Project

…coming soon to another post near you…

Tiki Me Two

I wanted to up the tiki-ness of this one. So I created more complicated shapes, more layers, and a more exaggerated facial structure. I even started with a photograph and used contour lines to determine which elements would be layered and where.

After the CNC

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Tiki Me

Subtraction: CNC


Per usual, I wanted to make something functional so as to not waste material and aside the skills learned, get something tangible from the project. But a combination of builder’s block (?) and slim picking in the materials department forced my hand. I had to think creatively.

I remembered a really cool project by a design studio called Hey. They’ve been posting minimalist illustrations of pop culture figures, real and fictional, on Instagram.  I love the self-imposed constraints, clever designs, and brilliant use of simple shapes. For whatever reason, this got me thinking about tiki masks which lead me to a pretty excellent tiki-version of a Chicago restauranteur named Paul Mcgee. (He owns a tiki bar called Three Dots and a Dash. I highly recommend it.).

I wanted to create a tiki-style portrait of myself using simple shapes, adding dimensionality by stacking layers of material. 

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My initial sketch.
Illustrator file


After a few false starts, Ben schooled me on the most efficient workflow for the Techno Router CNC. The key is to separate each feature into it’s own Master Cam file (and eventually into its own G-code file). This allows you to reset the origin point relative to each individual tool path. Which is super helpful because you’re able to CNC each shape at will, and by re-zeroing the CNC you don’t waste nearly as much material. In the first image below you can see that I was reset the origin point, just outside of the previous cuts, for each shape.

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I decided to paint each layer in varying shades of one color. I think it looks killer. And the monochrome will help make the layers pop. (One caution is that that the acrylic paint I used added a few millimeters of thickness on the sides, so the pieces next to each other on the same layer don’t fit as well as they should.)


Tiki Me




The Othermill

Full Metal Jacket

The Othermill is a desktop 3-axis CNC router. It’s quiet and it packs a lot of power and precision into a small footprint. It’s basically the Makerbot of CNCs. It comes with its own software, Otherplan, which reads SVG files output from any vector-based software–think Illustrator or if you’re a poor student, Vectorworks.

The Othermill is tiny, but it can charge through a variety of materials. This week we were given aluminum. Or al-lu-min-imum if you’re a Brit, Aussie or just pretentious.

Two and a Half Plan

2.5D is a term used to describe a lot of what comes out of ITP’s CNC machines. It’s not 2D but it’s also not true 3D. It’s what it’s called when you design a two dimensional object on a flat surface plane then cut perpendicular to your design lines through the depth of your material and/or engrave partway through it.

So this sketch for a bottle opener…

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…gets turned into several vector files that, together, complete the design…

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…which gets placed into Otherplan and milled, section by section…

…and ends up looking like this…

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