Category Archives: Experiments

The Thingiverse “Heart Gears” Phenomenon – A Physible Family Tree

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Last September, I wrote over at MAKE about the Thingiverse “Cube Gears” phenomenon, briefly tracing the origin of user emmett’s Screwless Cube Gears through its evolution from Haruki Nakamura’s papercraft geared heart sculpture via user GregFrost’s printable Broken Heart thing. At the time, I really wanted to exhaust the graph of the cube gears / heart gears phenomenon, but didn’t have the available free time. I’ve had some good publishing experiences using Graphviz to generate directed graphs, before, and kept dreaming about using it to show the family tree of Thingiverse physibles descended from Broken Heart. Well, I finally got around to doing it. These data were mostly gathered manually, but Thingiverse is already tracking derivation information for things, and it would not be a great coding challenge to automate the generation of these types of graphs using Graphviz, which is free software. The SVG version, above, should be fully clickable so you can navigate to the various things as you please. If you can’t see it, for whatever reasons, there is a standalone SVG version here, and a large (non clickable) image here.

Here’s the Graphviz source:

digraph tverse_heart_gears {
graph [fontname="Helvetica",  fontsize=12, fontcolor=lightgray, bgcolor=white, tooltip="REMOVE THIS PHRASE"]; 

/* SVG tooltips are a PITA and require post-processing the SVG output to eliminate tooltips where you don't want them, e.g. over the whole background of the graph.  "REMOVE THIS PHRASE" just makes it easier to find manually. */

edge [penwidth=0.7, color="#1989FF", arrowsize=0.5];
node [shape=box, margin="0,0", penwidth=1, color="gray", label="", fontname="Helvetica", fontsize=8, fontcolor="#1989FF"];

915 [tooltip="Companion Cube by Gianteye", image="915.png", URL="http://www.thingiverse.com/thing:915"];
1614 [tooltip="Weighted Storage Cube (from Portal) by cyrozap", image="1614.png", URL="http://www.thingiverse.com/thing:1614"];
3219 [tooltip="Stellated octahedron by Wootfish", image="3219.png", URL="http://www.thingiverse.com/thing:3219"];
3575 [tooltip="Parametric Involute Bevel and Spur Gears by GregFrost", image="3575.png",  URL="http://www.thingiverse.com/thing:3575"];
4683 [tooltip="Broken Heart by GregFrost", image="4683.png",  URL="http://www.thingiverse.com/thing:4683"];
6073 [tooltip="Cube Gears by emmett", image="6073.png", URL="http://www.thingiverse.com/thing:6073"];
6190 [tooltip="Exploitable Heart by emmett", image="6190.png", URL="http://www.thingiverse.com/thing:6190"];
6291 [tooltip="Heart Gears by emmett", image="6291.png", URL="http://www.thingiverse.com/thing:6291"];
6336 [tooltip="Heart Gears on a Plate by JadeKnight", image="6336.png", URL="http://www.thingiverse.com/thing:6336"];
6375 [tooltip="Weighted Storage Cube Gears by whosawhatsis", image="6375.png", URL="http://www.thingiverse.com/thing:6375"];
6499 [tooltip="Eccentric Sphere Gears by whosawhatsis", image="6499.png", URL="http://www.thingiverse.com/thing:6499"]; 
6533 [tooltip="Gear gears by whosawhatsis", image="6533.png", URL="http://www.thingiverse.com/thing:6533"];
8581 [tooltip="Portal Companion Cube by grimm", image="8581.png", URL="http://www.thingiverse.com/thing:8581"];
9104 [tooltip="The head of Stephen Colbert by Colbert", image="9104.png", URL="http://www.thingiverse.com/thing:9104"];
9148 [tooltip="Colbert Head Gears by emmett", image="9148.png", URL="http://www.thingiverse.com/thing:9148"];
9194 [tooltip="Sun Gears by 67restomodder", image="9194.png", URL="http://www.thingiverse.com/thing:9194"];
10288 [tooltip="Pin Connectors by tbuser", image="10288.png", URL="http://www.thingiverse.com/thing:10288"];
10483 [tooltip="Screwless Cube Gears by emmett", image="10483.png",  URL="http://www.thingiverse.com/thing:10483"];
10493 [tooltip="Portal Companion Cube w/hearts by CarryTheWhat", image="10493.png", URL="http://www.thingiverse.com/thing:10493"];
10541 [tooltip="Pin Connectors V2 by tbuser", image="10541.png", URL="http://www.thingiverse.com/thing:10541"];
11253 [tooltip="Motorized Cube Gears by dougc314",  image="11253.png", URL="http://www.thingiverse.com/thing:11253"];
11660 [tooltip="Two Color World by m6mafia", image="11660.png", URL="http://www.thingiverse.com/thing:11660"];
12208 [tooltip="Screwless Heart Gears by emmett", image="12208.png", URL="http://www.thingiverse.com/thing:12208"];
14070 [tooltip="Earth Shot by WilliamAAdams", image="14070.png", URL="http://www.thingiverse.com/thing:14070"];
16442 [tooltip="MOTORIZED screwless heart gears! by Zh4x0r", image="16442.png", URL="http://www.thingiverse.com/thing:16442"];
16893 [tooltip="Keychain Screwless Heart Gears by Zh4x0r", image="16893.png", URL="http://www.thingiverse.com/thing:16893"];
16909 [tooltip="Big Love <3 - Heart Gears by faberdasher",  image="16909.png", URL="http://www.thingiverse.com/thing:16909"];
17336 [tooltip="Textured Earth by bld", image="17336.png", URL="http://www.thingiverse.com/thing:17336"];
17713 [tooltip="Earth Gears by bld", image="17713.png", URL="http://www.thingiverse.com/thing:17713"];
18061 [tooltip="Stellated Octahedron Gears by Lemon_Major", image="18061.png", URL="http://www.thingiverse.com/thing:18061"];
18134 [tooltip="Screwless Heart Gear Replicator Plates by IWorkInPixels", image="18134.png", URL="http://www.thingiverse.com/thing:18134"];
18144 [tooltip="Screwless Heart Gears - Plated by toybuilder",  image="18144.png", URL="http://www.thingiverse.com/thing:18144"];
22069 [tooltip="Gear Heart with Handle by catzpaw164",  image="22069.png", URL="http://www.thingiverse.com/thing:22069"];
23237 [tooltip="Screwless Companion Cube Gears by LocheMage", image="23237.png", URL="http://www.thingiverse.com/thing:23237"];

subgraph cluster_gregfrost {
	style="rounded,filled";
	color=lightgray;
	3575 -> 4683;
}

subgraph cluster_bld {
	style="rounded,filled";
	color=lightgray;
	17336 -> 17713;
}

subgraph cluster_tbuser {
	style="rounded,filled";
	color=lightgray;
	10288 -> 10541;
}

subgraph cluster_Zh4x0r {
	style="rounded,filled";
	color=lightgray;
	16442;
	16893;
	}

subgraph cluster_emmett {
	style="rounded,filled";
	color=lightgray;
	6073 -> 10483;
	6073 -> 6291 ;
	6190 -> 6291;
	6291 -> 12208;
	6291 -> 9148;
}

subgraph cluster_whosawhatsis {
	style="rounded,filled";
	color=lightgray;
	6375 -> 6499 -> 6533;
}

8581 -> 10493;
10493 -> 23237;
915 -> 1614;
4683 -> 6073;
4683 -> 6190;
/* 3575 -> 6073;  redundant derivations pruned */
6073 -> 6375;
/* 6073 -> 6499; redundant derivations pruned */
1614 -> 6375;
/* 10288 -> 10483; redundant derivations pruned */
10541 -> 10483;
10483 -> 11253;
10483 -> 12208;
6291 -> 9194;
6533 -> 9194;
9104 -> 9148;
6291 -> 6336;
12208 -> 22069;
12208 -> 18144;
12208 -> 18134;
12208 -> 18061;
12208 -> 17713;
14070 -> 17336;
11660 -> 17336;
12208 -> 16909;
12208 -> 16893;
12208 -> 16442;
12208 -> 23237;
3219 -> 18061;
}

These data were gathered on 2012-06-06 and are already obsolete, I should note. The graph has new nodes since then.

Warm canned air kills ants

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http://youtu.be/b8ggvETiBiU

My friend Jon, whose new house has a bit of an ant problem, has observed that gas from a “Dust Off” type spray duster kills them very quickly. His intuition, and mine, was that this is an unexpected phenomenon. I was intrigued at the possibility that the fluorocarbon that’s pressurized to make this so-called “canned air” (it is generally 1,1,1,2-tetrafluoroethane) might have some unexpected toxicity—unexpected, of course, because fluorocarbons are generally assumed to be relatively inert, biologically.

In any case, we Googled first, and discovered that others have noticed the phenomenon before. The hypothesis on this thread seems to be that it is the cold of the rapidly expanding gas that kills the ants, an explanation neither Jon or I found satisfying. This video shows the simple test I ran in response, which involved loading a rubber balloon with “canned air,” allowing it to warm to room temperature, and only then exposing the ants. Admittedly, the gas is still expanding here as it flows out of the balloon, but not nearly so much.

This test was conducted on October 15, 2011, at about 8:40 PM, in my garage, which was at a comfortable “room” temperature. The ants had been collected about five hours previously from the site of a sawn-off limb of an oak tree in a friend’s backyard. He identified them as “acrobat ants,” and observed that they give off an unusual “coconut” odor (even when undamaged), which I also observed. The test chamber is made of clear PETE, and is covered with a scrap of paper towel secured with a rubber band. The balloon, fixed to a cut polypropylene syringe body with Parafilm, was charged with gas from a Falcon “DustOff” brand compressed air duster (labeled “contains difluoroethane”) more than an hour before the test, sealed gas-tight by wrapping the needle-cap with Parafilm, and allowed to warm to ambient temperature. To perform the test, the needle-cap was removed, and the paper towel pierced with the needle, allowing gas to flow from the balloon into the test chamber. No temperature change was felt on the test chamber wall. The balloon was left in place for five minutes. No ants survived.

However, when I performed an identical procedure with propane instead of canned air, the ants died just as quickly, which leads me to believe that they are, in fact, simply suffocating.

And, no, to anticipate the comment, I honestly don’t feel great about killing trapped critters like this. But my curiosity won out over my moral compunctions, and is now satisfied. So I don’t anticipate any more of these experiments. Even if the balloon method does not adequately control against the possibility of “cold kill,” the identical effect with propane eliminates the possibility that the fluorocarbon has some unique toxicity, which was what struck my interest in the first place.