Day 112 - Tetris T's

I like the rounded and nicely-spaced design of 3DAndy's Pentominos on Thingiverse, but wanted to print some tetrominos instead, for math/puzzles (for example, polyomino packing problems) and for future Tetris-related art projects.  Since 3DAndy was nice enough to post his OpenSCAD code, it was easy to modify his pentomino-T into a tetromino-T.

STL file: http://www.geekhaus.com/makerhome/day112_tetrisT.stl
Thingiverse link: http://www.thingiverse.com/thing:212995

Settings: MakerWare .3mm/low, with 8 T's printing in 45 minutes and weighing only 16 grams. Tetris pieces is a great "stash-busting project" for those of you with lots of little scraps of filament that are too small for any normal print job.

Technical notes: Download the OpenSCAD code here or cut and paste from the below.

// mathgrrl tetrominos - example with Tetris "T"
// based directly on 3DAndy's pentominos

////////////////////////////////////////////////////////////
// PARAMETERS ////////////////////////////////////////////////////////////

//resolution
$fn=32;

//dimensions
length = 10;
radius = 1;
space = 0.2;

///////////////////////////////////////////////////////////////
// RENDERS ///////////////////////////////////////////////////////////////

//render an instance of the Tetris "T"
tetromino_T();

///////////////////////////////////////////////////////////////
// MODULES ///////////////////////////////////////////////////////////////

//define the blocks and connectors that make the Tetris "T"
module tetromino_T() {
union() {
// the blocks
translate([0,0,0]) 
myCube();
translate([length,0,0]) 
myCube();
translate([2*length,0,0]) 
myCube();
translate([length,length,0]) 
myCube();
// the connectors
translate([(0.5)*length,0,0]) 
myConnect();
translate([(1.5)*length,0,0]) 
myConnect();
translate([length,(0.5)*length,0]) 
myConnect();
}
}

//module for making the blocks
//eight spheres translated to the corners of the desired cube
//then convex hull of those spheres makes a rounded cube
module myCube() {
dist = length/2-radius-space;
hull() {
translate([dist,dist,dist]) 
sphere(r=radius);
translate([-dist,dist,dist]) 
sphere(r=radius);
translate([dist,-dist,dist])
sphere(r=radius);
translate([-dist,-dist,dist]) 
sphere(r=radius);
translate([dist,dist,-dist])
sphere(r=radius);
translate([-dist,dist,-dist]) 
sphere(r=radius);
translate([dist,-dist,-dist]) 
sphere(r=radius);
translate([-dist,-dist,-dist]) 
sphere(r=radius);
}
}

//smaller cubes used to connect adjacent blocks
//space between blocks is small enough that no support is needed to bridge the gap
//even though these hang in the air between the blocks they connect
module myConnect() {
translate([space+radius-length/2,space+radius-length/2,space+radius-length/2]) 
cube([length-2*space-2*radius,length-2*space-2*radius,length-2*space-2*radius]);
}

Day 111 - One MetroTech Center

This is a model of the building that houses the MakerBot Headquarters in Brooklyn, with a hole in it for a couple of pens or whatnot.  The basic building shape was downloaded from Trimble 3D Warehouse, then resized and converted to STL in Sketchup, with windows added in Tinkercad.

Happy holidays, MakerBot!

STL file: http://www.geekhaus.com/makerhome/day111_metrotech.stl
Tinkercad link: https://tinkercad.com/things/gQtw7tgKg06-day-111-one-metrotech-center-in-brooklyn
Thingiverse link: http://www.thingiverse.com/thing:208623

Settings: MakerWare .3mm/low in 3-4 hours.

Technical notes, short version: Get the model from Trimble, open and resize in Sketchup, clean up and add features in Sketchup or Tinkercad, and download the .stl for printing.

Technical notes, step-by-step version:

1. Download a Sketchup (.skp) model of a building from Google's Trimble 3D Warehouse.
2. Open the model in Sketchup. In order to look around with your mouse you'll have to first press "Orbit" or "Pan" from the button menu.
3. The building in this example had a flat ground-level piece attached to it. If this is true of your model then use the "Select" arrow to highlight that piece and delete it.
4. Sketchup is for buildings so the scale is HUGE in there. You'll have to shrink down the model a lot. One easy way to do this is to use the "Tape Measure" button, clicking first at one corner of the front of the building, then at the other. At the bottom of the window is a text box where you can enter the new length for the line segment you just selected with the tape measure. In the example model this length started as 214' 10 1/2" and I shrunk it down to 10'.  Now, I know that doesn't make sense because I can't print a 10-foot model, but shrinking it down to inches made it too small in Tinkercad for some reason. Fiddle around and see what works for you in the next steps.
5. Your model will now look really really tiny in Sketchup! You'll have to zoom in a lot if you want to find it, by using the scroll button on your mouse and pointing at the center of your desired zoom area. Hopefully your model is still near the origin. At this point you could modify your model in Sketchup but I think Tinkercad is easier so I'm going to do the rest over there.
6. Sketchup doesn't automatically know how to do export to STL, so you will have to install this free STL export plugin from Sketchup. If you have install problems then scroll through the comments on that site, where most problems you might encounter are discussed and solved. Once you have the plugin set up you should have an "Export STL" option under the "File" menu in Sketchup. Export your file.
7. Open this new .stl file in Tinkercad by using the "Import" tab at the top of the right menu column. Use inches as your unit of measurement, or at least give that a try and if it doesn't work then use millimeters. If your model is still too large or small you can change what you did in Step 4 with Sketchup, or you can just resize in Tinkercad. I have this weird feeling that extreme resizing in Tinkercad can cause problems, so if the size is way off then I would suggest going back to Sketchup to fix it.
8. Clean up your model in Tinkercad by using rectangular shapes to fill in or hole off things that you don't want. The model may be aligned one or two degrees away from the axes, which in particular could make it not sit flat on the Workplane. Use a rectangular hole to shave off the bottom of the building and make it flat, and then move the model back down to the Workplane.
9. If you want to add a hole to the building to make it a pen-holder or whatever then add a hole. I would advise doing that only after you have resized the building to the size that you will be printing at, so that you can control the size of the border around the hole accurately. 
10. Add windows or other features using small holes. It will go fairly quickly if you are good with the Align, Copy/Paste, Workplane, and Control-D tools. You don't want to be placing the windows of a skyscraper one at a time, so this would be a good time to go through some of the corresponding Tinkercad Lessons if you haven't already.
11. Download your finished .stl model and print! 

Day 110 - Rocking knot

Today's print is a knot with a special property: No matter how the knot sits on the table, it never touches the table in more than two places. This property makes the knot rock back and forth easily, and roll down even very shallow inclines. It's a fun thing to have on your desk, and it's the knot that I usually print at demos and talks.

STL file for thicker knot: http://www.geekhaus.com/makerhome/day110_rockingknot1.stl
STL file for thinner knot: http://www.geekhaus.com/makerhome/day110_rockingknot2.stl
Thingiverse link: http://www.thingiverse.com/thing:205464

Settings: Custom MakerWare profile to control the supports and how they attach to the models; see below for details. The knots in the picture were printed at 50%, 25%, and 15% scale from the STL files above.

Technical notes, math flavor: The thicker model was created in Mathematica using the following code:

a = .8 
 

b = Sqrt[1 - a^2]
   

(* a and b have to be numbers with a^2 + b^2 = 1 *) 

ParametricPlot3D[  

     {a*Cos[3 t]/(1 - b*Sin[2 t]),     

      a*Sin[3 t]/(1 - b*Sin[2 t]), 
  

      1.8*b*Cos[2 t]/(1 - b*Sin[2 t])}, 

     {t, 0, 2 Pi+.01}, 
 

     PlotStyle -> Tube[0.25, PlotPoints -> 24], 

     PlotRange -> All] 

Export["tritangentless_thick.stl", %]

The parametric equation in this code comes from Morton's paper Trefoil Knots Without Tritangent Planes, Bull. London Math Soc. 23 (1991), 78-80. Changing 0.25 to 0.15 in "Tube" creates the thinner model. The "+.01" at the end of the t-range is to make sure that the knot connects back to itself again when it closes the loop. If you take that part out then you will be able to pull apart the model in that spot, which is useful if you want to put the knot around something but not so useful if you don't want your model to look a little broken.

Technical notes, custom slicing profile flavor: The standard MakerWare profiles work very well for nearly everything I print, but for these knots those profiles leave too much support inside the knots that is difficult to remove.  Here's what I changed from the "PLA standard" profile:

• "roofThickness": 0.5,   (down from 0.8)
• "floorThickness": 0.5,   (down from 0.8)
• "sparseInfillPattern": "linear",  (instead of hexagonal, which shows through badly for these models when using translucent filament)
• "infillDensity": 0.2,   (up from 0.1, to make sure the knots are sturdy since they curve around a lot)
• "minSpurLength": 0.4,  (up from 0.34, but can't remember why i did this now – possibly because my knot models have bad mesh/slice problems sometimes and this was fixing the problem)
• "doSupport": true,
• "doSupportUnderBridges": true,
• "supportDensity": 0.1,   (down fro 0.2 – this is the part that helps the most for these models)
• "supportExtraDistance": 0.8,  (up from 0.5, since parts of the model can swing out far and need some extra support)
• "supportModelSpacing": 0.5,  (up from 0.4, to make the support further away from the model and thus easier to remove)

Action video! Note that the very slight incline of the closed laptop is enough to make these knots roll.

UDPATE: You can now order a print of this model from Shapeways at the new Geekhaus store.

Day 109 - Sharpie print

This design was inspired by DesignMakeTeach's excellent post Sharpie to 3D Print in 30 Minutes on his blog designmaketeach.com. Such a fantastic idea for introducing someone to 3D printing and for helping kids make simple prints! I wanted to take Shapeways out of the equation so I found a way to do the conversion step with my two favorite free and easy tools, Inkscape and Tinkercad; see the instructions below. The design we chose to work with was a picture of a house that C drew.  It was so great to see his drawing actually come to life and even stand up!

STL file: http://www.geekhaus.com/makerhome/day109_sharpieprint.stl
Tinkercad link: https://tinkercad.com/things/d1bVQxD8Aoh-day-109-sharpie-print
Thingiverse link: http://www.thingiverse.com/thing:204816

Settings: MakerWare .3mm/low with a Replicator 2 in about 30 minutes for the large one, and 10 minutes for the small one.

Technical notes, short version: Draw on paper with a Sharpie, take a photo, change to bitmap and save as an .svg file in Inkscape, load into Tinkercad, download as .stl and print.

Technical notes, long version: Since this project is so good for someone very new to 3D printing, in this long version I'm going to go through the instructions as if you haven't used Inkscape or Tinkercad very much before. But it's easy, I promise!

1. Draw a small picture on an index card with a Sharpie marker. Use thick lines and make sure that your entire picture is connected. (I had trouble explaining what this meant to kids until I had this example - now I can show them this picture and explain that the windows had to push out to touch the sides of the house to keep things connected.)  
2. Take a photo of the drawing with your camera or phone. I found that things work best if I don't use flash but I do make sure that the drawing is very well lit.
3. Open the photo in Inkscape and select the drawing with the arrow tool in the upper left. It will select the entire rectangle.
4. From the "Path" menu in Inkscape, select "Trace Bitmap". The default options work well, which means you should have "Brightness cutoff" selected and set to Threshold 0.450. Hit "Update" and you should see the drawing appear in the small Preview window. It might not look that great in the Preview window but that is okay.
5. Select "OK" and then close the "Trace Bitmap" window by clicking on the red button in the upper left. 
6. Save your file in .svg format. Make sure that you also change the extension of your file to .svg; this might not happen automatically.
7. Open a new model in Tinkercad and open the "Import" tab at the top of the right column menu. Select "Choose File" and go find the .svg file you made.
8. I suggest setting the Scale to 30% and height to 10mm. That will make the larger size of model that you see on the left in the photo above. Scaling to 15% and setting height at 5mm produced the smaller model in the photo.
9. If you want to use Tinkercad to modify or add to your drawing, now is the time to do that. For example, if you don't want to worry about the connectivity of the original drawing then you can add a back to the object at this step. DesignMakeTeach had a great suggestion for how to add a perfectly-shaped backing to your drawing on this Twitter post. Sure, it's obvious NOW, but it wasn't until I looked at that Tweet. 
10. Export your model from Tinkercad by selecting the "Design" dropdown menu and choosing "Download for 3D Printing", and then "STL" format. You'll have to close the "Download for 3D Printing" window after you do that; for some reason it does not close automatically.
11. Now you can use a 3D printer to print your .stl file. If your original drawing had a flat base then your model will probably stand up on its own!

UPDATE: jbreynoldsTRT used this method for a student's first design: 

Send us your pictures of printed Sharpie drawings and we'll post them here!

Day 108 - Minecraft castle

Minecraft is "The Last Starfighter" of 3D modeling and printing - a game that gets kids ready for the next industrial revolution by teaching them how to move, build, and think in a virtual 3D environment. Even better, you can load your 3D-modeled creations into your Minecraft worlds and also 3D-print your Minecraft creations in real life! Here is a simple castle that C and I made on a Printcraft server and exported to an .stl file we could 3D print (very detailed instructions below):

STL file: http://www.geekhaus.com/makerhome/day108_minecraftcastle.stl
Thingiverse link: http://www.thingiverse.com/thing:204613

Technical notes, Minecraft flavor: We used a lot of upside-down stairs to keep the amount of overhang to a minimum (thank you, Jeb!). The front archway stairs lead to an arrowslit that you can shoot arrows through. This slit is only the height of a slab - half of a block - and this small slit printed perfectly on the Replicator 2 with no supports!

Technical notes, 3D-printing flavor: MakerWare was unable to open the model as exported directly from Printcraft, so we had to do some tweaking in MeshLab. MeshLab is free but a bear to figure out, with dozens of incomprehensible menus. For this particular model the following sequence of menu options worked for us:

1. Cleaning and Repairing --> Remove Faces from Non Manifold Edges
2. Cleaning and Repairing --> Split Vertexes Incident on Non Manifold Faces
3. Repeat "Split Vertices" until the number of vertices shown at the bottom of the screen stops increasing. 
4. Remeshing, Simplification and Reconstruction --> Subdivision Surfaces: Catmull-Clark

The first three steps above remove some mesh problems, and the fourth step makes it so that MakerWare can open the file without crashing. Thank you to my student Ryan Moneymaker for showing me that you can accomplish a lot with MeshLab if you have the courage and patience to keep trying everything.

Here are detailed instructions for going between Minecraft and 3D printing:

*** TWO WAYS TO GO FROM MINECRAFT TO 3D-PRINTED OBJECT ***

Printcraft server ---> STL ---> Possible MeshLab repairs ---> 3D print

1. Open Minecraft and select Multiplayer to join a Printcraft server at us1.printcraft.org or eu1.printcraft.org. For more information see www.printcraft.org. 
2. Choose a plot on the Printcraft server and click the command block to "Claim" your plot.
3. Build your model! You won't be able to use chests, doors, or other decorative items; pretty much just blocks and stairs.  
4. Click the command block to output your model to an STL file.
5. Type "t" for chat and then click on the link; you'll be able to download your STL file from the website that is brought up.
6. Your model might be ready to print as-is! If you're using MakerWare then try to open the file; if it opens then use the Preview to see if the layers appear correctly. If things go sideways then try some MeshLab repairs such as the ones described earlier in this post.

Minecraft world with WorldEdit ---> STL ---> 3D print

1. From any Minecraft world, build your model! When you're done you can close Minecraft, since you'll be doing the rest of these steps from outside of Minecraft. You'll need to know where your Minecraft world file is kept on your machine; on a Mac it will be under YourUserName/Library/Application Support/minecraft/saves. 
2. Download and install Mineways.
3. Mineways provides two video tutorials (here and here) to help you get started. Basically you'll open your Minecraft world in Mineways and then from a map view you'll choose the area that you want to select as your model. You'll also need to know how high/low to select for your area (the y-coordinate), so make a note of that before you leave your Minecraft world. 
4. Open and print your STL model! (This is the method we used for the Videogame Dice in Day 12.)

*** TWO WAYS TO GO FROM 3D MODEL TO MINECRAFT WORLD ***

STL ---> Tinkercad ---> MCEdit ---> Minecraft

1. Make a 3D model however you like (or even scan/Digitize one!) and save as an STL file.
2. Get a free account at Tinkercad and import your model using the "Import" menu option at the top of the right column. (Unless you used Tinkercad to create your model, in which case you already have it there!)
3. From the Tinkercad "Design" menu, select "Download for Minecraft". (I know, right? How awesome is it that they actually have this option built into their menu? Thank you, Tinkercad!) This will export your 3D design as a .schematic file.
4. Download MCEdit and use it to import this .schematic file to the place you want it to be in your Minecraft world. Tinkercad has a great blog post describing how to do this.

STL ---> Tinkercad ---> WorldEdit ---> Minecraft

1. Follow steps 1-3 above to get a .schematic file for your 3D model. 
2. For this method you have to have WorldEdit, either installed on a Multiplayer server or on Singleplayer as part of Single Player Commands. Put your .schematic file where WorldEdit can find it; on a server installation this will be somewhere like Minecraft/plugins/WorldEdit/schematics.
3. From within your Minecraft world, use //schematic load yourfilename to load your .schematic file into the WorldEdit clipboard, move to where you want the model to be, and then //paste the model into your world. You may have to //rotate or move around to find the positioning you want; remember you can always //undo to try again!
4. Enjoy having crazy models in your Minecraft world - like the mathematical knot shown below (see Day 9, Day 11, Day 66, and Day 67 for knot models).

Day 107 - SEGA Sonic cartridge sleeves

We love Sonic 2 on the SEGA Genesis, and we've recently been enjoying the whole series all over again with our son. Our ancient cartridges don't have protective sleeves, so we printed some custom ones! Designed in Tinkercad with some help from Inkscape and the internet (specifically, the nice .svg images on Wikipedia here and here).

STL file: http://www.geekhaus.com/makerhome/day107_sonicsleeves.stl
Tinkercad link: https://tinkercad.com/things/8BEl67GPJBF-day-107-sega-genesis-cartridge-case
Thingiverse link: http://www.thingiverse.com/thing:203998

Settings: MakerWare .3mm/low in about 37 minutes on the Replicator 2.

Technical notes: We had hoped that since we found the "SEGA" and "Sonic" logos in .svg format we would be able to import them into Tinkercad without problems, but unfortunately the importing process made the insides of the letters all filled in, rendering the words illegible. To fix this we opened the files in Inkscape and did the following:

1. Select image with the arrow tool.
2. From the "Path" menu select "Object to Path".
3. Using the node-arrow tool (under the usual arrow tool), select and delete parts of the image that are not desired. In this case there was an outline around the letters that needed to be deleted before exporting for Tinkercad. The "delete" key did not work for us, but using "Cut" under the "Edit" window did. This is not needed for all images but it was needed for both of the ones in this example.
4. Save the image in .svg format.
5. Import the image into Tinkercad using the "Import" tab at the top of the right column menu. 

Day 106 - Filament Shelf Clip

I keep my filament on an old curtain rod over a shelf, and the rolls that are far away from the printer don't unroll correctly. This shelf clip fixes the problem. The open loop design allows it to open a bit to fit over the shelf with a small dot of poster-tack-gum underneath to keep it from sliding to the side. Made in Tinkercad.

STL file: http://www.geekhaus.com/makerhome/day106_filamentshelfclip.stl
Tinkercad link: https://tinkercad.com/things/byqokD7ZUIX-day-106-shelf-clip-fliament-guide
Thingiverse link: http://www.thingiverse.com/thing:203978

Settings: MakerWare .3mm/low on a Replicator 2 in 20 minutes.

Day 105 - Bow Box

Tired. Need simple. Something that just works. How about muddtt's Christmas Gift Box on Thingiverse?

Thingiverse link: http://www.thingiverse.com/make:56796

Settings: MakerWare .3mm/low with the base and the bow in one print and the top in another.

Stuff to change: I really love siesauers' Make of this model where they printed everything in translucent filament and colored the bow and ribbon with Sharpie afterwards. It looks great to have the bow and ribbon the same color and all around the box. Next time!

Day 104 - Tetrapuzzle

One nice entry from the Makerbot Math Manipulative Challenge on Thingiverse was GeorgeHart's Five Screw Puzzles. Here is the tetrahedron puzzle from that entry.

Thingiverse link: http://www.thingiverse.com/make:56078

Settings: MakerWare .3mm/low worked well, with no raft or supports (prints in two identical pieces).

Technical notes:  PLA can be sharp so don't push too hard while trying to solve the puzzle or you could get sliced up by a pointy or broken piece! If you're forcing it then you aren't close to the solution anyway; the pieces fit together pretty well without too much forcing.

Stuff to change later: Although this is beautiful in the translucent PLA, I think the puzzle would feel better in your hands and twisting together if printed in ABS. Will try this on the Afinia next.

Day 103 - Cheese labels

Today we used Tinkercad, Inkscape, Fontspace, and the technique from Day 27 to make four cheese labels for a party tray.

STL file: http://www.geekhaus.com/makerhome/day103_cheeselabels.stl
Tinkercad link: https://tinkercad.com/things/9CAI51WG5Pw-day-103-cheese-labels
Thingiverse link: http://www.thingiverse.com/thing:199111

Settings: MakerWare .3mm/low, switching filament when it got to the letters.

Technical note: Star fruit turns out to be quite tasty!

Day 102 - Fidget rings

Today we made two copies of AmazingSpanoMan's Customizable Fidget Ring on Thingiverse. The center ring spins around very nicely.

STL file: http://www.geekhaus.com/makerhome/day102_fidgetrings.stl
Thingiverse link: http://www.thingiverse.com/thing:188275 (customize your own!)

Stuff to change: The size I printed is a bit too big for me to wear, but still fun to play with. Next time I'll print one that is a bit smaller.

Day 101 - More dodecahedra

Of all the nets from Day 80 through Day 86, I think the dodecahedra works the best. Easy to put together, easy to take apart, at least as printed from my Replicator 2. Surely extra dodecahedra nets will be good for something, right?

STL file: http://www.geekhaus.com/day101_moredodecahedra.stl
Tinkercad link: https://tinkercad.com/things/0tzDh8wA7RP-hinged-dodecahedron
Thingiverse link: http://www.thingiverse.com/make:55728

Settings: MakerWare .3mm/low on a Replicator 2 in a little over an hour an a half.

UPDATE: Now not enough clear snowy filament left for holiday snowflakes! Curse you, extra dodecahedron nets.

Day 100 - Tiny icosahedron surprise ball

I have a small gift I have to give someone secretly at a party, so I enclosed it in this tiny hollow icosahedron. Safe to show off at the party and they can open it when they get home. (By breaking it, unfortunately, but it would only take a few minutes to print another one later if they want one!)

STL file: http://www.geekhaus.com/makerhome/day100_tinyicosahedron.stl
Thingiverse link: http://www.thingiverse.com/thing:196410

Settings: MakerWare custom profile starting from "Low PLA", with the following settings changed:

"numberOfShells": 1,
"roofLayerCount": 0,
"floorLayerCount": 1,
"infillDensity": 0,
"bridgeAnchorMinimumLength": 0.3,
"bridgeAnchorWidth": 0.3,
"doRaft": false,

Technical notes: This is really the same .stl file as we used in Day 32, but scaled down and combined with an upside-down copy of the model so that the top face gets repaired/leveled as we did earlier for the bottom face. In the future, it would still be better to just use a fresh Mathematica .stl output of an icosahedron but this was easier today.

Day 99 - Snowflake Ornaments, Part 2

Printed the rest of the ornaments!

STL file: http://www.geekhaus.com/makerhome/day99_snowflakeornaments2.stl
Tinkercad link: https://tinkercad.com/things/2TE1FmDGaKP-day-99-snowflake-ornaments-part-2
Thingiverse link: http://www.thingiverse.com/thing:195032

Settings: MakerWare .3mm/low in 7-9 minutes per ornament.

Technical notes: I tried printing one of these on an Afinia H-Series at work and it did not go well, either with or without raft, and even after thickening. I'm not sure why I can't get similar results on both printers, but this is a battle that the Replicator 2 wins hands down.

Day 98 - Snowflake Ornaments, Part 1

For the Thingiverse/Studio 360 Ornament Challenge we remixed the snowflakes from Day 70 and Day 71 into thicker, hangable snowflake ornaments. Here is the first half:

STL file: http://www.geekhaus.com/makerhome/day98_snowflakeornaments1.stl
Tinkercad link: https://tinkercad.com/things/aZjXsjxhaZS-day-98-snowflake-ornaments-part-1
Thingiverse link: http://www.thingiverse.com/thing:195032

Settings: MakerWare .3mm/low on the Replicator 2 has each snowflake printing in 7-9 minutes.

Technical notes: Although the .stl file above has eight snowflakes at once, we recommend printing these only a few at a time. Otherwise the ones at the edges can get a little messed up, even if your build plate is very level.

Day 97 - British Pound Trap

Today's print is one of the drop-down choices from the Customized Coin Trap model that we posted about yesterday: a trap for a British pound coin.

STL file: http://www.geekhaus.com/makerhome/day97_poundtrap.stl
Thingiverse link: http://www.thingiverse.com/make:55310

Settings: MakerWare .2mm/standard on a Replicator 2.

Technical notes: Pound coins are so thick that this model is really tight to the coin. I wimped out and hit "pause" to put the coin in.

Day 96 - Customizable Coin Traps

Finally I have gotten around to learning how to use OpenSCAD, and thus also the Thingiverse Customizer. Our first customizable design: traps for coins of any size, from any country!

Did you lose a bet? Pay them back with a coin they can never use. Or, did you win a bet? Immortalize your winnings in this trophy bank. Also good for stocking stuffers and little presents, and as good "first 3D print" jobs to introduce people to 3D printing.

The customizer includes pre-loaded diameters for all major US coins and the top 10 world currencies, as well as the option for entering coin diameters manually. Here is a picture of the US coins, each in their own trap:

STL files: http://www.geekhaus.com/makerhome/day96_customizabelcointraps.stl
Tinkercad link: https://tinkercad.com/things/1rOL6U6owk6-day-96-us-coin-traps
Thingiverse link: http://www.thingiverse.com/thing:193941

Settings: MakerWare .2mm/standard settings with a Replicator 2. Traps took between 15 and 35 minutes depending on their size.

Technical notes: Below is the OpenSCAD code that makes these coin traps. Thank you to my student Patrick Moran for pointing me to Patrick Connor's easy video introductions to OpenSCAD.

// mathgrrl customizable coin traps 

////////////////////////////////////////////////////////////
// PARAMETERS //////////////////////////////////////////////

// ignore this variable
$fn = 24*1;

// Choose the type of coin you want and leave the size below as 0. They'll all look basically the same in the output window but they are different sizes.
coin_type = 0; // [0:Enter Manually,19.05:US Penny,21.21:US Nickel,17.91:US Dime,24.26:US Quarter,30.61:US Half Dollar,26.49:US Presidential Dollar,23.25:Euro,20:Japanese Yen,40:Chinese Yuan,25:Indian Rupee,20.5:Russion Ruble,22.5:British Pound,26.5:Canadian Dollar,23.2:Swiss Franc,23:Polish Zloty,27:Brazillian Real,21:Mexican Peso,25:Australian Dollar]

// *OR* choose "Enter Manually" above and then type in any diameter you like, in millimeters. Values between 15 and 35 mm work the best. 
coin_size = 0; 

// this chooses one of the above for the diameter
coin_diameter = max(coin_type,coin_size);

// other parameters based on the coin diameter
coin_radius = coin_diameter/2;
corner_radius = coin_diameter/10;
corner_distance=coin_radius-corner_radius+1;
cylinder_radius=coin_radius-1.5*corner_radius;
cylinder_bevel_distance=corner_distance+2*corner_radius;
cylinder_bevel_radius=cylinder_radius+corner_radius/2;
sphere_radius=coin_radius+1;

////////////////////////////////////////////////////////////
////// RENDERS /////////////////////////////////////////////

// build the trap
difference(){
box_hull(); // enclosing box area with rounded edges5
cylinder_holes(); // three cylindrical holes
cylinder_bevels(); // six spherical holes to bevel the holes
sphere_hole(); // one spherical hole for coin clearance
}

////////////////////////////////////////////////////////////
// MODULES /////////////////////////////////////////////////

// overall rounded cube shape
module box_hull(){
hull(){
translate([corner_distance,corner_distance,corner_distance])
sphere(corner_radius);
translate([-corner_distance,corner_distance,corner_distance])
sphere(corner_radius);
translate([corner_distance,-corner_distance,corner_distance])
sphere(corner_radius);
translate([corner_distance,corner_distance,-corner_distance])
sphere(corner_radius);
translate([-corner_distance,-corner_distance,corner_distance])
sphere(corner_radius);
translate([-corner_distance,corner_distance,-corner_distance])
sphere(corner_radius);
translate([corner_distance,-corner_distance,-corner_distance])
sphere(corner_radius);
translate([-corner_distance,-corner_distance,-corner_distance])
sphere(corner_radius);
}
}

// holes for the sides
module cylinder_holes(){
rotate([0,0,0])
translate([0,0,-(coin_radius+5)])
cylinder(coin_diameter+10,cylinder_radius,cylinder_radius);
rotate([90,0,0])
translate([0,0,-(coin_radius+5)])
cylinder(coin_diameter+10,cylinder_radius,cylinder_radius);
rotate([0,90,0])
translate([0,0,-(coin_radius+5)])
cylinder(coin_diameter+10,cylinder_radius,cylinder_radius);
}

// beveling for the side holes
module cylinder_bevels(){
translate([cylinder_bevel_distance,0,0])
sphere(cylinder_bevel_radius);
translate([0,cylinder_bevel_distance,0])
sphere(cylinder_bevel_radius);
translate([0,0,cylinder_bevel_distance])
sphere(cylinder_bevel_radius);
translate([-cylinder_bevel_distance,0,0])
sphere(cylinder_bevel_radius);
translate([0,-cylinder_bevel_distance,0])
sphere(cylinder_bevel_radius);
translate([0,0,-cylinder_bevel_distance])
sphere(cylinder_bevel_radius);
}

// center hole to guarantee coin clearance
module sphere_hole(){
sphere(sphere_radius);
}

Day 95 - Kinematics bracelet #2

Yesterday's bracelet was so great that we decided to print another one today, again from Nervous System's Kinematics@home site.

STL file: http://www.geekhaus.com/makerhome/day95_kinematicsbracelet2.stl (but go make your own instead of using this one!)
Thingiverse link: http://www.thingiverse.com/make:56292

Settings: MakerWare .2mm/standard, since the bracelets from Kinematics are optimized for that layer height.

Technical notes: The clasp in this bracelet design needs work; it's a bit clunky and results in a double-layer section of the bracelet. I'm hoping that this is something they will fix in the future.

Stuff you might want to change: Tinkercad has trouble opening the .stl file from Kinematics. However I bet that some remeshing in Meshlab could get the .stl file into a form that Tinkercad could understand, and then the hinge could be improved directly in Tinkercad however you like.

Day 94 - Kinematics bracelet

The design studio Nervous System has put up a great free morphing/algorithmic/supercool bracelet-making site at Kinematics@home where you can modify bracelet designs within certain parameters and then either download an .stl file or send the design off to be 3D-printed for you. I need larger bracelets than what I can usually find in a store so the ability to set my own bracelet length was great!

STL file: http://www.geekhaus.com/makerhome/day94_kinematicsbracelet.stl (but go make your own instead of using this one!)
Thingiverse link: http://www.thingiverse.com/make:56291

Settings: MakerWare .2mm/standard, since the bracelets from Kinematics are optimized for that layer height.

Technical notes: The hinges use cones just like the ones in the polyhedral nets from Days 80-86, but the hinges are the easy and obvious part. The hard part is everything else that Nervous System does, from generating structures algorithmically in a live online interface to figuring out how to print an entire dress in a crumpled-up ball that fits into a small building area.

Day 93 - Pig and Veg toothpicks

For the holidays, here are some toothpicks that you can use to label foods according to if they contain meat (bacon!), are suitable for vegetarians, or have some potential allergen for one of your guests.  The images at the tops of the toothpicks were extruded from files found in an icon pack at findicons.com after tracing a bitmap and then exporting to .svg format in Inkscape.

STL file: http://www.geekhaus.com/makerhome/day93_pigvegtoothpicks.stl
Tinkercad link: https://tinkercad.com/things/3j7L9oP9NM7-day-93-pig-and-veggie-toothpicks
Thingiverse link: http://www.thingiverse.com/thing:192023

Settings: MakerWare .3mm/low on a Replicator 2, with about 2 minutes per toothpick if your nozzle is already heated.

Technical cooking notes: These are dates stuffed with various kinds of cheese. The ones with the purple allergy tag are filled with honey-fig goat cheese and walnuts. The ones with the vegetarian leaves are stuffed with plain cream cheese and pecans. The ones with the pig toothpics have jalapeno-bacon cream cheese and bacon.

Day 92 - Weeping Angel from Dr. Who

Great, now we're too terrified to take this out of the printer. This beautiful and horrifying model is fantasygraph's Dr. Who Weeping Angel on Thingiverse. We printed it in honor of the Day of the Doctor, and in particular for the joy of seeing David Tennant play the Doctor just one more time.

STL file: http://www.geekhaus.com/makerhome/day92_weepingangel.stl
Thingiverse link: http://www.thingiverse.com/make:54833

Settings: MakerWare .2mm/standard settings in about 3 hours.

Stuff to change: The robe collides with the wings in the back of the model. Possibly this will be fixed later by fantasygraph?

Day 91 - Truncated Icosahedron

We didn't have time to make this one earlier, so here it is now. A truncated icosahedron (Buckyball/soccerball/football depending on who you are). I made the snaps really tight so this model would stay together very solidly. If you want to take it apart over and over then I recommend loosening the snaps in Tinkercad.

STL file: http://www.geekhaus.com/makerhome/day91_truncatedicosahedron.stl
Tinkercad link: https://tinkercad.com/things/jUqMMtH0GmA-tiles-for-truncated-icosahedron
Thingiverse link: http://www.thingiverse.com/make:54743

Settings: MakerWare .3mm/low filled four build plates and took nearly four hours. From an earlier test I believe that the snap tiles also work well scaled down to maybe 60% size, so you can make a smaller one if you want to try to speed things up a bit.

Technical notes: To make the snaps looser, rotate or use the "Workplane" in Tinkercad so that you can make the snap tines larger. This model was tight enough to hurt my hands when assembling it but it is very sturdy. A small amount of planning or moving things around is needed to make sure that the 2-snaps and 3-snaps fit together at the end of the object when everything closes up.

Day 90 - Stellated Octahedron

And finally, the last of the set of models from my entry to the Makerbot Academy Math Manipulative Challenge on Thingiverse. This model shows that we can use the individual snap tiles to make non-convex polyhedra. Here is the stellated octahedron:

STL file: http://www.geekhaus.com/makerhome/day90_stellatedoctahedron.stl
Tinkercad link: https://tinkercad.com/things/i7RhQW0w6z6-tiles-for-stellated-octahedron
Thingiverse link: http://www.thingiverse.com/thing:185859

Settings: The tiles are optimized to work with the low/.3mm MakerWare setting on a Replicator 2.

Day 89 - Icosidodecahedron

Today, the simplest Archimedian solid using triangles and pentagons, the icosidodecahedron:

STL file: http://www.geekhaus.com/makerhome/day89_icosidodecahedron.stl
Tinkercad link: https://tinkercad.com/things/9rjPDpql1vO-tiles-for-icosidodecahedron
Thingiverse link: http://www.thingiverse.com/thing:185859

Settings: The tiles are optimized to work with the low/.3mm MakerWare setting on a Replicator 2.

Day 88 - Truncated Octahedron

Yesterday's model was the simplest Archimedian solid with square and triangle faces. Today we have the simplest semi-regular polyhedron with square and hexagon faces, the truncated octahedron:

STL file: http://www.geekhaus.com/makerhome/day88_truncatedoctahedron.stl

Tinkercad link: https://tinkercad.com/things/l19z2AjEssx-tiles-for-truncated-octahedron

Thingiverse link: http://www.thingiverse.com/thing:185859

Settings: The tiles are optimized to work with the low/.3mm MakerWare setting on a Replicator 2.

Day 87 - Cuboctahedron

To get more flexibility constructing polyhedra we can use individual snap tiles instead of pre-arranged hinged nets. This also allows us to make nice two-color semi-regular polyhedra, such as this cuboctahedron:

STL file: http://www.geekhaus.com/makerhome/day87_cuboctahedron.stl
Tinkercad link: https://tinkercad.com/things/58BQvUFOlo8-tiles-for-cuboctahedron
Thingiverse link: http://www.thingiverse.com/thing:185859

Settings: The tiles are optimized to work with the low/.3mm MakerWare setting on a Replicator 2.

Technical notes: The sizes of the snap tines is crucial to these models. Tighter snaps make very sturdy models that are difficult to snap together but very solid when finished. Looser snaps are better for models you want to experiment with, taking apart and putting together over and over. Finding that sweet spot in the middle where the tiles snap together easily but still sturdily is the key, and that spot varies depending on the angles in the model and how the edges meet between tiles.

Day 86 - Rectangular Rhombohedron

The last of the polyhedral nets so far is for a rectangular rhombohedron:

STL file: http://www.geekhaus.com/makerhome/day86_rhombohedron.stl
Tinkercad link: https://tinkercad.com/things/4QmyBzqKqlL-hinged-rhombohedron
Thingiverse link: http://www.thingiverse.com/thing:185859

Settings: Low/.3mm MakerWare settings on a Replicator 2 in one hour and 10 minutes.

Technical notes: These fit together to tile 3-dimensional space, so if you print a lot of them trying to get them to work then you can test that out. Just saying. It was hard to get the last bit of the model to work correctly so I have a lot of these.

Day 85 - Hexagonal Prism

Of course there are many polyhedra that aren't one of the five Platonic solids that we just posted about. For example, prisms. Here is a hexagonal prism made out of a folded hinged net:

STL file: http://www.geekhaus.com/makerhome/day85_hexagonalprism.stl
Tinkercad link: https://tinkercad.com/things/0sl3FylfUsi-hinged-hexagonal-prism
Thingiverse link: http://www.thingiverse.com/thing:185859

Settings: Low/.3mm MakerWare settings on a Replicator 2 in an hour and 25 minutes.

Technical notes: In order to get the hexagons to fit correctly I had to make them larger than one would expect. I guess a lot of space gets eaten up with the hinges and angles somehow.

Day 84 - Hinged Icosahedron

The final Platonic solid in the set of models we entered into the MakerBot Academy Math Manipulatives Challenge was the icosahedron.

STL file: http://www.geekhaus.com/makerhome/day84_icosahedron.stl

Tinkercad link: https://tinkercad.com/things/iBwf0NJMgfY-hinged-icosahedron

Thingiverse link: http://www.thingiverse.com/thing:185859

Settings: MakerWare .3mm/low on a Replicator 2 in two and a half hours.

Technical notes: This is the hardest hinged net in the set to print, because it takes up so much of the build platform; I often have trouble with prints of models that go too far into one of the corners. 

Stuff you might want to change: This particular model is a bit loose, so you might want to make the edge snaps a bit tighter if you want a sturdy model. On the other hand if you like being able to easily push the model between net form and 3D form, then the looseness might be an advantage for you.

Day 83 - Hinged Dodecahedron

Of all the hinged polyhedral nets we made for the Makerbot Academy Math Manipulative Challenge, the dodecahedron came out the best. It just hit the sweet spot of angle and snap closer tightness. You can even see a video of 8-year-old C assembling it in under 30 seconds.

STL file: http://www.geekhaus.com/makerhome/day83_dodecahedron.stl
Tinkercad link: https://tinkercad.com/things/0tzDh8wA7RP-hinged-dodecahedron
Thingiverse link: http://www.thingiverse.com/thing:185859

Settings: MakerWare .3mm/low on a Replicator 2 in an hour and 45 minutes, printed in one piece with hinges fully assembled.

Day 82 - Hinged Octahedron

Working our way through the five Platonic solids that were included in my entry for the Makerbot Academy Math Manipulative Challenge, today's blog item is a hinged octahedron.

STL file: http://www.geekhaus.com/makerhome/day82_octahedron.stl
Tinkercad link: https://tinkercad.com/things/fJxQSsf4YRW-hinged-octahedron
Thingiverse link: http://www.thingiverse.com/thing:185859

Settings: Replicator 2 MakerWare .3mm/low settings with no raft or support, in an hour and 15 minutes.