3D Printed Sea Urchin Light

IMG_20200301_Sea Urchin Light

This project has been a little while in the making and it’s exciting to finally be writing about it. About a year ago I posted about 3D scanning some shells, and as part of the scanning I captured a sea urchin shell. At the time I didn’t know what I’d do with it, but fast forward a year and I’ve found a perfect application; turning the sea urchin shell into ceiling light covers in my house.

Sea Urchin GIFIn this post I’ll go over the main processes and experiments I went through to get the finished product, but in case you’re just here for the big finale, here’s the link so you can download the final Sea Urchin Light exclusively from my Pinshape account and 3D print as many as you like!

3D Scanning

ScanAs explained in further detail in my previous post, I used an EinScan Pro 2X Plus 3D scanner, which included a turntable to automatically capture all angles of the sea urchin shell. This resulted in a full-colour, highly detailed model of the shell, as shown to the right. However, as anyone familiar with 3D scanning will know, this model is just a skin with no thickness or solid geometry, and was just the starting point for the design process.

Design

If you don’t have access to expensive CAD programs, good news; this project was completely designed in free software! I’ve used Autodesk Meshmixer for many of my tutorials and posts, it’s a surprisingly powerful tool and a must for anyone involved in 3D printing. Additionally, it’s quite useful when you are working with 3D scan files, which are typically a mesh like a STL or OBJ. The process took a little time, but has been outlined in 6 basic steps below:

IMG_20200301_Sea Urchin Meshmixer Tutorial

  1. Fill any holes and errors in the 3D scanned sea urchin shell. In Meshmixer, this simply involves using the “Inspector” tool under the “Analysis” menu.
  2. Scale up the shell to the appropriate size, then use the “Extrusion” tool to thicken the skin into a solid shell. So that the shell would allow a lot of light through, I used a 0.7mm thickness for the overall design.
  3. I wanted to create an interesting pattern when the light was turned on, so separated several areas of a copy of the original mesh to be used to create thicker sections. This was a slow process of using the brush selection tool to remove areas, before repeating step 2 with slightly thicker geometry. For this design I ended up with 3 different thicknesses around the shell.
  4. To allow the light fitting within the shell, a larger opening was needed at the top. A cylinder was added from the “Meshmix” menu and placed in the centre.
  5. By selecting both the shell and the cylinder together, the “Boolean Difference” command became available, subtracting the cylinder section from the shell.
  6. Lastly, a neck section measured off the original light fitting was added. I cheated slightly and modelled this in Autodesk Fusion 360 (also free if you’re a student), but you could use Meshmixer – it would just take a bit longer to get accurate measurements. Then the separate parts are joined together using Boolean Union, and the design is finished.

3D Printing

As well as the new design needing to fit the geometry of the existing light fixture, it also needed to fit the build volume of the 3D printer – in this case a Prusa i3 MK3S. As you can see below, the shell is only slightly smaller in the X and Y dimensions than the build plate.

IMG_20200130_Shell on Prusa i3 MK3S

In terms of print settings, I stuck with some pretty typical settings for PLA, including a 0.2mm layer height. Support material is necessary with the light printed with the neck down – this is the best orientation in terms of ensuring the surfaces visible when standing below the light (remember, it is ceiling mounted) are the best. Where support material is removed is always going to be messy, and you wouldn’t want to have these surfaces being the most visible. Overall, this meant that each light took ~32 hours to print.

Material & Finishing

One of the steps that took a bit of experimentation was choosing the right material in order to look good when the light was both on and off. Each of these lights are the main, or only, sources of light in the spaces they are installed, so they need to provide a good amount of light.

IMG_20200218_Sea Urchin Light Materials

As shown above, 3 different materials/finishes were trialled. Initially I began with a Natural PLA from eSUN, which is a bit like frosted glass when printed. While this allowed all the light to escape and illuminate the room, most of the detail was difficult to see in both the on and off settings. It was just like a random glowing blob. I then tried pure white PLA, hoping that the print would be thin enough to allow a reasonable amount of light out. Unfortunately very little light escaped, however, the shadows from the different thicknesses looked excellent, and when the lights was off, it was very clear this was a sea urchin shell. Perhaps this would be a good option for a decorative lamp, but not so good for lighting a whole room.

So the “Goldilocks” solution ended up being in the middle – I 3D printed the shells in the translucent Natural PLA, and then very lightly spray painted the exterior with a matt white paint. Just enough to clearly see that it is a sea urchin shell when the light is off, and translucent enough to allow a lot of light out. Perhaps there is a material/colour of filament that would achieve this with needing to paint, but I didn’t want to have to buy rolls and rolls in order to find it. PETG would be interesting to try, and if you have any other suggestions, please leave them in the comments section.

The Result

IMG_20200219_143458 Dimensions CropTo the right are the dimensions of the ceiling light fixture within which the sea urchin light comfortably fits. The light itself is a standard B22 fitting, so the sea urchin can comfortably fit most standard interior lights. However, if you have a different sized fitting, or want to fit it over an existing lamp, you can easily scale the design up or down to suit your needs. I’ve already fitted one of the early small test prints over an old Ikea lamp, it just sits over the top of the existing frame. In total I’ve now installed 5 of the large ceiling light covers in my house, and am planning a new design to replace some of the others (my house is full of this terrible cheap fitting!).

As mentioned at the beginning of this post, I have made this design exclusively available on Pinshape – it’s just a few dollars to download the file, and then you can print as many as you like! If you 3D print one, please share a photo back onto Pinshape, I love seeing where my designs end up and what people do with them.

– Posted by James Novak

Mannequin Head Remix

3D Print Mannequin Head

Close but no cigar.

Sometimes you find something close to what you want on Thingiverse, Pinshape or other 3D printing platforms, but it’s just not quite right. Well, there is often something you can do about it, and it won’t cost a cent.

I’ve written several tutorials about using free software Meshmixer to make various modifications, for example creating a mashup of 2 different files or adding some text to a design. On this occasion I found a 3D scan of a styrofoam mannequin head on Thingiverse, which included all of the messy details you’d expect from a foam model (smaller head in the image above right). Great if you’re after realism, but not great when you want nice smooth surfaces for 3D printing. The model was also not at the correct scale, and I wanted a mannequin head to use as a model.

The scale was an easy fix, and of course could be done in your slicing software.  Cleaning up the surfaces was also quite simple using the ‘Sculpt’ tool and choosing one of the smoothing brushes. This essentially irons out all the rough details, smoothing out the model as you brush over it. A few minutes of work and a rough model is now clean and ready for 3D printing – which of course I’ve uploaded as a remix on Thingiverse so you can download it for yourself.

The above left image shows the 3D printed result from a Creality CR-10 S5, a very cheap, very large FDM machine with a build volume measuring 500x500x500mm. Obviously my settings weren’t great, the seam is in the worst possible position, and because I wanted a quick result I used only a single wall thickness and almost no infill, which split apart at the top. However, it’s fine for my purposes, and the surface quality on most of the model is fantastic.

Happy smoothing!

– Posted by James Novak

Shim the 3D printed shim

IMG_20190226_3D Print Shim Doorstop

We’ve all experienced that wobbly table at a cafe and struggled to wedge coasters and napkins under the legs to balance it out. This is where you need a shim, a small wedge that can fill the gap and ensure your drinks don’t go flying. Shim is also fun to say, quick to 3D print, and a good test of your print settings due to the top surface exhibiting the stair-stepped effect.

There are many designs available on popular 3D printing file websites, but I just wanted one that was a useful size (easy to carry with you in a small bag) and that said what it was. So here it is, Shim the shim! You can download it for free on Thingiverse, Pinshape, Cults or MyMiniFactory. Alternatively you can follow the basic outline of the design process below to make your own from scratch in your favourite CAD software. It’s similar to some of my previous designs including an “edditive” desk logo which might give you some inspiration for different ways to use text in 3D.

IMG_20190226_Solidworks TextShim was designed in Solidworks by using the text tool on the top sketch plane. The key is to squish all of the text together so that the letters intersect, meaning they will 3D print together as a single object (in Solidworks you can simply change the spacing of text within the text tool). The text was then extruded 10mm, creating solid geometry. All you need to do to create the wedge shape is then slice a triangular portion off the top, which in Solidworks uses the extruded cut tool. Save to STL and 3D print, it couldn’t be much simpler!

This is a nice quick 3D print and could easily be used as a keyring or give-away item, especially if you design your own. Enjoy, share and print!

– Posted by James Novak

Yes I Wrap, Don’t You?

20180831_3D Print Vase Wrap String

One of the common features of desktop 3D printing is the sharp, hard feel of plastic with that scratchy horizontal layered surface finish. Sure plastic has many benefits, but when you handle 3D prints all day long you sometimes forget that there are other textures in the world that are soft, delicate, pleasurable to touch. Enter the wrap, an experiment that softens those 3D prints in a crafty, hand-finished way.

For this project I downloaded the Customizable Twisted Polygon Vase from Thingiverse, which you will notice when you download is a solid block. This print takes advantage of a feature known as “vase mode” in many slicing programs, although if like me you are using Cura it’s called “Spiralize,” and you will need to activate it in your settings in order to have it available in your main screen settings. Basically the idea is that you can load any solid 3D model and automatically turn it into a vase-like shape i.e. a base and an outside wall without any interior or top surface. The outer wall is a single perimeter, which the printer continually extrudes in a spiralling/helical fashion as it works its way up the vertical height of your object. So no need to use a “shell” command in your 3D CAD modelling software, you can design a solid block and let the slicing software automatically create a single perimeter based on the extruder settings of any FDM 3D printer. A fun project in itself.

Phase 2 of the project was to use some wool yarn to wrap the exterior. What’s interesting about this process is that the layered surface finish of the 3D print actually helps hold the yarn/string in place, stopping it from slipping down the vase and helping align each rotation of the yarn. A relaxing project while you’re sitting in front of the TV or Netflix! The yarn I used was very fine so took quite a while, however you could easily use a thicker yarn to reduce the amount of effort to achieve a similar result. The result is really interesting; it keeps the layered appearance of a 3D print, yet is soft to the touch and provides a unique finish to the vase. Something you could easily customise with colours and different types of yarn materials. Ultimately, it creates an interesting combination of a highly digital process with a more craft-based process and material… Something worth a bit more experimentation I think.

If you give it a go, please share a photo with me, I’d be interested to see your results!

– Posted by James Novak

A 3D Printing Workflow with Free Software

Solid Hollow Lattice

One of the challenges for designers (beginner and advanced) creating objects for 3D printing is finding software capable of doing the complex things we enjoy seeing in 3D printing news and exhibitions. There really doesn’t seem to be one program capable of doing it all, and this has been re-emphasised to me during my recent studies at MIT and a visit to Autodesk. However, there is some good news: if you’re able to quickly learn software, you can find an increasing number of freebies that seem to be specialising in small aspects of the workflow, which you can move between to create complex designs.

Form 2 Print Lattice

This tutorial will show you how I used completely free software to create a complex object during my time in the MIT course “Additive Manufacturing: From 3D Printing to the Factory Floor” as part of a group project, and is actually very quick once you become familiar with the programs. This particular design combines a hollow object with an internal lattice structure suitable for SLA printing on a printer like the Form 2 from Formlabs, which is what was used for the translucent version in the photo above. The white version in the background is a cross-section view of what is going on within the SLA print.

Step 1: The Overall Form

Clip 01 - 01

There are loads of free programs to use for creating 3D models – Tinkercad, Sketchup, Openscad, Sculptris, Fusion 360 (if you’re linked to an educational institution)… there are many more and you can certainly use your favourite. For this project, I actually used Onshape for the first time, which runs completely in the cloud (so no software downloading or limitations on computer operating systems/specifications). If you are at a school or university, you can get a free license. It works very similar to Solidworks or other high-end CAD packages, so if you are familiar with sketches and features, you will pick it up very quickly.

Basically, whichever CAD software you use, you want to create the overall shape of your object. In this case, I created an organic tear-drop shape using a “loft,” and cut a section out of the back so that it would clip onto a desk and act as a bag hook (part of the MIT design challenge).

Step 2: Make it Hollow

Many CAD programs will allow you to “shell” your design, making it hollow inside. However, if you can’t find the tool, or aren’t getting good results, we can do this in the next piece of software. But first, export your solid file as a STL (and if you managed to shell it in this step, export a STL of the hollow version as well and skip the rest of this step. You will still need a solid version for the lattice process).

Meshmixer Hollow

The next free program, which I think is a must for anyone with a 3D printer, is Meshmixer. It allows you to edit the normally un-editable STL file format, and I have previously written tutorials about how to do download files from Thingiverse and combine them in creative ways or add your name to a downloaded part.

If you weren’t able to hollow out your design previously, click on Edit>Hollow and set your wall thickness. Just like that, your solid object is now hollow, and can be exported as a STL.

A note for SLA printing:

Meshmixer Drainage Holes

When using the Form 2 3D printer for the first time, I was surprised to learn that the PreForm software doesn’t allow for the user to specify infill patterns in the same way that is commonly done with FDM printing. That is what created the need for this custom lattice infill, and this tutorial. So, being a liquid resin printer, the final important step is to add drainage holes so that the form doesn’t end up completely full of liquid, and errors don’t occur during printing.

Meshmixer again has this function built in. While in the Hollow tool, you will have the option to “Generate Holes” and manipulate their location. This is really important, as you won’t be able to do it again later once your hollow and lattice are combined (unless you’re familiar with the boolean commands in Meshmixer and manually add a cylinder from the Meshmixer menu to use as a cutting tool).

Step 3: Creating a Lattice

Lattices and 3D printing are best friends. But creating a lattice in many CAD programs is close to impossible, usually requiring advanced skills and a computer that can handle very large patterning features. nTopology Element is a free program that will dramatically simplify the process for you – simply load a STL file, choose a lattice pattern, and boom! your object is now a lattice. But let’s go through it a little more slowly.

1. Import your solid STL file into nTopology Element.

2. On the top menu, click Lattice>Generate

3. In the pop-up, you can play with the lattice patterns (called “Rules”), the size of each lattice volume, and click Generate to get a preview. When you’re happy with the result, click on Apply.

nTopology Lattice Trim

4. You will notice that the result has the lattice coming outside of the original object. This is because only whole lattice volumes are used to fill the object, rather than automatically being trimmed to fit. So we must do this manually. In the top Edit menu, click on the Trim tool. A new pop-up will appear, asking you to select the Lattice geometry and the Trim Volume (original model), which you can select from the drop-down menu on the left. Click apply and the lattice will be trimmed to fit perfectly within your original design.

5. At this point, the lattice is made up of vectors – they have no volume. So the next step is to use the Thicken tool on the top menu to provide a diameter to your lattice.

nTopology Tutorial

6. Lastly, the thickened lattice needs to be turned into a single mesh that can be 3D printed. The Mesh button (where it says Interchange on the top menu) will join everything together and give you a single mesh. In the drop-down menu on the left, you can now right-click on the mesh, and click on export to get your STL file.

Step 4: Bringing it all Together

The free version of nTopology won’t let you stitch multiple files together, however the Pro version will if you ever end up with the need for a full license. So back to Meshmixer to bring it all together ready for 3D printing.

1. Import the hollow STL and lattice STL into Meshmixer (when you click on import for the second file, use the Append option).

2. You will notice that the ends of the lattice stick out from your object. There are 2 ways to correct this: Option 1 is to use the sculpt tool with the “Flatten” brush to go around and push the ends of the lattice inside of the object boundary – it’s just like pushing clay.

Meshmixer Sculpt Lattice

Option 2 is to ever so slightly reduce the scale of your lattice. With the lattice selected in the pop-up Object Browser window (on the right of my window), click on Edit>Transform and you can either manually manipulate the scale, or more accurately type in the reduction in the transform window (with the uniform scaling option ticked). You should only need a small reduction until the lattice fits just inside the outer skin of your object.

3. By turning off the hollow part in the Object Browser, but keeping it selected, you will get an X-Ray view into your object to check if the lattice and hollow part are intersecting. This can help with any final alignment. Remember; you want the lattice touching the solid shell, but not poking through so it’s visible, or loosely floating within the hollow.

Meshmixer Lattice View

4. In the Object Browser, [shift]+click to select both parts at the same time. A new window will appear that will allow you to Boolean Union or Combine both parts together, creating a single object.

5. Export the final STL and you are ready for 3D printing.

SLA Form 2 Print Fresh

Step 5: Getting Creative

Meshmixer Creative Lattice

Once you get a bit of experience with this process and some of the other tools in Meshmixer, your imagination is the limit! You can really begin to play with different combinations of solid and lattice structures depending on the result you want. Have some fun and feel free to share any of your own creations in the comments section.

– Posted by James Novak

The Meshmixer Mashup: Mashup-Rex!

Tutorial Meshmixer Mashup

The mashup is a favourite technique in the music world that combines two or more songs together into a single song. They might be from completely different eras or genres and when cleverly mashed together, they create a new smash hit. But did you know that creating a 3D printable mashup is just as easy as creating a musical one? Take a bit of File A, mix it with File B, and you now have your own creative design.

Over the last few weeks I’ve been putting together a new tutorial for my friends at Pinshape, which includes my first video tutorial as well as the usual step-by-step process to follow along with. Click here to learn how to mashup STL files in only 10 easy steps using the freely available software Autodesk Meshmixer.

The mashup is often called a Remix in the 3D printing world, and is a great way to build upon other designs and add your own creative touch, or re-purpose a design for a new application. The video tutorial is a real-time look at the process, which with a bit of practice, will have you remixing new designs in a matter of minutes. If you want to follow along, you just need to install Meshmixer on your computer, and download the 2 T-Rex files used in this tutorial which are free on Pinshape:

  1. Low Poly T-Rex by steven_dakh
  2. The T-Rex Skull by harry (we are only using the head piece, not the jaw)

Mashup-Rex

Alongside the tutorial is my latest design, the Mashup-Rex. I have made this available for free on Pinshape, just click here to download the file. Maybe you you will create your own remix of my remix? If you do, or you just 3D print the Mashup-Rex for yourself, please share it on Pinshape to add to the community and see how far the design can go! In the version pictured above I simply used a coffee stain to “age” the skull, similar to my previous print of the Star Wars Deathtrooper. I’m enjoying this simple technique at the moment, although you may like to use a 2-tone print, or go all out with some painted effects.

Happy mixing!

– Posted by James Novak

From Sketch to 3D Print

Sketch to 3D Print

Designing your own 3D printable object can be daunting if you’ve never used a 3D CAD program before. This is a challenge that one of my university classes is facing, with most of the students new to 3D design, but eager to begin experimenting with 3D printing. So this week we explored a workflow that allows them to take their hand-drawn sketches through a couple of simple processes, resulting in a 3D printable file, without having to model in 3D from scratch. So here it is just for you – follow along and let me know how you go.

Step 1: The Sketch

biro sketches

This is the easy part! Find a sketch that you’d like to turn 3D. It’s best if it’s drawn clearly in pen, so if your sketches are in pencil just trace over them on a fresh sheet of paper. For this example I’m borrowing a sketch from online. You must then digitise your sketch – best using a flatbed scanner, or take a photo in good lighting conditions so you get good contrast between your linework and paper.

Step 2: Vectorising

Illustrator Tracing

We are going to use Adobe Illustrator to automatically trace the outlines of our sketch. Place your sketch into a new document, and you will see a “Live Trace” or “Image Trace” button appear (depending on your version of Illustrator) near the top menu. You may find that one of the preset options will give you an accurate tracing, or you will need to get into the options and start tweaking the settings. I have an older version of Illustrator, but the settings that work for me are shown above. What you are looking to achieve is a good level of detail, and nice closed lines. Once you have a good result, you can use the “Expand” button to turn the result into individual lines that can be selected. You can also go to the menu and select Object>Ungroup so that your linework is no longer all grouped together as a single item.

Step 3: Exporting

Illustrator SVG

If you have a collection of sketches like this example, you will want to now Save your file (so you can come back to it and make changes later on), and then delete everything from the file that you don’t want to turn 3D. For this example, I have just left the flower tracing that was in the top-right corner. Go to File>Save As and save this drawing as a SVG file. This is a 2D drawing format that will be recognised by our 3D software.

Step 4: Going 3D

For this example we are going to use the freely available 3D software Tinkercad – one of the best features being that it runs from your internet browser, no need to download and install anything. I recommend it as a great place to start your 3D modelling journey, however if you’re already using a more advanced 3D CAD program you can still follow along with this tutorial – the process will be quite similar.

Tinkercad Import SVG

Create a new Tinkercad file, and at the top right of the workspace is the “Import” button – select your SVG file and it will automatically be turned into a 3D object as shown above. Depending on your sketch and requirements, this might be all you need to do and you can jump straight ahead to Step 7: Exporting. However I want to make some modifications to this design now that I have a good starting point in 3D.

Step 5: Modification

Tinkercad Cut

For my needs this object is too thick – I only want it to be 2mm tall. In the right panel of objects is a translucent box – this box is like a cutting tool, anywhere it touches my 3D object it can be used to cut away at it. Place a box in the middle of your 3D model, and use the Length and Width sliders to fully enclose your 3D model. Lastly, rotate your model to a side view and you will see an arrow pointing up or down – click-and-drag on this to move the box up 2mm above the workplane.

Now select both the 3D model and the box (either click-and-drag a selection box around the workplane or hold the Shift button and select both objects) and you will notice at the top right the Group icon becomes available. Click on this and Tinkercad will subtract the box from the 3D model, leaving just a 2mm thick object.

Step 6: Patterning

Tinkercad Pattern Duplicate

Rather than just printing one of this design, I want to create a more complex pattern. Firstly I need to scale the design down so that it’s a bit smaller. Do this by clicking on the object, holding the Shift button and using the corner handles to click-and-drag the object down in size – mine is about 40x40mm.

With my object selected, at the top left of the window are the standard Copy and Paste actions, as well as the Duplicate option – this is the option I use to make copies. It may copy the object in the exact same position as the original, so when you click Duplicate just click-and-drag this copy out into a new position. Repeat as many times as you like to create a pattern.

When you’re happy with the design, you will need to join all of these individual elements together into a single object. Similar to step 5, select all the objects together and the Group button will become active – however because all of these objects are solids, the Group function will join them together rather than cutting away.

Step 7: Exporting

When your design is complete, use the Export function at the top right of the window to download the object to your computer. The STL option is most likely what you will want for 3D printing. The STL format is the standard file type for all 3D printers.

Step 8: 3D Printing

Up Plus 2 Pattern

Finally you can load your STL into your 3D printing or slicing software and 3D print! If the print doesn’t give you the result you want you can either go back to the Tinkercad file and make some more modifications in 3D, or take a step further back to Illustrator and modify the original linework.

The process is not perfect or overly accurate, however for designs like fashion or simple experiments, this can be a good workflow to try if you’re better/faster at drawing by hand than modelling directly in 3D software. If anyone has some different workflows they enjoy using, please feel free to share them in the comments section 🙂

– Posted by James Novak

Repairing 3D Prints with a 3D Pen

20161216_3doodler-repair

It’s been a while since I last played with my 3Doodler Pen to repair a broken 3D print – the results were pretty cool, although it takes some practice to get reasonable results. Check out the post and images here. Some people make pretty amazing sculptures with the pen, however I find the real value in using the pen to fill gaps created by warped 3D prints and fix other cosmetic problems.

One of my latest projects is assembled from 16 separate pieces printed on my Cocoon Create 3D printer (60 hours worth of printing!), and inevitably with such large pieces printed using desktop FDM technology, there are some gaps caused by print warping. Most of them are reasonably small, but some like the ones shown above and below are quite large. Unfortunately the 3Doodler uses 3mm filament, meaning that I couldn’t use the same 1.75mm filament used to print the parts to begin with, but given that this project doesn’t need to be cosmetically pretty (prototype only), a different shade of yellow that came in the box will do.

20161214_3doodler-repair

The first step is of course to use the pen to extrude material into the cavity, ensuring to move slowly and use the hot nozzle to bond the new plastic with the original. It can get a bit messy and smelly (do it in a well ventilated area – I had a fan blowing to keep a lot of the fumes moving away, but there were times my eyes were stinging), and as shown in image 2 above, might look a bit rough, but that’s OK. You can go back over some of the rough patches using the side of the hot nozzle to try and smooth them out, not extruding any material but using the nozzle like a hot rolling pin. This technique is also great for blending some of the sharp edges or smaller gaps that don’t really need to be filled. The final step is to use a metal file to clean things up, giving a much smoother finish.

Admittedly this process wasn’t all smooth sailing, my 3Doodler kept getting clogged despite me taking it apart and cleaning it out – I have a feeling it might be the material quality and/or the temperature of the nozzle not being quite as hot as it needs to be, so a lot of time was wasted trying to manually push the filament through the pen and get a steady flow. I did notice that when I pushed the hot nozzle into my original print (the darker yellow plastic) it melted much quicker than the 3Doodler filament, despite them both being ABS. So material quality is likely the cause. But the final result is worth the pain, gaps are cleaned up nicely and the surface is nice and smooth. Time for some testing!

– Posted by James Novak

3D Printed “Marshmallow Challenge”

collage

Have you ever done the Marshmallow Challenge? Chances are you’ve done something similar at school, or if you’ve ever been to a team building workshop it’s a pretty popular creative exercise. Basically teams must build the tallest freestanding structure they can in 18 minutes using 20 sticks of spaghetti, a yard of tape, a yard of string and 1 marshmallow on top. Tom Wujec has been running these challenges for many years and presented a great TED talk if you want to find out more about the challenge and what can be learned from it.

Well now I’ve put my 3D printing twist onto the challenge, running what turned into a very competitive series of workshops for the Intro to 3D Printing course at my university. Teams were given a selection of materials we had readily available for model making (20 paddlepop sticks, 1 paper plate, 2 paper cups, a few drinking straws, a length of masking tape and a length of string) and given a very simple brief – build the tallest freestanding structure possible during the 2 hour workshop. The catch:

Teams were each given an UP Plus 2 3D printer and laptop with Solidworks, and could print as much as they wanted to help build the structure.

Now that makes things interesting! These are first year students only new to CAD and 3D printing, so what can they both design and print in such a limited time? Do you print lots of small things, or 1 big thing? How can you tweak the 3D print settings to get things printed as quickly as possible? What do you do when your print doesn’t work? It turns out that this challenge can teach you a lot about 3D printing, and how to rapidly test, prototype and build without wasting any time like in the normal 6 week projects.

As you can see from the photos, the results are very impressive! The winning team built a structure up to 249cm, which basically meant they used all the materials end-to-end and could not go much higher even if they had more time. This team 3D printed small little rectangular connectors for the paddlepop sticks, and with a lot of delicate balancing, managed to get their structure stable at the very last second. Much much higher than I expected when I set this challenge! They were in a very close battle with the team that came second for the day, reaching 238cm with a slightly different connection method where they used 3D printing to connect the paddlepop sticks to the cups. What you might notice with the top 3 teams is that 3D printing was used for small connecting elements that could be quickly printed, whereas some of the other teams (eg. 4th place who I only have a photo of part of the structure) were 3D printing much larger bases and simply ran out of time to push their structures quite as high.

All of the students were very involved and motivated by this task, it’s something I will run again in future classes and 3D printing workshops as a way to push the limits of the 3D printers and break them out of being so precious about what comes off the printers. It also gets them thinking about how to combine 3D printing with other methods of prototyping, you don’t necessarily need to 3D print every part of your design as it’s quite a slow process, particularly for FDM machines. Feel free to make your own twists on this challenge in the classroom, and I’d love to see your results! Maybe the 3D Printed Marshmallow Challenge will be the next big thing?

– Posted by James Novak