3D Printed Gears Using Dual Extrusion

For our school maker project (in science class), we wanted to create something that kids everywhere would be interested in using, and we also brainstormed different ways to spread our creations beyond the school to reach a wider audience.  We wanted to use our knowledge of 3D printing.  As we saw the rise of fidget products all over our school and all over the country, we realized that we had found our project: we decided to 3D print some fidget spinners that we designed ourselves out of recyclable filament.  There were some technical challenges that we experienced: for instance, the design we created ended up with some overhangs, which you can see in the image above.  To deal with this, we decided to use dissolvable support material to hold them up. We also had to make a decision about what printer to use of the ones available to us at school.  We chose to use a Replicator 1st Gen because of its dual extrusion capabilities, and this served us pretty well.


At first we were just making very colorful objects with two different colors of filament. We made this two color frog, along with some other things. After making a few multi-color prints, we quickly realized that this printer wasn't made just for printing with different colors. There must be some other reason that they made a dual extrusion printer. After doing some research, we found out about dissolvable filament. With dissolvable filament we would be able to make very complicated prints and dissolve the support material in limonene. One of the biggest problems with 3D printing is that you can't get support material out of very small places. With dissolvable filament, it was also possible to make moving parts in one print. Our first test was to make this gear thingy. We then decided we wanted to make more, and designed a different two geared fidget. However, we had a problem, the sides were not fully connected and the model often broke. We redesigned it, and it look something like this:

2.0 coming out of a tub of water after getting soaked in Lemonine

We used TinkerCAD because of its very straightforward design software that all of our group members knew how to use and the fact that we could use geometric shapes very easily along with the community shape generators.

To get started with our project, we started out with a simple dual geared fidget because we had no experience making this type of project before. Starting simple was helpful, and we later were able to get more complicated and make things like triple gears and quad gears.

One of our greatest challenges was when one part of the 3D printer we were using broke. We were able to re-3D print this part but it was a bit of a hold up. We also had to come up with a way to fix the windows for our 3D printer because our print’s kept peeling and we needed to stop drafts from reaching the heated build plate.

Elan fixing The Replicator

Throughout this process we learned not to rely on machines because machine failure is common. We also learned that even if you are using a very baseline software, you can still make amazing creations with it, it just may require more work.

If we wanted to continue this project, we could create more gear designs using ball bearings. This would be hard though because we might have to not print the gears as one piece so we could insert them, or we would have to put them in mid print.

Our advice for other people who do this project is to start early and use a web based software (like tinkercad.com) so that they will be able to access and change their project from different places.

An estimated cost of materials in this project (not including the 3D printer) is about $40 because of the fact that the slicer and the design program (Tinkercad) were both free, so the only costs we had to cover were filament (ABS and HIPS) and electricity. This $40 could cover many, many gears, because they are almost hollow and therefore very efficient with the material.

Rolls of ABS and HIPS

To learn more about dissolvable filament check out this on MakerBot’s website.

One day while we were waiting for a set of gears to print we chose to make a website at www.thegearmakers.wixsite.com/gearmakers. Through our project we had to fix the Replicator about six times and replace some parts. By the end we had created four production lines. And already finished two of them (dual geared basic and dual geared +). We thought that with four different products to choose from we had finally done what we had meant to the whole time, we had finished with our fidget production.

THE AMAZING BUDGET CETUS 3D

Today we got a package and are proud to introduce to you, the Cetus 3D! The Cetus is a printer from Teirtime (the same parent company of Afinia).

The Cetus is a pretty new 3D printer that was on Kickstarter for pre-order late last year and was meant to deliver this January. We bought this directly from Cetus and it came in about 2 weeks from China. As you can see, it does require some assembly, but it is not too bad.

The Cetus seems like an amazing deal for $300. It removes all of the flashy boxes and accessories most of the new 3d printers have today, and gives you a great experience. With linear guide rails, a 7 inch cubed build area, wifi printing ability, and an easy to use software, it even came with a nozzle unclogger and snippers to cut filament and such, what's not to love? Well, not much.

The only bad thing is the Z axis is not supported without power. This means when you turn off the printer when it is at the top (or its idling position) the printer head will glide down and rest into the build plate. You can print a clip or lever to hold it in place and stop it from doing that so its an easy fix.

From the first test print, we can see it is super super great quality for a budget 3D printer. I do have to say that the next time anyone asks me for a suggestion on a nice, budget 3D printer, the Cetus is going to be the first thing I suggest. Its great for a classroom or your first 3D printer.

I was also surprised when I printed an overhang stress test and it didn't start stringing until about 60˚, and even after that it still printed with very very minimal strings (even to 90 degrees!!).

I was amazed, I then loaded up the Make Benchy boat stress test. Once again I was astonished at the quality of the overhangs and pure detail around every corner. Comparing it to the Afinia, the Cetus lacks a heated bed (and that means no ABS but it doesn't matter anyways because our classroom is trying to move away from ABS) and currently in their shop is a beta heated bed anyways so if you really wanted it you could get it. On the flipside, the Cetus has a much larger bed and is also quite a bit cheaper.

I'm excited to continue using this 3d printer as it is by far my favorite.

- Enzo (8th grade)

A Theremin in our Classroom

.... because every middle school classroom needs more things in it that make noise.

In all seriousness, I am proud of my students for building this theremin from a kit, then troubleshooting it until it actually worked. Now, they are experimenting with the goal of eventually producing music, instead of sounds resembling the screeching of a tortured cat.  You can read a little about the theremin's interesting history here, or watch the video about the science of how it works below:

Making Models in VR with Kodon and Gravity Sketch

Recently, I have been experimenting with making 3D models in programs called Kodon and Gravity Sketch in VR. Kodon is more of a sculpting program that you get a basic shape and from there you can push/pull/smoothen a material using the controllers of the HTC Vive. Whereas Gravity Sketch is a program similar to TiltBrush, but instead of having a colored brush, it's a 3D sphere that you can draw with. Both programs are in their early developmental stages and not very close to being a complete software but are both fairly easy to use and self explanatory.

The first program we got was Kodon. It was already on Steam and was just like downloading any other games. Once I put on the headset I thought that someone was standing in front of one of the sensors because it was flashing and almost re-calibrating. It slowed down and I eventually got used to it. Its most likely due to the capabilities of our computer not being able to catch up with what the software is doing.



Another thing that was confusing was the seemingly infinite number of menus that seem to change randomly, but after a few minutes of finding my way, I was able to navigate to any screen from anywhere. It was still a bit confusing but after fiddling with some settings I understood and was able to use the controller easily. One of the settings is turning the controller around so you can use it more as a pen than a controller. It was slightly easier to use but still had its glitches. After using this for quite a while and then seeing the final result, I concluded I didn't want to use this software on this setup again. It was quite difficult. In the end, it may not look like much, but this pig-head model is my first tangible 3D model designed in virtual reality!

Then I tried Gravity Sketch which was more so what I wanted. As soon as it booted up it was very blank. Nothing at all. But the controls were surprisingly easy to figure out how to use. In a matter of minutes I was proficient in using it. As I said before, it is very similar to TiltBrush  After finding the download button I decided to start my first real project in Gravity Sketch. Making it was very easy to do and exporting and saving was easy. My one complaint of Gravity Sketch would probably be that for some reason, all the strokes are saved separately in one model, making my arch nemesis  overlapping shells. It adds one step too many between drawing to print. I need to drag it into Meshmixer and combine all objects, however when you have too many strokes (as mentioned, due to my computer's processing power), it crashes. But once I do wait for an hour for it to load, the outcome is well worth it.  I could then print it on the 3D printer and it was a very nice model. The software is very easy to use even though its in its beta stages. - Enzo, 8th grade

Posts forthcoming!

Welcome to our blog. We have been up to so many things over the last two years but we are slacking on our blog. We plan to start regularly posting again soon!

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...perhaps we are just embracing "historical optimization"?

Duct Tape Flowers

Duct Tape flowers are an easy craft that only require a pair of scissors, at least one roll of duct tape, and a pencil to start with. I sincerely recommend you do this as I spent 4 and ½ hours with my friends making these, my friends learned how to make them in about 5 minutes, and then we made them for the rest of our sleepover. We found them very, very addicting to make. We also found that after a hour or so, the motions become automatic. You should try this if you want a easy, fun craft to do! 
- Lauren, 8th grade

Iteration, Constellations, and Model Clams

Both in the Makerspace and on this blog, we talk about appreciation of iteration. Every project goes through iterations, and in some cases a lot of iterations. Recently I've been working on a necklace and a modeling project that have both gone through a lot of iterations. The necklace (a model of a constellation, originally designed to test out the copper filament on our Afinia), was the first copper-filament project we'd done on the Afinia for a while, and I ran into some issues getting it to print well, as well as some general workflow issues.

At first, the printer wouldn't connect to the laptop, but that was resolved by unplugging and plugging it back in several times. This has turned out to be a fairly common problem with the Afinia, and we haven't figured out another solution yet.

Once we had it printing, the raft printed just fine, but it started to air-print after that. So I restarted it. And it failed again. And again. So I opened it up, cleaned out the inside, and ran it again. This print worked, but was the wrong size (iteration 1). So I ran it again. And it failed. So I opened it up again, cleaned it, and ran it again.

This one worked, but was missing some parts due to a software error (iteration 2). and some minor software and design issues later (iteration 3), I switched printers. Iteration 4 was quite nice, but the copper filament we have doesn't work on the Makerbot. So, back to the Afinia for iteration 5. A little analog repair work later (did you know a soldering iron can be used to melt 3D printed plastic?), iteration 5.5 was the final product.

Iterations 2, 3. and 4 of the necklace

My next project, a model for one of my high school classes, also started on the Afinia. It tipped over during  the first printing (iteration 1), so I cut off the bottom (iteration 2) and tried again. This one peeled off the build surface (iteration 3), so I switched printers again, to the Makerbot. Iteration 4 printed quite well, making this project slightly shorter.

The final model

Importing a 3D scan or STL into Fusion 360 for the Othermill

This is just a quick tutorial on how to import a 3D scan or STL file into Fusion 360 for Othermill, or any other CNC mill. Ends up, you can't just import in if it is made out of triangles and not quads. The easiest way to test this is to import and right click and see if it gives you the option to  convert to B-REP Surface. If it doesn't we have to go the long way to get it into Fusion 360.

1. Import the OBJ file into Autodesk Remake.  Remake is made for editing scans and other similar files.

2. Next we need to edit the file down to just what we need to do this use the Selection tool and then right click and select Delete. Next we need to fill in all the holes, which you can use the Fill Holes tool for.  

3. After that we need to decimate the file to less than 30,000 triangles (or decimate it to less than 10,000 if you are doing this on a laptop). This is for performance reasons after you get into Fusion 360.

4. Export as a OBJ file for Fusion 360.

5. Import to Fusion 360, using Insert Mesh



6. Next, Right click on the mesh, and click convert to B-REP
Now you have a Fusion 360 model which you can edit and mill on the Othermill. To read one way I've used this process in my own work, please visit my blog post: 3D Scan to Chocolate in 48 Hours.

Scan to Chocolate in 48 hours

This weekend's project is to create chocolates in the shape of my art teacher's face. My goal is to do this in less than 48 hours. The basic process includes the following steps:

1. 3D scanning of the face
2. Design chocolate CAD file
3. Export design for Othermill
4. Mill into wax
Create silicone mold
5. Pour chocolate

STEP 1: 3D scanning of face

To start out I needed to capture my teachers head in 3D. To 3D scan something there are many options, like using 123D Catch, and Remake both utilize your smartphone or DSLR camera to create 3D scans. I opted for an easier option using the Structure Sensor. It is a sensor that clips on to the back of an iPad. I choose it because it takes me 1-2 minutes to scan a head instead of 5+ minutes for 123D Catch and Remake. To scan somebody with the Structure Sensor all you have to do is walk around them then the app, ItSeez3D, processes the data and produces a 3D model. I then uploaded that file to Sketchfab.

Mr. Sanborn by gadgetsam on Sketchfab

STEP 2: Design chocolate CAD file

Now that I have the 3D model the next step was to bring it into Fusion 360. I thought this step was going to be easy. I was so wrong. 

I first tried importing it just as an OBJ file but Fusion 360 didn't like it. I went online and found different ways to import OBJ files. When I finally got it imported, the CAM part of Fusion 360 didn't work on it. So back with more googling, I found I needed to convert it to a B-REP Surface.  The steps I used to accomplish this are:

1. Import the OBJ file into Autodesk Remake.
2. Decimate the file to less than 30,000 triangles (decimate it to less than 10,000 if you are doing this on a laptop).  The number of triangles refers to the number of flat surfaces that make up the curved mesh--it is like the detail level of a 3D printer. (Read more about triangles in models here.) We need to make the number of triangles lower so the model is easier to process. 
3. Export as a OBJ file for Fusion 360.
4. Import to Fusion 360, using 'insert mesh'
5. Right click on the mesh, and click 'convert to B-REP'

You can read more about how to do this here.

STEP 3: Export design for Othermill
Now that it is in Fusion 360, I started the CAM process. CAM stands for Computer Aided Manufacturing, in this context it is telling the othermill how it should mill your part. This is similar to the slicing process for the 3D printer. This process was arduous because I only decimated it to 25,000 Quads and I was running on my laptop. I finally got fed up and just exported it for the Othermill, but in my haste I forgot to add a finishing process so the first version didn't turn out well. After I had a good night's sleep, I started running it on my desktop which is much faster and has a dedicated GPU. I am not going into much detail on how to use the Othermill with Fusion 360 because they already have a great tutorial on it. I choose the Othermill because it is easy to mill once you have the design and file.

Now back to the design, I wanted to make little faces of my teacher, I settled on making four of them. I copied the model four times and then moved on to the CAM process. You can view my file here.
For the CAM, I used an Adaptive Clearing tool and a Parallel Tool for the final finish. Next I exported it as a .gcode file for the Othermill and put it into the Othermill software.

STEP 4: Mill into wax
I connected the purple wax to Othermill with Nitto Double Sided Tape (available at OtherMachine Co or other suppliers). Nitto tape works extremely well, much better than double sided tape. Then I started milling. The milling took 4 hours to complete.  I  decided on using a 1/16 ball end mill, because 1/16 would give me enough detail, and want it to take more time. 1/16 bits also rarely break unlike smaller sizes.

STEP 5: Create silicone mold

Now it is time to pour the silicon. I use silicone from Other Machine Co, mostly because it is rated as food-grade. I mix the orange and white in equal parts in a cup, then pour it into the mold, I let this set overnight.

STEP 6: Pour chocolate! To melt the chocolate I used a double boiler, and then I used a spoon to take the chocolate and put into the silicone mold. I then put it in the fridge to set. Some tips for if you want to mold chocolate use some parchment paper on the top of the mold to keep it flat.

Hope you liked this blogpost please like/follow our blog.

--Sam Schickler

Our 3D Data From the Advanced Light Source - an Update and VR!

Data Visualization Animation of Student Scanned Sample - a Claw!

The Advanced Light Source is a synchrotron, a facility that speeds up and then bends an electron beam to produce high energy x-rays. The x-rays are used by scientists to image different samples. The 8th and 7th graders at our school have gone to the ALS for the past two years and participated in different projects, including x-ray tomography and crystallography.

Data Visualization - a Feather

Based on these experiences, I wanted to delve more deeply into 3D data visualization.  In particular, I have sought to learn how to use Avizo, which allows much more advanced image processing than FIJI (the open source alternative).  One big obstacle was cost: an Avizo license sells for $5000 -- with the education discount.  I emailed Avizo and requested -- and received -- a free trial.  When I looked online for video tutorials on how to use Avizo, I could only find one or two videos. During the trial, I made several tutorial videos of my own.  I then asked Avizo to extend my trial for as long as I continue producing high-quality tutorials. They agreed and it has been a great partnership. I have now made 15 videos, which are hosted on my YouTube channel.  Currently, my tutorials have over 3,500 views and 9,450 minutes watched. 

Our School Director Trying Google Cardboard

Working our booth at the 2015 San Mateo Maker Faire, I was able to explore other makers' work and became interested in Google Cardboard, a virtual reality viewer that uses cardboard, a few lenses, and a cell phone (and app) for viewing. I saw an opportunity to use the Cardboard to display the 3D models of our class data from the Advanced Light Source in a way that would foster a compelling learning experience. I asked the people at Google’s booth if I could have the extra Google Cardboards at the end of the Faire. They agreed. When I returned home with the Cardboards, I did some research and found an app called InsiteVR, which I have used to display the models. I started off sharing the project with my teachers and fellow students.

Meeting with Scientists at the ALS

Soon after, I contacted Dula Parkinson, a beamline scientist at ALS who has been a critical supporter of both our school's work and my independent projects.  We met and talked and he is now planning to put Google Cardboards in the lobby of the Advanced Light Source to showcase for the public the amazing imaging work that is done at the ALS!

I also played around with OpenDive, "free DIY 3D VR glasses by using your 3D printer, a non-commercial project by Stefan Welker" and was able to print out my own set on our school's Makerbot!

Dive printed and ready to be assembled - just add cell phone!

I plan to continue my data visualization work and since its announcement in May 2015, have been interested in learning more about working with Google's Jump! 

- Sam S (9th grader in the fall, BPC Maker Club intern)