The New Hobbyist

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3D Printing School: Print. It. Big!


In summer 2014 I made my way out to the Science Museum in London to check out my WALLY – Wallplate Generator on display. It was pretty awesome. While I was there I stopped in Oxford for a day and captured some  “scanvenirs“. One of them turned out particularly well.


My scan of the Marble portrait of the Greek playwright Menander (342-291 BC) is available for download on Thingiverse and was generated by running 45 images I took on my iPhone 5S through 123D Catch. Considering I only took 2 minutes to take all the photos (according to the photos Exif data) in a crowded museum, I’m very happy with how it turned out. When I got back to the states I processed the scan in Meshmixer and printed a few copies of the model at pretty small scale. I also used the model for the base of a couple other remixes, and because the scan and prints turned out so well I just keep going back to it, trying to figure out new ways to use it.

I’ve been following Cosmo Wenman’s amazing work with 3D scanning for a couple of years now. One of the things that really stood out to me was his life size recreations of sculptures.


Head of a horse of Selene. Photo courtesy of Cosmo Wenman


Between printing at full-size and the finishing work/paint jobs he does they end up looking incredibly close to the real thing. Now don’t get me wrong, I love my miniature prints but there is something really striking about seeing a sculpture at the original scale it was meant to be viewed. Because my scan of Menander turned out so nice I thought this would be a perfect opportunity to try printing something life-sized myself.Screen Shot 2015-08-15 at 7.38.08 PM

The first step was the scale the STL file to the appropriate height in Meshmixer. I did this using the the Units/Dimensions tool under the Analysis menu. I scaled this to 18 inches (457mm) tall which is around life-size.

Screen Shot 2015-08-15 at 7.38.55 PM

The next step was to hollow out the model. I’m not sure if this is necessary (or even a good idea), the only large scale print project I’ve been involved with (WeTheBuilders) used solid blocks through out the model. But I thought using a thinner walled print might help with alignment and filling any gaps that formed form curling or shrinking during printing. I hollowed out the model to 5mm which I thought would be a good mix between strength and print bed adhesion.Screen Shot 2015-08-15 at 7.51.56 PM

Then the cutting process began… My printer, the Makerbot Replicator 2 has a build volume of 285mm x 153mm x 155mm. I used Netfabb Basic to slice my model into “chunks” that fit these dimensions. I made my slices 150mm tall (5mm under my max build volume), I thought I could just cube up my model to fit my printers build volume, but this wasn’t as cut as dry as I had originally thought.

Screen Shot 2015-08-15 at 7.52.26 PM

As it turns out, simply slicing the model into cube-ish peices that fit your printer isn’t really the best option. As you can see from the picture above if I had continued to slice the model into 150mm slices tall I would have cut right through the middle of the face. I feel like having a smooth seamless face is pretty important for this print, and while I know things like that can be hidden during my finishing process I’m not quite good at it to do a very good job hiding the seam.


I ended up slicing some parts slightly smaller or larger to help hide seams. The animation above shows a pretty good break down of how that worked out. So there are definitely some artistic considerations when slicing up a large model for print.

After slicing all my parts I gave them a quick look over. A couple of the parts had some pretty severe overhangs, but I was able to avoid using support material by rotating the parts so the overhangs would print build-plate side down.

Screen Shot 2015-08-15 at 7.58.30 PM

When everything was said and done this project had 9 huge prints. With the shortest print coming in at 3.5 hours, and the longest at 16 hours I thought it might make sense to find a way to track my prints. I put together a Google Sheets document to track all my prints and printer settings. I’ve since continued to improve upon it to give me better print time estimates and even a real-time print timer/dashboard.


After 56(!) total hours of printing I had myself a nice pile of parts. Assembly was the next step and involved some processes I wasn’t super familiar with before starting. I started by gluing all my parts together using Loctite “Gel Control” Super Glue. This worked pretty well, but I ended up reinforcing all my internal seams with some heavy duty superglue from McMaster Carr (Part #7518A61). I’ve used this hot glue in the part on my Proton Pack build and it’s held strong for years so far.


While I had pretty good luck with my print bed adhesion and used PLA to reduce shrinkage during my prints there were still some gaps after gluing. I used Apoxie Sculpt (a two part epoxy putty), to seal all my cracks. The putty is pretty easy to work with, you mix the two clay-like parts (wear gloves!) until it’s a solid color. Then use it like clay to fill the holes in your model. I found that using small clay/sculpting tools helped avoid large globs that would need to be sanded down later. Wetting your fingers also helps smooth the epoxy after applying it. The epoxy has a working time of a couple of hours, but after waiting overnight it cures into a very hard plastic that can be sanded smooth.

After letting the epoxy cure overnight I sanded the seams smooth. I’ll admit looking back I should have spend more time on this step, but I was pretty anxious to get panting. Before moving on to paint I gave the whole print a coat of filler primer. This made the surface of the print look even nice and hid some of the prints imperfections.


Then came the exciting part, the final coat of paint. I used Rustolium Ultimate White Satin spray paint. I’ve used this in the past for painting prints and it seems to adhere pretty well to plastics, I figured with a primer coat it would work perfectly. I really didn’t have any issue with the paint and I like the slight sheen the satin paint gave to the print.


While I may not print everything I make at a true to life scale, this was a really fun project. It’s really interesting to see what details hold up to the scale.

3D Printing School: Color Printing with SketchUp


This has eluded me for a long time. But as you can see from the photo above, I’ve finally figured out how to print in color on Shapeways from SketchUp! I’ve read several “Color Printing with SketchUp” tutorials but I always seemed to have strange issues. I’ve finally managed to solve all my problems by mashing up the many tutorials I’ve read and troubleshooting my issues. I have a feeling other people out there are struggling with some of the things I was so I thought I’d share my own “Color Printing with SketchUp” tutorial.

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Speaky: The DIY Airplay Speaker


I’ve had a Raspberry Pi 2 sitting around my workshop for months now. I knew I had to have one as soon as they were announced (because, reasons), after it was delivered I quickly realized that I didn’t have any immediate need for it. I’m not sure I completely remember why I thought of it, but the other day I googled “Raspberry Pi Airplay” and found this handy article from Make Magazine. Now most of the time finding a well written article on something that I thought I had invented would discourage me from trying a new project (I’m a big fan of trying things I haven’t seen done before). But instead, reading this article inspired me to move away from the nitty-gritty details and think about something else. Design.

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3D Printing School: Dual Extrusion Confusion


I’ve had my dual extruder printer (Makerbot Replicator 2X) for about two years now and I’ve come to realize that there are not very many two (or more!) color models out there to print with it. I imagine this is caused by 3 things:

1. They’re more difficult to model.
2. They’re more difficult to print.
3. There isn’t much demand.

I know personally I was held back by #1 for quite awhile. I had printed Makerbot’s pre-built demo models, as well as maybe one or two other models I found on Thingiverse but that’s about as far as I got. With the exception of text labeling, and small accents, my (mostly) utilitarian prints don’t always lend themselves that well to multi-extruder printing. I hadn’t really put much thought into my second extruder other than it being a “back up extruder”. That is until I attended the Thingiverse Make-a-thon in November 2014.

At the Make-a-thon there were several really interesting panels and presentations on 3D modeling and 3D printing. But the one that really stuck out to me was the 30 minute session on MeshMixer.

MeshMixer is a free program from Autodesk that I often describe as “Photoshop for 3D models”. It allows you to combine models, make repairs, generate support material, and even send the models directly to a printing service like Shapeways. During the presentation some more advanced features I’d never experimented with were demonstrated and really got me interested in learning this program inside and out.

Over the course of the past few months I’ve learned a lot about the program. Unfortunately much of my journey was self taught, mostly because there seems to be a lack of good instructional material for the program. I can’t complain too much (the program is free after all), but it inspired me to generate some of my own training material for the program.

So linked below is my first instructional video. This one shows how I used MeshMixer to take an existing model (Left Shark Monochrome by cerberus333) and turned it into a dual extruder two color print. As I said, this is my first attempt at a training video so feel free to leave comments on what I’ve missed or could be explained better either on the video itself or here on my blog.

Hopefully this might lead to more makers out there creating some awesome dual extruder models that I can print!

I’ve uploaded “Sharkie Dual Extrusion” to Thingivese for those of you with dual extruder printers out there. If you have a chance to print it upload a photo! I’d love to see it.

3D Printing School: Tools!


I’ve been slowly building up a tool kit since I built my first printer in 2011 so I thought I would make a list of my “must have” 3D printing tools. I found some of these by reading 3D printing blogs and news sites, and while pretty much none of these tools are made specifically for 3D printing, they have turned out to be super helpful.  So here it is: the tools I find essential to my printing process.

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