Max Mahoney (Chemistry) and I worked on a mechanical automata project this morning. Our long-term goal is to create laser cut wooden versions of the various mechanical mechanism building blocks in the beautiful book Karakuri: How to Make Mechanical Paper Models that Move by Keisuke Saka. To get a sense of what the design and development considerations might be, we decided to start with a Thingiverse search, and found Simple Machines – Geneva Stop (CC BY-NC-SA) by Zombie Cat. A few minor adjustments to the layout, and we cut the parts out of 1/4″(ish) hobby plywood. We ended up having to tweak a few of the parts to fit the dowels we had on hand, and we made a few slight modifications to the design based on the differences between the vector files and the thickness of our plywood, but overall it’s a great design and turned out pretty well for our first automata.
The rest of the afternoon was spent working with Nicole (student and Innovation Center staffer) on a stencil for organic chemistry. Max hung around finishing the automata, and answered a few technical questions as Nicole and I worked through the layout in Illustrator. We tested the first prototype, and decided that the various cut-outs representing the bonds needed to be scaled up a bit. Below is version 2, including Nicole’s beloved chicken in the lower left hand corner, and a fancy star on the right.
The design finished and tested, we cut the final version out of acrylic. Success!
In order to better enjoy the three dimensional holographic molecules, we quickly cooked up a little blanket fort…
Now that we have the parts in place, we can move on to developing the enclosure and making the system portable. It’s great to have the space, tools, and people to be able to turn good ideas into working prototypes, and we’re looking forward to making quick progress on this one (finally).
Some photos from the very successful cyanotype photography activity Max Mahoney (Chemistry) and Christa Oberth (Chemistry) and Heike Schmid (Art) led last week, using using the exposure boxes we built…
A view of the internals, and the wiring harness, which was scavenged from a PC power supply:
Max attaching a heat sink to the light bar. We finished the final box at about 1:45 PM, and the activity started at 2!
The boxes lined up in the Chemistry lab:
Fired up and working – students developing their prints:
A view through the fan port:
My kodama print:
We were initially worried about the LEDs heating up, but the fans – poached from some recycled external CPU cooling units, and heat sinks, also from the parts bin – pulled so much air that the aluminum bars (themselves functioning as heat sinks) to which the LEDs were attached were entirely cool to the touch throughout the whole process. The LEDs in these particular units are super bright and powerful, and students were very pleased with the resolution, detail, consistency, and intensity of the finished prints.
Max Mahoney (Chemistry) and I have been working on version 2 of some UV LED boxes for use in a cyanotype photography activity. We’ve been talking about these for a long time, so it’s nice to finally get to building.
Each box will have three 10 watt 380 nanometer UV LEDs arranged on a piece of aluminum bar stock. We were able to build up the prototype in about a day, working out some of the details about the access hatch, and the arrangement of the lights and so forth.
We also used the new laser to engrave one of the side panels.
Today Nicole (student) helped out mass producing three additional boxes (for a total of four).
As it turns out, these LEDs get HOT, so we brainstormed some fan arrangements, and settled upon a design. We quickly developed a diagram using Illustrator, running a paper prototype on the laser to ensure that our measurements were correct before engraving and cutting the final piece out of 1/4 hobby plywood.
Looking forward to getting these buttoned up and in use at the end of the week!
Some significant failures recently in the 3D printing department. Inspired by Steve Holzberg’s (Biology) cancer prints, Linda Abraham (Biology) found a model of a rhinovirus for printing. Given the complexity of the model, and the intricately folded surface detail, we decided the Form 2 was the printer to use. Loaded up the clear resin and let it print. The result:
Mostly it worked fine, but the top of the model had problems. A strange rupture appeared in the sphere:
The anomaly coincided with, was caused by – or maybe left? – this cloudy residue in the tray:
The tray was fresh out of the wrapper, and it was the very first run of clear, so I’m not sure exactly what caused the failure. In any case, the model is still perfectly usable, after a little filing to smooth out the jagged edges of the rip.
The center part of the model printed beautifully, and after some careful calculations to determine where things went wrong, Max set out to print the remainder of the model – in pink, since we ran out of white filament – with the idea of gluing them together somehow.
This one too is failing out on the margins. Support material configured as a tower seems to be the common failure point. Stay tuned…
Max Mahoney (Chemistry) and I spent much of today building out some cyanotype exposure boxes for an upcoming Science Center activity. The boxes are re-purposed lighting fixtures. For the lids, we used the removable access panels from old Gateway desktop computers I had stored in the closet years ago, cutting them in various ways to mount two different styles of UV LED lights that will be used to expose the prints.
Next steps include installing some handles in the lids, adding some kind of reflective treatment – foil or silver metallic spray paint? – to the inside surfaces, and creating viewing windows with UV filtering acrylic to allow students to monitor the progress of their prints.
Below is Alex Hartigan, a Folsom Lake College Engineering student preparing some Calculus III models he’s been developing in collaboration with Kevin Pipkin (Math) and that he printed on the new Form 2, which has gotten a lot of use lately, most recently with the Enabling the Future project.
Alex and I connected last semester, and finally got the chance to work together on this Math project. Alex has a lot of skills in 3D design and printing, as well as experience on the Form 1, and through the process of preparing the Calc models, he taught me a whole lot about the finer points of printing on the Form 2, including various layout tips, and the manual editing of supports.
The Form 2 models came out great:
The Ultimaker 2 ones, not so much, though the failure at least resulted in some interesting artifacts:
Best of all, Max Mahoney (Chemistry) dropped by, and we recruited Alex to work on the chemistry project we prototyped the other day. One of my favorite parts of working with students is learning from them, and I hope to learn a lot from Alex before he heads off to Sac State next fall.
Max Mahoney (Chemistry) printed one of the models from the aforementioned paper, and we got to discussing how we might fill it with sand and inject some energy in the system to motivate the sand to shift around to demonstrate concepts of chemical reaction kinetics and dynamics.
I found a Sonic Ghost VX-GH72 Electro-Mechanical Audio Transducer in the workshop. I purchased it some years ago hoping to replicate a sweet project I once saw at Maker Faire, developed by Sasha Leitman and involving 50 gallon metal drums with contact mics attached, with the drums acting as…well…drums, but also acting as speakers. Anyhow, we hooked the transducer up to a piece of metal and threw some sand from the aquaponics project on there, and played around with different frequencies.
We ended up breaking the transducer, and substituting a speaker, upon which we place the metal sign, with the model taped to the top.
We were able to get the sand to bounce out of the lowest spot and into one of the higher ones, so the rough prototype is showing promise…
The SpecPhone is a 3D-Printed smartphone spectrophotometer for research and education. The device can make analytically accurate measurements of concentration and can be used for teaching analytical chemistry and DIY science projects.
After some sketchy results and strange print decisions by the Ultimaker, it seems that the model doesn’t quite sit flat. That is, the legs don’t seem to be the same height. Using Netfabb Basic, I dropped in a Z plane to visualize:
Taking that plane up, it seems that it’s not just the bottom of the model, but that the skew continues all the way to the top:
With support structure enabled in Cura, we were able to print it after a few botched attempts, so it’s not a deal-killer, just a bit awkward. Now we just need to find an iPhone 5s…