Meet Dunbar!

After years of thinking about adopting a dog, we finally made the plunge, and adopted a dog. Meet Dunbar! We got her from a rescue, Enzo's Acres. Dunbar's mother was found wandering and pregnant in Central California with a big metal band around her neck and carabiner attached to it. The thought was that she was being used to breed bait dogs and escaped from her situation.

I named Dunbar after Captain Dunbar of Catch 22, a personal favorite book and character. I've read a lot of dog training books over the years in anticipation of adopting a dog, but boy did they not really communicate how much time goes in to raising these little pups. She's a great puppy, and someday will be a great dog!

Graduation!

After four years of schooling, I am finally proud to say that I've graduated with a Bachelor of Science in Mechanical Engineering from Portland State University, with EIT designation to boot! It was a long journey, and quite the leap from my marketing career, but thanks to all the support from my friends and family, I made it. Now, back to work.

3D Systems Capstone Project: 3D Printed Clock

Today we presented our final capstone project, a no-assembly-required 3D printed clock. Our capstone team: Ondrej Fercak, M. Jeff Gunderson, Sasha Friedman, Anh Ha, and Jack McCollister. Capstone sponsor: 3DSystems, Project Adviser: Dr. Trevor Snyder,  Faculty Adviser: Dr. Sung Yi.

Folks have made all sorts of 3D printed machines before, but what set this project apart is that our clock requires no assembly by humans. This is remarkable for a number of reasons, mainly in that we are severely restricted in materials, in this case in one type of UV-cured resin from the 3DSystems Projet 3500 HDMax. All of the different pieces of the clock, from springs, to gears, to bearings, all had to be made of this same resin, and printed in place by the printer. Clearances were developed via the support material that is cleared away in the normal post-processing of 3D printed devices; for this machine wax is used as a support material and then melted away in an oven.

Since the resin the clock is printed from is translucent, it is difficult to see in photos, so I'll use some renders to highlight various pieces. The clock was designed in Solidworks with engineering calculations done in MATLAB. The core components are the case and packaging, the power input, and the frequency input and regulation.

Due to the limited size of the print area of the 3D printer, we made a design that would print in a folded state, then unfold for use. On the left the clock is as printed, 5.8" x 8.0" x 8.7", and on the right is the clock in operational stance, 4.6" x 10.9" x 8.7".

Several design options were considered for the case, from a fully-enclosed box to the skeleton design that we settled on. A fully-enclosed box would reinforce the fact that the design was in fact printed with no post assembly, but as it would obfuscate all of the interior design, so we went with a skeleton case.

 

The power input and transfer system starts with a helical torsion spring, or mainspring, that is wound via a key (also 3D printed, of course). We initially were skeptical about the ability of a 3D printed material to act as a spring, but after a rigorous set of testing we determined that the material (VisiJet M3 Crystal) does in fact work great as a spring and lasts many duty cycles. Once wound, the spring power is transferred through a freewheel into the gear train, driving the hour, minute, and second hands of the clock.

 

In order to move time forward, we used a pendulum and escapement system, which performed the dual duty of keeping time moving at the correct rate, and keeping the spring from unwinding instantly.

All in all, it was a great project and a great learning experience to not only work on such a complex system, but to move forward in such an uncharted realm of engineering!

Team Earl Grey - Portland State University Senior Capstone

For my senior capstone project I have the honor of leading Team Earl Grey, working with 3D Systems on an ambitious 3D printing project. Our goal is to create a fully-functional 3D printed machine that is no assembly required. This doesn't sound like the biggest challenge on face value, but to actually get a 3D printer to create a working machine is quite the challenge, as usually they print the parts, then someone puts them together, using all sorts of fasteners.

Side note on how we got our name: 3D printers creating fully-functional machines is pretty much the spiritual predecessor of the replicator machine found on Star Trek. So, Team Earl Grey was born.

There will be more to come with our final design!