Levi Sitts | Mechanical Engineer, MBA
Trebuchet

Trebuchet

Trebuchets have always been a fascination of mine. Years ago I saw a NOVA documentary where two teams built authentic replica medieval trebuchets, and launched 300 lb projectiles over 200 yards. The impressive power created by these simple counterweight contraptions inspired me to investigate the physics and engineering principles that made them possible. The trebuchet shown on the right is one that I build as a teenager, and demonstrated at various science club events at Portland Community College. Later on, the campus president would ask me to bring the trebuchet back to display as an example of student activities during the faculty inservice meeting.

Below are more photos of the trebuchet at various stages of development and redesign. The original design used a swinging wooden bucket filled with sand as the counterweight. Later on, I replaced the bucket with an 840 lb concrete collar and upgraded the timber used for the throwing arm. I’ve also experimented with different pulley mechanisms for retracting the throwing arm, eventually settling on a type of large wooden ratchet.

Trebuchet  Trebuchet  Trebuchet
3D Printing

3D Printing

Everyone needs a hobby; mine is 3D printing. In 2013 I purchased a mid-grade desktop 3D printer just to see what I could do with it. I had learned about 3D printing in college, and was excited to get my own machine and start making some of the 3D models that I had created over the years. Since acquiring the printer, I have created hundreds of parts, toys, and random creations, pushing the limits of the hardware and software. Over time, I've become very good at judging whether a model is "printable" or not, and also how best to print it. There are many limitations to the technology, but overall I see it as a major disruptor to multiple industries. New printers are coming on the market every year, and I can't wait to see where this technology goes.

Below are pictures of some of my favorite prints that I've made over the years. Each one was modeled from scratch. The two Disney pieces were modeled by looking at many photographs and freeze-frames. The mountain diorama was extracted from public elevation data and converted to 3D.

Print  Print  Print  Print