Jason K. Firth, C.E.T.

Instrumentation, Control, and Automation

The Power Destructitron X

Dec 082014

December 8, 2014


I'm Jason Firth.

This post is meant to test embedding youtube videos into a post. This video is relevant to the blog because it is my term project from college: The Power Destructitron X.

The story of this surprisingly complicated project has two completely different morals. I think which one you decide on depends on your attitude.

As part of the instrumentation program, everyone has to take part in a term project. Each term project had a certain difficulty, tailored for a certain number of people working on the project. One guy was building a weather station. Another group was building a heat tester. Yet another was building an XY table.

The project I ended up being given was to create a controller to very precisely control a rotary table. I had a rotary encoder, and a stepper motor and stepper motor controller, and an inductive proximity switch. The basic theory was quite simple: Find a home position, determine the number of stepper motor counts that reached 100%, and control the number of counts, while paying attention to the binary encoder. I was going to do all the control in a modicon momentum PLC, and use Wonderware to display the data.

Well, I sort of jumped the gun. All the parts fit together beautifully, the programming was really easy, and I was basically done the assignment on the first day.

When I showed Mr. Shirtliffe, the teacher in charge of the instrumentation engineering technology program there for 30 years at that point that I had completed the project, He seemed to get pretty excited. He stared picking up random parts -- a robotic hand here, a piece of an old laser printer there, a brutal looking 24vdc motor, and he gave me a new task: To build a "pick and place robot".

Well, the project that was originally a difficulty level of 1, just became a difficulty level of 11. I went from having some nice low voltage, low current stuff, to having a huge variety of devices. There was suddenly now air, high current DC, AC, low current DC, I even ended up building some motor controllers from scratch...and I had to find some way to put them all together in a way that would somehow move a block around.

This isn't hyperbole either; I was always in the classroom at 8am, but for weeks on end I'd stay in the lab until right before the last city bus that would take me home for the night. It was a huge amount of learning, research, work, and rework.

This video shows what I ended up with. Obviously this was before I had developed any real trade skills, but I'm still proud of the fact that I was able to somehow make a thing (no matter how contrived) out of these completely random parts.

(and no, this is probably not what I'd build today with an extra 8 years of design and field experience under my belt.)

As for the two different morals, it depends on your point of view: On one hand, there's the saying that "the nail that sticks up gets hammered down". That's a perfectly legitimate way of looking at things: I would have gotten just as good of a mark if I'd kept my head down and pretended to be working on this thing that was already working, after all. However; I think of it this way: Instead of simply doing a fairly simple project that wouldn't teach me that much, I got a chance to really stretch my legs, and learn first-hand the best way about a bunch of different controls.

Thanks for reading!