General Lab Skills
Many of the earlier projects I worked on at EHT involved machining of custom components for diagnostics, power supplies, or other items. A prime example such as my internship project constructing an inductive ring tossing experiment, which involved a great deal of metal/plastic machining as well as electrical work. My electrical and machining knowledge is derived from hands-on experience through projects like the ring tosser, as well as a substantial amount of contractor-style remodeling work while working with EHT while it was still a fledgling company. In addition, our commercial and research-focused power supplies are initially cobbled together as prototype, and my work creating these prototypes has contributed substantially to my experience.
Along with being generally handy and mechanically-inclined, I have a wealth of experience ranging from builds where speed is the priority to those in which precision is paramount. A few examples can be seen at right, and below is a general list of some of my experience.
Shop Machining Skills
- Lathing, both small- and large-scale objects
- Includes challenging-to-machine metals, such as tantalum
- Mill work, including working with both cartesian-based and polar-based designs
- Includes work with both plastics and metals
- Drilling (hand and press)
- Tapping and dieing of metals and plastics
- Plastic welding (using solvent-based adhesives)
- Use of viscous material fillers (wood filler, putties, RTV caulking, etc)
- Composite layup (Fiberglass and carbon fiber)
- Table/Chop/Reciprocating/Hand saw
- Practical familiarity with ANSI and metric screw sizing
Shop Electrical Skills
- Familiarity with all types of AC wall voltages
- Single phase, two phase, delta/wye configuration 3-Phase power
- NEMA Plug/receptacle standards
- Intuitive understanding of wire gauges for low-power signals and high-current power
- Installation of power outlets, light switches, etc
- Understanding of ground loops, inductively separated grounds, etc
- Electrical Safety
While I was an intern, my boss checked if an outlet was live by inserting the prongs of a multimeter into the socket. It had been ingrained into me from childhood that this was a bad thing to do. When I expressed this to my boss, he handed me the multimeter and said, "I want you to stick this in and out of the outlet until you don't feel anxious about it anymore." I did, and I only got more comfortable from there - not from becoming more reckless, but by developing a hands-on, practical intuition for what is truly dangerous and what is not.
- Chemical understanding of solvent/surface interactions (which solvents to use when)
- Familiarity with the mechanical properties of common metals/composites/plastics for practical use
- Familiarity with dielectric strength, relative permittivity, and relative permeability of most common material
I've developed a strong sense of the aspects of a lab that allow it to run smoothly. Dominantly, this is comprised of ensuring that all tools, components, and materials have a dedicated "home", and ensuring that they are returned there after use. In other words, everyone needs to clean up after themselves. It makes for a much more efficient and usable work space.
I've also kept strict notes in a lab notebook, after having learned (the hard way) how critical it is to document experiments and work, no matter how apparently trivial. There will always be a reason you'll need to recall the work you've done, even if just to contextually inform your memory of something more important. I also periodically write summary documents for my work, to allow for quick review in the future without having to resort to reading more-cryptic lab notes.
Even though it's not always possible in a budget-conscious environment, the experimental freedom afforded by a substantial back-stock of components and technology is often underrated. Having the full (or mostly full) series of a useful model of resistor makes testing and prototyping much faster. While periodic cleaning is important, so is ensuring that you have the ability to attempt interesting solutions and ideas by virtue of having the necessary parts.
Left: Threaded aluminum compression ring
Center: Brass compression cap
Right: Threaded tantalum housing
Constructed of three different pieces: 1) Top magnet-retaining ring, welded to (2) The central lathed tube, welded to (3) the base, machined with a mill and turntable for cylindrical symmetry. (Welding was hired out)
Alex and I hand-tapping a 1-8 hole in 1/2" Steel