OESH

The senior class of University of Virginia (UVa) mechanical and aerospace engineering students who’ve been working all year with me at OESH, just gave their final thesis presentation in preparation for graduating next month.

They had to give their presentation in front of the rest of the professors and students in the department. It was the first time this year that we met not at the OESH factory but in one of their classrooms at UVa where I got to just sit and listen.

Boiling down a year’s worth of work into one hour was challenging but they did it beautifully. They had to first present all the problems with current shoe manufacturing that is largely being outsourced to China – e.g. toxic foams, adhesives, wasteful tooling, etc. Then they had to systematically review all the things we do at OESH that solve these problems – e.g., sustainable design and tooling (where even the metal molds are recycled in a local foundry) and of course, the complete absence of toxic materials.

They talked about our using FEA (Finite Element Analysis), a mathematical model, to help dictate the design of not only the OESH sole, but all the tooling and machinery used to make the sole. They discussed our using both additive and subtractive manufacturing techniques (e.g., 3D printing and CNC milling) to make all the foundation tooling as well as prototypes and final molds. They described how they determined the optimal amount and size of the cooling plates and lines needed to cool the hot injected (and recyclable) material. And they explained how they actually constructed all the foundation tooling and molds using the CNC (computerized-numeric-controlled) machinery in the factory. For example, they described how they made the cooling plates, drilling deep-bore holes into aluminum using the CNC milling machine outfitted with a specialized parabolic drill.

They did a lot. They learned a lot. As did I. At the end of the presentation they were challenged by one of the professors with the question “what was the single-most important thing that you learned at OESH this year?”

Their answer: “Machining is not trivial.” A respectful response but it conveyed all the many times that things went wrong, before they were right. There was not enough time to list the mistakes and lessons learned. E.g. the time that they hit the wrong button on the milling machine or the time that the injection-molding machine refused to work because of an inadvertently turned-on limit switch. Or the time that static electricity interfered with an otherwise perfect machine design.

At the beginning of the year, I told them a number of things that needed to be done so that we could make the entire OESH sole in the factory here. In their reviewing that list, I realized how daunting it actually was. I had forgotten that we hadn’t yet even had sufficient power to run all the new machinery. I was reminded of the trials, tribulations, and city approvals it took in our getting a whole new utility pole necessary to run the 3-phase machinery.

Their work at OESH serves as the basis for their graduating thesis. Fortunately, their presentation was very well received. In fact, if standing ovations were ever given in an academic forum, they would have gotten one.

Which means, graduation is just around the corner.

As is… the new line of OESH shoes!

Like a lot of women, I grew up not learning how to fix things. That might explain the special satisfaction I now get in fixing and re-building things, which typically begins with the first, often daunting task of pulling whatever needs to be fixed, apart.

In the course of building and maintaining the OESH factory, I’ve had ample opportunity to loosen up all sorts of frozen-tight nuts, bolts, screws, and pipe connections. Many of those stubborn connections have required more than just knowing which way to turn the wrench (almost always counter-clockwise to loosen it).

Maybe one of the first things I learned is what is a “cheater bar.” I couldn’t get the threaded nozzle off the end of the water jet saw with the big fitted wrench that I bought specially for the purpose. I didn’t want to just whack the wrench with a hammer as that annoying-wandering-in-delivery-guy suggested I do. The water jet saw is after all, a precision robotically controlled device that wouldn’t respond too well to whacking. Instead I called tech support. They suggested I get a “cheater bar” so I set off to the hardware store looking for one with no clue what that actually was. Embarrassed to ask the salesperson where the “cheater bars” were (since, who knows, he might be related to that delivery guy), I kind of figured it out myself…

This was a case where my appreciation for physics, specifically, the relationship between torque, force and lever arm came in handy. I’ve appreciated that relationship for years – in fact it was that appreciation that led to my discovering a link between different types of footwear and increased knee joint torques believed to be relevant to the development and progression of knee osteoarthritis.

Now all I had to do was apply that appreciation to that stubborn nozzle.

So… a cheater bar is just a long piece of pipe (or electrical conduit) that you fit over the end of a wrench to give it more leverage, which in turn, amplifies the force at the end of the wrench. Just go to your local Home Depot (or plumbing or electrical store) to find a piece of pipe that will fit over your wrench. The longer and stronger it is, the less man (or woman) power you’ll need. I now have several nice sized cheater bars. I’ve even made some special wrenches like the one below (with the aforementioned water jet saw) to fit inside the cheater bars that I have.

The other thing I do, especially if I think the threads are rusted, is douse everything first with a lubricant like PB Blaster, which is kind of like WD-40 but, according to my friend Bill at Specialty Fasteners, is better. At least it doesn’t smell as bad as WD-40. Like soaking beans, I try to plan ahead for the next day and let the lubricant sit over night. When I apply the wrench, I do give it a (slight) whack with the hammer, to hopefully break the seal and get more PB Blaster in there.

Occasionally, I’ve had to heat up a stubborn connection with a torch (for now, I just have a propane torch… an acetylene one gets hotter) before trying again with the cheater bar and some more PB Blaster.

Even when it looks like nothing will work, don’t give up. Just seek an even bigger wrench / cheater bar and more heat. Today, the engineering students and I were trying to get a two-inch threaded pipe out of a badly rusted but salvageable steel manifold (below) that I’ve wanted to re-build (to be part of a new cooling system for the injection molding process).

The students had already tried the PB Blaster/heat/cheater bar combination with one of the students literally hanging on the end of a cheater bar… to no avail. In need of a hotter (acetylene) torch and some long pieces of steel (to make a really long wrench), I hauled the 100 pound (ish) manifold hunk over to my friends at Quality Welding. There, Jason not only fashioned up a six foot long wrench but welded the manifold to a table to anchor it. It took a number of tries back and forth but then… the impossible happened… the pipe actually started turning. We all must have muttered at the same time,”Miracle.”

The to-be re-furbished bottom half of the manifold needed a name anyways.

“Miracle,” she is.