Highlights From a Week-Long Design Review

The crazy customer specification I described in a previous entry has a name - the Siberian Tow Truck spec.

Last week, engineers from offices all over the world (England, Germany, Mexico, France, and ummm, Tennessee) gathered at our location for a design review. This means 50 people made presentations during the week about their specific contributions to the design while everyone else took turns assaulting them with hard questions. Since I’ve only been with my group for 10 weeks and have yet to earn my title as Queen of Fasteners, I was excused from presenting. I didn't think it would be fair to grill people without having the opportunity to be grilled (like a George Foreman, grilling should go both ways), so on my own, I excused myself from asking questions.

On the first day, everybody introduced themselves. There were 50-some participants. Most are engineers. Three of us are female.

I think I’ve mentioned before that lots of times, the things we say about our steering gears can be taken out of context and that gives me the giggles at work sometimes.

Land Rover has a requirement that its steering gear must be fully operational when submerged in water at ambient temperature. This is called a submersion spec. Mazda took this spec one step further and requires that its steering gear is cooled to something around -40C and then is submerged in hot water. It must not crack, it must not let water in (ingress?), and it must function. At the design review, one of the British engineers called this a hot wet soak. Who doesn’t like a hot wet soak?

On the third day, we discussed my personal favorite component – the ballnut. As much as I love the ballnut, I can't tell you much about it. It is a key component for transforming input force to rack movement which in turn, allows turn. From what I can tell, a lot of the discussion focused on how to properly make the ball bearing in the ballnut. Someone asked our resident ballnut expert, “What happens if it loses one of its balls?” To which he replied, straight-faced, “Well, it would not be robust. If we go to the assembly line and see a bunch of balls on the floor, we know we have a problem.” You think?

One of the reasons I love my new job is that I am being made aware of all the holes in my engineering knowledge base. The number of potholes is frightening. I want to re-learn things I used to know so that I never forget them again. The most recent topic that I'm diving in to is pulleys and rope tension and mechanical advantage (in my mind, that's all one topic.)