Today begins my ninth year as a consulting engineer! It shocks me that I have now worked for myself longer than as an employee at any oth...

  We used to warn our children to “be careful what you wish for, you might get it.” Recently I blogged in favor of jump starting the econom...

  Continuing with the environmental theme of the previous blog, an impressive change has occurred in the recycling industry since I was col...

  We have all seen the Internet meme of politicians wearing corporate logos so the public will know who their backers are. I would like to ...

"Wall Street predicted nine of the last FIVE recessions," Paul Samuelson, Nobel Prize winner in economics, 1966. We get a lot more economic news...

My first airline trip of the New Year ended like the last one of the previous year: in a middle seat of a fully loaded plane fighting a respiratory...

One thing that struck me during the Gear Expo was the large amount of grey hair on the heads of those in the exhibit hall. While it was great to se...

A popular cable car customizing show recently featured a segment on using 3-D printing to produce a prototype part. There wasn’t anything original ...

Like most curmudgeons, I can do a five minute ramp on how cheap gasoline was when I was a kid and how outrageous the price is now. Living in Chicag...

Cracks initiated at the surface of case-hardened gears may lead to typical life-limiting fatigue failure modes such as pitting and tooth root breakage. Furthermore, the contact load on the flank surface induces stresses in greater material depth that may lead to crack initiation below the surface if the local material strength is exceeded. Over time the sub-surface crack propagation may lead to gear failure referred to as “tooth flank fracture” (also referred to as “tooth flank breakage”). This paper explains the mechanism of this subsurface fatigue failure mode and its decisive influence factors, and presents an overview of a newly developed calculation model.