After Further Review

Unless it is your team being robbed, you probably hate having a live broadcast interrupted by a video review. We sometimes feel this way during a design project when someone throws out the red flag on something that seems obvious to you. Unlike a sporting event, there is no reason for winners and losers in engineering. Everyone wins when we take the time to double check our assumptions.

Anticipating the Problems

I am a big fan of cross-functional design and process reviews where people from around the company sit in to decide the way forward on a project. Far too many designers isolate themselves from the challenges faced out in the shop and this is a great way to educate them.

After hours of negotiating about the required level of grind burn inspection some years back, the host called for a break so we could tour their very impressive workshop. We had been lectured by their design chief that they never burned a gear and he saw no reason for my client’s insistence that every single gear be subjected to nital etch inspection.

Yet there in the final inspection “hold area” were four pinions tagged as scrap due to grinding burns. There was no need to gloat as the “100% clause” was reluctantly agreed to on the spot by the sales manager. Had the design chief been part of the non-conforming material triage process, he would have been spared a very embarrassing professional moment.

This is another reason to embrace that attitude of humility and skepticism discussed in my last couple of blog postings; you are not required to have all the answers — just to be prepared to study the situation and have a recovery plan in case you happen to be “wrong.”

Why not work very hard at avoiding grind burn while still studying ways to remediate the damage once it occurs? Perfection is a great goal, but problem anticipation is much more practical. Especially when dealing with large custom made components, an understanding of what can go wrong and how those “defects” will influence field performance is vital.

We need more study of things like grind burn, grind steps, material defects, and case depth variation. Unfortunately, our legal climate prevents full and open discussion of “defects” and the trade suffers. Imagine medicine if there were no autopsies. Thankfully, we have mandatory investigations of transportation “accidents,” so the headlines are not dominated with reports of aircraft falling from the sky.

About Charles D. Schultz 627 Articles
Charles D. Schultz is President of Beyta Gear Service and one of Gear Technology's technical editors.

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