February 2008 Edition

LETTERS

Letters

"Cover" Story

Having worked in a foundry I appreciate the weighty issue of lifting, moving, and casting such items [October 2007, Vol. 41, No. 10, "Putting Manhole Covers on a Diet Saved Half a Million Bucks," p. 36]. We did bathtubs. We never really cleaned up!

As a manufacturing engineer, now in aerospace, I understand fully the emphasis on weight reduction and the attendant cost reduction. I just hope these folks haven’t done the common thing and outsmarted themselves.

Weight is a necessary evil in some things. If a manhole cover is too light it might be induced to pop out of its retainer when a fast moving vehicle applies uneven force on a portion of the cover near its edge. Turning tires on irregular surfaces do strange things, not to mention rainwater impacted sewer drains with the attendant pressurized lifting force. I hope the lawsuits don’t equal the material savings over time. Maybe they have incorporated a latch.

Richard Olzak
Sr. Manufacturing Engineer
Honeywell Avionics
Redmond, Washington

Forecaster

In the November issue [Vol. 41, No. 11, Editor’s Corner, "Gaze Into Your Crystal Ball," p. 6], I asked MAN readers to put on their Nostrodamus hats and predict the near-, middle-, and long-term future of metalworking. Here is one response.

Thank you for your insights, I find your articles full of good info, and occasionally you wake us up with the "Duh Factor."

The most important factors I have seen in my career: CNC machining, high-speed machining, and measurement accuracy increases.

The major change in the future might be additive metal manufacturing – if you can dream it up, it can be designed and made.

In our industry – aerospace actuation – I see additive metal manufacturing as the next major cut in cost and lead time. Designs will no longer be defined, in large part, by manufacturing constraints. Imagine a world not requiring long hole drilling and deburring. Imagine a world with only finish machining. A world where only mating surfaces and threading is required.

In the world of hydraulics, seeing a decrease in volumes of oil, due to not having to over-drill to interconnect passageways. It will have dramatic effects. This alone will have a multitude of systemic improvements, from system stiffness, reduced phase lag response, less pressure drops, and much quieter, cooler oil.

From a manufacturing standpoint the parts will have about half the manufacturing time on the machine.

In the design phase, engineers will no longer be constrained by the plumbing to nest components.

Then there are the decreases in weight we will see by the elimination of pin plugging and all the associated machining and inspection of these tight tolerances.

We will see weight savings, from only having the metal added that is needed, to not removing as much excess metal. It will be a complete reversal of paradigm; this is already having a rippling effect in existing mind sets.

For the – not so – far-out future, robotic assemblers building one-off items, and R&D houses doing automated assembly.

Louis D. Marecek
Manufacturing Engineer
Procurement Team CSD
Parker-Hannifin Corp

A Rose is a Rose, but the Right Name is Best

In the article, "Quality Never Takes a Tumble at a Finishing Shop," [December 2007, Vol. 41, No. 12, p. 22], reader Larry Garbarek, Kellogg International, Inc., Des Plaines, IL, pointed out that we inadvertently used "Wheelabrator" without capitalizing it since it is a trademarked term. Wheelabrator is a proprietary term of the Wheelabrator Group, which has U.S. headquarters in LaGrange, GA. We regret the error. – Editor