Tuesday, June 26, 2012

Precision engineering.

Here's an experimentalist complaint for which I do not think there is an analogous theorist problem.  In my lab we have a piece of equipment of European manufacture that is very good and beautifully engineered.  The one problem is, it's so precisely made that it's impossible to service.  For example, after years of repeated thermal cycling, an electrical connector has failed and needs to be replaced.  The problem is, the way the system was put together, there is essentially no slack in the relevant cabling.  They strung the cable through during the original assembly, cut it precisely to length, and then attached connectors that make it topologically impossible to take apart without their removal.  One can't replace the connector without either cutting cabling and inserting more connections, or other approaches with similar levels of inconvenience.  This is the lab equivalent of having to remove half of the guts of a car in order to get to the oil pan.  Ahh well.  Let this be a lesson to mechanical designers:  It's never a bad idea to design a complex system with the possibility that it may need to be taken apart nondestructively someday.

6 comments:

Anonymous said...

Oh, they thought of that. The industrial lab with the same equipment as you will fork over the $100k they want for an overhaul.

corcoted said...

Reminds me of a Douglas Adams quote:

The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair.

Josh Einsle said...

you know i have heard about this being done by some European factories as a cost saving measure. ie the pennies saved by making the cable that short....

Carl Brannen said...

In addition to your complaint cables should have slack in them because it decreases the chance that there will be an open-circuit caused by tension. One can't know in advance how things are going to be moved around.

It's not caused by saving pennies, it's just lousy construction.

Alexi Davenport said...

I see what you mean about precision engineering being hard to service. We had a precision engineered machine at my last job that was hard to fix because of how it was engineered. I'm just glad it hardly ever needed to be fixed! If the damage got to be too bad, I don't know what we'd do.
Alexi | http://www.hargo.com.au

Jim Tracy said...

I think that precision engineering takes an already hard task, and makes them harder. I would love to learn more about it, and how it works. I have always been intrigued by it. http://www.hargo.com.au