Engineering shortcomings

[Cowie]

I am interested in specific and well-defined shortcomings or deficiencies in processes, procedures, machinery and tools. There are many instances where those closely involved are unhappy about how well a task or part of it is performed. The shortcomings can sometimes be so simply stated or clearly defined that the problem could be understood by mostly anybody, even those outside the discipline involved. Any likely example will be greatly appreciated.

 

[nbucska]

For what ? which discipline ?

<nbucska@pcperipherals.com>

 

[Cowie]

Awareness, has been a longtime interest, attempting a solution can be fascinating. All these problem areas and mostly only those involved know about them. No particular discipline as long as the problem is of a practical nature.

 

[rhodie]

I share your interest, but the problems or shortcomings I have observed are all so specific to machinery, processes, and locations that to list them and have other people understand them would border on obscurity.

 

[Iskit4iam]

I think this could be a fascinating subject. Sometimes there are processes problems so simple anyone can understand them. Here's one of my candidates.

About 15 years ago I was R&D manager for a company that had a pipe coating mill. We used a shot blaster to clean the pipe prior to coating. Coating adhesion inconsistancies were driving me crazy. I knew from studies that as long as the shot blast drive motor was operating in a certain amp range the cleaning process was optomised. The shot blaster degraded the cleaning medium and the amount of shot in the machine decreased with time causing the amperage to drop. When out of the control range the operator was supposed to add more shot to the machine. One day I just happened to notice that the machine amperage was out of range and brought it to the operator's attention. &quot;No problem&quot; he said, and then he took a small screwdriver out of his pocket and turned the zero adjust screw on the amp meter until the needle moved into the proper range. I now had a pretty good idea of where my adhesion inconsistancies came from.

 

[bklauba]

Probably my favorite involves a project to save several 8&quot; dia., 20+ foot long solid 4140 propulsion shafts for a Coast Guard cutter, that had been &quot;re-qualified&quot; using Navy specs. They had been heatstraightened to w/i 0.005&quot; over their length. The ship was back in dock within weeks due to mechanical problems; they turned out to be all related to the shafts being way-out-of-straight. None were within spec, and two were out more than 0.125&quot;. After heat-straightening again, they were found to warp 0.020 - 0.035&quot; during a 100 yard tow to drydock. (Maybe it was that hot Georgia sun) and the consulting eng. refused to let them on-board. After several trips of this sort, they did what turned out to be a final heat-straightening, then we gently set them up for a resonant VSR Processing. Two of the six moved a bit: They were w/i 0.008&quot;; they rest were OK, even after being (somewhat abusively) towed around for a while. When Navy engs on-site said they wanted to put them back thru the heat-straightening again, the consulting eng and I stood up and shouted (in unison, no less)&quot;NO, that is the source of your whole problem!!&quot; Please tell me that someone at the Navy knows the diff 'tween accuracy and stability. They backed off the HT Str when it was pointed out that the foundations weren't any near that straight.