[starbox] Blogging about emerging 3-D printing technology reminded me of occasions when it was necessary to “stretch the envelope” to get things done. Those of you in the job shop side of the gear trade will no doubt relate to the need to squeeze just a bit more capacity out your existing machine tools. It starts off simply enough — someone in sales or estimating doesn’t take the time to verify whether a part will actually fit into a particular machine or furnace. Next thing you know, your maintenance gang is “enlarging” the machine with hand-held grinders. At one point I joked about never having seen an un-modified Fellows 36″ shaper. Every machine I saw had a spacer in it to allow taller parts. I have also been involved with “stretching” the work envelope of gear grinders and inspection machines. Perhaps the most challenging was converting a 70″ bevel gear planer to a 90″ capacity. That project took much longer than we planned, but we ended up with a very fresh and accurate machine, although it still had the limitations of 1930’s design. Hopefully it will remain active until the ability to machine big bevels on multi-axis milling machines is fully developed. The high cost of capital equipment has made the gear trade a haven for people who are willing to modify their environment rather than just surrender to it. Our shops are full of equipment that would be considered obsolete in much of industry yet is perfectly suited to certain tasks that come in. A job shop thrives on capability not capacity so the clever engineer or mechanic who can figure out a way to make a workpiece fit when “the book” says it won’t will always be welcome.