Blast from the Past
I happened to be scrounging through the supply cabinet at work and found this relic of the computing world, a 5.25″ floppy disk. Putting them in the cabinet may have just been someone’s idea of a joke, but it brings up the very real point of dealing with legacy data and compatibility. If there was anything on the floppy, it was probably so old that it couldn’t possibly be important to us anymore, but if it was, the chances of finding a computer on the premises that could read it would be slim to nil. Now as a mechanical engineer, I don’t typically encounter legacy operating systems (COBOL, anyone?), but I have had to dig up some very old technical drawings. I was working on a radar system upgrade and had to pull up technical drawings from the radar’s original construction in the 1960’s. The drawings were stored on microfiche, and…
Parlez-vous engineering?
An article in the Guardian newspaper today drew my attention to a rather stunning online archive of drawings and sketches from the engineers who designed and built Britain’s railway network in its 19th and early 20th century heydey. I heartily recommend you have a browse here. Whilst that collection is certainly a wonderful resource, I have a rather ambivalent relationship to engineering drawings. Like butterflies pinned into collection books, they are a fixed, dead representation of what once was an idea fluttering merrily through an engineer’s mind. Throughout the initial phases of concept and the first wobbly-lined and crossed-out sketches, to 3D CAD models spinning and rotating on the monitor, through to prototypes, parts take on a life of their own. They grow from chrysalis to caterpillar, evolve before your eyes and then – they are ossified, sectioned, labelled and numbered like any other sample. Their drawings sit there gathering dust on the desk, yellowing…
ProE Etiquette
How well you get along with your coworkers can have a huge impact on how effective an engineer you can be. I’m not just talking about meetings, but how well you can collaborate on projects. People generally know you don’t pass off shoddy work or incomplete projects to the next person who has to work on it for you. But sometimes I’ve seen exactly that in the design world. Even though most CAD programs track everyone who touched that part or drawing, people seem to think they can get away with things they generally wouldn’t try in a report or presentation. A couple months ago Peter J Francis asked whether MCAD or ECAD was more trouble than it was worth. GEARS discussed his love hate relationship with it but admitted that the skills he learned with ProEngineer allowed him to really kickstart his career. Skills with a particular CAD or…
Flexure Design
I talked a couple weeks ago about how you can design fixtures and constraints for holding pieces in precise alignment. But not always do you want machine pieces to hold still – sometimes you want them to move. If you want pieces to move a long way (also called “large range of motion”), you can use things like bearings, slides, and gears. But because I work in the precision world, often I want things to move only a small amount – a millimeter or less. (This is much the same as you would use bolts or clamps for fixturing a non-precise machine, but I need to use kinematic couplings for micrometer precision). So I thought today I would talk about designing flexures. And because I came down a little harder than I intended on theoretical engineers last week, I’ll show the modeling I use to design a flexure. (I do…