[Editor’s note: Years after “simultaneous engineering” and “design for manufacturing” promised to bridge the gap between design engineers and manufacturing personnel, true cooperation between practitioners of the two disciplines can still be elusive. Designers are often insulated from what happens on the shop floor. They create their designs almost in a vacuum, without regard for the potential issues certain features or tolerances could present for those charged with manufacturing the product. The following are a few tips for design engineers who would like to start to bridge the gap between design and manufacturing.]
n Go to the shop flooring. Component designers need to devote some time in the shop to respect some of the issues metalworkers deal with. Their standing in the eyes of shop people today is instantly relevant to how substantially time section designers expend in their earth.
n Talk. When doing work on a new style and design, converse to the store individuals who will be doing the work ahead of a task is much too much alongside. They will see factors you may well never ever take into account.
n Immediately return any borrowed software no make any difference how small or seemingly insignificant. I are unable to overstress this place. After all, an Allen wrench is no reason to obtain by yourself scratching the within of a rough picket box in a shallow grave beneath a lonely freeway overpass, now is it?
n Use shop floor experience. Often it’s a lot a lot easier to notify the shop what you want than to check out to overspecify or depth it specifically. Push fits, sliding matches and threads are good illustrations.
n Impress the shop with a very clear hand sketch. Almost nothing screams skill a lot more immediately than an great sketch finished on the fly. Your drawings and recommendations are your calling card in the store. Make them seem superior or, greater nevertheless, great. Awful drawings and lousy recommendations develop a name that is hard to break after proven. Just one prime-notch designer presented me lunch whenever I could uncover a mistake or omission on his get the job done. It was 5 many years ahead of I identified one particular and gathered.
n Be realistic about tolerance specifications. This place marks a single of the fantastic all-time abuses of shop means. If you really don’t have time to set some thought into essential tolerances, then go away them off fully or at the very least check with the shop what is practical.
n Let cleanup cuts on inventory sizes if the design enables it. Your linked tolerances need to give the fabricator a choice. A plate that is nominally .50 ” thick might have a notice indicating .485 ” minimum amount. This allows up to a .015 ” cleanup if the uncooked materials is rough or comes undersize. If the drawing carelessly phone calls out .500 ” with a title block tolerance of ±0.005 “, then your part just tripled in price.
Courtesy of T. Lipton
A very clear hand sketch demonstrates a designer’s means.
n Involve inventory product variances in the tolerance review. Fifty percent-inch-thick plate or bar stock is rarely .500 “, which is what I see on virtually each individual drawing that crosses my desk. Most of the time, the designer has no intention of machining or surfacing stock content. A brief observe next to the dimension stating “0.50 ” (Stock)” is a fantastic way to converse the proper intent.
n Only talk to for greatest pace and hard work when you actually will need it. There is no quicker way to put on out your welcome than to abuse this ask for.
n Regard the shop’s time. You could be in for a significant surprise when your friendly yak time gets billed to your project.
n Really don’t try out to support in the shop unless of course asked. Metalworkers are territorial and not only bark but occasionally chunk.
n Incorporate the shop in critical manufacturing conclusions. By having incredibly specialized content and procedure awareness, shop personnel will place products of worry from their viewpoints.
n Have a typical presence in the shop. I know stores can be chilly and smelly, but it is much easier to get responses to your inquiries when you get more than a passing desire. You may possibly have experienced a semester of shop expertise, but most shop folks have a long time less than the bridge. Use this to your edge. CTE
About the Writer: Tom Lipton is a job metalworker who has labored at many career shops that produce sections for the consumer item development, laboratory equipment, health-related solutions and custom made machinery style industries. He has been given 6 U.S. patents and lives in Alamo, Calif. Lipton’s column is adapted from info in his reserve “Metalworking Sink or Swim: Strategies and Tips for Machinists, Welders, and Fabricators,” published by Industrial Push Inc., New York. The publisher can be arrived at by calling (888) 528-7852 or traveling to www.industrialpress.com. By indicating the code CTE-2010 when buying, CTE visitors will acquire a 20 p.c discounted off the book’s listing price tag of $44.95.