阅读时间：6分钟
Creating innovative mechanical designs is hard (I should know—I do it for a living). Sometimes, you’re pushed to the very limit to imagine a concept or mechanism that could actually work. At times like this, manufacturing is a distant utopia that we can only hope to reach, so we ignore it. But, at the end of the day, we’re only fooling ourselves if we dream up uneconomical designs. The most brilliant machine ever conceived is nothing if it doesn’t make financial sense to produce and operate. For example, why aren’t water desalination, electric cars, and solar photovoltaics more prevalent? Why are we thirsty in the middle of an ocean, making tiny explosions to turn wheels, and drilling for oil when the sun shines all day? Because all ideas are subject to the constraints of available technology, and the benefits must always outweigh the costs. Just because something is possible does not mean it is economical.
在基于“增大化现实”技术e often many ways to perform the same exact task, each with different制造成本. As designers and engineers, it’s our job to find the least expensive ways to design for manufacturing. To that end, here are some practical tips to increase your manufacturing efficiency through design.
Manufacturing Efficiency
Manufacturing is all about efficiency. This is achieved through specialization—the more dedicated a tool or process is, the better and faster it generally is. Generally speaking, versatility comes at the cost of specialization. Humans, being very versatile creatures, are usually not the best factory workers: We take time to train; we’re slow; we need breaks; and we make mistakes. That’s why we turn to customized machinery to replace human labor—it’s overwhelmingly faster, more precise, and longer-lasting.
Of course, creating dedicated tooling and machinery requires up-front human labor. The cost of custom tooling must be weighed against its long-term gains. This is why it can be useful to amortize tooling cost into a “piece price” (price per unit) in the pursuit of calculating the time it takes to achieve ROI (return on investment). Naturally, production volumes are central to this equation—if you’re going to crank out millions of widgets a year, your customized tooling will pay for itself. This is common in the automotive industry. On the other hand, manual manufacturing processes can make more sense than customized tooling for low-volume production. For example, sailboat and airplanes are largely assembled by hand. These are all commercial decisions driven by the free market. Designers and engineers must have their company’s financial abilities and expectations clearly communicated, so that they’re able to make prudent manufacturing decisions.
做与买
一种极具吸引力，最佳世界的方法是使用现成的解决方案。换句话说，不要重新发明轮子！多亏了资本主义，发明家和创新者提供了绝对的预制零件，以至于您几乎可以像厨师制作三明治的方式一样设计产品。当有屠夫可以为您做的时候，为什么要杀死牛，比您更便宜，更便宜？同样，购买预制组件比自己设计更有意义。这对于螺栓，轴承，电动机等都是直观的。其他类别（如齿轮和外壳）可能会抛弃，因为自定义的需求开始超过现成的可用物品。下次您发现自己进入未知的设计领域时，请记住这一点 - 机会是，其他人已经提供了预制的解决方案（Google是您的朋友）。
Manufacturing methods
There’s more than one way to skin a cat. I’m not sure why you’d want to skin a cat, but if you find yourself in that situation, you should use a cat-skinning knife, rather than a spoon or chainsaw (sorry). Let’s apply that same logic to manufacturing methods. Here are some of the most common manufacturing methods, their (dis)advantages, and relative costs.
Casting/molding
Casting involves the liquid pouring or injection of hot materials into a mold. This process is often used for making very complex shapes. Casting creates a “rough” shape and is a somewhat imprecise process. That’s OK, though, because precision is not always needed. Casting is a versatile process that can produce many different materials, from metals to plastic. This method is extremely popular and is used everywhere from automotive housings (transmission, engine, etc.) to toys. Molds and their associated tooling are expensive and complex; they’re often the best method to achieving many general, three-dimensional shapes with a larger volume/surface area ratio.
钣金
钣金forming, a sub-process of cold-forming (as opposed to the hot-forming of casting) is a process used to create thin metal enclosures that don’t need to be pretty or watertight. For thin, complex shapes, forming makes more sense than casting because of the difficulty of forcing a molten material around tight corners and into long, thin channels. It also takes much less energy to deform a thin piece of metal than it does to melt the metal into a liquid state. Stamping is a forming process that uses dies under massive load to crush metal into a desired shape, and is extremely common for automotive outer parts (hood, door panels, etc.). Electrical boxes are made by stamping a blanket sheet to add cuts and holes, and then bending to form the box into its final shape.
Machining
加工，无论是CNC还是手动，都是从物体中删除材料的过程，通常是用旋转的切割机或钻头。加工过程可以达到极高的精度，通常用于放置准确的孔并制作平滑平稳的平面。越多的轴（无伐木工人）CNC machine，它具有更多的用途。加工是一个昂贵的过程，只有在无法实现任何其他方式时，才应使用功能的必要精度（位置，尺寸，表面饰面）时使用。beplay app. co 是另一种通过电气放电（火花）去除材料的加工方法。非常适合非常小巧的功能，切割工具将难以实现。但是，EDM也很慢而昂贵。
2D cutting
Plasma, lasers, drills, and even water can be used to precisely cut 2D shapes out of flat sheets of material. This method shines when precise and/or deep cuts are needed. Like machining, 2D cutting provides great results but is but slower and more expensive than stamping.
3D打印
3D打印is the futuristic holy grail of manufacturing. Also known as additive manufacturing, this method is prized for its ease of use and versatility in creating impossibly complex shapes with remarkable precision. Internal cooling channels, undercuts, and an Eiffel tower that fits on your hand are all commonplace and easy to make. 3D printing is extremely useful for quick prototypes. While 3D printing is relatively slow and expensive in manufacturing, it is currently being investigated and adopted by companies for mass production.
Plastic thermoforming
As an analogy to metal processes, plastic thermoforming falls somewhere between casting and cold-forming. (Note: The word “Plastic” can refer to a specific material, or be a synonym for “permanent”, ie. plastic deformation = permanent deformation. In this case, we are referring to permanent deformation of plastic material). A thin sheet of material is heated and then formed to a one-sided mold to create a basic shape. Tooling cost is lower than注射成型，但是这个过程更加艰辛，使其适合较低的批量产量。
Tolerances
这些天，宽容是一种美德。不宽容将不会被容忍！Tolerance是指允许偏离理想ate. In manufacturing, the less tolerant you are, the more precise your manufacturing must be, and thus more expensive. This is central to choosing your method of manufacturing. For example, imagine that we must mount two objects together using bolts. The location, size, and direction of the bolt holes are all important, as is the parallelism of the two mounting faces. GD&T (geometric dimensioning and tolerancing) is a field dedicated to establishing quantifiable geometric constraints on 3D features. Tolerances should be back-calculated as the greatest allowable deviation, while still maintaining function (plus some safety factor). There are various tricks you can use to make manufacturing easier and cheaper (they’d literally throw gearboxes together, if they could) while still maintaining functionality. For example, “bonus tolerances” allow greater deviations in one aspect if a corresponding relevant variable is adjusted (for bolt thru-holes, positional misalignment can increase if hole size increases as well).
做到
用什叶派·拉布夫（Shia Labeouf）的明智话语，“不要让你的梦想只是梦想。”您正在尝试生育自己的创意，而成本效益的制造是最终的，痛苦的手套，如果我们希望您的想法看到一天的光明，则必须经过。通常，我们应该使用制造限制来指导我们的设计决策，也就是说，如果您想节省$$$并变得富有。你想富有，对吗？然后与您的同事分享这篇文章，并考虑到制造效率的工程师设计。
