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3D Printing

by adminpower

3D printing is the new thing. The prices have come down considerably so that now you can buy them for as low as $350. Of course, there are others for $3,500 and for industrial purposes, much more than that.

What is a 3D printer?

Well normally, you think of a printer putting ink on a piece of paper. This is 2D printing since you just have the X and Y axes. (Technically even paper is 3D because it does have thickness but we are only considering the surface.) You can have dot matrix printers, laser printers and ink jet printers among others. The 3D printers are variations on ink jet printers.

Instead of printing ink through the “ink jets” they put out plastic or metal. This was developed first for plastics in the 1980s.  Some people also call it additive manufacturing.  Layer upon layer of plastic is laid down and cured with ultraviolet light. Because it is being built as you go, it is possible to create things that would be impossible to create in any other way unless you later glued or bolted parts together.

Cost benefit analysis

Generally it has been more expensive than creating something on an assembly line where the unit costs are very low because of the volume. However, the costs are rapidly coming down. Even so, there have always been cases where the expense is justified and cheaper than the alternative. A good example is in the car industry. In the past when they were working on a new car, they would come up with a design for a part and then have to get it tooled and made and it might take several weeks and be quite expensive. With 3D printing, they can just feed the specs into the computer and out it comes a short time later. It is not only cheaper than the alternative method of making the part, but it also saves a lot of time in the development process which also saves a lot of money.

Subtractive Manufacturing

Processes for metals have also been developed although originally they were called laser sintering and laser melting among other terms but it is now considered to be under the general 3D printing or additive manufacturing category. At first when people thought about 3D manipulation of metal they thought more about removing metal from what was there rather than adding metal. CNC milling would be an example of this. This concept is most commonly called machining but now is sometimes called subtractive manufacturing.

Sacrificial / Support Materials

Another twist that has been added are sacrificial or support materials. If you want to create 2 cogs for example, you don’t want them fusing together as you are laying down the layers. So, you can lay down more than one type of material, not just plastic or metal. The other material will separate or support the parts so they are in the right place and then when done can be removed. Ingenious, eh. Not unlike the masking and other techniques they use in creating computer chips and circuit boards.

We will go into other aspects of 3D printing or additive manufacturing in the future.