If you happen to have access to 3D printing capability, is it worthwhile to print a given item?
Certainly 3D printing can be quite a thrill: to see an object appear from seemingly nothing is about as near magic as currently accessible technology can manage. But, if one has a desktop 3D printer, when is it appropriate to 3D print an item? Just because you CAN print something, does it mean you SHOULD print it?
In some cases there is already a case for 3D printing objects, if the machine was obtained for a specific business purpose. We’re not talking about that scenario. We’re talking about the random casual ideas people may have to print something.
For us the question is two-fold: is the printed object suitably functional, and can it be made for less cost (and effort) than obtaining it from alternative sources.
For functional suitability, we have to think about strength, appearance and environmental performance. Does the part require a certain strength to perform its function? Is it the correct color? Is the surface texture appropriate? Will it melt or deform if used in the expected manner?
If a 3D printed version of your part doesn’t meet those requirements, then you shouldn’t be printing it anyway.
But if it passes that test, then the second question must be examined: can you get it somewhere else for cheaper?
This depends entirely on the part. In some cases, it is clearly more effective to print the part yourself, assuming you have or can create a suitable 3D model. An example of this scenario is the unfortunate USD$39 price tag on the simple plastic knob for your washing machine. For that price, you can buy an entire spool of plastic and make hundreds of knobs. Best to make it yourself.
On the other hand, it is more effective to simply buy items if they are readily available, particularly if you need quantities of them. LEGO blocks, for example, are relatively inexpensive in quantity, compared to the effort you’d require to print them yourself. And the purchased blocks would be of much higher quality, too.
Do consider the effort required both to buy an item and the effort required to 3D print an item. A complex object might take several attempts to successfully 3D print, taking potentially considerable time. Is your time worth the wait of several days or even weeks? Similarly, if a purchasable object is not readily available - as in you must order it from strange places, or travel far distances to purchase - it might be more appropriate to attempt a print yourself.
3D printing is merely a tool, and like any tool it must be used effectively by making solid choices based on an analysis of your needs and situation. Choose carefully