How Practical is a 3D Printer?

This school year, I am teaching science at the junior high level at our local grade school. Normally I teach at the college level, so teaching junior high is a new experience. Among these new experiences is learning how to teach down at their level. Something that occurs very frequently is talking about fun asides: little side issues that are only tangentially related to the main topic but are fun to talk about.

One recent side topic we talked about in class was 3D printing. After talking a little bit about how 3D printers work and the different types of materials that can be printed, we ended with a few questions. These were questions provided by the publishing company of the textbook: Savvas.

One of the questions struck me as very odd. Here is the question:

Imagine a remote village where the villagers have a difficult time getting clean water. The wells are old and the parts break often. The villagers may have to wait weeks for replacement parts to arrive. How would you use a 3D printer to help the villagers?

Since it had been emphasized in the text that 3D printers can print any shape using a wide variety of materials, it is obvious from the context that the answer to this question is supposed to be something like:

By using a 3D printer, any replacement part can be fabricated quickly. The villagers will no longer need to wait weeks for replacement parts and their wells will be able to supply clean water consistently.

There are several things that struck me as odd. First, if replacement parts take weeks to get to the village, what about the raw materials for the printer? A 3D printer is not like a replicator from Star Trek: it cannot fabricate material out of thin air. To print something the printer needs a filament, a wire of plastic or metal, as the material used by the printer. What happens when the printer runs out of filament?  What happens when a part is needed but the village has the wrong type of filament for that particular part? Unless the shipping process for filament is faster than the shipment of replacement parts, you still run the risk of running out of material and waiting weeks for a new shipment. That does not really solve the problem.

The second thing that struck me as odd about the question was, who would operate the 3D printer? Either someone trained in modeling parts in a computer program would have to move into the village or one or more of the villagers would have to be taught how to model 3D objects in a computer. Without someone to operate the machine, the machine would be useless.

The final thing that struck me as odd was, where is the power to run the 3D printer coming from? We know the village has regular trouble with its well, so is its electrical infrastructure in better repair? Does it have a steady supply of electricity to run a printer? If the supply of electricity were to every cease, due to a problem with electrical production, failure of electrical wires, and so forth, the printer will become useless.

Lest someone say, “Oh, just use a solar panel,” even those will take some effort. Assuming that it would be practical to run a 3D printer with a solar array, you would need someone who can maintain the panels to make sure that they are free of dirt and debris and to repair them when they are damaged. Finally, how large of an array of solar panels is needed to run a printer and its computer? Would it be feasible to set up an array that can run the printer?

As an aside, none of these questions even address another crucial question, which is, how much would all of this cost the villagers? What is the cost of the printer, the solar panels, the filament, the cost of training someone to run the printer? Unless these things are going to be given as a charitable donation, surely there will be an economic cost to installing and using a 3D printer in the village.

The more I considered these odd aspects to the question, the more I realized that they all stem from a common cause: they all fail to take into account the practicality of the solution. Yes, in theory, a 3D printer could supply the villagers with any replacement part whenever they need it. In practice, you need to get raw material to the printer, you need someone to operate the printer, you need a supply of electricity to run the printer.

When I began teaching Junior High, I was well aware that I would encounter biases with which I do not agree. The theory of evolution and long ages of the Earth are two biases I expected to encounter. Now, I am noticing that there is a more pervasive bias: a trust and respect for science regardless of the practical impact of that science. It reminds me of the year of Covid, when we were all told to “follow the science” and wear masks, shelter in place, and not gather in large groups. What happened? We wrecked our economy and caused an increase in depression and mental problems. We were so concerned with following the science, we never stopped to consider whether we should follow the science.

That is the ultimate pervasive problem with the current philosophy of teaching science in schools. Students are taught to respect science but they are not taught how science intersects economics, morality, theology, or any other topic. Science stands alone and alone it is expected to provide us with answers. All of that other stuff? They are just side issues that have no real bearing on the quality of life.

Thoughts from Steven

P.S. In my class, we talked about how a 3D printer would be largely impractical for the village and villagers. I tried to show my students that there was more to consider than just what a 3D printer can theoretically do.