DIY engineering is a hobby of making systems by oneself, as the name implies. Making original designs has several advantages, including reduced cost, more customization and easier repairs. However, there are also disadvantages.
One of the biggest advantages is the ability to create custom parts. Just 15 years ago this was not possible. CAD softwares could barely run on home computers and 3D printing was only available as a tool for large companies with printers, often costing tens of thousands, nowaday that has changed. A consumer can buy a decent printer today for between $200-300. This accessibility has made them an invaluable tool for prototyping due to the ability to create custom parts, quick iteration and diverse materials.
3D printers are a broad and complicated subject, but in the context of creating custom mechanical parts, they are invaluable. Factories often produce higher-quality parts than 3D printers, but they are limited in type and size. The ability to design original parts and make them is invaluable. If a planetary gearbox needs to fit in a 40 mm hole, designing and printing out a custom one is not out of the question. This also allows for easier and better design of frames as one is no longer constrained to the aluminum box section and parts can be whatever shape is designed.
The second massive benefit to 3D printing is quick iteration. Some services offer custom 3D printing as well as CNC and turning services, but shipping takes time. On the other hand, if a part does not fit quite right, one can adjust a few parameters in the CAD model, send it to the printer, and in a few hours, a new part is available. This allows an individual to try lots of different designs to see which one works best instead of just making an educated guess and hoping it works out.
3D printing also offers a massive amount of materials, all with fancy abbreviations. The basic ones are PLA, PETG and ABS, but that is just the beginning. There are hundreds of others, all with different properties. One common process involves reinforcing the brittle plastic with fibers, so carbon fiber filaments are also available.
The second advantage of buying raw plastic is that it is cheap. A roll of PLA costs about $15 on Amazon, and one can find bulk discounts as well. After the initial investment, 3D prints can usually cost around 30 cents or so. Another thing that helps with rapid prototyping is that it is not that expensive to just make a new one.
There are some downsides, though. For starters, 3D printing a lot of prototypes makes a lot of waste, and though there are methods to recycle prints back into usable filament, they are somewhat expensive. After buying a 3D printer, it just does not seem attractive to try to recycle your filament due to the low cost of just buying more.
Overall, 3D printing is a useful technology for DIY engineers due to its convenience and infinite part options. When doing engineering work, having access to rapid prototyping is invaluable in many cases and can save months of headaches.
