What is 3D Printing Good For?

Overview

There are a lot of folks out there who are interested in 3D printing, but then they look at one of the many sites of free models like Printables and see a lot of silly tchotchkes that seem like a waste of plastic and space, or cheap things they can already buy cheaply like pen holders. Recently someone asked the following question on Reddit.

What type of people need a printer?

I’ve been sitting on the idea for 4 years to buy a 3D printer but every time I decide against it. In my mind, If I need a small part for something, I’d rather just buy a quality version of it instead of a brittle plastic one. I considered it for small tools for locksmithing but … why would I? I can just buy the real thing and have it last years. I think it’s useful for intense D&D players or cosplayers but that’s not me. And every time i research useful things to make with a printer it’s always stuff like “pen holder, mini plant holder, phone case, remote mount”. Which I have to admit are pretty lame for a $200-$500 machine and materials. Everything I read can be found at a dollar general. But they have to be popular for a reason right?

So who consistently uses a 3D printer? What do you personally use it for that isn’t just a holder for a small thing? Can you justify printing something over just buying it?

It’s a totally reasonable question, and one that I’ve answered variations of a bunch of times. This post assumes you don’t know a lot about 3D printing and are wondering if there’s any “real” value to getting one.

First though, let’s address some conceptual housekeeping so that we have a common understanding going forward.

Terminology

When people say “3D Printing” what they usually mean is “FDM” (Fused Deposit Modeling) printing. This is where you’ve got a spool of filament that is gradually extruded through a hot nozzle and builds up a print layer by layer. There are countless practical uses for this, but it’s not good at printing fine details (sub millimeter).

However, at the consumer level there’s also “Resin” printing, which uses light (laser or LCD) to strategically harden layers of goo. This is a messier process that involves dealing with some nasty chemicals but produces pieces with incredibly fine detail. This is great for things like D&D Minis.

Plastic types

short version: PLA, ABS, and TPU are 3 of the many filament types available, and I’ll be referring to them later. If you don’t care about details skip this bit.

PLA is the most common filament. It’s made from Polyactic Acid which is technically “plant based” but even when there aren’t additives it’s not something that’ll break down quickly in the environment or even in a composter.

ABS is what’s most commonly used in injection molding, but some home 3D printers can print with it too. As a rule of thumb, if you buy anything plastic it’s probably made with PLA. It’s got a lot of good properties. However, it releases some truly nasty Volatile Organic Compounds when you heat it for printing that you really shouldn’t breathe. The biggest reason to use it is that it’s got enough heat resistance to be stuck on the dash of a hot card in summer and not melt. There are better alternatives, and many aren’t as nasty.

TPU is a “rubbery” filament that can be used for gaskets or things where flexibility is important. It comes in multiple levels of… floppyness. Technically this is called the “Shore Hardness”. I don’t know why. What’s important, is that this is a very useful option for consumers The softer it is, the harder it is to print.

Resins Unfortunately this is not an area I can really speak to with authority. I know there are many available, and that it’s easy to mix pigment and sparkles into the clear resin to make something a particular color, but most folks seem to use it to print grey things that they paint afterwards.

Misconceptions

Strength

For most things you’re likely to want to print FDM prints are more than strong enough. Especially when it comes resisting compressive forces. They’re less good at resisting being pulled apart. However, we’re talking over 900 Newtons of force to rip a standard PLA (the most common filament type) print in half.

Lasting Power

3D prints last a LONG time. Despite being “plant based” the things you print with PLA are going to outlast you. It may fade in sunlight, but that’s true of most plastics. PLA is NOT good in water, but other filaments are.

Degradability

Multiple filament makers promote the fact that PLA is “Plant Based”. It would be equally accurate to say that petroleum based plastics are also “Plant Based”. Some filaments say they can be composted. Alas, this is only technically true. It would have to be an industrial composting facility which has significantly higher temperatures than your back yard, and even there it’s so problematic that they generally won’t accept them.

PHA filament from ColorFabb is the only one I’m aware of that is truly compostable, even in a home composter. However, at the time of writing (Feb, 2024) it’s pretty new, not cheap, and very few people have actually worked with it.

Filament Reusability

It’s technically possible to re-melt filament from old prints, but in practice it’s surprisingly expensive and non-trivial. I have a blog post explaining how to recycle 3D prints.

Food Safety

Even if you print with a food safe filament, FDM printed items are not food safe. The problem is that bacteria can hide between the layer lines and resist cleaning. Using a food safe filament for things like organizing your cutlery drawer is fine though, because the print is never going to come into contact with food.

Printing Minis

People who play tabletop games like D&D or Warhammer generally like to have miniatures representing their characters or troops. Your common FDM printer is not going to be good at this. They just can’t reproduce the level of fine detail you need. You need a Resin printer for this. The good news is there are some really affordable, good quality ones that can easily print most minis.

What’s it good for?

If your primary desire is to print gaming minis, a cheap resin printer from a reputable maker will pay for itself in a week. There are tons of excellent mini designers out there with very affordable models. You’ll never need to model your own. Just be careful about getting one with a big enough print plate for the things you want to print.

For everything else though…

It depends on your willingness to learn how to model things yourself. Simple shapes are easy with tools like Tinkercad, but the more you get into this the faster you’ll get frustrated with how hard it is to do anything but the simplest of shapes. Learning real CAD (Computer Aided Design) software is a fair amount of work, but it’s absolutely worth the time investment. There aren’t many good options between “beginner” and “professional”. The most popular professional tool for amateurs is Fusion 360. It has a free plan, and there are tons of video tutorials that’ll help you learn it fast.

If you’re not interested in spending time learning a professional level tool, then frankly I don’t think you should bother getting a printer. Tinkercad is fun and easy but incredibly limited and hard to do anything complicated with. Sites like Printables do have a ton of things you can download and print, but most of it is not anything you really need often enough to justify buying a printer. The big exception might be the ever-expanding Gridfinity organizational system.

Where 3D printing really shines though is not the stuff you can download and print. It’s the things you can’t buy, and sometimes the things that are unreasonably expensive to buy, or ship.

Fixing Things Manufacturers no longer value “high quality, well made” things that last a lifetime. Things are constructed as cheeply as possible, have no replacement parts available, and are rapidly abandoned by their makers. Things will wear and break in ways that shouldn’t require throwing them out and researching potential replacements.

If you know how to measure and model things you can make just about any plastic replacement part you need: replacements for worn gears, broken switches, lids, etc.. The only real restriction here is heat. If you need something that can survive the heat of a car on a hot summer day with full sun, then you’ll need some special filaments which require higher end printers and ventilation systems that aren’t easy or cheap to set up.

3D prints can also be used to make molds for poured metal parts like brass gears, or metal sculptures.

Prototyping Thinking about making a physical object for sale? Need a way to cheeply iterate on something in the real world? Maybe confirm that it fits and does what you expect before spending a lot on making a metal version? 3D printing’s great for this.

Solving Unique Problems This is where 3D printing truly shines. Once you learn how to quickly model your own things the possibilities for solving real world problems are endless. It’s hard to convey a sense of just how many things you can do, so instead I’ll give you examples of what I’ve used mine for in the following section.

How I use Mine

Non-exhaustive - and unordered - lists of things I’ve printed and hope to soon print.

Things I have printed

  1. a custom system for managing notecards to help keep track of all my ideas

    3 red plastic card holders with many offset slots each filled with one or more cards. In the front of each is a pen holder with a pen in it. below them you can see my keyboard halves and the clips holding them to the desk.
  2. bolt covers to keep the bolts on the bottom of my desk from ripping my jeans, and pressing into my legs uncomfortably.

    the underside of a bamboo desk. In the center is a piece of square  metal tubing with a small piece of metal welded to it. It's been painted black. There are two 3D printed lozenges protruding from it. Each one is covering a bolt.
  3. custom dividers and inserts for Milwaukee packout cases

  4. things to organize my tool drawers: bit organizers, socket organizers, lots of Gridfinity things

  5. a custom keyboard and trackpad holder to address a friend’s accessibility issues (palm rejection doesn’t work for him so laptops always think he’s mousing when he isn’t). Technically this is still in-progress.

    a 3D rendering of a custom holder for an apple keyboard and trackpad that covers most of the trackpad and has wrist wrests
  6. custom mounts for my split keyboard to attach to my desk so that the right half stops “going walkabout” while I’m trying to use it.

    an image divided horizontally showing two copper colored objects attached to a desk. there are two holes in the top. In the top image there is nothing in the holes. in the bottom image you can see each half of a split keyboard has been set into those holes.
  7. one for my friends desk with an longer curved & angled front because his keep sliding down the front edge.

    a 3D rendering of a chunkier version of the keyboard holder in the prior image.
  8. a Camera Jib for product photography and some upcoming videos. Technically i’m still waiting on parts and filament for that. It’ll cost me ~$200 to make after paying for the models with assembly instructions, all the filament, and bearings and rods. However, i don’t think “real” ones this size exist and if they did they’d be well over $2,000 for the same quality.

    a 3d rendering of a swiveling camera arm with a counterbalancing weight and a heavy-duty looking foot holding it all up.
  9. custom dice trays, with leather bottoms that attach to the sides of my wooden lap desk, and then connect together with a rubber (TPU) gasket that holds them closed like a clamshell.

    a close-up of small purple dice tray with a lip that is slid over a wooden lap desk. The bottom of the dice tray is lined with leather and has 5 colorful dice in it from the Genesys System Role Playing Game
  10. a valet tray that I use in our freezer because the weird silicone ice cube tray i use to make Tea Cubes has a habit of overflowing and leaving a creeping frozen brown in the freezer… or it used to.

    an orange tray with a lime green silicone ice tray that is subdivided into hexagons. within the hexagons is liquid black tea.
  11. Currently working on an adapter for my Dremel Drill press to allow it to mount the soldering iron I use for heat-inserts

  12. custom organizers for board games with lots of pieces and / or cards

  13. a custom organizer for games with lots of little tiny markers or dice that suck to put into or remove from those terrible little zip-lock bags they come in.

  14. a custom pen/pencil holder that attaches to the side of the little side-table shelf thing that sits next to my side of the couch.

    an off-white penn holder with slots for pens that are half-filed. It's slid onto a small wooden shelf.
  15. a custom single index card clipboard that fits in a pocket and allows me to write a note on one anywhere.

    a dot-grid index card sits with its left edge slightly under a blue piece of plastic. What you can't see is that the back of the card is supported by the rest of the clipboard so that you can write on it anywhere. They are on a bamboo desk background.
  16. custom switch cover to install a switch in a big gaping hole in our ambulance.

    a horizontally split image. In the top you can see a hole in a blue vinyl surface with some wires behind it. There is a metal cover with a knob above it. To the left you can see the right side of a black plastic plate with large black toggle switches on it.
  17. new discs for my disc binder

  18. bookmarks that attach to disk binder disks

  19. custom tool holders

  20. adapter to allow me to use cheaper, easier to find HEPA filters with my printer enclosure

    a black plastic square with a hepa filter in it, and an orange plastic square with 2 hepa filters in it.
  21. tons of mods for my 3d printing stuff. Everyone does this though.

  22. Tool holder wall (I went with the Honeycomb wall, might go with Multiboard if i revisit this.)

  23. jigs for holding dice I laser etch.

    an orange l-shaped piece of plastic with many blank white dice in it.
  24. jigs for holding other things.

  25. magnet insertion tools

  26. D&D Minis. These were on my last FDM printer and they were not very good.

  27. Headphone hangers

  28. Fixed a lamp. It fell over and the ring that held on the diffuser no longer fit. So I printed a replacement out of flexible filament.

    an image divided horizontally into 3 sections. it shows a lamp  with a purple ring between its top and bottom halves. the top image is looking at it from above with the light off. The middle image is looking at it from belowe with the light on. the purple ring is glowing. the bottom image is looking at it from above with the light on. you can see the LEDs behind the diffuser and the glowing purple edge of the replacement ring.

Things on my to-print list:

  • replacement cover part for the siren mode selector on our ambulance
  • protectors for the many control panel switches in the ambulance so that a dog doesn’t accidentally turn on the flashers
  • custom organizer for archiving note cards
  • unannounced productivity product
  • electrical outlet cover for when we plug in our ambulance outside to help keep water out.
  • light box / mini set for product photography
  • custom split-flap display (that’ll require electronics though)
  • a CNC frame
  • a multi-magnet insertion “pen” tool thing…
  • a better single note card clipboard
  • more tool organizing things

I’m sure there are more things in both lists that I’ve missed, but you get the point.

Warning

If this post has convinced you to get a 3D printer, I must give you a warning before you do. Cheap FDM printers are, in my opinion, a pain-in-the-ass. I almost never used my first printer because it was a constant series of frustrations and poor quality prints. There are thousands and thousands of posts on reddit of people asking why their print has one of a hundred different possible problems. Getting a $200 (USD) printer dialed in to make great prints is possible, but it’s a lot of frustrating work that feels like your trying to read tea leaves.

My current recommendation (February 2024) is to get any of the printers made by Bambu Lab. The more you spend the more you’ll be able to do with it. The reason I recommend Bambu is because their printers are the closest anyone has ever come to making a printer that’s as easy to use as a Laser Printer. It’s not quite as easy yet, but it’s damn close. Getting a printer with an enclosure like their X1 Carbon (X1C) will make your life easier, because the ambient temperature has a significant impact on the quality of your prints. Unfortunately, the X1C + the multi-filament management system (don’t buy it without that) is like $1500, and then you’ll need to buy filament.

I use my X1C probably 3 times a week on average. I never print tchotchkes.

Feel free to ask me questions on Mastodon. I’m happy to help people out.