As an engineer I was initially interested in making parts. For example I designed and printed a better part for something which wasn't available locally, and even had a client who wanted 150 of them. But print time was 23 hours per part. and I didn't have full confidence in the robustness of the part. The layer lines are a big weakness and anything less than 3 mm is so flimsy that it's a waste of time. So robust performance parts are out. As are high tolerance ones. Build volume makes it even less useful. And the design compromises you have to make are difficult to justify if there are other ways.

Then with other network parts I thought of designing the vast majority needed other bits and pieces, screws, shafts, connectors in metal that I'd need to source and assemble. Enclosures were okay, but weak, and I can fabricate those stronger and faster in other ways.

So now I mainly just print to what I perceive to be 3D printings strengths and have almost given up on parts.

Has anyone had a different experience?

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    $\begingroup$ Seems like a very broad, opinion-based question and not a good fit for SE in general. That said, there's probably a reason you don't see commercial 3D printing businesses using home/desktop/hobby type printers. $\endgroup$
    – FreeMan
    Apr 15, 2022 at 18:21
  • $\begingroup$ @FreeMan which is why I asked. A previous question and surfing around the site shows lots of answers talking about parts and precision etc,. as if it's justification for the answer or important, so I was wondering who actually makes parts. Because if they don't then their answers are irrelevant. I'm new to this site, but I intend to ask the hard questions because thats how everyone progresses together. Especially as more serious professionals start looking at 3d printing and looking for realistic information. $\endgroup$
    – Kilisi
    Apr 16, 2022 at 0:58
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    $\begingroup$ I don't understand the complaints about this question. Professional use of 3D printers, and whether they're appropriate for particular professional uses, is certainly on-topic for this site. $\endgroup$ Apr 17, 2022 at 2:58
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    $\begingroup$ Not all that come here are hobbyists! We have members in printer design and development of high end machines. I work in aerospace R&D in which 3D printing is becoming more interesting these days. Note that you can print metals and very high performance plastics on high performance printers. One of the most challenging aspects is certification and being able to produce parts that have consistent properties. We've successfully printed non critical flight parts that are much lighter than parts that are fabricated through CNC for instance, this is viable for small quantity batches of products. $\endgroup$
    – 0scar
    Apr 17, 2022 at 5:25
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    $\begingroup$ Whilst interesting, this question seems to be opinion based, and there is no right answer... "Everyone's a winner"! Personally (and I may be wrong), I think it should be closed as it will end up inviting wishy-washy opinionated answers. However, in order to preserve the already existing interesting answers, it might be more suited to Meta.3DP.SE and could be moved there, maybe??? $\endgroup$
    – Greenonline
    Jun 7, 2022 at 13:00

5 Answers 5


Under what circumstances

When your part has internal geometry that would be difficult and expensive to reproduce using other methods. For example fishing lures which need internal water channels. Fittings or covers that would normally require several parts to be sealed together could be simplified to a single part and gasket.

When your part is a complex shape but has no need to be particularly robust because it doesn't come under stress.

When you need a part that you can design with a specific weight and shape you can control the weight with the infill percentage and other factors.

When your part is a niche one that goes with 3d printing strengths. Such as short term or single use items like name plates for conferences, key ring giveaways. Items of novelty value etc,.

When the part is not just functional, you may want a simple functionality in an ornate part for promotional, branding, or other reasons. I was tasked to create a container of certain dimensions. I could have done this a number of ways. But they also wanted their logo and a bunch of designs along a particular theme incorporated into it. Only with 3d printing was this able to be accomplished.


A production run of parts is generally a bad idea. The 3d printed part works as a proof of concept, testing measurements and tolerances even if the printed part can never take the load/pressure of the proper part.

The costs are also significant - filament is ridiculously expensive for what it is, and the power costs of running the heaters for 23 hours per part add up too.

You can also rapidly iterate on a design without having to wait days/weeks for a fab shop to cast/machine/make it out of metals.

I find myself integrating 3d printed parts into a larger build using other items. Example, 8x printed blocks with holes sized to epoxy to metal tubes, then covered with stitched fabric held down by hook&loop to the frame. Buying those parts would be okay, if they existed to find in the first place.

If you're under time constraints for something and can't wait for the proper item to arrive from a supplier.

Sometimes "good enough" is literally true.

To paraphrase...
When it's after midnight and I need this part right now goshdangit!

  • $\begingroup$ Good answer, unless you print to 3d printings strongpoints in which case a production line will work $\endgroup$
    – Kilisi
    Apr 16, 2022 at 9:12

As an engineer I was initially interested in making parts.

First of all, a lot of people who need "parts" (I'll define that term as something playing a physical functional role in the operation of the thing it goes in or becomes a part of) are not engineers, and don't have routers, lathes, saws, drill presses, etc, available to them. A decent 3D printer is comparable in price to a couple small low-end power tools, but the range of what parts it can make is a lot broader, and it can make them with a lot less tool-use and safety expertise necessary.

But a 3D printer is also potentially a very useful tool here even if you are an engineer and even if you do have access to a large toolbox:

  • When you need the part in quantities larger than one, but too few to make by injection molding or other mass production techniques, 3D printing is one of the few solutions that's not prohibitively labor intensive.

  • Some types of parts are difficult to produce with techniques other than 3D printing due to geometry that's not conducive to molding or subtractive manufacture techniques.

But print time was 23 hours per part.

3D printing has a reputation for being slow. It doesn't have to be that way. At present, unless you're willing to become an expert with the tool or spend a lot of money buying something high-end, you're probably stuck with it being slow. But this is changing.

I didn't have full confidence in the robustness of the part. The layer lines are a big weakness and...

This is another area where the field has progress to be made. Weak layer adhesion and inconsistency of part strength are problems caused mostly by a mix of bad slicers, bad slicing setting defaults, and bad extruders. The first two can be mostly mitigated with some expertise using the slicer; the latter is a matter of spending more on the printer or knowing what to upgrade on a cheap printer and doing it.

...anything less than 3mm is so flimsy that it's a waste of time. So robust performance parts are out.

I use printed herringbone gears that are just 4 mm thick, with pitch of pi mm (making tooth thickness about half that), in my printer's extruder drive train, which is a fairly demanding application with momentary speeds up to about 4000 rpm. And that's without any "engineering" plastics, just basic materials like PLA and PETG.

Aside from that, I use a lot of other printed parts for less-stressed roles on my printer, and outside of my printer, I have printed housing for various electronics, custom fluid hose couplers, replacement door closer mounting brackets, replacement soft feet and end caps (TPU) for patio furniture, impact-protection phone and tablet cases (in TPU) for models where it's hard to obtain mass-prouced ones with necessary features or fit for where the items are being used, etc. I'm not sure what of this qualifies as "parts" to you, but I think most of it meets the definition I opened this answer with.

One particularly underappreciated class of parts I'd like to highlight here is soft parts made with TPU or other flexibles. TPU is extremely durable, and at hardness 95A or above can even be quite rigid when printed at 100% infill. It holds up really well under abrasion, exposure to weather, and exposure to oils etc.

Build volume makes it even less useful

This is really dependent on the scale of things you're working with. 3D printed parts seem more appropriate to me at the scales where build volume is not a limiting factor. Most of the people I encounter using printers with large build volume are using them mostly to do whole plates of parts at a time (for example, parts for building printers) rather than single large parts.

When you do need large parts, however, 3D printing can still play an important role, producing jigs or molds to use with other tools and materials.

  • $\begingroup$ I'm talking abut 'real' parts that you could confidently sell to the public without worrying about irate customers in the next few days. $\endgroup$
    – Kilisi
    Apr 16, 2022 at 22:38
  • $\begingroup$ @Kilisi: In mass production or being sold to customers for low-volume or single-unit-custom equipment? $\endgroup$ Apr 17, 2022 at 2:08
  • $\begingroup$ Small production, obviously single unit is worth doing. Mass production would depend on product and market $\endgroup$
    – Kilisi
    Apr 17, 2022 at 2:36
  • $\begingroup$ @Kilisi: I think replacements for almost any plastic gear (and some metal ones even) are something you could easily print and sell without worrying about irate customers. Just make sure you use a material appropriate for the load. $\endgroup$ Apr 17, 2022 at 2:40
  • $\begingroup$ Have you done it? I can make a useable toothpick that would be suitable, but doubt I'd find a buyer $\endgroup$
    – Kilisi
    Apr 17, 2022 at 2:48

Outside of hobbyist objects the only commercially useful use of 3D printing that I can think of is in support of prototyping new parts or products that will ultimately be produced by other methods. If an engineering team is developing something new that may require a few iterations to get form and fit perfected, 3D printing is a viable way to make changes relatively quickly as the design process progresses.

Things that support mass production methods such as molds, dies, jigs, CNC scripts, etc. are expensive and time consuming compared to 3D modeling and printing and typically must await a finalized design. Prototyping with 3D printed parts is a reasonably rapid way to get to that point with the assurance that a hold-it-in-your-hands prototype provides.

Another thought has occurred to me - geocaching containers. Geocaching - stashing things in odd places for others to find using published GPS coordinates, clues and hints - is a popular pastime and custom containers are always a welcome change from the usual pill bottles or food storage containers. I've made dozens for a friend who hides geocaches. I'm not entirely certain whether this market would be commercially viable but it's a big hobby. As I understand it there currently are over 1 million active geocaches in the US and probably tens of thousands of enthusiasts hiding them and/or seeking them out.


I've only just started my journey in 3d printing, but I have a little hobbyist experience in other forms of "structural crafting". I can see a few ways you can use 3d printing to enhance other techniques - the main one being that a printed part can be used to make a mold, which you can then use to cast aluminum, bronze, or whatever else.

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    $\begingroup$ True, but you could also 3D print in metal directly, with the appropriate printer. $\endgroup$
    – Greenonline
    Jun 6, 2022 at 22:55
  • $\begingroup$ Yes, molds are another viable use. $\endgroup$
    – Kilisi
    Jun 6, 2022 at 23:40

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