Design for 3D-Printing
75 comments
·May 4, 2025hengheng
digdugdirk
I've investigated this space, and I'm not entirely sure its even a desired goal from the perspective of a mechanical designer. The benefit tends to be for smaller aspects (ensuring hole sizes are appropriate for the desired thread, or that holes aren't too close to a bend line on a sheet metal part, etc) but the final design of a 3d part is so non-deterministic, and the variety of manufacturing methods are so varied and unique, it might just cause more issues than benefits.
lucasoshiro
Amazing. Again: amazing!
I've been playing with 3D printers for 7 years, and I even assembled mine at home during the pandemic. Some topics described here I already found out by practice and I think most people with experience in 3D printing also do that.
But having everything studied, compiled and explained in that level is just, again, amazing! Not only that, but there are so many other topics covered here that I still have to learn.
Great work, thank you!
pclark
I know they get a lot of hate in the HN community but my Bambu Labs P1S is mind blowing. It’s so easy to use I print 100x more than with my old Ender. It’s motivated me to learn Fusion360 … i’m actually printing droids for my kids to color this very minute.
the__alchemist
Enders were... not a great experience. I understand they were in a good price spot at the time, but from my experience and from what I gather online, very finicky. People who liked tinkering with the printer itself loved and recommended them because 3D printing became a skill of its own (Not for the design considerations in the article, but to make the equipment work consistently).
I've heard that Bambus are much better. I have a Raise3D E2 from the Ender era, and it's rock solid. A step up in price, but no finicking. Just works, when new, and now.
zoky
I know two people with that exact model of 3D printer. Both printers are routinely out of commission for weeks on end due to some failure that the owners lack either the technical expertise to diagnose and fix or the desire to pay exorbitant prices for proprietary replacement parts to fix (or both). Meanwhile my Ender 5 is always chugging along, and is never out of commission for more than a day or two while awaiting replacement parts from Amazon that cost between a few cents and up to maybe $20 each.
I don’t actually think Bambu makes unreliable printers; to the contrary, they are excellent machines that, if anything, are much more reliable on the whole than Creality. But they’re kind of like sports cars, in that their target market is either people who want something fast and flashy and are willing to throw money at any problems to make them go away, or for technical types who want something they can take out on the track and don’t mind wrenching their own machines. The problem is that Bambu printers are marketed and touted as being great for beginners, and while they certainly make it easy to get into 3D printing for nontechnical people, I think most of them will end up ultimately being disappointed at either the lack of customization they allow or amount of time, effort, and money required to diagnose and fix them when something goes wrong.
Max-q
I think that conclusion is wrong, they are absolutely for beginners. No bed leveling. Lidar scan of first layer. Filament sensors. Good software. Enders are sold to beginners but you actually need to be an expert to get good results and keep them running.
vjvjvjvjghv
My Bambu A1 just works. I had an Ender 3 before and it almost killed my interest in 3d printing because my prints constantly failed. I don’t see a path where the A1 could disappoint me.
pclark
as I said, as a Bambu owner, i’m really impressed with mine and highly recommend them to others.
the_af
Hate? I missed this. Why hate?
Rebelgecko
GPL issues and concerns about the SaaS-y aspect. Folks on HN and often techy folks in general don't like it when hardware requires an internet connection vs local control. These concerns are somewhat warranted based on recent moves Bambu has made
kiba
More than that. They tried to gaslight people after people found out the changes Bambu Lab was making.
ipdashc
> There is no excuse to not add text to a printed part.
Super off-topic, but I've always kind of been let down by the appearance of 3d printed text. As noted, engraved seems to be better than embossed, but it still just looks kind of weird. I envy the clean, crisp labels that seem to be commonplace on commercial injection-molded plastic parts.
The toner transfer technique seems kind of promising. I think I've also seen people spray painting 3d-printed parts, and then lasering away the paint to draw text, which is interesting (if somewhat more materials- and equipment-intensive).
Really cool article though.
prashnts
Another option is water slide decal. It can give a really seamless look, but is time consuming and expensive.
Zekio
I've heard people have had pretty good luck laser engraving text onto 3d prints with fiber lasers, though it is pretty steep price bump just to get some text on a 3d print
antirez
Also useful to turn spheres into two parts you can screw one with the other, like in this design of mine: https://makerworld.com/it/models/99223-death-star-christmas-...
sgt
Has there been any interest in leveraging LLM's for 3d modelling? Sort of an AI assistant with CAD software, to help beginners get going and also more rapidly design simple objects.
oofbaroomf
Yes, there has been. Unfortunately, there are a few core issues blocking this from becoming a big thing:
1. The majority of 3D modeling is not done parametrically, meaning there is not a lot of data. The little data there is is generally in OpenSCAD, which isn't very powerful or extensible for useful CAD. 2. Generally, when you want to do CAD, you need to come up with a way to define everything precisely. Like I want this hole 2 millimeters from the bottom, and this exact edge next to the hole to be beveled, etc. Saying all that to an LLM is slower than just making the whole.
That said, these still can be useful for beginners, and there are things like Adam AI that are starting to catch on for simple stuff.
ai-christianson
There are AI models that can generate 3D models, e.g. Hunyuan3D. Not quite CAD models, but maybe this could eventually be adapted to that use case.
Then there's the possibility of an agent automating an actual CAD program. This has already been done with game dev, e.g. Unity MCP.
finnjohnsen2
6 months into 3D printing and I couldnt have asked for a better article to stumble upon. What a massive field this is and I love some of the take aways. Paricularly circles into hexagons, and making things adjustable.
I’m not making my own designs yet. It is too difficult. Modifiying a little here using Blender is where Im at
sysrpl
It's super easy to design using OnShape. Hit me up with private message and I will show you everything you need to model 3D printable parts in under 5 minutes.
stavros
Agreed, you need to know three things:
* Sketch a 2D design on a surface * Make the elements in that design depend on each other (this is parallel to that, this is equal to the other, X is at an angle to Y) as much as possible * Pull the 2D shape up into 3D space
Now you know how to design your own things! The rest is just learning the buttons, but there's usually one called "sketch", one called "constrain", and one called "extrude".
alextousss
Incredible article, learned quite a lot. To me, a very good supplementary reading would be Structures by J. E. Gordon [1]. Helped me grasp a lot of the mechanical design notions necessary for that sort of work.
[0]: https://archive.org/details/StructuresOrWhyThingsDontFallDow...
lukeinator42
My friend and I have been getting into forge molding carbon fibre using 3d printed molds like this: https://www.youtube.com/watch?v=25PmqM24HEk. It is a great technique for making small batches of really strong parts and I'm surprised it isn't more common.
no_wizard
I always thought 3D printing would make multi widget machine[0] manufacturing possible
While it’s done a lot of cool stuff and enabled rapid prototyping etc it never scaled the way I really thought it would
[0]: there may be a better turn for this however this is what I mean: that is one machine that can output a wide variety of different things using the same common material, IE maybe one day it produces ball bearings and the next it could produce a bunch of car pistons, with only having to make minimal changes to the machine itself if not changing anything at all
analog31
"Flexible" or "Quick Turn" manufacturing are terms used for this kind of thing. Quick-turn comes from being able to change from one kind of part to another, quickly, with no added setup cost.
codingmoh
In theory, it seemed perfect for flexible manufacturing: same machine, same material, endless outputs. But in practice, it hit limits in speed, material properties, and post-processing. You still can’t print a high-tolerance metal part at scale and cost-effectively replace traditional machining. It’s amazing for prototyping or niche parts
earleybird
"You still can't print a high-tolerance metal part at scale and cost-effectively..."
Dan Gelbart has a response (with caveats)
al_borland
There are companies with big print farms that offer this service. But of course it’s limited to materials that can be 3D printed, and if the product reaches a certain scale, it’s likely best to invest in injection molding or some other process.
That said, for smaller scale products, news businesses, or things where 3D printing is the only way the thing can exist, these services exist.
WillAdams
One technique which bears mentioning is printing in 100% infill using a filament which will allow re-heating/cooling and then putting it in a tray of powder salt (very finely ground table salt) and then backing and cooling it.
the__alchemist
What is the purpose of this?
noosphr
You get a solid plastic part without layer lines. This makes it about as strong as injection molded plastic.
the__alchemist
Nice! Want to try.
justaj
Nice article, though what I'd personally love to see is a resource where I can go from zero to actually making (basic) designs using open source tools, which can then be taken to a 3D printer and printed.
mikewarot
The learning curve was steep, but FreeCAD has allowed me to start playing with 3d printing gears and other things on my Bambu Lab P1S. I'm largely self taught with electronics and programming, so just starting and making small experiments got me going. For inspiration, there are lots of sites that share 3d print designs.
Great article. This is all above the skill level of the average part on thingiverse or printables, but the good parts on there are going to follow similar ideas. Love the mouse ears, press-fit holes and step-by-step alignment of layers to build impossible bridges.
Notably, in fusion 360 this would all be designed in "plastics" mode, and yet that mode is oblivious to whether the part is printed or moulded. I wonder if any CAD engine can do "production-aware design" that constrains design to the capabilities of standardized machines, e.g. keeping a metal part 3-d millable. I've seen strict design rule enforcement with PCBs, and I have seen sheet metal macros, but nothing for general mechanical CAD.