Great article. This is all above the skill level of the <i>average</i> 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.<p>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.
I'll start out by saying that the article seemed to cover most/all of the areas I would advise people tune around...great work to the OP.<p>About a decade ago I was pushing for more "designing for 3d printing" classes, not only in my own curriculum but also telling anyone who would listen how important it is. Having a design that is designed from the start knowing that it will be manufactured on a printer makes the end result much more usable.<p>Having a solid machine is the first step (this was a major limiting factor to a large number of people in Reprap). This though...is not the most important step. The slicer is the most difficult thing for people to actually "learn". This is why printers like Bambu have such a large "new user" following...they have presets that "just work". To most who have printed for a long time this is less of an issue (which is part of why printers like Voron are still popular).<p>By designing properly you can ease the pain of slicer "tuning", as well as, making your parts stronger in the use case they are planned for. Orientation for strength is a major thing that the inexperienced seem to forget about. I don't know how many designs have been given to me to print that not only are bad for printing, but also, they are not designed in a way which ANY conventional machining/molding can make in a cost effective way. I have wasted a lot of time explaining the things that are in this article to designers...often for them to have me print it as is.
Amazing. Again: amazing!<p>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.<p>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.<p>Great work, thank you!
Best thing to cross hn on 3d printing in years.<p>Many of the design considerations they outline are classified under "Compliant Mechanisms"<p><a href="https://en.wikipedia.org/wiki/Compliant_mechanism" rel="nofollow">https://en.wikipedia.org/wiki/Compliant_mechanism</a><p><a href="https://www.youtube.com/results?search_query=compliant+mechanism" rel="nofollow">https://www.youtube.com/results?search_query=compliant+mecha...</a>
This is a fantastic article. It neatly summarizes several tricks that took me years to pick up.<p>Another useful trick to minimizing material in a print is to not print surfaces at all. Most of the mass in a print is concentrated in the shell. If the top and bottom surfaces are not particularly critical to the function of the part, then you can remove either surface. The slicer can still fill in the volume enclosed by these surfaces with infill. If you use a planar infill, such as a rectilinear, hexagonal, or triangular infill, the parts can look quite nice. This trick works particularly well on mostly flat parts.<p>I use two TPU parts printed in this manner daily: A phone case [0] and a relief strap for a pair of headphones [1].<p>[0] <a href="https://www.printables.com/model/615154-google-pixel-8-case" rel="nofollow">https://www.printables.com/model/615154-google-pixel-8-case</a><p>[1] <a href="https://www.printables.com/model/577575-hifiman-comfort-strap" rel="nofollow">https://www.printables.com/model/577575-hifiman-comfort-stra...</a>
These are excellent tips. Also helpful is the fact that since Bambu came into the scene, the tooling (slicers) and printers (core-xy and others) are all stepping up their usability game, getting the entire space into a "just print" mentality which is really driving a lot of adoption, model creation and just good for the overall ecosystem.<p>I design a lot of parts in fusion360 and have been printing for nearly a decade, and even I found some good tips in here.<p>I would add one very important section here which is filament selection. Modern filaments like PC-CF (carbon-fiber impregnated polycarbonate) are unbelievably versatile for real-world prints and parts, and the higher-end consumer printers can print this (requires a ~300'C capable print head and hardened steel nozzle) with relative ease. There are so many different filaments out there outside the standard PLA that really shine in many ways and aren't 10x more expensive to print with.<p>Slicers are getting pretty good now too with a lot of work going into slicers to improve print quality, speed and part strength.<p>Love seeing cnckitchen called out here so many times - such a great resource to follow and learn from if you're getting serious about new developments in 3d printing and unbiased reviews. The quality of models on printables and thingiverse is really getting better and the amount of things you can simply download and print and have a fully functioning device with 0 external parts (print-in-place and single-print components) is really encouraging to see.<p>Once generative AI gets a grasp on object modelling and cad principles I think we'll see an explosion in functional part models in the same way parameterized models are becoming more mainstream.
> Cut threads into printed parts with a thread tap for quick design of low-reuse joints.<p>I've found wood screws work well for this. The wood screw can cut its own threads without needing to use a tap.<p>It does put some stress on the part, though. I mostly print in PETG, which is strong enough; but PLA might split if the hole was parallel to the layers.<p>> A design limitation of threaded inserts is that they are not reliably usable for screws inserted from the back side. During insertion, heat-set inserts often push some molten plastic into the hole beneath them, preventing easy insertion of a screw from the back side.<p>A trick I sometimes use:<p>1. Before installing the insert, insert the screw from the back side<p>2. Screw the insert onto the protruding screw<p>3. Use a soldering iron to install the insert+screw together into the plastic<p>Because the screw is filling the hole, the molten plastic can't block the hole. Instead, the molten plastic forms itself around the screw, and it acts like a Nyloc nut.
I started 3D printing about 10 years ago with the first Taz machines and they left me a broken, broken man.<p>Fast forward to a month ago, I bought a Prusa Core One, loved it, and then bought a XL 5-toolhead. It's been so much fun using printers that "just work."<p>I finished this 6-day print last week! <a href="https://www.reddit.com/r/prusa3d/comments/1kb3p0w/xl_full_bed_6day_fractal_finish/" rel="nofollow">https://www.reddit.com/r/prusa3d/comments/1kb3p0w/xl_full_be...</a>
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.
In the old days you needed to be a lot more cautious with sharp corners.<p>If you print into a sharp corner, the hotend has to decelerate to a stop and then accelerate in the new direction. During this time, a little extra plastic will leak out of the nozzle. You can soften this transition with a rounded over corner.<p>Current printers usually have pressure advance, so this is a lot less important now.
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.<p>[0]: <a href="https://archive.org/details/StructuresOrWhyThingsDontFallDown/page/n145/mode/2up" rel="nofollow">https://archive.org/details/StructuresOrWhyThingsDontFallDow...</a>
My friend and I have been getting into forge molding carbon fibre using 3d printed molds like this: <a href="https://www.youtube.com/watch?v=25PmqM24HEk" rel="nofollow">https://www.youtube.com/watch?v=25PmqM24HEk</a>. It is a great technique for making small batches of really strong parts and I'm surprised it isn't more common.
Also useful to turn spheres into two parts you can screw one with the other, like in this design of mine: <a href="https://makerworld.com/it/models/99223-death-star-christmas-ornament-two-halves-no-glue#profileId-707417" rel="nofollow">https://makerworld.com/it/models/99223-death-star-christmas-...</a>
> Divide and Conquer<p>This is the most important, it's so much better for obvious and less obvious reasons.<p>I tried to print a front basket in one piece for my wife's bike 2 times before I got it to print. It broke the next week. I changed it from 1 part to 5 and joined them with zip-ties, thread and 3d-printed pins. Despite the assembly time I was finished in less than half the time, every part was stronger because it was in best orientation, the linkages had some give to them which provides surprising amount of amortization that wasn't there when everything was in one piece. It shakes the contents much less on uneven road because the linkage to the bike is only rigid one-way. It also prevents parts breaking easily, and if something breaks I just have to reprint the weakest sacrificial part that joins the bike with the basket.<p>And if I think of an improvement - I just need to reprint small part instead of everything.<p>BTW another very useful trick is preventing layer splitting by designing a vertical through-hole into which you put a zip-tie in tension. Some people use bolts and nuts for that, but that's more expansive and much heavier solution.
The article states it is specifically geared towards FDM (i.e. filament) 3D printers.<p>I wonder if anybody with more experience knows how much of this would overlap with SLA (i.e. resin-style) 3D printers.<p>For example, there's rough guidelines like, overhangs are less of an issue with SLA - and the Z-height is ultimately what most affects print-time, but would be great to see something more in-depth here, with some engineering behind it.<p>Or if there's similarly in-depth articles for resin 3D printers?
This article reminds me of another I read first here, 'Reality Has A Surprising Amount of Detail' by John Salvatier. At first blush 3D printing seems easy, but especially with smaller parts that might go through many duty cycles it's anything but. I'm going to have to do more than skim this, I think this one is worth multiple reads over many days to really absorb the densely packed information.<p>Thanks to the author for being willing to put so much of their hard-earned experience into a resource for the rest of us.
This looks so good. I’ve gotten into 3D printing in the past six months with an A1 Mini. I initially bought it intending solely to do creative projects with my kid, but I’ve been surprised to find myself getting deeper into printing functional parts. I recently printed a 6” server rack for a GLi.net Beryl and Apple TV for travel, from a combination of pre-designed and self-designed parts.<p>3D printing as a pursuit can be time-consuming - there’s always a risk with these things that you take them on as a dilettante and they end up gathering dust in a corner. I initially scraped by with some middling Blender skills (leaning into non-destructive operations where possible), but that is far from ideal - you really do need CAD. But to anyone considering jumping in, I would say: if you get an A1 (get the full size, not the Mini) and use Claude to write your parametric OpenSCAD scripts, the time commitment is such that you can _just about_ indulge in this hobby as a dilettante - eg, as a project for your kids. Without LLMs, I think it would be too much of a commitment unless you’re really dedicated, or already have CAD skills.<p>Anyway, gonna go read this in full.
Note also the more general concept of "Design for Manufacturing" - tailoring your design to use the strengths and avoid the weaknesses and maximize efficiency in your particular manufacturing process, whatever it is.<p>3D printing was once conceptualized as a magic way to create absolutely anything. It turns out to be just one more tool in the manufacturing toolbox, bringing some very unique strengths and weaknesses, but still just another of many. DFM applies to 3D printing just as much as it applies to CNC milling, sheet metal stamping, plastic injection molding, or any other process - it's <i>always</i> important to think about how the end product is physically created, and optimize for that.
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.
This is fantastic-- while I'm aware of most of the techniques in it, it would have saved me a ton of time and trouble if I had it a few years ago.<p>Each of the points could basically be expanded to an article on their own. E.g. they don't mention for vase mode that you can get much better results using a big nozzle with it.
> There is no excuse to not add text to a printed part.<p>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 <i>weird</i>. I envy the clean, crisp labels that seem to be commonplace on commercial injection-molded plastic parts.<p>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).<p>Really cool article though.
I always thought 3D printing would make multi widget machine[0] manufacturing possible<p>While it’s done a lot of cool stuff and enabled rapid prototyping etc it never scaled the way I really thought it would<p>[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
One additional trick that some people are doing is printing just the shell and then filling the 3d print with some kind of resin, foam or concrete.<p>Here's a concrete filled CNC machine: <a href="https://www.youtube.com/watch?v=L8t82OQXefM" rel="nofollow">https://www.youtube.com/watch?v=L8t82OQXefM</a>
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.<p>I’m not making my own designs yet. It is too difficult. Modifiying a little here using Blender is where Im at
What an impressive looking article (I've only skimmed it so far).<p>I've been meaning to try my hand at CAD and designing models to print but I haven't quite made the jump.<p>One thing that has given me pause is a good CAD program for Linux, does anyone has any good tips for a complete Newbie where to begin?
A couple techniques I used the article doesn't mention:<p>- Molds: in my case for silicone joints for high pressure environments.<p>- Flexible filaments/TPU: custom shaped joints to make boxes rainproof. Custom elastic straps with a seam in the box makes for a very nice alternative to screws.<p>- Triboplastics: self-lubricating polymers that can be used as bearings.<p><a href="https://www.igus.com/3d-print-material/3d-print-filament" rel="nofollow">https://www.igus.com/3d-print-material/3d-print-filament</a>
This article is incredible, in the age of AI slip it’s refreshing to read content of this quality.<p>I’m very new to 3D printing (designed my first part this weekend), and so I learned a lot
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 moment the teacher realizes it was never about the perceived correct answer, but the questions that led to the paths taken. The sudden realization that teaching is more than the teacher initially perceived. Its not about teaching "this is so", but rather, "why do we know this is so?".<p>Which is what education should have always been about. It's not about responding with the correct answer. It's about asking the right questions. A famous Greek philosopher knew this, as did many before and after.<p>This is another after.
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.
Great article. Unfortunately it seems that there is a lot of information out there about DFM for 3D printing but not much about the actual print process itself: temperatures, bed flatness, bed adhesives, nozzle size, etc. Does anyone have any suggestions or resources on the subject?
Thankfully, support necessity will go away as 4/5axis 3d printing comes to consumer hardware over say, 10 years.<p>With 5 axis, you can print any model without the need for supports.<p>(I'm well aware of the difficulties/realities here, i've built 5 axis motion control systems before)
Question regarding two apparently conflicting bits of information:<p>- A: Fillet edges in the filament direction
- B: Have a sharp edge for the seam.<p>How would you crack that nut, as A prevents B. For example, on a rectangular box, maybe fillet 3/4 of the corners, and leave the 4th sharp?
Circles are not that harmful if you print a diameter template with 1-10mm holes with 0.1 or 0.2 step. Don't measure your bolt, stick it into the hole where it's tight enough and you're good to go.
Extremely interesting.<p>From a readers perspective as well, this was a long read, but the way it was written was very clear and interesting all the way through. So well done on both counts!