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Can I really throw failed PLA prints on compost?
So they say PLA is biodegradable. But I still don't know how much biodegradable.
I live in a flat and we have composting trash can in the courtyard. However if I throw PLA in there and it does not decompose, neighbors are gonna be pissed since many of them are intending to use the soil for their balcony flowers.
So can I really compost PLA, or does "biodegradable" just mean it falls apart eventually, eg. in years? And if it decomposes, is it safe to use for plants?

I doubt they will understand... I would not do this.

TL;DR - No... well, yes you can, but it won't decompose in your lifetime.

Addressing this question fully - from the point of composting, rather than landfill:

From Wikipedia - PLA - End of life:

Composting: PLA is biodegradable under industrial composting conditions, starting with chemical hydrolysis process, followed by microbial digestion, to ultimately degrade the PLA. Under industrial composting conditions (58 °C), PLA can partly (about half) decompose into water and carbon dioxide in 60 days, after which the remainder decomposes much more slowly, with the rate depending on the material's degree of crystallinity. Environments without the necessary conditions will see very slow decomposition akin to that of non-bioplastics, not fully decomposing for hundreds or thousands of years.

According to Is PLA filament actually biodegradable?:
It takes 80 years to biodegrade naturally. Although, how they actually know that for sure, seeing as PLA (for 3D Printing at least) hasn't been around for 80 years yet, is unclear.

In addition, PLA can only be recycled at plants that have separate facilities that deal with PLA (as bio-plastics interfere with the recycling of other plastics if combined), and (as an aside) the fumes from PLA are not as harmless as many people think, due to the (up to 40%) additives.
So, PLA is not such a "happy" plastic as many people are led to believe by the marketing folks...

I don't think the existing answers are accurate and would like to see more information in the form of actual test results. There's a great deal of misinformation out there about plastics taking hundreds or thousands of years to break down, which seems to be at odds with easily made observations about what happens to things like plastic cups left outside for a few months to a few years. There's also the matter of structure and whether it's crushed/shredded, think objects to begin with, or a thick object with high infill.

@R..GitHubSTOPHELPINGICE Regarding where those plastic cups go to: The big problem of microplastics - Wayback Machine: The big problem of microplastics.

Also worth Noting: CNC kitchen's experiments of 2021

@Trish - Just seen your comment/link. That is an interesting site. After some searching, I only found a 2022 article (not 2021, but I guess that the experiment was in 2021 and they wrote about it in 2022): PUTTING 3D PRINTS IN A HOME COMPOST. This looks interesting too, I think that there was a question about it, long ago: RECYCLING OLD 3D PRINTS INTO NEW FILAMENT

This question has been asked on just about every forum out there.  Here's one example from filabot.com .

The reality however, is that this process will take several hundred
years in a typical landfill. To biodegrade, PLA requires a laundry
list of conditions to effectively break down. Specifically - oxygen, a
temperature of 140+ degrees [Fahrenheit -- ed note], and a 2/3 cocktail of organic substrate.
Collectively, these are absent in any scenario outside of industrial
composting facilities.

I found similar comments -- tho' with perhaps slightly lower temperatures elsewhere.

note that those conditions are even absent in industrial composting!

PLA products will take up to 6 months to degrade in commercial composting facility. In home composting facility, it may take longer time.
Source: http://www.biogreenchoice.com/category_s/1866.htm

Based on the way they treat grammar, I have doubts about reliability of that site: How is unique about PLA and how it is different than regular plastic?

Based on tests conducted by several groups, the claim is simply wrong.


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Will 3D Printed Dice Be Fair?
Is there anything to the process of 3D printing that might make the dice unfair/land on a specific side more frequently? Or will any imperfections be negligible, thus making the dice fair? I'm more concerned about making a d20 than anything else, so focus on that shape if need be.

I am using a MakerBot Replicator+ with FDM, so take this into consideration if it affects your answer, and if you believe a different printing process would have an advantage over this don't hesitate to include it.

In the real world, no dice are perfectly fair. But for a sufficiently loose/lenient definition of fair, yeah sure 3D printed dice can be "fair enough", depending on what your criteria are.

It's confusing that your title asks if the dice will be fair but the question itself asks if it'll be unfair. People very often start their answer to a yes/no question with "Yes." or "No." but now it's not clear what those answers mean.

@TomvanderZanden I believe I was clear in my question that I was concerned with the 3D printing process in general, like how it produces from the ground up or some other process that could affect a die's balance. If you must know I have access to a MakerBot Replicator+ which is what I would use for the dice, but I still don't see exactly how the specific printer would make a difference. Feel free to explain or direct me to the different printer processes and how the differences could affect the dice, I would love to know.

"The 3D printing process" does not exist. Makerbot uses FDM, which builds a model by layering molten plastic. You could also use SLA/DLP, which uses light to cure photosensitive resin to form your part. You could use SLS, which uses a laser to melt together metal or plastic particles to form your part. LOM takes a piece of paper, cuts out a slice of your model, then glues these cutouts together to form the part. Moreover, even within a single process (like FDM) print settings would affect the outcome. If you ask about "3D printing in general" then the question is way too broad.

It probably won't be fair.
Incidentally, I have a decent amount of experience with 3D printing.
It depends heavily on the particular technology that you're using to do the 3D printing, but nearly all forms of printing aren't perfect--depending on the design you make (solid? honeycombed? hollow?), there will be slight, or not-so-slight variations across the faces, which will result in an unfair die. In particular, the faces that are parallel to the build surface will probably be different compared to the ones that are angled.
You could probably deal with some of these problems with some kind of post-processing, but honestly at that point buying dice would be easier. 3D printing is for making custom or prototype objects, and isn't really suited to mass production of simple shapes like dice.
Even manufactured dice have some imperfections, and a slightly unfair die probably won't make much of a difference in gameplay, but it will be hard for you to determine whether the imperfections from 3D printing are severe enough to make the die unfair without rolling it many times and looking at its distribution. Again, at that point, it's easier to just buy the dice.
That being said, custom d20s can be super cool looking, and if you're going to 3D print something, might as well make it look cool...

Your headline "probably not" is confusing, since the title of the question asks if the dice will be fair but the body asks if it will be unfair.

Of course, even if your manufactured die is structurally perfect in all ways, and you roll it on a battered and scarred wooden table, an edge hitting a groove will produce imperfections in the roll that wouldn't be present on an utterly smooth table. All things are relative.

@flith An imperfection in the table wouldn't systematically favour one roll over another, so the rolls would still be fair. Unpredictable imperfections are what makes a dice roll random; the problem with imperfections in the dice is that they can have a predictable effect, because they make it more likely to land in one orientation than another.

Random imperfections in either the table or the die are one thing, but it would be all too easy to design and 3D print a die that favored one face over the others. Such an imperfection could be made undetectable without destroying the die, dynamically balancing it or doing a randomness study, rolling the die many times and tracking the results. I'd rather play whatever game I'm playing than mess around with that.

There was another thread on SE about how to easily test the fairness of a dice. A top answer was to float it in water and poke it. If it stops spinning with the same number up each time, it's not fair, wheras a fair die will tend to spin longer and stop with different numbers up. http://rpg.stackexchange.com/q/65206/4119 has more details.

On a practical note: if I were going to 3D-print a die, to make it as fair as possible, I'd probably make a prism-shaped die (like this), and print it such that one of the ends (ie the faces it's not meant to land on) is the "base" during printing. That would - at least for the printer types I'm familiar with - give you a better chance of a fair die, because a lot of the non-uniformity tends to be in the vertical direction and/or with sloping faces, and this way all (important) faces would be affected equally.

It looks like all the answers are talking about theory. I have not seen any real tests. So I have decided to put my real-life test of purposely unfair d6 die - hitting and rolling plays much greater role than weight of some side.

I've printed a few dice, and thrown them ~100 times each to check -- they were very far off from fair. One reason, I think, is that the inner fill (and thus a lot of weight) is oriented a certain way. It might help to do solid-fill or no fill, but I haven't compared yet.

Thanks for the testing! Can I ask what printer/method you used to print the dice and what dice you tested?

My printer is basically a MendelMax 2, and I was printed with PLA and I think a 0.4mm nozzle. I definitely tried a d6 that's a hexagonal cylinder (I was hoping it would be fairer since it only rolls around one axis, but that didn't help). I think I tried some other shapes too, but I don't recall which.

Use of gyroid infill pattern (AIUI not available at the time this answer was made) would probably mitigate the infill orientation issue.

Custom 3D printed dice are distinctly lower quality than the dice from a FLGS you see in 'standard' dice sets, and around the same quality of die as the cheaper plastic dice available online.  It depends somewhat on your printer, but you can get very uniform results in terms of material density with the issues in die fairness being limited to problems with the surfaces (e.g. the sides aren't usually all the same texture).  You can fix this with statistical modelling and sanding to get a very good die, but it takes forever and is a huge pain and is totally not worth it from a practical standpoint.  A quick sanding to get all faces roughly the same texture is usually good enough, in my experience.  You can also just print the die so that the build-surface face and the face parallel with it (if it's not a d4) are unimportant faces, like the '10' and '11' on a d20-- being smoother they'll be rolled a little less often but the average roll will be the same regardless of what number pair that effects if you keep the 'opposite sides sum to die size + 1' rule.  A quick sanding doesn't take too long and works well, though; that's definitely what I would recommend from my experience.
As a note, the main advantage in 3d printing dice is that it's affordable, whereas otherwise acquiring truly custom dice (weighted to specification, unusual number of sides, etc) requires you to make them by hand or shell out many thousands of dollars.  3d printed dice are particularly useful when you want to concoct biased dice, as you can easily alter things like the physical die size, weight (by altering how much of the interior is hollow), weight distribution (by altering where the hollow cavities are-- known as 'floaters' when these gaps are used to bias the roll, much less good than weighting), and number placement to conceal the differences between your die and a 'fair' die you 3d printed.
In my experience, 3d printed dice work fine for RPGs, but feel a little light (at least with my feedstock).  I used them for a bit with a group I GMed for while on a bit of a 3d printing kick, and they definitely have some niche uses, but beautiful high-quality dice with a good feel to them are so cheap nowadays I just don't see any reason to go to the expense and trouble when you can avoid it.

Do you have any websites or stores that you would recommend for the cheaper and higher quality dice?

I have tried to make an unfair die by putting 100% infill in the conner opposite to 6, 5 and 4.
When you float it, it always comes with expected side up. So with floating you really can check if somebody has tried to make it unfair.
The real-life tests have unfortunately shown my complete failure :)
After 104 throws the average is 3.49. Even less than "fair" 3.5!
It looks like the weight of plastic is too low to compete with hitting and rotation. The next try could be to put something metallic into it during printing.

One theory I have, and might test to try to confirm, is that with 3D printing you can make the total mass so low that other effects dominate. For example my D12 is less than 1g (hollow).

Pretty much all die are unfair to an extent. If you are seriously concerned about accuracy then you will need to test what you produce and, if not satisfactory, modify the design reprint and retest. A simple/coarse test is to float your die in very salty water and note which face faces upwards, repeatedly perturb the die noting the upwards face. Any egregious bias should reveal itself after a handful of perturbations. Note that this test only reveals that a die has a bias, not which face it is biased to land on. It's also probably not massively accurate but should be good enough to let you gauge whether your printed die are any worse than your shop bought ones.

I doubt this will work for any die with surfaces of varying area, so be careful.

Well it is a bit more complicated than that. Changes are the d20 you buy in the store is a bit more favored as well. Now we are talking statically, it will like one side over the other. As the difference in weight distribution is not drastic if you print it solid, it will not matter. In use you likely will not see it.
That said if you wanted to be extra sure.. I would use the 3d printed model, make a silicon mold with it. Then use Resin to make the dice. Now you can start making whole batches of dice as good as what you get in the store.
My final answer is, technically it will favor but you will not notice.

I think your point about weight distribution could be quite important. I guess using a denser infill or few top and bottom layers could help, though.

I agree that creating a mold is the best thing to do with the 3Dprinter.  If you use ABS you could smooth the interior faces as desired w/ solvents after printing.

Not likely.
Creating true 'fair' dice is fairly difficult to do even with high tolerance processes. 3D printing (hobbyist level) is much lower tolerance and will definitely be weighted incorrectly especially if the infill is anything less than full. Professional grade 3D Printers will be better and more accurate but will still likely be weighted slightly to one side.
Regardless of process though it would be possible to create a fair dice using 3D printing as the primary means of manufacturing and then weighing, balancing and doing some post processing to even them out.

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Feasible 3D Printed Snap Connectors
I have Ultimaker 2+ 3D Printer and I need to print a piece that doesn't fit within the build volume of the printer. Even though it would fit I'd still need to print it in two parts because I'll need to fit some equipment inside. I could use glue to put it together, but I'll need to remove the equipment later.
So I'm trying to find some feasible solutions how to attach/snap it together. The wall thickness is currently 3mm.

Plane for cutting the part.

Cut cross section.

Could you highlight where the cut is?

I've added another figure of the full part and cut plane. The other shows the cross section of the cut.

By the way, have you considered putting equipment inside during the print? Pause print, put equipment inside, continue.

@TomášZato The equipment needs to be removable (presumably non-destructive)

Possible duplicate of Tips for making parts that push/snap together

@TomvanderZanden I don't think this is considered a duplicate. For this situation, the examples outlined in your link are not a viable option for re-joining a large model. Especially one with such thin walls.

If the equipment has to be removable, then there's no point in trying to make a one-piece object in the first place.  So it looks like you have two problems. The first is to decide what's the best way to split your container to facilitate both putting the equipment inside & removing it; the second is how to latch the two together.  I can't answer the first since you haven't shown us the equipment.
As to the second: there are a number of plans for spring-latching connectors (such as used with straps, backpack covers, etc) on thingiverse.com.  If you have no constraints on the exterior of your container, I would just merge the latching connectors into the container wall (e.g. with meshmixer) .

Thanks for your reply all. I think I have a solution for my need. Here are some figures!

More picture of the clip!

Right part of the model seem quite hard to print. You will most likely have to use support structures. It will be not easy to ensure that locks would fit.

I've added three more figures of the clip (what I believe you reefer to as right part), This is the first thing I'll 3D print but I've seen youtube videos showing much more cliff-hanging than this.

Possible issue is not overhang itself, but possible geometry distortion. You may get clips that either too tight or lock loose

Okay, that might happen. But I've asked a friend who uses this printer a lot. He thinks the precision is quite good so I'll give it a shot. Will post some pictures later. The printers producer claims precision down to 20 microns with the finest nozzle. Guess I'll use that one!

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White PLA prints frequently have rough sidewalls near top of the print
This has happened a few times whenever I print with the white PLA (Hatchbox 1.75 mm). It seems that the print job produces smooth sidewalls for most of the part but at a certain point and above, the walls become rough as if the alignment is off or something. I've attached a picture to show the issue. Does anybody have any insight?

I'm using a Printrbot Simple Metal and some of the print settings are listed below:

Slicer: Slic3r
[First] Layer height: 0.2 mm
Perimeters: 2
Solid Layers [top/bottom]: 3
Infill: 25%
Fill pattern: Rectilinear
Top/Bottom Fill pattern: Concentric
Perimeter speed: 30 mm/s
Infill speed: 80 mm/s
Travel speed: 150 mm/s
Acceleration (perimeters): 1000 mm/s2
Acceleration (default): 3000mm/s2
Default extrusion width: Slic3r chosen
Print temperature: 220°C

I've noticed in the Slic3r rendering that the affected area seems to be the point where the infill switches from 25% to solid as seen in the included picture. If this is the problem, is there any way to enforce solid infill a few layers below this to eliminate the awkward transition, or specify a smaller extrusion width at this point?

Thanks for the suggestions Itamar Green and lz42. I went back and printed the top of the part (slicing just below the referenced area in the Slic3r preview above) after lowering the print temperature to 210 degC and tweaking some Slic3r settings until the extrusion path appeared continuous on each layer (unlike above). I also changed to concentric fill pattern from rectilinear and adjusted the infill width until the preview artifacts disappeared. I think the modifier mesh approach would be best to fine tune the parameters as necessary for different layer regions so I accepted lz42's answer.

If you want to change settings on some area of your part check out modifier meshes in Slic3r.
It looks like to0 much heat is delivered when solid infill starts and some melting occurs. See 3D Printing Problems #22: Extrusion Temperature Too High.
You can try:

Lower extrusion temperature
Lower filament flow
Improve part cooling
Lower print speed

wow, I had always wondered if that type of setting override was possible in slic3r but I guess I never looked hard enough. Thanks for the tip on modifier meshes! I'll do some test printing to check my temperature setting too and update this post when I have some conclusions

Slic3r has an option of
Solid infill threshold area

which is the area that when you pass it (and start printing smaller than it), the infill becomes solid.
If you set it to a smaller number (or 0), then your infill won't become solid and the problem will vanish.
Source: Slic3r Manual - Infill Optimization

That's definitely a useful suggestion @Itamar Green. For this part I tried settings with 100% infill and concentric fill pattern and the pictured area still has an awkward transition where the software tries to adjust the infill width to fill with a single extrudate instead of the two extrudates for the layer before it. I'll keep this tip in mind in the future though.


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Scaling objects with constant wall thickness for 3D printing
The question is how to scale an existing mesh without changing the thickness of the walls?
I am using Blender to create STL files for 3D printing. Let's say I create a shell for a model railroad car. Since 1/87th is the most common scale I make the walls of the shell just thick enough to make it rigid in 1/87 scale. Now, if I want to print the same shell in a larger scale, say 1/48, the wall thickness will nearly double and it will waste material printing walls that are thicker than needed. If I want to print in 1/160 the printing may fail because the wall thickness falls below the minimum the printer will support.
Any ideas?

Your question falls into two different categories, here at 3D Printing SE and there, at Blender SE.
I would consider that your objective would best be solved using some form of parametric modeling, an aspect that is rarely embraced by Blender. Even though the limitations of Blender make life interesting for you, there may be a couple of useful features within (and without) the program.
On Blender SE, a question of similar format exists, with a somewhat open-ended answer. A quick search using The Google, with the terms "Parametric Modeling with Blender" results in a number of different approaches. According to a quick perusal of the search results, some of the solutions involve free plug-ins or add-ons for Blender. More complexity rather than less, perhaps.
I'm familiar enough with the very simple basics of Blender to know I would not be able to make use of those answers. I'm also well aware that Blender's power extends beyond my own limitations with features supporting scripting, animation and so many other tools. Seeing the workflow diagrams/charts that make up some of the advanced portion of the program leads me to believe that one can accomplish your objective, but one must be a certified wizard with the program.
As an alternative, one could engage any one of the many parametric modeling programs available. I'm a fan of OpenSCAD, although the text/scripting interface can be daunting for some. If you've become skilled in Blender, a non-GUI format isn't necessarily the best route, although the GUI options are no less confusing, in my opinion.

The minimum scale of your model
The modeling of your 3D file doesn’t necessarily require that you work with a given unit or scale. It’s particularly true with software like Blender in which you’re able to give proportion but no unit. This job will be done after the modeling phase when you send your model to a 3D printer. That’s why you need to pay extra attention to both the scale and the size of your model at that point. Creating a 3D print in millimeters instead of centimeters might very well result in a bad 3D print.
A powerful example of that can be found in architectural models. This is, in fact, one of the main issues we encountered while working with La Cité de L’Architecture on La Merveille’s reproduction. With architectural models, it can, for instance, be entirely possible to 3D print a scale 1/10 of something and just impossible to do the same at 1/250.
After a certain level of miniaturization, the details (present in the digital 3D file) are starting to vanish in the physical world because the 3D printer itself is no able to create them (or will create very fragile one). Quite often for architectural models, human intervention is necessary to decide which details will be kept and which won’t so that the 3D file doesn’t contain information that won’t be printable.

Make your model solid, then during slicing:

scale your object
set infill to 0%
set desired number of perimeters (that will be the wall thickness)
That way with just one model you may have any wall thickness independently of scale.

I'll have to learn about "infill", never used it before. My current plan is to create a shell with only faces, no thickness. Then just before I produce the stl file I would apply the solidify modifier, setting the thickness to be  adequate for the scale I plan to print.

The idea is to not model walls. Make model that's fully filled inside. Setting infill to 0% in slicer will make shell out of it. Perimeters will be your walls and since infill is 0% the print will be hollow inside. Learn about infill and perimeters (shells).

I think you are making too many assumptions about what I'm doing. First the slicer  for the formlabs printer I'm using does not have any "infill" feature that I can find. Maybe someone who is more familiar with the preform slicer can confirm this. Second I think you may be assuming that there is nothing inside the model. This is not always the case. If I'm modelling a truck cab for instance, I may want to print it with a dashboard and steering wheel inside.


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How does a layman get a 3D printed replacement part?
A plastic gear of an older DVD player broke. I always read about being 3D printing a "repair revolution". So I looked for a template to give to some printing service, but I found none (and nothing close to it).
Could you please explain me, what steps a layman should take to get the gear piece replaced using 3D printing?

Printing a gear for something that is likely very small will be very difficult, even for the more experienced printers and possibly not doable. Gears are really tricky and for a DVD player they're really small and require very tight tolerances. For this specific application it's probably best to find a replacement part.

If you have the remaining pieces of the gear and enough remains to determine certain measurements, one can either engineer the gear using a number of gear modeling designs, or one can take measurements directly from the parts and engineer a raw design.
If the gear you have is not particularly peculiar, it is possible to use a gear generator plug-in, template, or library to make the "foundation" of your gear. The modeling software would then be used to add the appropriate bosses and key ways required to complete the design.
If you are considering to create the part yourself, you have a wide selection of programs from which to choose. I'm fond of OpenSCAD, and it does have a number of gear libraries. Simple bosses and key ways are easily accomplished using OpenSCAD.

Another package available on the internet which includes the option of using a gear generator is Tinkercad which has a reputation of being easy to use. You'll find many tutorials for this program as well.
Tinkercad requires an "outside" program to generate the gear design which is then imported to the model workspace. Even a program as simple as Inkscape can create gear profiles to be imported into many design packages.
Fusion360 is available free for hobby or non-commercial use, but may not be the easiest to learn in a short time.
So many others as well. Use your favorite search engine for "gear generator modeling software" or similar wording and be overloaded with links.

This is not something "a layman" can do. If you want to replace that gear using 3D printing, you'll either need to go down the rabbit hole and learn a bunch of new skills, or hire someone to do it for you.
You need to have a 3D model of the part you want to replace. While 3D scanning is in some cases possible, it won't give you the resolution required to reproduce the gear with sufficient accuracy. This means your only option is to manually model the gear in CAD software. You'll need to take a bunch of measurements (outer and pitch diameter, thickness, mounting hole diameter) and figure out the tooth profile, and then build a model according to those measurements. A caliper is very helpful when doing this.
A neat trick that might help with a flat part like a gear is to scan it on a flatbed scanner, and then use the resulting photo to trace your CAD sketch over (but you'd still need to cross-reference it with measurements).
Unfortunately, most CAD software is quite complicated and "How do I model a gear" is not a question that can be answered concisely. @fred_dot_u offers a number of suggestions for packages that might work, and even offer modules specific to generating gears. However, if you are not interested in learning CAD for its own sake and really get into 3D printing, learning it just for the sake of replacing a gear in a DVD player is a very inefficient use of your time.

The only 'layman's' option is to find an existing design which solves your problem. If you are lucky, and the product you have has a common failure mode, someone else might have a) solved the same problem already, and b) posted their design online.
Sites such as thingiverse have plenty of designs, but finding the right thing might be hard. If you find something, you can then look for someone to print it for you. Its not clear if you tried this already, but maybe the answer helps someone else.

End of the day this is a extremely advanced solution to buying a replacement DVD play for 40 bucks..


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Building a pivot linkage for servo steering with 3d printed parts.
This question is more of a mechanical rather than 3d printing, but I am assuming 3d Printing communty have already come accross this issue, therefore this is a good place to ask.
I am building a simple RWD vehicle using 3d printer parts. See the picture below.
As you can see from the picture, I am using 3d printed linkages for steering mechanism and I used regular bolt and lock nuts to secure them together (thats what I had laying around the house at the moment). The problem here is that, holes in the linkages are not exactly the size of the bolt, and because the bolts are threaded, it generates a lot of friction. Other than that, the bolt seems to sit loose inside the hole and creates an unstable pivot.

If I tighten the nut more, it just presses them together making it hard for the servo to operate. I am looking for a solution that will use simple bolts, nuts and washers which can be bought easily off the shelf (or even with the bolts and screws everyone has around there house). What can be done to make this joint stable in xy plane, rotating freely around the bolt, or whatever the connection could be. By the way, even though I used nylon lock nuts, it seems to loosen after couple of repetitive rotations.
Thanks for your help in advance and I hope ya'll have a great day.

If you're really in a bind, you could potentially use two nuts on a single bolt. The first bolt acts like the shoulder mentioned in tjb1's answer. Obviously, tjb1's answer is the best solution, but if you don't have the resources and you just need to get it done, this is a possible temporary solution.

A correct length shoulder screw would work great in this application.  They have a shoulder that is held to a precise diameter and a length.  You can thread a nut on and tighten it against the shoulder to prevent clamping your pieces.  They may be hard to find locally in stores but are readily available at places like MSC, McMaster-Carr, and Bolt Depot.

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Prints falling off the bed towards the end of the print
I have been trying to print an object that is 4 inches tall. About at 3 inches it falls off the bed. I am using tape on the heated bed and right before the print I am wiping the bed with rubbing alcohol. After the first time I tried hot gluing it to the bed when it was mid way through so that it wouldn't fall off but that didn't work. I am printing at 185°C and the bed is 55°C. I am using PLA to print. Should I increase the temperature of the bed or is there something else that is wrong?

Possible duplicate of Can't get print to stick, no matter what I try

It's all about levelling and setting z-zero.

I thought at first that it was a leveling and zeroing issue, but the problem, per the post happens after a couple inches has printed. That points more to temperature than to calibration issues. If the bed is nearly the right temperature, the hot filament will transfer some heat to the bed, but it might begin cooling to a "release temperature" by the time it reaches the problem point.

@fred_dot_u Should I raise the bed temperate?

Tell us what tape you're using and if it's not blue painter's tape, consider to change to that. Yes, also consider to raise the bed temperature by 5°C between test runs.

Even though knowing the model of printer is slightly helpful, it's not critical to making your print work. Your PLA manufacturer should have recommendations for both the bed temperature and the nozzle temperature. Is your print bed glass or metal?
As an example, my bed is glass and I set the temperature to 70°C for PLA, but the real temperature at the bed is slightly lower than that.
I'm using 3M brand blue painters tape. What type of tape are you using? It will make a difference. I originally used cleaner on the tape, but found it was not needed. Blue tape means parts stick so well that you have to get them free before the bed cools too much, or you'll have to remove the tape to get the part free.
My PLA nozzle temperature settings range from 190°C to 230°C, depending on the filament. I use the manufacturer's figures and vary them five to ten degrees depending on the results.
Too hot at the nozzle will burn the filament possibly causing a clog, while too cold will cause extruder feeding problems. You did not reference having feeding problems, which implies your nozzle settings are acceptable.
Consider to change your tape and to increase the bed temperature. At a 55°C starting point, you could jump five degrees at a time until you get a good bond.
Also be certain that your bed is level and properly calibrated. The first layer should apply in a slightly "squashed" manner. Too close and the nozzle tears up the tape, but too far and the filament will sit on top and not properly adhere.

You might also try tweaking your settings to add a "raft", which is a wider area surrounding the first layer of your print. The added area is more area to "stick" to the build plate (or tape, or whatever). I've found that often helps.
I've tried using crazy glue in a pinch, to glue down a corner that's coming loose, but as you reported for hot melt glue, it's a long shot. I did get it to work once or twice.

Well, I had the same problem like you. I tried some raft but the result was ugly and a little hard to remove it from final part.
I notice that autolevel works fine but, if your printing on top lines are over warping  the nozzle will collide until the part fall off the printer. So is needed to minimize this warping controling speed and temperature, maybe the PLA is getting glued to nozzle and creating the warping.
I have set the printer from 185 and 190 to 210 for first layer to increase the adition to tape, the heat bed to 32 degrees to allow the first layer get cold faster to avoid PLA warping. This may vary depending on city climate
Remember the heat bed is to control room temperature close the part, not to mold or to print the part. At least, that you are printing a turkey to be finished and cooked.

If you have a dual-extruder printer, your second nozzle could be hitting the part. As the print grows taller, each hit with the nozzle has more chance to knock the part off the build plate.
This can happen from some of the following reasons:

Nozzles aren't level to each other
Build plate is not  level
Material oozed and solidify on second nozzle. (Similar to nozzles aren't level)

Check your Z-calibration.  I have a similar problem that I'm about to investigate.  I have a feeling the Z-axis pulses per mm may need to decrease ever so slightly.  The cumulative error may lead to the extruder poking at finished layers as the part gets taller.

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Infill pattern comparison
I'm relatively new to 3d printing, and wanted to get a few things understood.
Firstly, I am unclear on how Hexagonal infill is stronger than, say, diamond pattern.
Can anyone explain how the different shape causes the structure to be stronger? I saw a few places that hex is stronger; usually, more vertices means 'weaker' shape (i.e. a triangle is stronger than a square), so how does that work with hex vs diamond?
Also, in small objects, where the printer makes only a single dot as the infill (a dot instead of a line in larger objects), does the infill strengthen the object at all?
EDIT: I am trying to understand the effect of the infill pattern on the strength of the print, regardless of print time.

Hex grids are used for different reasons than triangular grids (such as you often see on bridges and roof systems). Triangles are especially good at being rigid, while hex grids are very material-efficient for a given strength. The second reason ($) is typically more important for 3D printing.
Triangles do have fewer vertices than squares, but it's not always true that "fewer vertices" means stronger. Vertices are one kind of weak point. But in a triangle, vertex "angle-holding" failures simply don't matter. You can fasten 3 bars together with hinges or other joints that have little resistance to changing angle, and the triangle is still rigid.
In contrast, rectangular grids can (and do -- https://www.youtube.com/watch?v=5t9MpNTSbYg) completely collapse if their vertices aren't rigid enough. That combines badly with the fact that vertices concentrate forces, so have to be much stronger than sides in comparable settings.
A triangle cannot change without changing multiple things -- at least 2 angles and a side, or all three sides. Intuitively, the sides and vertices of a triangle work together for strength. This advantage of triangles doesn't transfer to hexagons, but hexagons have two other advantages: First, if you want to fill a space with a repeating shape, hexagons use less material than other shapes. And second, hexagons keep all the individual "walls" shorter compared to others shapes, which makes them less prone to bend.
The material efficiency was proven by Thomas Hales in 1998, according to http://www.slate.com/articles/health_and_science/science/2015/07/hexagons_are_the_most_scientifically_efficient_packing_shape_as_bee_honeycomb.html. His paper "The Honeycomb Structure" is available at https://www.communitycommons.org/wp-content/uploads/bp-attachments/14268/honey.pdf

Correction: I believe I found what you are looking for:
Report from EngineerDog.com
The author concludes that rectilinear infill with a zero degree offset is the strongest. However, I have not seen consensus for or against a certain pattern being strongest. I recommend more investigation .
My original answer:

I don't know that one pattern is significantly stronger than another,
  provided they each bond well with other infill deposits as well as the
  perimeters.
There are studies around. In 3D printing, strength is rarely the only
  consideration; one must optimize for strength where needed versus
  time to print.
See
  this
  as an example of a report which supports the hexagonal or honeycomb
  pattern as the optimal balance between strength and print time. This
  one is
  more detailed, but only compares linear infill patterns of varying
  layer thickness and density. There are many such articles, some more
  scientifically conducted than others, available with a simple search.

This is not exactly what I meant. I will edit my question to clarify

Do you want to compare different infill patterns at a certain density? Because a high density (80%) pattern A will be stronger than a low density (20%) pattern B; and as densities approach 100%, any differences will approach becoming negligible. I do not know of anything like a finite element analysis of various 3D printed infill patterns. But if you want the most strong, use the most dense: 100%.

I edited my answer; see if that addresses your question.


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Folgertech FT-5 : Does not seem to be reading G-Code correctly
I recently purchased an FT-5 from Folgertech and finished assembly about a week ago. I have yet to accomplish a successful print. It seems like either the file is not being sliced correctly, or that it is possibly reading the G-code incorrectly. It will lay down the first perimeter layer of the part and then shift down the build plate a few mm in the y-direction, extrude another perimeter layer and then repeat. I have tried printing from an SD and through USB using Cura as the slicing software, with the same results.

I have doubled checked the tightness on all of the belts and pulleys
The Y-Driver was bad, initially so I swapped it with the spare on the board and it solved the issue.
I have gone through the entire code on the Marlin V3 Firmware, and everything seems to look as it should.
MKS Gen V 1.4 w/ Arduino Mega 2560
I have tried using Arduino 1.6.5/1.6.6/1.6.7
I calibrated the XYZ steps/mm

All of the mechanical movements and offsets seem to be correct. The printer connects to Pronterface without issue. It also homes fine from the machine and USB and moves where it should during these processes. Again, it seems to be that the issue is when it tries to interpret the G-code. I have tried multiple G-code files from different sources as well, still with the same luck.
If anyone has experience with similar issues or can offer any help, it would be greatly appreciated. I have no clue what could be going on!
In red filament is my attempt to print the 5 mm calibration cube this morning, an example of how this calibration cube should look like is seen in the picture with the white calibration cubes.

This smells like skipped steps.

I agree. My next attempt at fixing the issue will be tuning the stepper drivers this weekend. Any other suggestions?

@T_Robbins, did you resolve this?

I agree this looks like skipped steps along the front-to-back axis in this photo.  The machine is a 2 axis overhead gantry style machine, where the side-to-side inertia is much lower than the front-to-back inertia.  I'd suggest checking the acceleration settings, which could be too high, or could be set for a different architecture machine.

The image shows that somehow steps in Y direction (under the assumption that you have taken the photograph from the front) are missed.
Missing steps can be caused by too high settings for acceleration and jerk, too much friction on the undercarriage or the belt assembly, undercarriage catching something at a certain point, too less current through the stepper.
You could increase the torque on the stepper by increasing the Vref of your stepper driver is you have separate stepper driver modules, or a adjustment screw on the printer controller board. Furthermore reduce the acceleration and jerk settings and check the undercarriage for stick-slip movement by disconnecting the belt, then reconnect the belt and check for friction of the pulleys.

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Assisted manual levelling with Marlin
Marlin offers a bunch of different choices for auto-levelling and assisted manual levelling for bent build plates (mesh levelling), but for the moment I want to level things completely manually.
That is, I want to move Z to 0, disable steppers, and then move around the print head and adjust the distance between bed and nozzle at various points with a piece of paper.
With the old Repetier based firmware on my printer, selecting "home all axes" did not only home XYZ to endstops, but it also moved the head to position (0, 0, 0) afterwards. Then I could simply disable steppers via the menu and go on with my levelling. Note that in my case, the coordinates of the endstop positions are negative for all axes, so moving to the endstops alone isn't cutting it.
With Marlin, selecting the "auto home" option merely moves to the endstops and then to some positive Z position (+10). This means I have to use the menu to manually move Z back to 0, which is quite inconvenient, unless I have a PC nearby that allows me to enter G-code.
So, that leaves two related questions for me:
Is there some simple way to move to (0, 0, 0) with the menu?
Can I implement an assisted manual levelling (i.e. some procedure that simply moves the head between a number of different X/Y positions) easily? Does something like that already exist? If not, I wonder why.

If you move the print head manually (steppers disabled), the firmware will not be able to know its position, which is required for mesh leveling. If you just want to level corners, theres an option for that in Prepare. If you want to add specific points to the mesh easily, now thats a question!

Write a few pieces of gcode to do this. Place it on an SD-card (I assume you have a reader) and select the file you want to execute.
Home all:
G28
G1 Z0

Do you really want to home it directly? I would say you want to take it down slowly and adjusting end-stops incrementally.
First:
G28
G1 Z10

Then
G28
G1 Z3

Then
G28
G1 Z1

etc etc
You can also move it around in the X and Y plane:
G28
G1 Z5 X50 Y30

The way I manually level my bed is by connecting a computer to the printer via USB. As far as I am aware, if you have a touchscreen this should be available on the printer options as well for marlin.
But if you connect a computer, simply run something like pronterface or any other manual control gui and:
1) home axes
2) disable motors
3) move printhead in x/y directions as necessary by hand
4) adjust z height manually with the GUI software. This should not affect your x/y positions or turn on their motors.


text:
Print is not properly laminated at certain height
I have a Wanhao Duplicator i3.
I have done many excellent prints with this printer, and have first hand experience that it can do a pretty much flawless print.
But... Recently, I am experiencing weird results. My "flow" seems uneven. When laying down the first layer of the raft, I can see it looks like it "beads" in some places. Thin lines with little "beads" here and there (which seem to be in a constant pattern) i.e. -------()-----()-----()------()------ etc.
I initially thought, wet filament... But drying the filament had no noticeable effect. Further more, all my prints seem to be horribly laminated at a certain "height" of the print. This is really strange as it will print perfectly and only at a certain height, mess up about 5mm of layers (height wise), and then print great again. This seems to be a constant now.
I dont understand how/why this could happen, as the whole z-axis is on a linear spiral shaft. Unless there is a gcode issue somewhere that I am not aware off. I am using CURA as my slicer and I feel that even if there was an isnturuction hidden somewhere at a certain height, it would possibly effect a single layer, and not 5mm worth of layers.
Any ideas?
I have tried:
Different filament
Pushing flow % to 105 and 110% respectively
Cleaned extruder gears and print head
Oiled z-axis shafts
What baffles me, is the weird delamination (or rather lack of lamination) at a certain height. I have not measured this height exactly, but from guestimating, it looks like roughly the same height on every print where the issue is visible (about 3/4 up in the attached image). My support structures are also VERY messy, whilst they were very precise and perfect previously.

Thanks

Looks more like retraction issue. Need more data: 1) print retraction settings 2) heatbreak radiator temperature (should not be more than warm) 3) can you hear extruder motor clicks during the print?

Looks like either a retraction problem, or a heat setting issue. There could also be some buildup in your nozzle, but more than likely it's one of the first two.

Thanks to all the replies. Whilst all of them may be valid in some scenarios, my case seemed to have been a combination of things, that relates to most of the replies here.
I had my spool holder on the side of the machine, and I noticed some friction as the filament feeded over the "arm" on top of the printer into the extruder. I sat and looked at this for a while, and it seemed apparent that as the extruder moves up, the angle of the filament over the "guide arm" on top changes to a more severe bend. This may have been why it always battles to extrude nicely at a certain height, and then maybe recoveres after that to an extent. (SO yes, under extrusion may have been the issue)
I have now moved the filament to on top of the printer to feed straight down. I have also slowed down the travel to about half of what it was (40 now, was 60). I also dropped the infill speed a bit as that was also a mess most of the times.
So far I have had excellent results! I am not sure if its the travel speed drop or the extruder feed that helped the most, but I am a happy chappie again. (So far).
Thanks for all the input. It really made me re-look at all of this from a different view.

I have experienced similar issues with my cartesian printer. In my case, the force required to pull the filament from the spool was too great - on one occasion, the spool spindle was stuck so badly that the holder gave way and the spool crashed into the printer. After several iterations of spool holders, the problem is now gone for good.

This looks like a heating or retraction issue. I also have a Di3, and I encountered a similar problem a while ago. I have found that leveling the bed very well and making sure the z-axis is aligned fixes most problems with this machine. Re-calibrate your printer and try out a different slicer. This link from the 3D Printer Wiki is very useful.

Thanks, I have had better results with a higher printing temp, but it still shows every now and again. I will try the z axis squaring.. its easy enough to do frequently. I cant see it being a retraction issue, as that would manifest itself through the whole print, not just certain heights?

I had a similar problem with my prusa i3 variant i built. I found that this issue would decrease in occurance when retraction was disabled however would not completely disappear.
After much experimentation I found this to be a feed issue with the extruder. In other words the filament was not being pushed hard enough to the teeth of the hobbed bolt to have enough traction to pull the filament down as fast and easy as the extruder would to pull the filament up during retraction. Even without retraction enabled, my extruder's drive gear teeth would not dig deep enough into the filament to pull a consistent amount of filament for the same x amount of distance per instances of a similar timeframe.
Essentially because retraction speeds are much faster than normal extrusion and there is not enough force required to retract compared to having to pull filament from the spool the retraction and extrusion settings would yield results that do not match actual expected filament travel distance.
My recommendation in your case:
1) tighten your extuder idler so it puts more force on the filament. What might appear tight to you does not necessarily mean is tight enough for consistent pull. If yours uses the two long screws on springs for force maybe consider getting longer and tougher springs.
2) Be aware of your extrusion steps/speed. You don't want to grind your filament when retracting.


text:
Would 3D printing multiple copies at once saves time?
I am wondering - of course if the 3D printer's bed big enough - printing multiple copies of the same print could save me significant amount of time in a small production line, excluding minor wastage such as setup time, post-processing time, etc.

e.g. if my foo print takes 10 hours, printing 2x copies at the same time would take 2x times more, increasing linearly or it would be significantly less?

This depends. Are you printing everything from one extruder, or do you have multiple extruders working in parallel?

Both. The Beast with 4 and a maker

Saves which time; your time getting the prints off the bed one by one or the printer's time building all of those parts at once?

Actually no. It will take slightly more for each addition. You also then have the point of failure, where one gets knocked off and ruins all the prints.
The fastest way to print multiple objects is one at a time. In fact slic3r lets you do just that with their sequential printing feature.
The reason is, the time it takes to lift 0.5mm, travel the few MM over to the next object, lower the 0.5mm back down.. Repeat for inner shells, outer shells, infill.. all add time. Doesn't seem like much till you do it 14,000 times.
In the case of your example, it would be negligible. In more complicated or well spaced prints its another story.
For extra extra fast, look into loss PLA casting...

What does "loss PLA casting" have to do with this? How does it allow you to speed things up?

You might add to your answer that the user is pretty much responsible for verifiying that the  required X-Y clearance for the extruder head after a few objects have been printed is set properly.      And of course for those not using slic3r,  the advantage of printing everything at once is that we can walk away from the setup and come back when everything is done :-)

@TomvanderZanden They want to make a bunch. 3d print and make a casting.

That's not the right terminology then. "Lost PLA casting" refers to a process where a PLA print is encased in plaster, then burned/melted out, and then molten metal poured into the void left. The mold is then broken, and a metal part extracted. This doesn't help for making a bunch of parts, since both the master part and mold are destroyed. The idea to look in to (silicone) mold making and casting in resin is not a bad suggestion though, but not really related to the question (and there is no indication OP is looking to print that many copies of this part).

Yup, thats why it was a foot note and not the answer

If other processes are acceptable, "Cast Urethane Molding" would also be a really good option. It's a good option for the 20-1000 part numbers. Cheaper than injection molding or investment casting for those quantities. Faster and cheaper by far compared to 3D printing.
(suggested by Tom, but didn't have the terms explicit stated)

Silicon molds would be what I recommend now. There is also talk of DLP resin printing, that can do a whole plate at the same speed as a single item. Resolution is lower than say SLA.

Printing multiple parts can save you time.
The issues pointed out by the other posters are all bang on, but one factor that has been neglected is the time it takes you to clear the build plate and restart the print. I found for smaller parts (under 1 inch cube) printing several parts at a time was more convenient, and minimally faster. The time saved came more from the fact that I could leave the printer for several hours and work on other tasks without having to babysit the printer waiting for it to finish each part. I printed about 100-200 parts in this manner. I did end up losing one 'batch' when one part came loose and started causing problems, but I found that was a small price to pay for being able to get a lot of other things done.
It'll come down to the criticality of your deadline on the parts. If you're making parts for giggles and you don't need them done immediately, then i'd say one at a time. Less risk of failure, less wasted material and the time isn't super critical. If you're making parts for a prototype product that needs to be field tested in a few weeks, then i'd go with small batches of multiple parts. It'll give you more time to work on other things, less releveling, and you can check in once in a while to confirm it's okay usually without having to do anything assuming all is going well.

Yes, and no. It depends.
For FDM printing, the printing time mostly scales linearly with the number of objects. However, some printers have a "minimum layer time" whereby smaller layers are printed more slowly, to ensure each layer takes at least this minimum time. This gives the print enough time to cool.
Since the model shown in your example is quite small, it's quite likely that it will hit the minimum layer time. This means that printing one copy will take exactly as long as printing two copies, which will take exactly as long as printing three copies, until you hit the minimum layer time. At this point, adding more models will just add some constant number of minutes to your print time.
If the model is large enough for minimum layer time not to be a factor, then printing the objects one at a time is generally faster because you save on travel moves between the layers of the two objects (and also results in better quality print, since the inter-object travel moves may leave behind stringing).
This only holds for FDM printing. For DLP printing, the printing time for a (set of) models only depends on their total height and thus the number of layers required, since each layer requires the same amount of time regardless of the amount of material printed. Thus, the time for 1, 2, 3,...n models is exactly the same.
There are many other types of printing process where the number of layers is much more important than the amount of material used, such as binder jetting, SLA and SLS,... Here there usually is some time cost involved for material printed, but the main factor in the print time is the number of layers (and for SLS, the amount of time it takes for the build volume to cool down after each print, which is quite significant.).

The proportion of production improvement is dependent on the size of the items being printed, generally speaking. Unfortunately, it's variable enough to make a precise answer difficult.
Consider a single unit print. I'll use my printer as an example. Other printers may have similar sequences. The print is begun and the bed has to heat up to temperature. Once the set level is reached, the print head(s) also have to reach temperature. Ignoring for the moment the print duration, one then considers that the printer bed has to cool to release the print.
If you have ten items to print, you gain nine times the above elapsed time. That can be a substantial portion of production time.
On the flip side, there isn't going to be much benefit in time from ten prints opposed to one. You may lose some post-processing time if you have stringing between the items.
Directly related to quantity printing is yet another complication. If you have a single print fail, you've lost that time. As an example, one print may take 18 minutes. Twelve minutes into the print, you have a nozzle clog and have to abort the job. That's an unfortunate loss.
With ten prints on the bed, you are two hours into the print and have a failure. Much worse loss of time and productivity.
Obviously, one would prefer to have a properly fully working printer and be able to operate with the confidence that these failures won't appear.
Hobby grade printers can't provide that level of confidence, but industrial/commercial grade printers should, further improving the productivity time for printing multiple items on a bed.
If you have hot-swappable print beds, maybe combined with the ability to pre-heat the incoming bed, you gain time-wise. I don't know enough of the commercial grade printers to suggest that such a feature exists. My printer bed is attached with magnets and could be hot-swapped if I exercised care. The bed would begin to cool quickly, making a pre-heated plate all the more valuable. I'll just print multiple items and hope for the best, instead.

It generally takes longer to complete the actual prints because of extra travel moves, but it does save you time in one important way: if you trust your printer, you can start a large batch and then just walk away. Instead of resetting every hour or so, you can come back after several hours, or over night.
In this way, printing in batches can allow you to put more items through your printer in the same amount of time.

Actually the answer is yes and no. So I had to print 12 of the same small objects for a science experiment. Just some rocks I made from domes with some displaced faces, anyway my printers minimum wall width is 0.5 mm. The objects were 2 cm³. The first print failed because of them being disconnected but then I connected the 12 items by 1×1×5 mm solidified cylinders in blender and ran it through my cutter and it printed no problem. Afterwards I jusy clipped off the cylinder and was good to go. Just make sure you're object is connected at every point facing another.  Based on your picture it should be connected something like this:

Are you saying that your printer will not print multiple STLs as one job, they must all be connected and imported as a single STL?

Welcome to 3DPrinting.SE. Thanks for sharing your thoughts, but this doesn't answer the question. Furthermore, parts not being attached to each other and failing because of that is something I've never seen or experienced. Printing multiple things on the build plate and wether they are connected or not is not related.

It will save you and the machine time if done properly.
Simplify 3D has a setting that lets you do multiple layers at once; as most slicers do. Therefore if the part is 10cm tall, then you can set it to move to the next one after 10 cm. The machine would then build each one in turn on the build plate in sequence. You won't have to remove the parts very often, and the machine won't have to take the time to heat up after each print. If done incorrectly, as in moving from one part to another for each layer, then yes it will require a large number of slow retraction and Z-axis moves, costing you more overall time.


text:
G-code (M-code?) for Get Bed Temperature
I'm familiar with 3D printing, and the G-code concept. I'm also comfortable with programming.
Can anyone give me the G-code (or probably the M-code, actually) to read the bed temperature?
Is there an equivalent of M105 (Get Extruder Temperature)?

M105 should give you the bed temperature.
For future reference you can find a general list of G/M codes here - RepRap Wiki - G-code.
Most firmware files include a list, Marlin has it in Marlin_main.  I have no idea how often the list is updated but they don't change often.

M105 is the extruder temperature. I can''t find a way to get the bed temperature, though there is a code to wait until the bed has reached the target temperature.

@NomadMaker M105 should report the temperature for everything.

@NomadMaker please look into http://marlinfw.org/docs/gcode/M105.html

Your Marlin_main link had died, so I changed it


text:
Can 3D printers print details in the 1/10 of the micrometer for metals?
I'm starting to get familiar with 3D printers. I wish to know if printing details the size of 10-7 m (3.9*10-6 in) is possible these days with metals or any other material.
If anyone has information or articles as leads, I would really appreciate it.

You can get the 0.1 micron (100 nm) resolution with a 2-photon 3D printer, but only in a polymer resin.  Nanoscribe, in Germany, pioneered this technology, see Mechanical Microstructures.
Their commercial printer, the Photonic Professional GT, is about $350,000 US with software and accessories. There is some work being done to replicate the 3D printed polymer in metal using electroless plating or ALD (atomic layer deposition).  Other techniques are in development.
None of the direct metal 3D printing processes come close to your 0.1 micron resolution, although the field is rapidly evolving.  Only a couple of years ago, direct metal 3D printing was all based on powder bed fusion.  Now binder jet technology as been adapted to metals and, very recently, Xjet has developed a nanoparticle 3D printer. It prints "ink" composed of metal or ceramic nanoparticles suspended in a liquid.  The minimum layer thickness is 1 to 2 microns.  They have not released XY resolution data yet.
A good overall reference for the various 3D printing techniques (including Xjet, but not Nanoscribe) can be found at Explaining The Future - 3D Printing.

There's atom-based-printing 3D printers that only some universities have.
There aren't other 3D printers that can get even 0.001 mm precision, you want 0.0001 mm, that's pretty dicey. Just breathing on the device will make it shift a layer. Just walking on the floor next to such a device would kill it.
This one works with resins though, Ultra-High Resolution 3D Printing at the Micro-Scale with Nanoscribe.

The 'atom-based-printing' you're referring to I believe is a scanning tunneling microscope, which isn't a printer. I suppose the argument could be made that it could be used to build an object, however it isn't the primary role of the technology.

@AlucardPawpad can you please provide links or brand names of the printers you're referring to?

The 'atom-based-printing" is based on 2-photon polymerization and is, indeed, a 3D printing process--see my answer below.  However, many of the printed structures are so small that they can only be viewed with an SEM (scanning electron microscope).

There are no 3D printers (that I'm aware of) that can do 0.0001 millimeters, hobbyist or industrial, plastic or metal. For that matter I think you'll be hard pressed to find a CNC mill with that type of tolerances.
Sorry!

+1 Closest thing to it would be some sort of CNC grinder, but then you're limited in size and shape you can machine.

Today, only SLA/DLP will give features of that size (if even these technologies do), and I am unaware of anyone using these technologies to print with metals today.

They don't give features of that size. Form 2 adverises a laser spot size of 140um; 1000x bigger than asked in this question. It is impossible to print in metal with SLA/DLP because there do not exist metals that "cure" from a liquid into a solid state when exposed to light.

Thank you for the info, what would be the smallest order of magnitude we can print today with metals, any info on this subject would be helpful.


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What is the best color of PETg to use for outdoor durability?
I am doing a quad-copter now.
I am not sure what color is the best to use for outdoor durability, especially in sunlight.
They say PETg is the most durable material amongst cheap ones.
But what color to choose: white or transparent? Or it does not matter?

The best color for what characteristic? Durability, visibility, or something else?

@Davo, I need quad-copter to be durable at first place. I've read earlier plastics are somewhat vulnerable to sunlight.

I don't know why one color would be more durable than another... although white would probably be the most reflective, and have the slowest degradation from sunlight.

@Davo, how about transparent? I guess it's UV light that degrades plastic?

I haven't done a comparison; transparent might actually be better. But I expect reflecting the radiation is better than allowing it to pass through every bit of material. And even PETG is more translucent than transparent, so I expect it will be reflecting the light around internally off of the bead boundaries, and actually increasing the degradation. But as I've said, I don't know for sure.

Unless you plan to use your copter outside Earth atmosphere or expected lifetime is more than tenths of years, UV degradation should not be a problem for PETG. Yet if there are any concerns about this, lacquer car paint can help to absorb unwanted radiation.

Unless you plan to use your copter outside Earth atmosphere or expected lifetime is more than tenths of years, UV degradation should not be a problem for PETG. Some of the net sources indicate the possibility of degradation after significant time of constant exposure to outdoor conditions (mostly color change), which sounds mostly like absence of practical experience.
Yet if there are any concerns about losing mechanical properties from the sunlight, any opaque lacquer car paint can help to absorb unwanted radiation and add some nicer view to the model. Acrylic paint will also work (tried this once myself) but it may not be suitable for outdoor.

PETG might not be the best for long term UV exposure.
According to Midland Plastics, PETG doesn't hold up well in outdoor applications, and is susceptible to UV degradation. Unless you have an outdoor or UV rated PETG product which will have additional chemicals added to it, it may breakdown more quickly than you would expect. (the link I used was : http://www.midlandplastics.com/srtd_petg.htm)
Polycarbonate on the other hand does hold up better in outdoor applications and is better suited for long term exposure to UV light. Most quads and RC products you see that have a nice slick looking shell on them, are made from Polycarbonate. That stuff is usually vacuum formed sheets. It does still breakdown but it is a much stronger material. The downside is that PC requires a higher nozzle temperature, than PETG. (The reprap wiki has more info: http://reprap.org/wiki/Polycarbonate)
That being said PETG is not going to dissolve in sunlight. It will likely last upto a year if not longer depending on usage. If this is your first quad you're making, then odds are you'll have a crash due to hardware failure before excessive UV degradation (at least thats been my experience with prototype aircraft).
Good luck!


text:
Lines of PLA not sticking to the bed
When I am printing objects that have a lot of surface area on the first layer parts of that layer will rise up causing there to be gaps in the first layer. Here are two pictures. The first one was printing with a raft and the second one was without a raft. I am printing on 3M Painters tape, extruder temperature at 200, bed temperature at 60. I am using Hatchbox PLA Filiment.

Possible duplicate of Can't get print to stick, no matter what I try

I am able to get the print to stick onto the bed but it peals up during the infill. The rafts will print perfect, but the middle of the first layer is the problem

Still, it looks like you are simply too far from the bed - albeit slightly closer than in the potential duplicate question.

Too high a print speed for the infill.

You got a few things happening. First that temp seems low. I am printing PLA at 215.. but there are a lot of factors. Start with a simple calibration thin wall test. Which is just a wall, no body.
From there your bed could be closer. Maybe. I don't think that's really the issue. Slower speed and heat will make more of a difference. That said. I take a piece of paper and calibrate it so there just a little, but not too much, friction.
Make sure you are printing at 30% speed for first layer.
Last use a glue stick.

Do things in this order
1) Make sure your bed surface is appropriate. (PET tape, or elmers glue on glass. must be applied every 3 to 4 prints in used area)
2)Make sure extruder temperature is not too low or too high. Generally I'll start at the minimum recommended manufacturer's range for your specific filament + 5 degrees. Then bed temp around 55c to 60c.
3) Your bed calibration might be off. Bed calibration should be performed at standard operating temperatures. I.e. turn everything on as if you are about to print and wait to heat up and then make sure your nozzle is almost touching your bed surface (however not actually touching. Alternatively you can use a normal sheet of paper and test that way.

Too far from the surface for the first layer. Filament doesn't look flat enough
Possible slight under-extrusion (should be verified after fixing first issue)

In contrast to the other suggestions here, I would like you to try to slightly increase the distance from the bed.
The logic here is that the "thin walls" you are seeing during the first layer is is due to excessive extrusion as part of a too close bed leveling. The hypothesis is that the excessive plastic will "nudge" the previous laid down plastic, which will loosen it from the bed.
In my experience, this issue only occurs when printing large, connected first layers - situations where the excessive plastic builds up with nowhere to go.

I am having the same issue.  I saw one similar post describe this as "baconing" and said it comes from over extrusion.  Looking at the filament coming out I could imagine that if there is too much filament for the given travel speed, then it would buckle up. I tried decreasing the extrusion percentage. The Makerbot slicing program doesn't have a setting for that so I did multiple test prints and raised the filament diameter from the default 1.77 to 1.84 in the end, which is about at 20% decrease in the extruder output.  I also slowed the prints speed.  Both factors seemed to improve the quality, so over extrusion and speed both seem to be contributing factors, but the problem still hasn't gone away completely.  It's happening with white Makerbot brand filament on large layers but not with green Makerbot brand and small layer heights (I haven't yet tried green coarse or white fine).  I measured the white filament diameter with calipers and it is the proper 1.75mm, I'm just forcing it to extrude less by putting 1.84mm into the slicer settings.


text:
MakerBot replicator 2x glitches
I have access to a MakerBot Replicator 2X which I use to try to print ABS + dissoluble (both are MakerBot's original filaments). It is really a pain and the filaments most often gets clogged (80% of the prints have to be thrown away). I a supposed to use the printer in a professional context, but at the moment it is really problematic and I feel pressure going up...
I have initially tried the default parameters provided by the machine for known filaments (ABS: 230°C / dissoluble: 250°C / plate: 110°C + 0.1mm layers). As the nozzle got clogged I have made many other attempts with varying parameters and up to (250°C / 270°C / 135°C), which slightly improves things but is far from being really usable.
Any idea of where this comes from?
 - ABS being notoriously difficult to print?
 - The Replicator 2x being old tech?
 - A parameters problem?
Any advice on what I should do to improve the situation?

I have one and, you may want to check to make sure that both of the nozzles are at the same height off the build plate when you level. Mine is fairly old so they may have changed how they're installed. I found by adjusting the height of the nozzles to be closer to the same the prints came out more reliably. Mine were off by ~0.3 mm from the factory, and I was able to get them down to about ~0.1mm with a fair bit of playing with them. I hope it helps, but just to be clear this isn't a parameter set in software, this was a physical height that I checked using feeler gauges.

Thanks for the precision. I have tried parameters close to yours (getting inspiration from your parameters file) and with great success so far. It seems to be working now, especially with a reduced speed and higher thickness (as shown in your file). Thanks a lot!

I don't have a profile that has settings for the dissolvable filament anymore, but this is one I use for thin layers (second extruder at 232C my first extruder isn't working so just ignore that one).
You may want to try printing small simple objects with each extruder independently first to confirm that you have good settings, then try both together after you know you have good settings. ABS is a pain but mostly for warping and sticking to the build plate. The dissolvable filament I believe is PLA if you're using Makerbot materials.
{
       "_attached_extruders" : [ "mk8", "mk8" ],
       "_bot" : "replicator2x",
       "_extruders" : [ 0 ],
       "_materials" : [ "abs", "abs" ],
       "adjacentFillLeakyConnections" : false,
       "adjacentFillLeakyDistanceRatio" : 0,
       "anchorExtrusionAmount" : 5.0,
       "anchorExtrusionSpeed" : 2.0,
       "anchorWidth" : 2.0,
       "backlashEpsilon" : 0.050,
       "backlashFeedback" : 0.90,
       "backlashX" : 0.0,
       "backlashY" : 0.090,
       "bedZOffset" : 0.0,
       "bridgeAnchorMinimumLength" : 0.80,
       "bridgeAnchorWidth" : 0.80,
       "bridgeMaximumLength" : 80.0,
       "bridgeSpacingMultiplier" : 1.0,
       "coarseness" : 9.999999747378752e-005,
       "commentClose" : "",
       "commentOpen" : ";",
       "computeVolumeLike2_1_0" : false,
       "defaultExtruder" : 0,
       "defaultRaftMaterial" : 0,
       "defaultSupportMaterial" : 0,
       "description" : "External Definition",
       "doAnchor" : true,
       "doBacklashCompensation" : false,
       "doBreakawaySupport" : true,
       "doBridging" : true,
       "doDynamicSpeed" : false,
       "doDynamicSpeedGradually" : true,
       "doDynamicSpeedInteriorShells" : false,
       "doDynamicSpeedOutermostShell" : true,
       "doExponentialDeceleration" : false,
       "doExternalSpurs" : true,
       "doFixedLayerStart" : false,
       "doFixedShellStart" : true,
       "doInfills" : true,
       "doInsets" : true,
       "doInternalSpurs" : false,
       "doMixedRaft" : false,
       "doMixedSupport" : false,
       "doOutlines" : true,
       "doPrintLayerMessages" : false,
       "doPrintProgress" : true,
       "doPurgeWall" : false,
       "doRaft" : true,
       "doSplitLongMoves" : true,
       "doSupport" : true,
       "doSupportUnderBridges" : false,
       "endGcode" : "",
       "exponentialDecelerationMinSpeed" : 0.0,
       "extruderProfiles" : [
          {
             "bridgesExtrusionProfile" : "bridges",
             "feedDiameter" : 1.820000052452087,
             "feedstockMultiplier" : 0.9300000000000001,
             "firstLayerExtrusionProfile" : "firstLayer",
             "firstLayerRaftExtrusionProfile" : "firstLayerRaft",
             "floorSurfaceFillsExtrusionProfile" : "floorSurfaceFills",
             "infillsExtrusionProfile" : "infill",
             "insetsExtrusionProfile" : "insets",
             "layerHeight" : 0.20,
             "maxSparseFillThickness" : 0.20,
             "nozzleDiameter" : 0.40,
             "outlinesExtrusionProfile" : "outlines",
             "raftBaseExtrusionProfile" : "raftBase",
             "raftExtrusionProfile" : "raft",
             "restartExtraDistance" : 0.0,
             "restartExtraDistance2" : 0,
             "restartExtraRate" : 25.0,
             "restartExtraRate2" : -1,
             "restartRate" : 25.0,
             "restartRate2" : 25,
             "retractDistance" : 1.700000047683716,
             "retractDistance2" : 0,
             "retractRate" : 25.0,
             "retractRate2" : 50,
             "roofSurfaceFillsExtrusionProfile" : "roofSurfaceFills",
             "sparseRoofSurfaceFillsExtrusionProfile" : "sparseRoofSurfaceFills",
             "toolchangeRestartDistance" : 18.50,
             "toolchangeRestartRate" : 6.0,
             "toolchangeRetractDistance" : 19.0,
             "toolchangeRetractRate" : 6.0
          },
          {
             "bridgesExtrusionProfile" : "bridges",
             "feedDiameter" : 1.769999980926514,
             "feedstockMultiplier" : 0.9300000000000001,
             "firstLayerExtrusionProfile" : "firstLayer",
             "firstLayerRaftExtrusionProfile" : "firstLayerRaft",
             "floorSurfaceFillsExtrusionProfile" : "floorSurfaceFills",
             "infillsExtrusionProfile" : "infill",
             "insetsExtrusionProfile" : "insets",
             "layerHeight" : 0.20,
             "maxSparseFillThickness" : 0.20,
             "nozzleDiameter" : 0.40,
             "outlinesExtrusionProfile" : "outlines",
             "raftBaseExtrusionProfile" : "raftBase",
             "raftExtrusionProfile" : "raft",
             "restartExtraDistance" : 0.0,
             "restartExtraDistance2" : 0,
             "restartExtraRate" : 25.0,
             "restartExtraRate2" : -1,
             "restartRate" : 25.0,
             "restartRate2" : 25,
             "retractDistance" : 1.399999976158142,
             "retractDistance2" : 0,
             "retractRate" : 25.0,
             "retractRate2" : 50,
             "roofSurfaceFillsExtrusionProfile" : "roofSurfaceFills",
             "sparseRoofSurfaceFillsExtrusionProfile" : "sparseRoofSurfaceFills",
             "toolchangeRestartDistance" : 18.50,
             "toolchangeRestartRate" : 6.0,
             "toolchangeRetractDistance" : 19.0,
             "toolchangeRetractRate" : 6.0
          }
       ],
       "extruderTemp0" : 228,
       "extruderTemp1" : 232,
       "extrusionProfiles" : {
          "bridges" : {
             "fanSpeed" : 0.50,
             "feedrate" : 40.0
          },
          "firstLayer" : {
             "fanSpeed" : 0.50,
             "feedrate" : 10.0
          },
          "firstLayerRaft" : {
             "fanSpeed" : 0.50,
             "feedrate" : 50.0
          },
          "floorSurfaceFills" : {
             "fanSpeed" : 0.50,
             "feedrate" : 40.0
          },
          "infill" : {
             "fanSpeed" : 0.50,
             "feedrate" : 40.0
          },
          "insets" : {
             "fanSpeed" : 0.50,
             "feedrate" : 40.0
          },
          "outlines" : {
             "fanSpeed" : 0.50,
             "feedrate" : 10.0
          },
          "raft" : {
             "fanSpeed" : 0.50,
             "feedrate" : 90.0
          },
          "raftBase" : {
             "fanSpeed" : 0.50,
             "feedrate" : 10.0
          },
          "roofSurfaceFills" : {
             "fanSpeed" : 0.50,
             "feedrate" : 90.0
          },
          "sparseRoofSurfaceFills" : {
             "fanSpeed" : 0.50,
             "feedrate" : 90.0
          }
       },
       "fixedLayerStartX" : 0.0,
       "fixedLayerStartY" : 0.0,
       "fixedShellStartDirection" : 215.0,
       "floorSolidThickness" : 0,
       "floorSurfaceThickness" : 0,
       "floorThickness" : 1.0,
       "gridSpacingMultiplier" : 1.0,
       "infillDensity" : 0.3000000119209290,
       "infillOrientationInterval" : 90,
       "infillOrientationOffset" : 0,
       "infillOrientationRange" : 90,
       "infillShellSpacingMultiplier" : 0.70,
       "insetDistanceMultiplier" : 1.0,
       "jsonToolpathOutput" : false,
       "layerHeight" : 0.1199999973177910,
       "leakyConnectionsAdjacentDistance" : 0.0,
       "maxConnectionLength" : 10.0,
       "maxSparseFillThickness" : 0.1000000014901161,
       "maxSpurWidth" : 0.50,
       "minLayerDuration" : 5.0,
       "minLayerHeight" : 0.010,
       "minRaftBaseGap" : 0.0,
       "minSpeedMultiplier" : 0.30,
       "minSpurLength" : 0.40,
       "minSpurWidth" : 0.120,
       "minThickInfillImprovement" : 1.0,
       "modelFillProfiles" : {},
       "numberOfShells" : 2,
       "platformTemp" : 110,
       "purgeBucketSide" : 4.0,
       "purgeWallBaseFilamentWidth" : 2.0,
       "purgeWallBasePatternLength" : 10.0,
       "purgeWallBasePatternWidth" : 8.0,
       "purgeWallModelOffset" : 2.0,
       "purgeWallPatternWidth" : 2.0,
       "purgeWallSpacing" : 1.0,
       "purgeWallWidth" : 0.50,
       "purgeWallXLength" : 30.0,
       "raftAligned" : true,
       "raftBaseAngle" : 0.0,
       "raftBaseDensity" : 0.6999999880790710,
       "raftBaseLayers" : 1,
       "raftBaseRunGapRatio" : 0.8000000119209290,
       "raftBaseRunLength" : 15.0,
       "raftBaseThickness" : 0.3000000119209290,
       "raftBaseWidth" : 2.50,
       "raftExtraOffset" : 0.0,
       "raftFillProfiles" : {},
       "raftInterfaceAngle" : 45.0,
       "raftInterfaceDensity" : 0.3000000119209290,
       "raftInterfaceLayers" : 1,
       "raftInterfaceThickness" : 0.2700000107288361,
       "raftInterfaceWidth" : 0.4000000059604645,
       "raftModelSpacing" : 0.3499999940395355,
       "raftOutset" : 4.0,
       "raftSurfaceAngle" : 0.0,
       "raftSurfaceLayers" : 3,
       "raftSurfaceShellSpacingMultiplier" : 0.6999999880790710,
       "raftSurfaceShells" : 2,
       "raftSurfaceThickness" : 0.1400000005960465,
       "roofAnchorMargin" : 0.40,
       "roofSolidThickness" : 0,
       "roofSurfaceThickness" : 0,
       "roofThickness" : 1.0,
       "shellsLeakyConnections" : false,
       "solidFillOrientationInterval" : 90,
       "solidFillOrientationOffset" : -45,
       "solidFillOrientationRange" : 90,
       "sparseInfillPattern" : "hexagonal",
       "splitMinimumDistance" : 0.40,
       "spurOverlap" : 0.0010,
       "startGcode" : "",
       "startPosition" : {
          "x" : -112,
          "y" : -73.0,
          "z" : 0
       },
       "supportAligned" : false,
       "supportAngle" : 30.0,
       "supportDensity" : 0.2000000029802322,
       "supportExcessive" : false,
       "supportExtraDistance" : 0.50,
       "supportFillProfiles" : {},
       "supportLayerHeight" : 0.2000000029802322,
       "supportLeakyConnections" : false,
       "supportModelSpacing" : 0.2000000029802322,
       "supportRoofModelSpacing" : 0.4000000059604645,
       "thickLayerThreshold" : 0,
       "thickLayerVolumeMultiplier" : 1,
       "travelSpeedXY" : 150.0,
       "travelSpeedZ" : 23.0,
       "version" : "3.9.4"
    }

I can already spot heavy differences with my params (ex: travel speed: you go rather slow (40) while the default values I use are much higher (90))... Thanks a lot!

authors: الناكح المريول


text:
What G-code commands tell the printer to change nozzle on a dual extruder printer?
I have been playing around with creating scripts to generate some custom G-code for a Malyan M180 and I am having trouble understand what commands to use to switch nozzles. Sometimes I can get the nozzles to switch and it doesn't recenter but sometimes it does.
I have been using:
G54
M108 T0; switch to left

and
G55
M108 T1; switch to right

Has anyone else looked into this and have any idea what commands or sequence of commands should be used to change nozzles?

Be careful with questions about G-Code as it is no longer standardized and can technically be different between manufacturers and even between models. This is true across all machines (mills, lathes, 3d printers, routers, etc.)

Adding on to tbm0115's comment, G-code differs across firmwares, and can change between firmware releases. The reprap wiki, linked in one of the answers, attempts to provide information for the most popular 3D printing firmwares, but it is not always accurate or up-to-date.

No, M108 does not do that. You are looking for T#, where # is the tool position you want:
T1 ; switch to tool position 1

T3 ; switch to tool position 3

This tells the processor to send all heating, cooling and flow commands to this tool until another tool change is specified, and invokes the X/Y(/Z) offset for the new tool position.
See http://reprap.org/wiki/G-code#T:_Select_Tool

As @tbm0115 has mentioned - it differs. Your M108 T{index of tool} command is perfectly fine on some FlashForge printers, a company known for its different sorts of proprietary code. It is indeed used for tool changing here.
While on the common Marlin firmware (e.g. used on the popular Creality Ender printers), M108 does a completely different thing-namely acting as a break sequence if the G-code parser is in a closed-loop-condition (after certain commands like M109 that wait until a certain action takes place).


text:
Reprap Ormerod 2 Duet web control not automatically starting, how can I fix?
I have an Ormerod 2 which is controlled by an Duet board with original up to date firmware. When I power it on and try to use the web interface (web control) it seems to not have started. When I connect my printer to my laptop and use Pronterface (printer interface) to send t0 to the printer it replies
Starting network...
RepRapFirmware is up and running.
Starting DHCP
Network up, IP=censored
which leads me to the conclusion that the printer isn't starting its firmware and the web interface before that.
After sending t0 and waiting 10sec for these replies it works fine.
Every source says it should start automatically.
So my question is how do I fix that? or what even is the problem?
Thanks in advance.
EDIT: For everyone wondering: One time I let the printer sit powered on for ~1h before trying to connect and use Pronterface, same story as above.

Hmm - this is an old one, so I'll assume it worked somehow. What versions of firmware did you have? What did you do to fix it?

First thing I would do is to update firmware to the newest version: https://github.com/dc42/RepRapFirmware/releases
See details on Duet wiki page: https://duet3d.dozuki.com/Guide#Section_Updating_Firmware_and_Duet_Web_Control


text:
Can functional hinges be built with food printer?
In trying to understand 3D printers, I have watched some YouTube videos where the crafters make items with hinges. That in itself blows my mind. It is hard to grasp how something with moving parts can be printed. But specifically I am wondering if the concept can be extended to food printers to make, for example, a sugar or chocolate telescoping lollipop (sucker)?

What specific food printer? There are lots of different ones out there, and there isn't really a canonical food printing technology. The answer would strongly depend on what you are actually printing with.

If you want to know what tags to use, ask a separate question on meta.

Hi, Wyatt! As pointed out by Tom, a specific answer to your question is highly dependent on the foot material which you choose to use. For this reason, I have to put your question on hold for being unclear for now. If you choose to add more details to your question, we will be happy to reopen it once edited. Good luck!

I don't know much about food printers. But at the very least, you should be able to print similar moving parts like hinges as you would with a standard FDM printer.
When printing things like hinges with a single extruder printer, the machine will typically be configured to include support structures. This is basically very thin scaffolding that higher layers of the print can sit on.
As Tom van der Zanden pointed out, though, this highly depends on the food medium you wish to use. With plastic, the material is heated to a less than liquid point, usually allowing the material to "bridge" across gaps. If your food medium is too thin (or close to liquid) you will not be able to effectively print supports as the medium will fall between the gaps.
If you are able to effectively print the supports for overhanging features, you should be able to knock off the supports with a small knife or toothpick. If it's a moving part, sometimes "shimmying" the part will knock the supports off.

This answer seems to focus on FDM-type printers. With food I think sintering (candyfab) and binder jetting (chefjet) are also common options.

I was thinking more along the lines of Frostruder, so similarities  to FDM made sense to me.

When I was looking at your question I thought it was impossible But a bit of research shows a resounding yes. If one looks at what Hershey can do, I see no reason why you could not printer a hinge.
Hershey Tech crunch
Also keep in mind this is pretty fragile..
You can take a powder printer that uses sugar as its base and a simple binder, maybe water. Tada you have advanced hinges and the like.
Here is Candy Fab open source Candy printer.
There are lots of ways people are doing this. Here is a SLS version where they just melt the chocolate with a laser..
SLS candy printer


text:
Arduino 3D printer sketch
I'm building an automatic warehouse system using three NEMA 17 stepper motor.
My problem is to move the motors with precision, since I do not have any kind of encoder on the motor and so I cannot know the position of the axes. I thought that the system could be similar to a 3D printer, since neither 3d printers have encoder on the motor.
Where can I find a sketch for Arduino of a 3D printer, to understand how they work? How do they move with such precision without any kind of sensor?

Hi Luca, have you tried http://arduino.stackexchange.com/ ? Unfortunately this is not a 3d printer so we cannot help..

A better title for this question would be "How does a stepper know its position without feedback from an encoder?". However, I'm not sure if this is on-topic here.

[For now] most of the open source 3d printer firmware written for Arduino-based hardware. This means you can just download the source and look through the relevant pieces of code.
Marlin is the most obvious example.

A stepper motor is different from a typical electric motor. Instead of being "on" or "off", or running a some approximate variable speed, the controller sends a series of pulses to drive the motor one step at a time. This can be driven forward or backwards.
Based on how the motor and machine is designed, the machine will move a tiny amount. If for example, one step moves , say 0.1mm. If you send 150 pulses in the forward direction, the machine will move 15.0mm If you then send another 8 pulses in the reverse direction, the machine will be 14.2mm from the starting point.
To know the absolute position, you need to establish the starting point. Most printers have limit switches at their "home" position. To initialize the position, drive the motor until it hits the switch, and then set position as zero.
Then count the pulses up and down as you send them, you will will keep track of the machine's position.


text:
Ugly 3D printing with high precision
I am a totally beginner at 3D printing and I have this question: I see many 3D printers (at amazon) with Z precision as low as 0.1mm! To me that's amazing but what does not amaze me is this: when I see the printed objects of those 3D printers you can easily with naked eye see the "vertical steps". How?
A precision of 0.1mm should be really almost impossible to see. If a person printed using 0.1mm precision how can I see the vertical steps?
I know there are some smoothin techniques to make the surface better but that shouldnt even be needed if the printer actually printed at 0.1mm in the first case.

The 0.1mm refers to the thickness of each layer. However, it does not say anything regarding:

How precise the layers are in the XY plane
How precisely each layer is aligned with the previous in the XY plane
How consistent the extrusion is: are all the layers printed with a consistent line thickness

No matter how fine the layers (and these printers that you refer to can definitely print 0.1mm layers just fine); if they're not well-aligned with each other, or the filament extrudes inconsistently, you're going to see the layer lines. It takes a rigid printer, with low-play bearings, a well-calibrated extruder and filament with a consistent diameter to get smooth-looking prints (but you will always see some layering, especially if you look up close). Also, since filament is extruded in a round shape, the sides of the object are not perfectly flat, but consists of many small arcs, which makes it easier to see the layer lines.

...and the filament that is extruded on each later isn't perfectly merged with the previous layer. Each layer on an outer shell is slightly rounded making the layer lines more prominent.

so it's a useless selling mark saying "Oh, with our printer you will have up to 0.1mm thickness of precision" if the extruder is not good, the structure is not rigid... Cause I am really amazed the amount of printers that state a 0.1mm precision BUT when you see the finished product it has very visible layers like a stair. Could you please tell me if there is any techinal detail that I can look at the printer to know if it's precision is good since I cant rely on the precision of the thickness of each layer?

@Samul There's no way to tell really. The layer thickness figure is completely useless, because printers that promise 0.1mm can usually do thinner layers just as well. Best way is to get a test print from the printer you intend to buy.

@Samul Probably the best thing that you can do is look at reviews (and working equipment) on YouTube. Thomas Sanladerer seems to be impartial (and his videos are excellent). There are plenty of useful reviews and tutorials out there. In the end, quality usually costs money.