Tobold's Blog
Wednesday, August 23, 2017

And if all others accepted the lie which the Party imposed – if all records told the same tale – then the lie passed into history and became truth. "Who controls the past," ran the Party slogan, "controls the future: who controls the present controls the past." And yet the past, though of its nature alterable, never had been altered. Whatever was true now was true from everlasting to everlasting. It was quite simple. All that was needed was an unending series of victories over your own memory. "Reality control," they called it: in Newspeak, "doublethink."
I have a memory problem. My memory is too good. When a few years ago I became interested in the history of the American Civil War and read a lot of books, saw a lot of documentary films and the like, the culture wars hadn't reached that area of history yet. And so my memory tells me that in those unpolitical history books Robert E. Lee was depicted as a decent person. Yeah, sure, he was fighting for the losing side, and the losing side was obviously pro-slavery and thus on the wrong side of history. But history, before it got redacted by "the Party", said that Lee wasn't a political firebrand. He only entered the war reluctantly, out of a sense of duty to his state. He was a slaveholder in a state where everybody who had any social status was a slaveholder. At the time history still judged him on his actions as a general in the war. And on that count he wasn't doing all that badly, being both competent and humane. If you took history documents from a decade ago and judged by them who the more decent human being was, Robert E. Lee would probably win over William T. Sherman, who was fighting on the winning side, but with far more brutal methods.

Of course that was a decade ago, and I really need to reformat my memory. Today the party line is that the statue of William T. Sherman in New York Central Park is honoring a hero, while the statues of Robert E. Lee are being torn down everywhere for being too offensive. An Asian American ESPN sports commentator, who unfortunately has the name Robert Lee, was pulled from a game because his name was considered too toxic to be on TV.

Now statues of the losers being torn down is quite a usual occurrence after a war, don't we all remember the pictures of people tearing down statues of Saddam Hussein? What is somewhat weird is doing it 150 years after the war ended. Hey guys, we just discovered that Robert E. Lee was fighting for the slave-holding South, so we need to remove his statues now! Sorry we didn't notice that earlier! What on earth has Robert E. Lee done in the past years to deserve such a fate now that he didn't deserve a decade ago?

Although blaming "both sides" apparently isn't politically correct any more either (or maybe it is if the other side is the "right" one?), I would say that the extreme right rallying around confederate symbols is of course a major trigger to those symbols suddenly becoming politically incorrect. That makes Robert E. Lee a victim, being caught in the middle of a culture war. It might have some rather hilarious results if the extreme right would chose symbols that more difficult to tear down, like the American flag. To some extent the Constitution of the United States of America is already a symbol of the extreme right, if you find somebody with a copy of it in his pocket he probably is a Trump voter. Or an immigrant in the process of learning it by heart as part of the naturalization process. Or a supreme court judge. So fortunately we don't have to burn it yet in order to be politically correct.

Nevertheless, as a student of history I find the efforts to change or re-interpret history 150 years later somewhat worrying. Imagine we would tear down the Arc de Triomphe in Paris, because Napoleon lost his wars 200 years ago, and for some reason we now find his symbols offensive. When the Taliban destroyed the Buddhas of Bamiyan, we lamented the loss of history. Isn't the preservation of history a bigger value for humanity than the need to remove anything that could be deemed offensive? If the culture wars rage back and forth, with both sides being in power at some point, aren't we in danger of losing all our history, because it doesn't fit with some party line? If history is offensive, which it certainly sometimes is, aren't we still losing more by erasing it than by preserving it as a reminder to do better next time around?

The 7th Continent

I received a parcel yesterday which contained the board game The 7th Continent. I had backed the production of that game on Kickstarter. I don't often do that, it is only the 5th Kickstarter project I backed. But I am happy to report that with that parcel I am now at 100% success rate, every single Kickstarter project I backed actually delivered. Of course they all delivered late, The 7th Continent had an "expected" delivery in October 2016, and so is nearly a year late. I think a year late is about average of the projects I backed.

Kickstarter claims that only 9% of Kickstarter projects fail to deliver if successfully backed. But curiously they don't back up that claim with hard data to which they should have access, but rather cite an opinion survey. Other sources claim much higher failure rates. And if you follow games media, stories about Kickstarter failures like this one aren't all that uncommon. Furthermore as long as the developers deliver *anything*, that isn't counted as a failure. That doesn't mean that every delivered product lives up to the hype.

I think that only a very small part of Kickstarter failures are actual scams. I always apply Hanlon's razor and easily explain failures with incompetence without having to imply malice. Some people are simply good at having bright ideas and marketing those ideas in an enthusiastic way, but are just plain bad at project management. Which both explains many of the total failures as well as the 75% to 84% late delivery rate of Kickstarter.

Of course I don't back Kickstarter projects that are predictable failures, like people promising a large MMORPG for under $1 million. In general I would also advise to stay away from all Kickstarter projects for computer games: If the project is an actual success, you will be able to buy it later. So I rather back projects like The 7th Continent, which is so niche that it isn't obvious that one can get the product outside of a Kickstarter campaign. If you want a copy of that board game, you'd actually have to back the Kickstarter for the second print run, it won't be available in your neighborhood games store. I also sometimes back Kickstarter projects that are basically donations for a good cause, like rebuilding EN World.

In short, as long as you are aware of likelihood of failure, and the near certainty of late delivery, backing a Kickstarter project can be a good idea. Just don't fall for the hype and get overly enthusiastic. Or you might still be waiting for Star Citizen 3 years later.

Tuesday, August 22, 2017

For weeks I have been having problems with my XYZ Da Vinci Jr. 1.0w 3D printer. Some prints work just fine, while other fail. Even worse, some prints which work fine if I try to print a single figurine then fail if I try to print multiple copies at the same time. It was driving me crazy, until with a lot of testing and observing I finally found out what the problem is: Retraction.

So what is retraction in 3D printing? Imagine printing a model of the Eiffel Tower. There is a lot of empty space in such a model. Because the print is done layer by layer, from the bottom up, the print head has to print a small thickness where a girder is, then move without printing to the next girder. In order to prevent PLA from coming out of the print head and causing strings to appear between the girders, the stepper motor is pulling the filament back a little bit before moving. That pulling back is called retraction.

Now what is happening with my printer, and I am not 100% sure how or why, is that the stepper motor is more efficient during retraction than during moving the filament forward. It basically retracts too much, and then after the movement pushes forward the filament by too little. So if I print a piece with lots of empty spaces and lots of retraction happening, while the solid sections are relatively thin, I end up retracting more and more, until the end of the filament has completely left the hot part of the extruder head. While the print head is still moving, there is no more plastic coming out of the nozzle at all, and the print fails.

Now there is a lot of 3D printing software with millions of settings where you can change the setting for retraction. Unfortunately the XYZ Printers don't work with any of those 3D printing programs. They only work with their proprietary XYZWare. Which is deliberately simplified to make "plug and play" printing for the average customer possible. Somewhere in the depths of the code there must be a retraction setting (you can observe the filament moving backwards), but there is no way to access or change that setting. And I don't want to "jailbreak" my 3D printer with some modified firmware, because that has the potential to completely break it.

Right now my solution is simply to avoid printing models with too much empty space in them. That means printing miniatures one by one instead of in batches, which would be more practical for prints during the night. But the long-term solution will be buying a better 3D printer which isn't so limited with what software I can use, and what settings I can change. Right now I am thinking of still waiting a bit with that, as I haven't found the printer of my dreams yet. One important feature for me is being able to print via WiFi, and surprisingly few printers have that. I want a pre-assembled 3D printer with a sturdy frame, not a wobbly self-assembly kit. But of course I don't want to spend a fortune on it either. My $500 printer is maybe not high enough quality, but I wouldn't want to spend more than $2,000 even on a good printer. As the market is developing, I might find the printer I want next year.


Monday, August 21, 2017
I'm shocked, SHOCKED, that racism is going on here!

When viewed from over here in Europe, American politics sometimes appear a bit weird. Last week it was weirder than usual. President Trump flip-flopped on his condemnation of white supremacists and racists, and there was a huge outcry about how he finally failed to take a strong verbal stand against racism. That left me very much confused! I had been under the impression that as a candidate Trump had run on a platform of pretty open racism and hate of foreigners, especially Mexicans and Muslims. I had been under the impression that a large part of the American electorate, somewhere between 30% and 50%, believed that foreigners were to be blamed for many American problems, and that an anti-foreigner "America first" policy would improve things. In short, I thought that once you stripped off the veneer of political correctness, the policies of xenophobia and racism were pretty much American mainstream. So how come everybody is so outraged if a president says what we all know that he is thinking?

What is so weird about political correctness is that people are okay with *actions* that directly target a specific race or religion, like building a wall towards Mexico, or a Muslim travel ban. But *speech* which contains racial or religious or gender discrimination is unacceptable? I can't help but wonder whether it wouldn't be a lot saner to do it the other way around: Have an open discussion about the fears and prejudices people have towards other races, religions, genders, or sexual orientations, but refrain from actually persecuting people for having a different race, religion, or sexual orientation. There is strong scientific evidence that a certain degree of xenophobia is something hard-wired into the parts of our brains from an earlier evolutionary period, and overcoming xenophobia means teaching the newer parts of the brain to override those outdated instincts. Prohibiting people from talking about those instinctive feelings isn't really helpful in that respect, because it doesn't make those feelings go away.

Friday, August 18, 2017
Preparing D&D adventures

Dungeons & Dragons is a game that combines tactical combat with interactive story-telling. As much of the game is free form, the results vary widely. And because the game is asymmetrical, the DM carries somewhat more responsibility than the other players for everybody having fun. While every DM is different in some aspects, there are a number of recognizable "schools" of the art of DMing. And one important distinction is the amount of preparation different DMs put in, which can vary from nothing at all to spending far more hours preparing than playing.

Personally I am at the more prepared end of the scale. I not only believe that preparing D&D adventures well gives a better result when playing; for me preparing is also an opportunity to spend more time with Dungeons & Dragons, seeing how there are frequently two or more weeks between my actual games of one campaign. I admit that some of my preparation is a bit over the top, like printing all the monsters with a 3D printer, or getting my battle maps printed in poster format. However the result of having maps, monster miniatures, and handouts is a far more visual game. That appeals to a lot of players, because the whole "theater of the mind" thing isn't really everybody's cup of tea. It doesn't make the game less imaginative, because the miniatures and maps are just visual aids, which don't keep players from imagining the situation in more detail in their heads.

If necessary I could play without those materials. But the preparation I consider to be absolutely necessary is knowing the adventure you are playing very well. It is the nature of the game that players will do surprising things, and if that reduces the DM to frantically paging his adventure module to try to find out how he should respond that really kills the flow of the game. Knowing your adventures well also allows the DM to foreshadow, dropping hints of things to come into the game which make the world feel so much more alive and less scripted.

Having said all that, being able to arrive at a good preparation result faster is an obvious advantage. Now that I am DMing a second campaign at a local RPG club in parallel to my "home campaign", I have the opportunity to use the oldest trick in the book to speed up preparation: Recycling. I am playing adventures in 5E which I previously played in 4E in my home campaign. Currently I am preparing Madness at Gardmore Abbey, an adventure I played in 4E back in 2013/2014. Having already played through the adventure for a whole year, I know the story very well. And I still have the files for the battlemaps, as well as flowcharts, handouts, and other preparatory materials. With me playing more, and 5E being a lot faster than 4E to play through the same adventure, getting the same preparation done is less time is certainly welcome!


Thursday, August 17, 2017
D&D Beyond splurge

D&D Beyond went from beta to release status, and I decided to buy the "Legendary Bundle": $280 for a digital version of *all* existing 5th edition Dungeons & Dragons books, plus rebates on future content. I wanted to have a legal, searchable version of the rules, and a character builder with all options, and that is what this bundle provides.

However there are some obvious caveats: While $280 is just about half of what I already paid for the physical books, it is still a significant chunk of money to pay for content I already owned in paper form. The content is digital, but to the best of my knowledge only available online, not offline, which isn't ideal for mobile content. And of course Dungeons & Dragons has 40 years of history of handling digital content very badly, from pursuing people creating homebrew content on Usenet to a string of digital products that over-promised and severely under-delivered.

To some extent it was a question of principle. A simple Google search gets you the same rule books and adventures illegally for free, as pirated pdf files, which work offline. But it is the fear of that sort of piracy that prompted TSR / WoTC in the past to restrict digital distribution. Buying the bundle is sending a message that digital content is very necessary for a pen & paper game in this day and age, and that some people are willing to pay for it.

Ultimately the purchase is a gamble, a risk. I'm betting that there is some benefit to having access to all this material online, and that Curse is going to improve the usefulness further, rather than messing it up. I just hope I am right about that.


Wednesday, August 16, 2017
Airline Tycoon Free Flight

Kalypso Media is a German video game developer and publisher. They mostly make simulation games, like the Tropico series. Their games tend not to be the highest rated, but they do okay, and what they lack in blockbusters they make up in number of different games released. And apparently they also make a handful of mobile games, one of which is Airline Tycoon Free Flight.

Airline Tycoon Free Flight (ATFF) is a business simulation game, which for mobile has been reduced in complexity compared with Airline Tycoon 2 or other PC business simulation games. The most important deviation from more serious business simulations is that in ATFF you can't make a loss on a flight; if the cost of a flight is higher than its revenue, you simply get 0$. Which makes the game very casual, which isn't necessarily a bad feature for a mobile game.

The basic game consists from flying passengers from one airport to another, on a world map which is flat, not round, and so there is no connection from Asia to America. At the start you only have access to small airplanes, cheap staff, and few airports. So you make money on those flights and invest that money in more and bigger airplanes, more and better staff, and more airports, which you can also upgrade to hold more passengers.

The passengers arrive at the airports in real time. So if you played for a while, you will run out of passengers, and better stop until the airports are full again. Other than that there is no artificial energy / stamina resource that prevents you from playing as much as you want. And once you got enough airports and have the upgraded, you can play for quite a while before you run out of passengers. Also in other aspects the game is unusually unobtrusive for a Free2Play game: At no point does the game present you with a pay wall, or nag you for money. There is a currency you can buy for cash, but it is not really needed for anything but a few special airplanes and staff members.

While ATFF is certainly harmless for a business simulation, it is actually quite fun to fly airplanes left and right and try to improve your network of airports. I would recommend trying out the game for free.

Friday, August 11, 2017
Is multiplayer an error?

I've never played Friday the 13th: The Game, but according to its Wikipedia page the game has 1.8 million players in spite of having only mediocre reviews. The only reason I know about the game at all is because this week's news about it: In this asymmetrical multiplayer game, one evil Jason against a group of camp counselors, the devs had to implement a patch to remove friendly fire, because the camp counselors kept killing each other deliberately instead of actually playing the game against the Jason player. Sigh!

Online multiplayer games are now about 2 decades old. Developers like them, because they have positive network effects, that is players serve as content which attracts other players; and you don't have to program a complicated AI if you just let players fight each other. But nobody managed to really solve the problem of gamers being such assholes in an anonymous multiplayer environment. Pretty much every multiplayer game has a long list of complaints, where players are unhappy about the behavior of other players. The removal of features which lets players communicate and interact with each other is more common than adding such features, because each such feature brings its own set of problems. The most successful multiplayer games are those in which players have the least opportunity to freely interact with each other, where there is no chat, and no way to hinder another player's progress.

So I have to ask whether this trend towards multiplayer games wasn't a mistake. Games which have positive network effects also have negative network effects, so that player number frequently fall precipitously a few months after release. When players leave it gets harder to find the necessary people to start a match, and nobody likes waiting for that. Some people like a game, but are then driven away by the nasty behavior of other players. And the multiplayer aspect frequently requires the game company to run game servers, so these games frequently die completely when the servers are shut down, as opposed to single-player games you can find on still decades later.

Whether players are annoyed about others deliberately griefing them, or just unhappy because their team members aren't competent enough, I am not certain that the positive effect of a game being multiplayer compensates for all the negative effects. I know already quite a number of games which I don't play because they are multiplayer, or would like more if they were single-player. The dream of being able to play with people from all over the world quickly turns into the nightmare of finding out that people from all over the world aren't actually very nice. And even game companies would probably recover the added cost of programming an AI over time due to having significantly less customer service costs for a single-player game.

Multiplayer has been tried, and failed. Maybe it is time to try something else, like developing better AI.

Thursday, August 10, 2017
A niche within a niche

I was watching a video on YouTube about 3D printing miniatures for tabletop wargaming. The conclusion for the guy who made the video was that 3D printing was okay for stuff like terrain, where he didn't care too much about, but not of high enough quality for his painted wargaming miniatures, where he cared a lot about how they looked. I don't disagree. But it makes me realize that in fact my personal application of 3D printing for my Dungeons & Dragons games is special, a niche within a niche. Because I have extremely low requirements, which a cheap 3D printer is well able to fulfill.

I was never much interested in painting miniatures, which was compounded by the fact that I never had much skill in that area. I have a small collection of metal miniatures, but they are either unpainted, or have been painted by my brother or friends who are good at that sort of stuff. And I wasn't even using these miniatures during the years I DM'd two 4th edition campaigns, I used tokens I printed in 2D on thick paper, and then stuck on self-adhesive felt pads.

The reason why I never was overly concerned with the quality of my monsters is that tend to be used for a relatively short time. Even more so in 5th edition, where the fights are shorter. But in a D&D campaign one usually uses a lot of different monsters. There are over 400 of them in the 5E Monster Manual. Some you might use several times: If you have an adventure about fighting orcs, you'll end up with several fights against orcs. But obviously always fighting the same monsters gets boring for both players and DM, and so one always tries to mix it up. And of course different monsters have different "challenge ratings" (as it is called in 5E), aka levels, and while at the start of your campaign you might have some interesting fights against goblins and kobolds, later on you fight orcs, ogres, or even giants.

I know some people spend weeks on building dioramas for D&D. The results can be highly impressive. But obviously it takes you far more time to build a diorama of a scene or a whole dungeon than it then takes to play through it. If you hobby is actually playing D&D, as opposed to building dioramas, putting too much effort into your monsters and terrain simply isn't worth it.

In my current 5E campaign, the first dungeon contained a bunch of goblins, a handful of wolves, and a bugbear. The biggest fight involved all three types of these monsters. So for me the "specifications" or requirements I had towards my 3D printed monsters were simple: I wanted the monsters to be at the right scale compared to the 28-mm scale painted metal figurines one of my players provided for the heroes, and I wanted them to be easily distinguishable, with no doubt of which one was the bugbear, the goblin, or the wolf. I didn't need them to be painted or very pretty. I didn't need their surfaces to be very smooth, the layered structure of a 3D printed object wasn't really a problem. I didn't need a whole lot of them, as rarely there are more than half a dozen monsters of the same type in a D&D fight. In short, my requirements are a whole lot lower than what somebody needing miniatures for tabletop wargaming might require. The monsters I print are cheap and not pretty, but they serve their purpose in my D&D game. And being 3D results in me and all players around the table easily being able to see from every angle which one of the monsters is the bugbear, which isn't quite as obvious with my previous 2D tokens.

In short, I am still using my 3D printer nearly every day to print out monsters for my campaign. I am preparing a big campaign, and I have some technical problem with my printer where it does well printing a single miniature, but fails if I try to print several of them in a single job. As 3D printing is inherently slow, printing the whole army for a campaign takes a lot of time, albeit not a lot of attention. But besides this specific niche within a niche application, I haven't really found another good reason to own a 3D printer.


Wednesday, August 09, 2017
Regrets, I've had a few ...

I recently bought the game Egglia for $10 for my iPad, and now I regret that purchase. 10 bucks is relatively expensive for an iOS game, and the game turned out to be far from what I wanted. The description, as an JRPG with turn-based tactical combat on a hex grid, looked like exactly my sort of game. But in reality the combat system is so simplistic (you roll a six-sided die, which both tells you how many spaces you can advance, and how hard you can hit at the end of the turn) that it simply isn't much fun at all. It just feels totally random, there are no tactical decisions to make, and after a short while of hoping that it would get better, I just got completely bored with the game.

Of course that isn't the first time that I regret buying a game. I bought my first computer in 1981, and in the 36 years since I have bought a lot of computer games, some of which certainly disappointed. But the regret about Egglia stood out because it was going against a trend: Over time the percentage of disappointments in buying computer games has massively decreased. That is not because computer games are somehow better these days than they were before. Well, in technical specifications they are obviously better, but the games of 2017 aren't necessarily better games or more fun than the games of the 1980's. However two things changed since then: It is now much easier to get information about games before buying them, and the financial stakes are lower.

If today I buy a game on Steam, I first look at the user reviews. Not just the simple percentage of positive reviews, but what exactly the people who gave negative reviews are complaining about. I also check game reviews not on a single publication, but aggregated on Metacritic, again looking what are the strong and weak points mentioned. A game where somebody else gives a bad score because it is slow and makes him think too much might be a game I value more highly. A game that gets bad scores for being an unfinished mess full of bugs might be better to stay away from, at least for the moment.

Time is an important factor. I bought No Man's Sky nearly a year after release, and haven't regretted the purchase. I paid far less than the full price, and with the various patches the game had enough content by then and less problems, so that I felt that I got a reasonably number of hours of entertainment bang for my bucks. I'm pretty sure I would have regretted buying the same game on day 1.

On the iPad there are even less games I regretted. That starts with the fact that the majority of games is free to try anyway. And the "buy to own" games on the Apple app store frequently cost very little money, single digit amounts. Hey, maybe you don't like the game "Dawn of Crafting" I recommended. But as it costs only $3, it is unlikely you would deeply regret the purchase. A $10 game like Egglia in the app store is already relatively expensive.

As a customer and consumer of games, I feel as if I am living in golden times. I am not sure that this will hold forever, because as a hobby economist I feel as if there is an oversupply of games, fed by an oversupply of people willing to code games during long hours for very little money. I can't imagine that going on forever.

Tuesday, August 08, 2017
Facts and judgments

If you are an employee of a medium to big company, chances are that you will take part in various training courses. Not just technical ones which are directly related to your job description, but also behavioral training courses designed to get people to work together better. One of the frequent exercises in such courses is to first teach and then let people practice the difference between facts and judgments. For example an expression of a fact could be "the bottle of orange juice that I had put into the break room fridge is gone"; an expression of a judgment could be "somebody stole the bottle of orange juice that I had put into the break room fridge". The purpose of the training course is to get people to use more expressions of facts, and less judgments, because in the resolution of conflict the statement of fact is usually more helpful. The guy who accidentally and unintentionally dropped your bottle of orange juice in the break room fridge is more likely to come clean and apologize on hearing the fact statement than on hearing the (wrong) judgment statement.

Unfortunately very few people manage to express only facts. In a longer text they might have some facts in, but then put a judgment directly after that and by that link destroy the effectiveness of the fact. And if somebody complains about a longer text, it is easy to pick out just the wrong judgments as selective quotes and make the quote look far meaner than the whole text. The big story in the tech world this week is about the guy who wrote a 10-page memo on gender diversity at Google and got fired for it. The guy has a right-wing point of view, and the people who attacked him have a left-wing point of view. And because we have right-wing media and left-wing media, you get the story told in two very different ways, with very different quotes, depending on the bias of the news outlet. The left-wing media quote the worst expressions of judgment, many of which are obviously offensive. The right-wing media quote the expressions of fact, which can be shown to be true (especially due to the obvious irony of somebody getting fired for writing a memo in which he says that you can get fired for writing your opinion).

Personally I would say that Google was justified in firing the guy, because of the offensive judgments in his memo, e.g. saying that women make less good software engineers. However I do think that if he had edited out all the judgments from his text, there would have remained a memo full of facts that would well be worth discussing, e.g. the fact that the current set of gender policies at Google haven't worked in achieving better gender equality. And that gets us into an area which I consider far more dangerous: Culture wars in which attacking the opponent's judgments has become so commonplace, that attacking the opponent's facts is considered normal. Both sides do that: In other news the White House has received an official report that has the best scientific evidence on the contribution of mankind to global warming, and it is nearly certain that they will dismiss those facts because they don't fit with their ideology. On gender it is a fact that if you were to take an MRI image of the brain of a man and an MRI image of the brain of a woman, a neuroscientist will be able to tell the difference. It is a scientific fact that men and women are different, and think differently. Numerous studies have shown that *on average* certain skills and modes of behavior are more prevalent in one sex than in the other. And yes, even in a hypothetical world free of sexism and only based on merit and free choice, we wouldn't have a 50:50 distribution of genders in every profession. I believe however that in this hypothetical world's Google, men would likely be lowly paid code monkeys, while women would hold the majority of better paid management positions (that is a judgment on my side, not a fact, because hypothetical situations can never be facts). What we need to work on is to improve everybody's judgment of the relative value of different skills and modes of behavior. Trying to deny that differences exist just isn't very helpful. Just like trying to deny global warming isn't very helpful. Facts and science aren't subject to ideology and disputable in a culture war. If you treat even scientific facts as only opinions, you weaken the edifice of human knowledge on which civilization is built.

Saturday, August 05, 2017
3D printing supports

The technology used in most home 3D printers is fused deposition modeling or fused filament fabrication. Which means the material is fed to the printer in the form of a plastic filament, and the print head melts that plastic and deposits it layer by layer on a print bed. The obvious disadvantage of this bottom-up layer-by-layer fabrication is that you can't deposit plastic on an upper layer if there isn't some support for it on the lower layer. You can print overhangs of up to 45°, so your model can be bigger on top than on bottom. But for example printing a figurine with an arm stretched out horizontally is a problem.

The general solution for that problem is printing supports, that is printing something that goes from the bottom up to the outstretched arm, so that you can print the arm on top of it. Once the print is finished, you can then remove that extra support part. The 3D printing software XYZWare that came with my XYZ printer is able to automatically add supports. So far, so good.

My main application for the 3D printer is still printing figurines for my Dungeons & Dragons game. And lately I've been printing animals, like spiders, hyena, or an elk. If you think of how these animals look in nature, you will realize that they have relatively thin legs which aren't directly below the center mass of their body, but rather in the corners. Which means that if you print them in 3D, you need to print them with supports. That works, but I was getting more and more annoyed with the way that XYZWare is adding supports. Basically the software adds supports everywhere, so that the whole area under a spider's body is filled with it. So at the end of the print there is a lot of work to do trying to remove the support with a scalpel, while not breaking or cutting the thin legs. Also there always remains a visible trace of the support, so these models end up full of imperfections.

There is better software than XYZWare which gives you better control over supports, but unfortunately that software isn't compatible with the XYZ Printer. So I had to find a different solution: I am importing my models into TinkerCAD, and I am adding 1 mm thick columns manually at selected locations. The I print the result without automatically added supports. If I added enough support columns at the right places, that works just as well as the automatic supports, but I need to remove far less material afterwards.



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