3D Printing

Moving from Closed to Open

My new Prusa 3D printer kit is supposed to arrive next week, about three months after I preordered it.

During that long wait I've been learning some of the software used in the open source printer world, including Slic3r, the slicer that's been customized to work with the Prusa printers. Fortunately, TierTime recently opened up their hobby printers to accept gcode from other software, allowing me to experiment with using Slic3r with my existing printers.

New Adventures in 3D Printing

It's been almost exactly six years since I bought my first 3D printer. In that time I've owned three 3D printers, all of which still work, and two of which I still own and use fairly constantly.

To date all of my printers have been fully-built models from the Chinese manufacturer TierTime. I've decided that it's time to take the next step and build my own printer.

State of Home 3D Printing (Summer 2013)

The home 3D printing market has changed a lot since I wrote about the state of the market last fall.

Consumables: Cheaper and Easier to Get

Maybe not the most dramatic change, but one which makes a big difference is that it has gotten a lot easier to find high quality, inexpensive filament for home 3D printers. At the beginning of 2012, when I first got started, there were only a handful of suppliers. "Out of Stock" was the order of the day (many sellers were perpetually out of more than half their colors), and when you could get plastic it was often poorly extruded and jammed frequently.

All that has changed. There are now dozens of places to buy filament online (including Amazon), and quality control has become much better. I'm also seeing prices come down a lot: from $60/kg in early 2012 (including shipping) to where it's easy to find reputable plastic for $35-$40/kg today. If you're willing to buy in bulk, you can cut that down to under $20/kg, though specialty plastic like glow in the dark is going to be a little more expensive.

There are also some interesting new materials on the market now, like flexible plastic, color-changing plastic, and even "wood." Some of these are challenging to print well, but they give the serious hobbyist some fun options that not even the commercial-grade printers have.

Stratasys Buys Makerbot

Just in the past few weeks it was announced that Stratasys, an 800-lb gorilla of the commercial 3D printer market, is buying Makerbot, the 800-lb gorilla of the hobby 3D printer market.

This acquisition makes a lot of sense for Stratasys, since the hobby market poses a clear competitive threat to the high-end commercial machines. Many hobbyist-grade printers can do nearly everything a Stratasys machine can do, and at a tenth (or less) the cost. The main difference is that the commercial machines are generally more reliable and easier to use. A significant segment of the market will be willing to put up with the quirks of a hobbyist-grade machine for the cost savings, and the usability gap has been closing fast.

I see this acquisition possibly going either of two ways. The more exciting outcome will be if Stratasys really commits to nurturing the hobbyist market. Stratasys has a lot of technology and a patent portfolio which could be deployed to significantly improve the Makerbot printers without a significant price increase. If Stratasys does this, they will likely own the hobbyist market for many years to come.

The more depressing alternative will happen if Stratasys tries to defend its high-end printer business, and winds up crippling Makerbot. This sort of thing happens all too often when a large established company buys a smaller upstart rival. The larger company doesn't want to risk undercutting its existing business, so it carefully segments the market and doesn't allow the acquired company to develop products which might threaten the established business. Eventually, the innovation which drove the smaller company to its initial success gets strangled by the needs of the larger parent company.

It will probably be a couple years before we know how this acquisition shakes out. I really want to see it succeed, but I don't think the odds are in Makerbot's favor. It's just too hard to escape the big-company logic of not undermining your own products.

So, Have You Printed a Gun?

One of the unfortunate side-effects of the massive hype over 3D printing is that you get people trying to ride the wave to promote their own agenda. For the benefit of future readers (in case this has been mercifully forgotten in a few months), recently someone managed to 3D print a gun and fire it without killing himself. This was intended to make some sort of political point about firearm regulation: I'm a little fuzzy on the details, but it was something along the lines of "if anyone can 3D print a gun, then there's no point in trying to regulate them, so just give up."

Others have made the counter-arguments, which boil down to "anyone with access to basic metalworking tools can already make a gun, so what's your point?" and "why would you bother when it's easier and safer to buy a manufactured gun," and "just because something is easy doesn't mean it should be legal." My own opinion is that this is really just a publicity stunt, and only distracts from the more interesting (and separate) issues surrounding 3D printing and firearm regulation. It clearly is not a demonstration of either a particularly useful application for 3D printing, or responsible gun ownership.

But because it has been in the news so much, the first question I always get is, "So, have you printed a gun?" And it seems to me that if the only thing the average Joe on the street knows about 3D printing is that you can print a gun, that's not a good thing for anyone.

State of Home 3D Printing (Fall 2012)

It's hard to believe, but I've had my 3D printer for nine months. In that time I've printed hundreds of things, a couple dozen of which are my own designs. I've consumed something like 15-20 kilograms of plastic filament (yet still have an inventory of 20 kg in 15 different colors). I've replaced the platform heater on my printer about ten times, the extruder nozzle once, printed a half-dozen other replacement printer parts, and tweaked my printer in four or five ways.

So this seems like a good time to take a few steps back and make some observations about the state of home 3D printing as it stands near the end of 2012.

Home 3D Printing is Still a Hobbyist's Market

The first thing that's very clear is that home 3D printing is very much a hobbyist's market. The actual usefulness of a 3D printer in the home is still very limited, though they definitely have a role in education, architecture, engineering, and other professional settings. Arguably the most immediate economic impact of inexpensive 3D printing is to bring the technology within the reach of professionals who have a real need, but couldn't afford to spend five or six figures for a commercial-grade machine.

The vast majority of home 3D printers on the market today are very much hobbyist-grade. These are not plug-and-play: even the easiest printers require adjustment and maintenance from time to time, and most of them are very temperamental. With some of the kit printers, I've heard it can take longer to get the printer tuned and adjusted than to assemble it in the first place.

Makerbot made a lot of noise at the beginning of the year claiming that its Replicator was designed for the average consumer. Makerbot has a great history of making kits, but I don't think the company really understood what "consumer grade" means. Many reports I've seen are that the Replicator still needs fussing to get consistently good prints, and has some design and engineering defects. Makerbot recently announced the Replicator 2 which addresses some of the most obvious flaws of the Replicator (for example, the wood frame is now steel, which is important in a machine which has to be adjusted to within a tenth of a millimeter), but the Replicator 2 isn't shipping yet. I'm skeptical when Makerbot claims a product is "easy for anyone to use," so we will have to see.

My printer, the Up!, is now being OEMed in the United States by Afinia. I had a chance to meet the Afinia team and tour their facilities a few weeks ago, and I was impressed that they are putting some real design and engineering work into improving the product. The Up! is a good printer and produces very nice looking prints with only modest adjustment, but it also has its flaws. Some of the cables are underdesigned for the amount of heat, stress, and motion they have to handle (hence the ten heater cables I've gone through), and some of the adjustments have to be repeated too often. For the most part, these are solvable problems--they just haven't all been solved yet. Fortunately, the Up/Afinia is a very "hackable" printer, making it easy for other hobbyists to tinker with it and improve the design.

The printer which comes closest to being a true consumer-grade product is the Cube, a low-end product by 3D Systems. From what I've heard, the Cube requires a minimum of fuss (though it does require a little bit of adjustment, and the use of a proprietary "magic glue" platform adhesion material) and produces acceptable output. However, 3D Systems chose to lock the Cube into a proprietary filament cartridge, forcing users to buy consumables at wildly inflated prices. That may be okay for occasional use, but heavy users like me will wind up spending crazy amounts of money on plastic.

(How expensive is the Cube filament? Right now I buy filament in bulk and spend around $20/kg including shipping. Retail pricing ranges from $35/kg to $60/kg depending on the source. 3D Systems charges $50 for a filament cartridge and won't say how much it holds, but it seems to have between 200 and 500 grams. That's $100 to $250/kg, or between 5x and 10x what I pay now. Since I go through about 2kg/month, the Cube would cost me between $160 and $460 extra per month in filament.)

3D Systems is going after a mass-market audience with the Cube, but I think they are at least five years too soon to market. We are still at the point where the only people interested in buying a home 3D printer are hobbyists and hobbyist/professionals--and those people want a machine they can take apart and tinker with. Worse, if the Cube is discontinued and 3D Systems stops supporting it, there is no other place to get filament. This scenario would quickly turn a Cube into a brick.

My Personal Toy Factory

I usually get one of two reactions when I tell people I have a home 3D printer: either "Cool! Where can I get one?" or "What's that good for?"

The hobbyist printer manufacturers have sometimes bent themselves into knots trying to answer the second question: You can make replacement knobs for drawers! Personalized bottle openers!

Get real. Nobody is going to spend upwards of a thousand dollars on a machine just in case they need to replace a ten cent plastic knob someday. And until the manufacturers start posting 3D files for replacement parts you'll have to design your own, which is way more work.

In fact, the most popular "useful" things on Thingiverse are....replacement parts for 3D printers.

But there is one thing a home 3D printer is really good at: making toys. The ABS plastic is cheap, nontoxic and durable, there are thousands of toy designs on Thingiverse for all ages and interests, and you can design your own if you want. I've made toys for my kids, toys for my friends, toys for my kids' friends, birthday presents, you name it. For my nephew's birthday I designed and printed an entire gear toy system just for him (then uploaded it to Thingiverse for the rest of the world to enjoy).

For some reason, "making toys" seems like a trivial application for a high-tech piece of fabrication equipment. But I say: let's embrace it. The toy industry is a $21 billion dollar industry in the United States. There's nothing small or trivial about that.

The great thing about having a Personal Toy Factory is that it lets me get away from the mass-produced cheap plastic junk. It's still made out of cheap plastic, but the toys are now made specifically for the child. There are thousands of ready-made designs to choose from, and I can customize or design my own. If my nephew decides he wants to be a "Space Sheriff," then I can make him a badge with a starship on it and a six-shooter ray gun. Good luck finding that at Toys R Us.

Given that the average American household spends something like $200/year on toys, it's actually not so farfetched that an upper-income family with kids would spend a couple thousand dollars on a machine to custom-build toys for their kids. It's easy to rationalize as useful for school projects--my kids have all used 3D printed stuff for their classes--and the gee-whiz factor would close the sale.

Home 3D Printing is More Art than Science

One of the first discoveries for a new 3D printer owner is that the technology doesn't quite live up to the hype. Many people come in to 3D printing thinking that they can print Anything--that was certainly my thought at first.

And you can print Anything, as long as Anything:

  • Isn't too big: most home printers have a fairly limited print volume, and big prints can take a very long time (over a day in some cases).
  • Isn't too small: small parts and fine details might not print at all.
  • Doesn't have to be too strong: 3D printed parts can be quite strong if they are carefully designed and printed, but they can also be very delicate since the bond between layers is relatively weak.
  • Doesn't have intricate overhangs or interior voids: support material can be a difficult or impossible to remove without damaging the print.

Hobbyists also struggle with making sure prints stay attached to the print bed while printing (yet come off easily when done), and keeping prints from warping or splitting due to internal stresses. Commercial printers have solved these problems using techniques like carefully temperature-controlled chambers and disposable print platforms, but (for now) those techniques are proprietary and too expensive for the home market.

So there is definitely an art to getting good 3D prints from a home printer. You can't just throw any old 3D object at it and expect good results, and many hobbyists are still experimenting with new techniques.

There's also a lot of artistry in designing multi-piece things that fit well and have a "finished" look without too much cleanup work. Since 3D printed models tend to warp a bit, you can't just glue two parts together on a flat side without a visible seam. Joints need to be incorporated into the design, with allowances for gaps and other imperfections in the printing process.

More Fun Than....

I've gotten a crazy amount of enjoyment and satisfaction out of my printer. For me personally, it requires just about the right combination of tinkering and design to give me a perfect cocktail of artistry, technique, and instant gratification.

When someone asks me if he (it's usually a he) should get a 3D printer, my response is usually a little more guarded. This isn't for everyone yet, and it isn't even for most people. But if you are the kind of person who both enjoys working with mechanical stuff and also creative design, you will probably get a lot out of a 3D printer.

Seeking Plastic

My 3D printer consumes three things: my time, electricity, and miles (*) of plastic filament.

To date, I've been going through plastic at about two kilograms per month. At about $60/kg (including shipping) for the manufacturer's plastic, that's about equivalent to a bad Starbuck's habit--an affordable luxury, especially since I don't otherwise have a Starbuck's habit.

There are two problems with buying plastic from the manufacturer, though: first, it costs $60/kg and I'm cheap. Second, it only comes in white.

So I have been on a hunt for alternative sources of 1.75mm ABS filament to feed my 3D habit. Hobbyist 3D printers seem to have settled on 1.75mm ABS and PLA as the "standard," so there are may sources including other 3D printer manufacturers, third party vendors, and guys who bought a palletload of plastic filament and sell it on eBay.

So far I've tried five different sources of filament and I'm still evaluating two others. I've paid prices ranging from $25/kg (for bulk orders) to $60/kg. And I've discovered that all plastic is not created equal.

Size: To get the best and most consistest results in my printer, the actual diameter of the 1.75mm plastic filament needs to be between 1.70mm and 1.80mm. Plastic as small as 1.60mm and as large as 1.80mm can be made to work with some effort, but diameters outside that range will not feed properly.

So far this has been the largest challenge in finding reliable suppliers. I've bought reels of filament which vary between 1.55mm and 1.95mm over a distance of less than two meters. That's simply not going to work. The result is jammed filament, failed prints, wasted plastic, and frustration.

Of the five suppliers, three have delivered plastic which is consistently in-spec: Up (the manufacturer of my printer), Makerbot (which makes a competing hobby printer), and ProtoParadigm. The guys at ProtoParadigm get extra credit for offering bulk 30-lb spools at a substantial discount, but you have to special-order it and wait a couple months for delivery.

Plastic: It turns out that there are lots of different kinds of ABS plastic. The stuff Up sells is an extra-strong grade which gets extruded at 260C. Most other suppliers offer a lower grade of plastic which they recommend extruding at between 200C and 225C.

So far, every ABS plastic I've tried has extruded just fine in my printer, though with the lower grades of plastic it is often harder to remove support material and there tends to be more warping and lifting from the print surface. If I was trying to get perfect models every time this would bother me, but I consider this a worthwhile tradeoff for having a choice of colors and lower cost.

Colors: If Up offered a choice of colors I probably never would have started looking for other sources of plastic. Right now I have reels of about ten different colors, including glow-in-the-dark and metallic silver (which is more like graphite, but still looks sharp). Printing in color gives much more appealing results than boring old white.

Quantity: Most retail sources sell ABS filament in 1 lb or 1 kg reels, at prices around $45 - $55/kg including shipping. Special colors, like fluorescent, glow, and metallic, often cost a few bucks more. A few carry 5lb reels at a discount. ProtoParadigm lets you special order 30lb reels for a significant discount.

I'm just starting to explore ordering directly from wholesalers. Minimum orders range from 10lb to 25kg, making this a little risky since I don't want to buy a year's supply of plastic and discover it consistently jams my printer. On the other hand, wholesale prices seem to be generally around $20 - $25/kg including shipping, so there's the opportunity to save a lot of money if I can find a reliable source. Wholesale orders also seem to have one to three month lead times.

Stock: Right after Christmas, most sellers of 3D printer filament seemed to go out of stock on most colors. I'm not sure if this is a post-Christmas spike in demand or what, but at the moment it is a challenge to find many colors. I'm hoping that availability will improve over the next month or two as the wholesalers catch up.

My Buyer's Guide for Plastic to Feed an Up

Up: You can't go wrong with the manufacturer's own plastic. Pros: best performance and strength. Cons: comes in white only; more expensive than other retail sources; ships from China so options are limited for quick delivery.

ProtoParadigm: These guys are obsessive about quality, and their plastic works really well. Pros: Competitive prices, bulk pricing for 30-lb reels (by special order), very responsive and easy to deal with. Cons: Limited colors, but they say more are coming soon. Right now they have Natural, Black, Glow, and Fluorescent Green, all in stock.

Makerbot: A little more expensive, but consistently good quality. Pros: Lots of color choices, quick shipping, and easy to deal with. Cons: Right now most colors are sold out; prices are at the high end.

3dPrinterStuff: I can't recommend because the plastic they sold me was consistently inconsistent in the filament diameter. When I complained about the poor quality control they were not responsive. They used to have a good selection of colors and some 5-lb reels, but all they list now is black and white.

3dInk: Also can't recommend because of out-of-spec filament diameters, but the owner was helpful and offered a refund when I complained (I refused the refund and am using the plastic). There's hope here. Very competitive prices and respectable selection of colors, though all but one are sold out right now.


(*) My rough estimate is that so far I have used about one mile of filament in my printer. Give or take about a half-mile.

The State of Consumer 3D Printing

There were several new 3D printers introduced at the Consumer Electronics Show a couple weeks ago. The Replicator, from Makerbot, is probably the most impressive from a price/performance perspective: a large print area, two extruders, and fully assembled for under $2,000. Unfortunately, from everything I've seen, the software is pretty much the same as Makerbot has always used, and that's a significant weakness. I want to just print and not have to fiddle with the settings to get good results. Better software and less fussing is why I chose the Up even though it is more expensive.

Another new model, the Cubify, is aimed squarely at the consumer market with a $1,300 entry point and an aggressively friendly look. They take the inkjet printer approach by sellng the printer cheaply but using a proprietary cartridge design to force you to buy the consumables at outrageous prices. It's hard to tell exactly how much Cubify's plastic costs, but my back-of-the-envelope calculation is that it's between $0.10 and $0.20 per gram--which would make it as much as five times the price of the same stuff from a third party.

Despite these new products I'm skeptical that 3D printing is really ready for the mass consumer market. I (and many other hobbyists) really enjoy designing and printing stuff, and I'm willing to devote a lot of time to tweaking my models, seeing what works, and accepting a fair amount of failure along the way. Not every model will print well, and there's a certain amount of art and experimentation which goes into designing a model which gives good results. An ordinary consumer isn't going to expect that.

There are also safety issues. Not loss-of-life-and-limb safety, but lots of opportunities for minor cuts and burns. Parts of the printer get hot enough to burn, and cutting support material off a model entails all the normal hazards of working with sharp knives. I speak from experience, since I was careless when trimming the support raft off one of my models a couple weeks ago. The knife slipped, and I needed seven stitches in my finger. I am now much more careful, but these kinds of injuries will be common until multi-headed printers and dissolving support become the norm.

I still think there's a good chance that someday 3D printing will be a mainstream household technology. Just not today. For all the breathless press coverage over the past few weeks, this is not yet ready for the average Joe and Jane.

First 3D prints

I got my 3D printer late last week and have been having fun making a variety of models to see how it performs. I bought the Up Plus instead of one of the many kits like the Makerbot or the Reprap. The Up is more expensive, but everything I read suggested that the kit-based models require a lot more fussing to get working properly (even if you buy them preassembed) and the software is fairly painful to work with.

The Up, on the other hand, comes fully assembed and tested and has relatively user-friendly software which works out of the box. The software is a big deal, because it will automatically add support structure (for printing overhangs) and take care of other routine chores without too much tinkering from the end user.

Most hobbyist/home 3D printers work through extruding a thin filament of melted plastic--imagine a hot glue gun mated to an old-fashioned pen plotter. There are probably a dozen different basic technologies for 3D printing, but this one seems best suited for the hobby market: it is relatively inexpensive, the materials are also cheap and readily available, and safety issues are minimal.

On the downside, this method is slow, and limited in the materials you can use. The core of the unit (and most expensive component) is the print head, so hobby printers generally have a single head. That means that each model must be made from a single material, so only one color of material can be used and the support material has to be the same stuff as the model itself.

Professional units often have two or four print heads--that lets you use some other type of material for the support (making it easier to remove all the support scaffolding), and have several colors of plastic included in the same model.

I've posted some pictures of models I've build on Thingiverse. So far I've found that the printer can produce really amazing output, though sometimes the software needs some tweaking to get the best results. Support material is a pain to remove, so it's best to use the least amount of support which will still give good results.

I've also found that kids (of all ages) find the 3D printer endlessly fascinating--it's a great way to inspire interest in designing and building stuff, and my kids have already started making models in Sketchup to print.

Would you have bought a personal computer in 1975?

A personal computer in 1975 cost about $2,500 in today's dollars if you bought it assembled. It didn't do much, as there was no third-party software and it only had 256 bytes of memory. (However, for an extra $1,350 in today's dollars you could upgrade it with another 1,024 bytes of memory). A few thousand units sold that year, which was a shocking success.

As a laughably downsized version of what were then giant industrial machines, it was hard to see then what a personal computer would eventually be useful for. It would be another four years before Visicalc--arguably the first really useful thing you could do on a personal computer.

So would you have bought a personal computer in 1975?

In retrospect, many people would probably say Yes, but that's only because we now know how the technology evolved. It's much harder to be in 1975 and see how this expensive toy (which is all an Altair 8800 would ever be) would change the world.

It's this line of thinking which made me decide to buy a home 3D printer. I want to learn about this new technology not because it's useful today, but because it has such interesting potential over then next 10-20 years.

Commerical grade 3D printers are powerful pieces of industrial equipment, and have no place or purpose in the home. Their smaller cousins have only been on the market a couple years and are pretty much expensive toys with limited practical value.

On the other hand, a small 3D printer isn't much more mechanically complicated than an inkjet printer (in some ways it is actually simpler). There's no reason that, with enough manufacturing volume, someone couldn't sell a 3D printer for only a few hundred dollars and put one in every home.

The only reason nobody's selling millions of cheap 3D printers is because nobody knows what your average household would do with one.

I don't know if we will discover the Visicalc of 3D printers, the killer app which transforms this from expensive toy into useful tool. I don't think a lot of people in 1975 knew what the future held, either.

There was another interesting piece of industrial technology scaled down for home use which came around only a few years after the Altair 8800. Unlike the personal computer, however, not too many people today have a personal robot.