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You might want to look into 3D-printed molds from Stratasys. It's not as strong (i.e. very limited runs) as metal molds but for short runs of prototypes it seems to be an excellent solution.

By definition a tool used for a hobby is also a toy.

Really? Who's definition is that? Does your hammer become a toy if you repair something in your house with it? You should look up the definition for the word "toy". A hobby is not "playing" with something.

That is kind of strange since the lowest cost Stratasys, the Mojo, can do 0.178mm layers.

It's a Stratasys uPrint Plus. In the specifications page, it says "Layer thickness: .254 mm (.010 in.) or .330 mm (.013 in.)"

This also brings up the question of how hard is it to "properly calibrate" and how long does that celebration last? If it takes hours of setup to print one item it is a toy.

It depends. If it takes hours of setup every time you print one item, it's just an unreliable tool, but still not a toy. If it takes hours of setup to properly calibrate once in a while, it's just normal wear and tear. We're talking about fractions of millimetres here.

Sure, if you compare low quality prints done by a hobbyist and the same prints using similar equipment by a service the hobbyist will always be cheaper. You have to pay something for not doing it yourself. There are quite a few services that use technologies other than FDM. I was referring to companies like Shapeways and Quickparts.

Of course the quality from higher-end 3D printers will be much better, but so will the cost. If we're talking precision alone, an FDM from Stratasys won't stand a chance against a Polyjet from the same company.

But comparing the output quality of a Stratasys FDM vs a well-calibrated RepRap? You'd be surprised which one you'd pick and the price difference between the two.

I'm not calculating my time because the parts I make are for personal projects, i.e. it's a hobby.

By definition a tool used for a hobby is also a toy.

What commercial services use FDM? The one I have seen use much more expensive technologies.

One service I called was proud that their Stratasys was able to make 0.25mm layers even though a properly calibrated home-made printer can do 0.10mm layers.

That is kind of strange since the lowest cost Stratsis, the Mojo, can do 0.178mm layers. This also brings up the question of how hard is it to "properly calibrate" and how long does that celebration last? If it takes hours of setup to print one item it is a toy. Sure, if you compare low quality prints done by a hobbyist and the same prints using similar equipment by a service the hobbyist will always be cheaper. You have to pay something for not doing it yourself.
There are quite a few services that use technologies other than FDM. I was referring to companies like Shapeways and Quickparts.

According to Stratasys, for small runs and development, 3D-printed plastic molds are faster to make and cheaper than CNC-milled aluminium or steel molds.

Well, of course SSS will claim that, after all they sell 3D printers. How about comparing molds of similar materials.

According to Stratasys, for small runs and development, 3D-printed plastic molds are faster to make and cheaper than CNC-milled aluminium or steel molds.

UPS' own website includes a video which explains they are using Stratasys uPrint SE Plus. This provides a print area of 203 x 203 x 152 mm (8 x 8 x 6 in.). It can print in thickness of either .254 mm (.010 in.) or .330 mm (0.13 in.).

UPS doesn't indicate which of the two models of the uPrint SE Plus they have. There is both an one material bay model and a two material bay model. Having a two material bay model could allow printing two color items or more importantly allow printing supports to hold up parts that don't have enough plastic to hold themselves up while the plastic is still hot. For example, if you are printing the statue of liberty, you may find that her outstretched arm falls off during printing since the plastic hasn't hardened and there isn't enough holding it up. For cases like this, Stratasys provides a water soluble material to print under the plastic to hold it up. They then provide a WaveWash device to remove the soluble material. But UPS doesn't state if they stock the water soluble material or have any WaveWash devices. It doesn't state which colors of ABS material they keep in stock.

Even worse, the website gives no details on if they hold the customer responsible for misprints. A 3D printer is a complex device and proper care/maintenance can greatly impact the quality and reliability of print outs. With incompetent and poorly trained employees handling the care of the printer, it seems likely there will eventually be bad print outs. It may seem like a $60 iphone case is a little over priced but imagine having to pay just as much for something that can't even function as a case because the printing got interrupted.

I once had an UPS employee explain to me that a two day shipping guarantee means that each location handling the shipment gets two days to deliver it to the next location. So, if a package is scanned by UPS on September 1st in California and then scanned on September 3rd in Chicago, then Chicago still has until September 5th before it even has to attempt to deliver it. To make sure there was no miscommunication, I had the employee explain three times the dates and that she was aware that the length of time from September 1st to September 5th is longer than 2 days. The employee made it clear, it doesn't matter when UPS first gets control of a package, as long as the final location delivers within 2 days of the final location receiving the package then it still adheres to their 2 day guarantee. Which means UPS' 2 day delivery can take up to 4 days while Fedex 2 day delivery means 2 days from receiving to delivery. While what she stated may not be UPS' actual policy, it still impacts the quality of their service. If she can justify 3 day delivery as being part of UPS 2 day service then I would hate to see what type of misprints she would still charge me for.

From the article:

Bentley cars have come to stand for a way of doing things. 3D printing allows for an extremely quick turnaround for design and prototyping

Notice they say nothing about tires that provide "better, longer lasting, provide a smoother ride". Also notice they say "design and prototyping" and not production. Sure you can 3D print a tire on a hub there is no way it will be a complete functional long lasting tire.
Here is their list of items that can be created with their "rubber like" material;

Exhibition and communication models
Rubber surrounds and over-molding
Soft-touch coatings and nonslip surfaces
Knobs, grips, pulls, handles, gaskets, seals, hoses, footwear

Notice that functional tires is not on the list.
The final nail in the coffin is that there are no metals on the material list.

That, however, assumes the ability of the Grocery-store printer to handle a wide variety of plastics. Some parts have fairly exacting specs for strenghth, etc. I see INDUSTRIAL printers with multiple types of feedstock, but not really sure that a Consumer-access printer will have that at a reasonable cost in the next few years. . .

The press release is deceptive. They did not build a working turbofan engine with a 3D printer. They built a plastic scale model of a Rolls Royce turbofan engine with a Stratasys 3D printer. It will rotate if powered with compressed air. Rolls Royce gave U of VA a $2 million dollar grant which supported that effort.

The plane itself wasn't printed as one piece. It was more like printing the parts of a plane kit. Very slowly. 80 hour weeks are mentioned. Not sure where the $2000 cost figure comes from, but it doesn't include labor or 3D printer time. Maybe that's just the plastic cost.

http://www.stratasys.com/Privacy/Terms-and-Conditions.aspx

4. MAINTENANCE USE AND LOCATION. Lessee ... shall comply with all laws, ordinances, regulations, requirements (from the manufacturer or otherwise) and rules with the respect to the ... operation of the Equipment

It's usually referred to as Rapid Prototyping, and properties are limited to whatever the particular technology you're using can support. The good news is some companies (disclaimer - previous employer) like Stratasys have evolved their FDM technology to the point of creating usable plastic parts.

Sadly, the venerable, verbose, and error-prone STL file format is still the standard input for most of these systems.

So, perhaps Tex will support STL output for 3D printing :)

Anything with a laser is much more expensive (with fewer material options) than what's being discussed here. You are referring to a Stereolithographic process, primarily commercialized by 3D Systems, Inc.. This group uses more of a heated extrusion, similar to the Fused Deposition Molding process used by Stratasys, Inc. Even the liquid resins, though, have limits to degree of overhang permitted before the cured material will sag or fall in.

That said, there are likely a lot of things you could do with room temperature epoxies and investment casting, and cheaper modelers for those casts. Cheaper, though, still means typically $10k or more. And even then, the raw materials aren't cheap.

So, how to bring things down? How about the Fab@home project? Nothing like open source 3D fab. I think the current cost estimate to build the tool is about $2500. I'm surprised every engineering school hasn't set their undergrads to work to make something like that (as a useful project, a teaching tool, and a development platform). The material set is a bit limited at present, but really guys, they've demonstrated Chocolate!! what more could you want? :)

You are asking the right questions. It seems like the machine will definitely be able to make combs and plastic dishes - and maybe not much more until some major breakthroughs in other areas. First, the machines they are modeling their project around are made by the Stratasys company. The university website does not state which model they use as a basis for their estimates, but none of the existing models are metal capable. So at least for the present, anything but plastic parts must come from elsewhere. The size limit is about 12 inches, so any large structures would have to be composites. The materials are heat sensitive. No hair dryers or friction parts are possible. The raw plastic is also a special compound - the machine process is patented, I'm not sure about the plastic. One of the key assumptions in this plan is the use of conducting and semiconducting polymers to "print" electronic circuits. These assemblies tend to be weak and slow, limiting uses. It is impossible to guess what modifications would have to be made to his model machine to utilize this technology. I suspect he is low balling the price and the simplicity of the mechanical design. It's a nice dream, but has got a long way to go. It probably WOULD make pretty good action figures though.

billy - hanging on to his Costco card for now

You have a very valid point.
Give it a few years, and you will be able to do this. Don't laugh! You can already "print" plastic and metal parts with rapid prototyping. Give it a few more years, and printed circuits will be available in 3D at home. They already do it in cellphone manufacture.
I have a functional adjustable wrench at home from a US company made from ABS plastic (just don't expect too much torque!) which was made by a computer linked to a 3d printer in ONE piece! The tolerancing was done with a water soluble plastic that was disolved afterwards.
How long before the local gang-banger can print an Uzi? Not very. How long before you sign an NDA and license before taking delivery of your new fridge? What will happen to the market for things when you can print a new CPU cooler at home?

Is the internet, which can be used for almost anything besides transferring actual physical objects (wouldn't that be cool!)

• Z-Corp makes color 3-D printers that make plastic objects. These'll generally run you under $10k.
• Strata Sys makes stereolithography printers. More expensive, and not in color, but stronger. They're about $30k.
• EOS GmbH makes printers that make metal parts. You can print out replacement parts for your car, rocket ship, etc. (Warning - web site uses Flash, Mozilla-squashed popups, annoying no-copy PDFs) No mention of price on the site :-/

I'm surprised that anyone would attempt to argue the merits of using any computer language as the appropriate mechanism for communicating the intent of an algorithm/function/method. The code is for the machine, not for humans! It's more precise, but only because it's so much more constrained. If you want to quickly port it, or have any hopes of releasing your work as an API for somebody else to code to (or test against), you've simply got to have good documentation.

In your scenario, the problem was not simply that the documentation was out of date. If you're operating in a shop where a change can be made in a core component without triggering regression testing, or core components can have their functionality change without revving the API, you need to fix your process.

It is bad to have out of date documentation, but this typically occurs because it's too far away from implementation. Making documentation coincident with implementation, either by convention (embedding comments), or by language design (Literate Programming languages) is an improvment.

In general, I prefer less high-level documentation and more at the class and library level. I know I'd much rather have a well documented class header and methods (with code fragment examples) and a good unit test than having to dive into an implementation and reverse engineer somebody else's code.

For that matter, for C++ I prefer incorporating documentation into the code itself, and use packages like Doxygen or Cocoon to extract it (there are many more, I'm sure).

BTW, now in danger of getting on topic, Leo does look pretty interesting... esp. for web work.

Oh, and where the hell was this guy's boss when he used the quarter million dollar rapid prototyper to make a two dollar aluminum pulley for a sander... Don't even tell me that polycarbonate will be a good substitute for a pulley in a sander which was originally made from aluminum.

When down, most production lines cost the company huge amounts of money per hour. The production lines in some plants cost hundreds of thousands of dollars every hour that they are down. Why? Well, first, no product is being made. Second, you're paying x hundred employees to sit on their butts waiting for the line to be fixed. The labor costs alone are staggering.

The guy who made this part had two choices: Leave the line down for a few days while waiting for a replacement to arrive (and likely costing the company $Millions), or create a new one and get the line back up and running in just a couple of hours. Wherever his boss was, I bet he gave him a nice fat raise. The guy just paid for the quarter million dollar machine and then some.

As for the new part not being a good substitute: "It's been a month now, and the belt sander is still going strong... I have an aluminum replacement pulley now, but I'm in no hurry to install it. With the way this one has performed, I want to see how long it lasts!" (Link to quote)

Does anyone know what the minimum scale that this gizmo can produce is? They've got some pictures of a fully-functional wrench (WOW!) on the Stratasys web site, which would imply that there's some fairly fine control (for the spinny groove things). I just ask since one of the coolest things I can imaging is a box like this spitting out a fully-functional (mechanical) watch. And of course, taking that to the most ridiculous extreme, having a box that could spit out a computer - in the form of Babbage's Difference Engine. ;-)