The changing face of 3D printing

It seems just about everyone is busy printing objects in 3D. Examples range from high-end airfoils to jewelry, lattice structures, and even self-portrait figurines. Here, we kick the tires of a few machines, both consumer and commercial. The machines we profile have one thing in common — a price tag of under about $20,000. And most are much less expensive.

LeapFrog
Aimed at the home user, the Creatr 3D printer from LeapFrog in the Netherlands distinguishes itself from other consumer printers in several regards, says company cofounder Mathijs Kossen. First, unlike other printers, the device is made entirely of aluminum, so it is sturdy and steady. “And it also has larger, more-reliable electronic components,” he says. “For example, stepper-motor drivers in consumer printers typically break almost right away. We replaced them with professional drivers, as well as a more-robust belt and driving shaft. The printer, therefore, wears out less quickly.”

While most printers in the Creatr’s price range (approximately $1,500) need calibration, the Creatr comes preassembled and precalibrated, so users can just start printing, out of the box. “The machine targets people who don’t want to spend 20 to 40 hours building a machine and calibrating it — they just want to design immediately. This makes our printer accessible to a broad range of people.”

In addition, the 23 × 27 × 23-cm build volume is large for a consumer printer. What’s more, the device sports an optional dual extruder. “The Creatr builds using thermoplastic extrusion. A machine with a single extruder would not be able to build a bridge, for example,” says Kossen. “To make the pylon, when the first layer on the road is printed, the plastic coming out of the nozzle would fold down into the air. But the second extruder fills in that space with a soluble material, letting users print almost every shape and form. When the build is complete, users can easily wash out the water-soluble material that supports overhangs during a build.”

Building materials are in the form of a filament that comes on reels. The machine prints ABS or PLA plastic. PLA is a little more brittle than ABS with a lower melt temperature, making it possible to print smoother edges. “Users might be more likely to print end models with ABS,” says Kossen. “On the other hand, they may be more likely to print display models out of PLA. PLA is also biodegradable. Interestingly, ABS is the material used to make Legos.”

The Creatr typically builds in 200-micron layers. “But mechanically and experimentally, it’s possible for the tolerances to go much lower, say, to 100 microns,” says Kossen. The speeds of the X and Y axes go up to 0.35 m/sec and the extrusion speed is 200 mm/min. The machine can print an iPhone casing in about 10 to 15 min.

FormLabs
According to FormLabs founder Maxim Lobovsky, the Cambridge-Mass.-based company recently introduced the Form 1, the first stereolithography (SL) machine that is anywhere close to costing only $3,000.

“We have made it easy to use the machine to target what we call ‘prosumers’ or designers, engineers, and makers,” he says. “The software is intuitive and it includes tools to handle the finishing steps. The machines use a less-common version of SL, where resin is exposed from the bottom of the tank, rather than from the top. We didn’t invent that overall process, but we simplified it and reduced costs. For example, new lasers on the market make that part of the system way less expensive.”

For materials, the machine uses a proprietary photopolymer, a liquid in a bottle that costs about $149/liter. “The resin price is about half that of the higher-resolution machines, says Lobovsky.

The machine produces layers with a minimum thickness of 25 microns and a minimum feature size of 300 microns. The machine prints at a typical rate of about 15 mm of height per hour. The build envelope is 4.9 × 4.9 × 6.5 in.

Stratasys Stratasys
Technical Director John Cobb says the company recently introduced the Mojo 3D printer, which uses fused-deposition modeling (FDM) to print ABS, for everyday design engineers who use CAD as part of their jobs. The company first introduced its other FDM product lines, including the Dimension in 2001 at about one-half the price of other 3D equipment available at that time. It has since developed numerous Dimension products, taking the price down to about $20,000. About five years ago, the company introduced the uPrint, which was in the $15,000 to 20,000 price range. The Mojo came out in April 2012. It is said to be the first professionalgrade printer to cost less than $10,000.

“What’s striking about the Mojo is its shape and size,” says Cobb. “The machine really mimics the form factor of a 2D printer one might get from HP. Also, its software lets users drag and drop from CAD files, as well as quickly print second, third, or fourth models. The system also arranges the parts in the build envelope.

Mojo build material, which is in the form of a filament, along with the feed head, is all part of the print cartridge. Stratasys says users can set up the printer in about 10 to 15‹min.

The Mojo comes with its own part-cleaning apparatus, which Stratasys calls the WaveWash 55. The size of a traditional coffee maker, the WaveWash 55 is geared toward desktop users. It holds up to a gallon of water, which is good for about 8 lb of material. Users simply drop the soap in the water and place parts in the cleaner. It removes the support material in about 15 to 30 min, depending on part complexity. The printer and accessories come in a bundle costing about $9,900.

The Mojo’s build envelope is 5 × 5 × 5 in. It prints in layer thicknesses of 0.007 in.

RepRapPro
The RepRap 3D printer, which also prints using thermoplastic extrusion, is touted as being “self-replicating.” This label comes from Adrian Bowyer, director of RepRapPro Ltd. in the U.˜K., who says that even as a child, he was interested in creating a self-replicating machine.

“One only has to look at the natural world to see what can be created by things that copy themselves, which is after all, the very definition of a biological entity,” says Bowyer. “When I was an academic, my university bought a few RP machines, and as an engineer, I found them a complete liberation. For the first time, I had a device that let me sit at a computer screen and design whatever I wanted and then have it in my hand an hour or so later. Once I became aware of the versatility of the technology, it seemed a good way to make a machine that could copy itself.”

In this endeavor, Bowyer was concerned that whatever he created would be “evolutionarily stable.” “This is to say, any self-replicating object, whether it’s a butterfly or a whale, must sit at a whole series of points that are optimal in relation to their surroundings. And most of the surroundings are themselves self-replicating entities,” he says. “This idea of optimal positioning is the basis of a rigorous mathematical idea that supports an evolutionary stable strategy.”

Says Bowyer, “The RepRap copies itself by printing its own parts, but it obviously can’t succeed on its own — it needs a human to put the bits and pieces together, which is the equivalent of insects helping flowers reproduce. How might the machine persuade humans to do that? The answer is by giving them consumer goods. Humans then have an incentive to help the machines copy themselves. This is a way to make the machine stable in the world.”

By the machine’s nature, it had to be open source, says Bowyer. “Should you put a machine that copies itself out in the world and try to patent it, what you are saying is, I’ve made a machine that copies itself. Now, world, you can’t copy it,” he says. “That’s a recipe for spending the rest of your life in court trying to stop people from using the machine for the one thing it was designed to do.”

Estimates are that between 20,000 and 30,000 machines now exist. Bowyer’s company is currently shipping machines at the rate of about 100/month. The build envelope is about 8 × 8 × 5.5 in. The machine prints in layer thicknesses of 0.020 in. The minimum feature size is 0.080 in.

Mcor Technologies
With its Iris 3D printer, Mcor Technologies Ltd. in Ireland has modernized an old idea — that of creating 3D models by gluing together layers of paper. Many designers may remember a similar idea that surfaced years ago. According to Mcor spokesperson Deidre MacCormack, the difference between the old Helisys machine and the Iris is that the Helisys used a large roll of paper that was preapplied with adhesive, making waste removal difficult. The old machine also cut with a laser, which proved to be a fire hazard. In addition, the models from this machine were brown because the laser burned the paper. In contrast, the Iris uses sheets of office paper and it selectively applies the water-based adhesive. The machine cuts the paper with a tungsten-carbide blade.

“We have been in business since 2005,” says MacCormack. “The Iris is both low cost and eco friendly. All of our competitors are either using a plastic or powder to produce 3D models. Parts that come out of the Iris are strong and high quality. They have a resolution of 0.1 mm, about the thickness of a sheet of paper, so surfaces are smooth and parts can be quite complex. The machine mostly targets the commercial and educational markets.”

Recently, the company introduced a full-color version of the printer. It applies colored ink to white paper and from that builds up 3D models. “The quality of the print is high — 5,760 × 1,440 × 508 dpi and 1 million colors,” says MacCormack.

The company sells its products in an interesting way. “As well as buying the machine outright, users can purchase one of our ‘3D plans,’ which go for one, two, or three years. The price is set and users can use the machine and also get unlimited consumables — as many blades and as much glue as needed to run the machine for the length of the contract. This opens the door to educational and professional users who couldn’t otherwise afford the technology.” The machines start at $15,000.

The Iris build size is 9.39 × 6.89 × 5.9 in. Layer size is 0.004 in.

© 2013 Penton Media, Inc.