3D Printing (Additive Manufacturing) is a Family of Technologies

When we talk about 3D printing, it is a catch-all phrase that encompasses several distinct technologies, each with its own strengths.  Here are some comparisons of additive manufacturing options in plastic, metal and composites:

3D Printed Plastics

Fused Deposition Modeling (FDM)

Learn more about FDM

Standard Materials: ABS

Relative Cost: ★★☆☆☆

Machine Finish: ★★☆☆☆

ABS Prime Finish: ★★★★★

Typical Lead Time:  2-5 Business Days

Specialty Materials: PC, nylon, ULTEM and many more (See FDM page)

Relative Cost: ★★★★☆

Machine Finish: ★★☆☆☆

Typical Lead Time: 3-7 Business Days

FDM Pros: Very high accuracy on large parts, diverse materials, rigid and tough, fast turnaround, sparse fill for light weight with high part volumes

FDM Cons: Striated machine finish, low resolution on features under 0.030"

Polyjet (Objet) Printing

Learn more about Polyjet

Standard Materials: Acrylic and polypropylene-like

Relative Cost: ★★★☆☆

Machine Finish: ★★★★★

Typical Lead Time:  2-5 Business Days

Specialty Materials: ABS-like, various elastomers and digital materials (See Polyjet Page)

Relative Cost: ★★★★☆

Machine Finish: ★★★★★

Typical Lead Time: 3-7 Business Days

Polyjet Pros: Top quality detail, best surface finish, clear material option, embedded textures, fine features, single piece mechanical assemblies

Polyjet Cons: Resins - not industrial thermoplastics, lower heat resistance, better for smaller parts

Selective Laser SIntering (SLS)

Learn more about SLS

Standard Materials: Nylon and glass filled nylon

Relative Cost*: ★★★☆☆

Machine Finish: ★★★☆☆

Typical Lead Time:  5-10 Business Days

Specialty Materials: Rubber (TPU), carbon filled nylon and other composites (See SLS page)

Relative Cost: ★★★★☆

Machine Finish: ★★★☆☆

Typical Lead Time: 5-10 Business Days

SLS Pros: Real thermoplastic and thermoplastic composites, uniform matte finish, great thermal and mechanical properties

SLS Cons: Large and thick parts can warp, longer production lead times, porous material, low resolution on features under 0.030"

*In volume SLS can become one of the least expensive printing processes.

Large Format 3D Printing

Learn More about Large Format 3D Printing

Standard Materials: Epoxy infused Acrylic

Relative Cost*: ★★★☆☆

Machine Finish: ★★★☆☆

Typical Lead Time:  5-10 Business Days

Specialty Materials: Sand (Sand Casting), Low Ash Burnout Resin (Investment Casting)

Relative Cost: ★★★☆☆

Machine Finish: ★★★☆☆

Typical Lead Time: 5-10 Business Days

Large Format Pros: Largest build size of any 3D printers, cost effective for large parts, casting patterns and molds without any additional tooling

Large Format Cons: Not as durable as SLS or FDM, not intended for small objects, longer production lead times compared to smaller printers

3D Printed Metals

Note: 3D printed metals tend to be 5 to 10 times the cost of 3D printed plastics and are often more expensive than machined metals.

Direct Metal Laser Sintering (DMLS)

Learn more about DMLS

Standard Materials: Aluminum, stainless steel, tool steel and titanium

Relative Cost: ★★★★★

Machine Finish: ★★☆☆☆

Typical Lead Time:  5-15 Business Days

Specialty Materials: Cobalt chrome, inconel, (nickel alloy) and more (See DMLS page)

Relative Cost: ★★★★★

Machine Finish: ★★★☆☆

Typical Lead Time: 5-15 Business Days

DMLS Pros: Stronger than cast parts, works with exotic and expensive to machine metals, can make parts that are otherwise not manufacturable

DMLS Cons: Limited part size (generally under 10"), rough finish, lower tolerance than machining, generally more expensive than machining

Printed Metal

Learn more about Printed Metal

Standard Materials: Stainless steel bronze alloy

Relative Cost: ★★★★☆

Machine Finish: ★★☆☆☆

Typical Lead Time:  10-20 Business Days

Specialty Materials: None

Relative Cost: N/A

Machine Finish: N/A

Typical Lead Time: N/A

Printed Metal Pros: Half to a third the cost of typical DMLS parts, beautiful bronze polish look, easily plated, larger bed than DMLS

Printed Metal Cons: Single available material, low strength to weight ratio for metal, long lead time relative to other 3D technologies

3D Printed Composites

Colorjet Full Color Composite

Learn more about Colorjet

Standard Materials: Full color composite

Relative Cost: ★☆☆☆☆

Machine Finish: ★★★☆☆

Typical Lead Time:  2-5 Business Days

Specialty Materials: None

Relative Cost: N/A

Machine Finish: N/A

Typical Lead Time: N/A

Full Color Composite Pros: Full gradient of 390,000 colors, generally least expensive material, fastest way to make large models, very rigid

Full Color Composite Cons: Features thinner than 0.100" can be brittle, does not have the flex of real plastic

What's the Difference Between Selective Laser Sintering (SLS) and Selective Laser Melting (SLM)

Samples of metal printed parts

What's the difference between Selective Laser Sintering (SLS) and Selective Laser Melting (SLM)?  Here's one of the better descriptions I've found that explains it:

"Selective Laser Sintering and Direct Metal Laser Sintering are essentially the same thing, with SLS used to refer to the process as applied to a variety of materials—plastics, glass, ceramics—whereas DMLS refers to the process as applied to metal alloys. But what sets sintering apart from melting or "Cusing" is that the sintering processes do not fully melt the powder, but heat it to the point that the powder can fuse together on a molecular level. And with sintering, the porosity of the material can be controlled.

Selective Laser Melting, on the other hand, can do the same as sintering--and go one further, by using the laser to achieve a full melt. Meaning the powder is not merely fused together, but is actually melted into a homogenous part. That makes melting the way to go for a monomaterial, as there's just one melting point, not the variety you'd find in an alloy. To nutshell it, if you're working with an alloy of some sort, you'll go SLS or DMLS; if you're working with say, pure titanium, you'll go with SLM."

So in lay terms, SLM is stronger because it has fewer or no voids which helps prevent part failure but is only feasible when using with a single metal powder.

RapidMade works extensively with SLS and DMLS processes.  To learn more, click here or contact us.

Original release: http://www.eurekalert.org/pub_releases/2014-06/dlnl-lrd061614.php

"Cool" Ultrasonic Additive Manufacturing "Foils" Its Competition.

Photo Credit: Plant Services/Fabrisonic

Additive manufacturing technologies are evolving at such a rapid pace that it sometimes feels like a full-time job keeping up with new innovations.  Recognizing that each 3D printing process has its own strengths, weaknesses and applications, practitioners and researchers alike are inventing alternative methods "to get the job done."  Ultrasonic Additive Manufacturing (UAM) is one of the more recent technologies to be adopted.  The following is an excerpt from an article in Plant Services that describes UAM in greater detail...

"One of the newest alternatives to conventional metals and thermoplastics printing is the Ultrasonic Additive Manufacturing (UAM) process. Developed by Fabrisonic, this process takes thin metal foils on the order of 6 to 10 thousandths of an inch thick and typically 1 inch wide, and ultrasonically welds those together in a brick-laying pattern to build up a near-net-shape item.

" 'All of our machines are actually 3-axis CNC mills," says Mark Norfolk, President at Fabrisonic, "so we use the additive piece to get near-net shape, and the subtractive piece to get the exact-fit finished tolerance that you need out of the part. We’re welding with ultrasound, which is unique to our process and which happens essentially at room temperature, so we don’t have to worry about a lot of metallurgical interactions.' "

"The solid-state nature of the final printed product is a key advantage of the UAM process, as it bonds dissimilar metals without creating brittle inter-metallics (see Figure 2), and enables the embedding of electronic components including microprocessors, sensors, and telemetry into solid metal parts."

" 'For example, in aluminums, we see peak temperatures in the range of 200 °F, so we’re not changing the metal at all," says Norfolk. "We can also combine dissimilar materials since we’re doing this at so low a temperature. Taking ultrasound and vibrating the metals back and forth and essentially scrubbing off the oxide layer, with a little bit of temperature and a little bit of pressure, we get a solid-state metallurgical bond.' "

Selective Inhibition Sintering Seen as Affordable Metal Printing Technology

Wrench printed by SIS (Photo Credit:  3DPrint.com)

Many consider the affordable 3D printing of metal to be a breakthrough that would allow greater adoption of additive manufacturing for end-use parts.  According to 3Dprint.com, researchers at the University of Southern California are working on a novel approach to that end:  Selective Inhibition Sintering (SIS) which inhibits powder from melting, instead using it a mold:

"Using this new technique, a machine first lays down a layer of metal powder on a print bed. At this point a commercial piezoelectric printhead deposits a liquid solution which acts an an inhibitor, preventing the metal that it is sprayed upon from melting once it’s heated. The printhead, which is similar to that found in an inkjet printer, only sprays in an area which represents the boundary of the actual print. Where this solution is sprayed, the metal clumps together and hardens.  Layer by layer, more metal powder is deposited, and more of the inhibiting agent is sprayed onto the print bed. The boundary of the object slowly is built up, with metal powder inside.  It basically becomes a mold filled with pristine metal powder. When complete the entire print is then melted at a high temperature, leaving behind a solid object encased inside the inhibitor shell, which is then easily removed."

SIS is being touted as an affordable alternative to other metal printing processes because:

• It relies on printhead technology which is seen as cheaper
• It builds only the boundary of an object and is therefore faster.
• Unused powder can still be reclaimed since the inhibitor is made from sucrose which can be dissolved in water.

While not yet perfected - part shrinkage and inhibitor application problems have occurred - researchers are encouraged by their preliminary results. 

3D Printing Helping Decommission Nuclear Power Plants

Image Credit:  Wikipedia/Engineer.com

One under-appreciated benefit of 3D printing is being able to 3D scan and reproduce obsolete parts - either through traditional or additive manufacturing.  For example, we've been working with the State of Oregon to reverse engineer, improve and manufacture obsolete parts for some of its correctional facilities - saving several thousand dollars for each cell door that is refurbished rather than replaced.

This same approach is now being used in England to decommission nuclear power plants.

"Sellafeld recently designed a new lid for one of its 40-ton nuclear waste export flasks. By using 3D scanning engineers were able to quickly and accurately recreate the geometry of a legacy component, saving time and thousands of dollars. From those 3D scans a new lid will be printed, saving even further costs.

That’s only one example of the way 3D printing will be used to curb expenses, engineers expect AM to play a big roll in a number of future component redesigns in both plastic and metal.

Given that the estimated cost of the two plants’ decommissioning has ballooned to $118 billion, any savings that can be wrung out of the project will be greatly appreciated by the UK taxpayers."

High-profile cases like this will hopefully help reduce one hurdle to adoption:  getting agencies to appreciate the potential cost, time and ecological savings associated with reverse engineering and additive manufacturing of obsolete parts.  

Inconel Alloy 625 Now Available for 3D Printing

Inconel 625, a nickel-based alloy is said to be the first single metal alloy for 3D printing industrial applications at greater than 99 per cent density according to ExOne which creates the metal using its binder jetting technology.

Inconel 625 is commonly used for components in the aerospace, chemical and energy sectors, with applications including gas turbine blades, filtration and separation, heat exchanger and moulding processes. The metal is considered desirable thanks to its oxidation and corrosion-resistant qualities and its ability to retain its strength in extreme environments.  

The alloy, which was developed by ExMAL, ExOne's R&D arm, is scheduled to be released sometime in June.  This introduction supports ExOne's strategy of qualifying at least two new industrial materials each year.  Of particular interest, it has reportedly seen promising results in its attempts to develop a titanium-based material.

Save Thousands and Make a Splash at Tradeshows!

Monitor produced for close to half the cost of and in far less time than traditional manufacturing

Exhibiting at tradeshows, while rewarding, can be very expensive and stressful:  transporting and staging large equipment can consume a large portion of a company’s marketing budget.  But it doesn’t have to.  Using 3D printing techniques, firms can get to-scale, full-color prototypes and models of their equipment that can easily be carried and displayed on site. 

The Client:

FlatHED, Inc. is an industrial design company which specializes in designing appealing and sleek consumer goods that are also cost effective to manufacture.

The Need: 

Not all cost-effective designs for manufacture are cost-effective in small quantities for tests and tradeshows.  FlatHED designed an all-in-one computer that would house electronics that their customer wanted to show off at a trade show.  To CNC machine the design out of aluminum would have cost over $10,000 for just one unit and then they  would have been left with an unfinished, heavy part covered in tool marks.  They needed two working devices and had only $8,000 to budget for both, so they turned to RapidMade™.  

 The Solution: 

Working with FlatHED to modify the design for a special mix of manufacturing methods, RapidMade™ was able to create a finished product out of ABS plastic, ceramic, and sheet metal.  The final part was indistinguishable from the metal design and finished with high quality automotive gloss and matte finish paint, contained all the electronic components, held the weight of a heavy computer monitor, and (most importantly) cost slightly over half the original $8,000 budget. 

To-scale, full-color model shows internal components of large equipment

The Client:

Cornell Pump Company produces some of the best pumps in the business and attends over a dozen trade shows every year for food processing, mining, agriculture, and other industries that require pumping. 

The Need:

Cornell has had great success shipping and displaying their actual pumps for view at these shows, but they wanted a way to show potential customers the inner mechanics of the pumps in an attention-getting way.

 The Solution:

Cornell asked RapidMade™ to produce tabletop models of their large pumps with color coding and cutaways.  Customers can see the inner components and compare the colors with a labeled legend near the pump.  Having a tool that helps to explain the mechanics of the pumps is a valuable sales tool; it helps customers connect the dots for application.  Seeing the 3D printed colored replica also draws the attention of browsing show attendees.  On top of all of that, the ceramic model can be easily carried under the arm of a tradeshow representative, eliminating the need for expensive shipping.