Metal 3D Printing a Shift Knob

I have always had an issue with leaving well enough alone since the day I bought my Subaru. I have altered everything from the crank pulley to the exhaust, the wheels and tires to the steering wheel. I’ve even 3D printed parts for my roof rack to increase its functionality. One of the things that I have altered multiple times has been the shift knob. It’s something that I use every time and all the time when I am driving my car, as it is equipped with a good ol’ manual transmission, a feature that is unfortunately lost on most cars in this day and age.

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I have had plastic shift knobs, a solid steel spherical shift knob, a black shift knob, a white shift knob, and of course some weird factory equipment shift knob that came with the car. What I have yet to have is a 3D printed shift knob. For this project, not any old plastic will do, so with the help of Concept Laser, I’m going straight for some glorious Remanium Star CL!

One of the great things about metal 3D printing is that during the design process, I was not bound by the traditional need for a staple of design engineering, Design For Manufacturing (DFM). The metal 3D printer uses a powder bed which is drawn over the build plate and then locally melted using high-energy fiber lasers. The build plate is then lowered, another layer of powder is drawn across the plate, and melted again. This process continues until the part is complete.

The design for the knob was based off my previously owned shift knobs, mainly the 50.8 mm diameter solid steel spherical knob. I then needed to decide how best to include features that would render traditional manufacturing techniques, especially for a one-off part, cost prohibitive, if not impossible.   I used ANSYS Spaceclaim Direct Modeler as my design software, as I have become very familiar with it using it daily for simulation geometry preparation and cleanup, but I digress, my initial concept can be seen below:2016-10-18_16-19-33

I was quickly informed that, while this design was possible, the amount of small features and overhangs would require support structure that would make post-processing the part very tedious. Armed with some additional pointers on creating self supporting parts that are better suited for metal 3D printing, I came up with a new concept.

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This design is much less complex, while still containing features that would be difficult to machine. However, with a material density of 0.0086 g/mm^3, I would be falling just short of total weight of 1 lb, my magic number. But what about really running away from DFM like it was the plague?

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There we go!!! Much better, this design iteration is spec’d to come out at 1.04 lbs, and with that, it was time to let the sparks fly!

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Here it is emerging as the metal powder that has not been melted during the process is brushed away.

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The competed knob then underwent a bit of post processing and the final result is amazing! I haven’t been able to stop sharing images of it with friends and running it around the office to show my co-workers. However, one thing remains to make the knob functional… it must be tapped.

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In order to do this, we need a good way to hold the knob in a vise. Lucky for us here at PADT, we have the ability to quickly design and print these parts. I came up with a design that we made using our PolyJet machine so we could have multiple material durometers in a single part. The part you need below utilizes softer material around the knob to cradle it and distribute the load of the vise onto the spherical lattice surface of the knob.

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We quickly found out that the Remanium material was not able to be simply tapped. We attempted to bore the hole out in order to be able to press in an insert, and also found out the High Speed Steel (HSS) was not capable of machining the hole. Carbide however does the trick, and we bored the hole out in order to press in a brass insert, which was then tapped.

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Finally, the shift knob is completed and installed!

Want to learn more, check out the article in “Additive Manufacturing Media.”

 

Be One of the First to Witness 3D Printing Reinvented

 

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According to some, the novelty of 3D printing has been wearing off — its mentioned in daily conversations, used on Grey’s Anatomy episodes, incorporated in high school and college classes. Most iPhone-wielding millennials know what it is and how it works. It’s not a “new thing” anymore, right?

Wrong.

Coming to Denver, Salt Lake City, and Phoenix — Phoenix Analysis & Design Technologies (PADT) invites you to be one of the first to meet the Stratasys J750 3D Printer: the latest introduction in the portfolio of PolyJet 3D Printers. The Stratasys J750 is the first-ever full-color, multi-material system, which finally addresses the frustration of designers who want realistic models but have to contend with inconsistent color results and rough finishes from current technology.

Ready to register now? Click here and jump right to it! Or keep reading . . .

Unlike other 3D printers currently in existence, the Stratasys J750 can operate with five different colors: cyan, magenta, yellow, black and white — all of the primary colors in the CMYK color process, just like day-to-day 2D full-color printers. The Stratasys J750 also achieves very fine layer thicknesses, enabling high surface quality and the creation of models and parts with very fine, delicate details, where current 3D printers usually result in relatively rough surface finishes.

What does this mean for those who use 3D J750_Hand2 - High Resolution JPGprinting? The Stratasys J750 not only delivers incredible realism but it’s also the most versatile 3D printer available. Designers and producers can say goodbye to the days of adopting multiple 3D-printing technologies and still resorting afterwards to extensive post-processing, such as sanding, painting and bonding.

Before the Stratasys J750, no single 3D printer could deliver full color, smooth surfaces and multiple materials. Now, however, you can print realistic prototypes, presentation models, Digital ABS injection molds, jigs, fixtures, educational and promotional pieces, production parts – or all of the above, with one system.

The Stratasys J750 even goes one step past versatile, simultaneously being the fastest, simplest, and easiest 3D printer to use. The printer includes several user-requested upgrades, such as server functionality, six-material capacity, and even three print modes that are suitable for different priorities: high speed, high mix and high quality. Additionally, where some 3D printing processes must run in a dedicated facility due to the possible hazard of the materials, chemicals and post-processing steps involved, the Stratasys J750 3D Printer uses a clean, easy process, with no hazardous chemicals to handle.

The Stratasys J750 is one choice among an ever-growing array of 3D printers in the marketplace. But its capabilities and versatility make it more than just a 3D printer; It’s a solution-maker.

In other words, Stratasys has just invented 3D printing. Again. PADT’s 3D Printing team can help you pick the best printer for your job and provide you with one-on-one engineering and prototype support.

If you’re at all interested in technology, you won’t want to miss this printer’s big coming-out day.

Check out times and locations below.

Denver – Monday, July 25th    J750 Shoes 1

Saint Patrick’s Brewing Company

3:00 pm to 6:00 pm

REGISTER

Salt Lake – Wednesday, July 27th

Hilton Salt Lake City Center

3:00 pm to 6:00 pm

REGISTER

Phoenix – Friday, July 29th

ASU SkySong

2:00 pm to 5:00 pm

REGISTER

   

 

3D Printing to Combat Deflategate

3d-printed-footballIn honor of the big game this weekend the folks at Stratasys scored big time with a 3D printed footballStratasys has had a history of using 3D printing to improve on a variety of sports; however this time they out did themselves by possibly solving the infamous issue of deflategate. Since the Ideal Gas Law doesn't exactly explain it, maybe 3D printing could help prevent it from interfering in the big game until an answer is found. I’m not sure the NFL will be too keen on using these balls but it’s a thought

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The football was created on the Objet500 Connex3 Color Multi-Material 3D Production System and was printed in three materials.  VeroMagenta and VeroYellow was used for the bulk of the design however they were also able to replicate the true texture and feel of a real football using the rubber-like TangoPlus material and all in one print job.  It is heavier than a game ball but can still be tossed around.  Of course they wouldn’t print a football and not test it.  Check out their video below. 

Bonus Link – Here is a fun Brady Deflategate Inaction Figure from Shapeways. 

Additive Manufacturing Motor Trends

Additive manufacturing (AM) has been used in the motor sports world for years.  Now more than ever, race teams have found that additive manufactured parts have the quality and durability to meet their demands. From NASCAR to the World Rally Championship, race teams around the world are excited about the possibilities that AM brings to the table. For an interesting webinar on-demand and a great whitepaper, click the image below. 68905-Motor-Trends-Webinar_960x350

A look inside the Objet500 Connex3 Multi-material 3D printer

This week our we printed some beautiful multi-colored sponsor awards for the 2014 Arizona SciTech Festival which officially launches in August.  Intern extraordinaire, Diserae Saunders, placed a GoPro inside our Objet500 Connex3 to record the magic.  Enjoy the video and check out the Arizona SciTech Festival for information on this great program that promotes science, technology and innovation in Arizona!

An inside look at our Connex500

We wanted to see what 3d printing looked like from the inside of the machine so our new intern, Diserae Sanders, placed a GoPro inside our Connex500 during a print job.  The item being printed is a demo bicycle pedal printed in multiple materials.  

This video is the first in a series we plan to do on 3D printing. If there is something you would like to see us do a video on, please post it in the comments below.

Stratasys adds flexible color to their digital material palettes

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Earlier this week, Stratasys announced the addition of 10 new color pallets expanding the digital materials offering to represent hundreds of new options of both flexible color materials and rigid gray materials available for the Objet500 Connex3 Color Multi-material 3D Printer

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The first three pallets are built using TangoPlus combined with combinations of VeroCyan, VeroMagenta and VeroYellow. These new pallets allow for the printing of a range of colors and translucent tints in nine Shore A values (Shore A 27-95).

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Three additional pallets using TangoBlack Plus and combinations of VeroCyan, VeroMagenta and VeroYellow allow for users to blend a wide range of subtle vibrant-to-dark shades into the same part with TangoBlack Plus in seven Shore A values.

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The final four palettes that were introduced offer additional combinations of VeroWhite and VeroBlack with either VeroCyan, VeroMagenta or VeroYellow allowing for users to build sophisticated prototypes in a range of subtle grays alongside muted or vibrant color. 

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The addition of these ten palettes combined with their existing palettes allow for virtually limitless combinations of flexible, rigid and translucent colors in one print job.

“The Objet500 Connex3 is the only 3D printer that combines colors with multi-material 3D printing. The ability to mix rigid, flexible, transparent and opaque colors offers users unprecedented versatility to design and perfect products faster,” says Stratasys Director of Materials & Applications Fred Fischer. “By extending the range of material options available, users can improve workflow speeds and enhance efficiency.”

These new options are available immediately to Objet500 Connex3 Color Multi-material 3D Printer owners through a free software update. 

Check out this great video on the new materials.

PADT Talks about 3D Printing on Channel 8’s Arizona Horizon

PADT-Horizon-PBS-PicOur latest journey into mass media was a real pleasure.  We were invited to come on to the local Phoenix PBS station to talk about 3D Printing.  The team of students from the Walter Cronkite School of Mass Communications at ASU that do most of the behind the scenes work were great. The host and producer were true professionals who asked some of the best questions we have ever been asked on this topic.

You can the full program here:

http://www.azpbs.org/arizonahorizon/play.php?vidId=6037

Eric’s interview is the second half.

Those of you who know 3D Printing know that they showed a CNC mill instead of one of our 3D printers.  We gave them a bunch of background video to use (from another interview) and they kind of picked the wrong one. But hey, Bob and Luis got on TV!  And all that really matters is that they spelled our name right.

A great opportunity and we look forward to evangelizing the promise of additive manufacturing in the future. You can learn more about the whole world of 3D Printing on our website by starting on our prototyping support page.

A Guide to Creating Good STL Files

imageThe STL file is the linqua-franca of the prototyping world, the file format that all geometry creation tools write, and that all prototyping systems read. When you make a prototype it will be an exact copy of your STL file. If your file is not accurate, then your prototype will not be accurate. If there are errors in your file, you may not be able to get a prototype made. Therefore, a little bit of time understanding STL files and how to create a good one is a good investment that will pay off in the long run.

About STL Files

When additive manufacturing was just starting the manufacturers of machines faced a problem – they needed a way to get 3D solid models from a large number of CAD systems to their machines for processing. The common file format for geometry interchange, IGES, was not robust enough because of toleranceing issues. Writing a program to slice up each CAD format was also not practical. So they looked at the problem and realized they did not need exact mathematical models made up of NURB, Bezier, or analytical geometry. The algorithm that sliced up each layer just needed polygons on the surface. So the STL file just needed to have those polygons. And the STL file was born.

Lets talk about that slicing process. If you remember, almost all additive manufacturing processes work by creating stacked layers that are a cross section of the part you want. To build the part you must slice the geometry in software, calculating that cross section. Doing the intersection of a plane with a complex NURB surface is hard math, but the intersection with a triangle is very easy and results in a line segment. This makes creating the path for each layer much easier.

STL stands for STereoLithography, or Standard Tessellation Language, depending on which source you check. It was invented for 3D Systems by the Albert Consulting Group way back in 1987 to support the first Stereolithography machines. The format describes a collection of facets, or polygons. Each polygon is defined by a normal “outward” vector and the vertices that define it. Although the format supports more than three vertices per facet, in practice everyone uses three, defining a triangle. The file can be a text file (ASCII) or a binary file.

Users almost never have to worry about the file because the programs they use to create their geometry automatically generate STL files in the proper format. If you do need to write your own routine to output an STL file, it is fairly simple.

Faceting

clip_image001 The way an STL file is made is the program that creates the STL file goes through the topology of the model and meshes it:

1: First it puts points on all of the shared edges of all the surfaces
2: Then it creates triangles on each surface

The algorithm used to create the facets varies from program to program, but most of them use the same routines they use to make facets for the 3D graphics you see on your monitor.

There are two things to note about faceting. The first is that each corner must be coincident with at least one other corner. No corners can touch the edge of another triangle. The second is that a triangle is flat and your surface can be curved. To make your curved surface look curved you need enough triangles to make it appear like a continuous surface.

Leaky Geometry

The most common problem these days with STL files is leaky geometry. When your CAD tool creates the STL file your solid may not be a true solid in that you have holes in your topology. This can be caused by gaps, ill-defined curves and surface, or corners (vertices) not lining up. If you cut out the triangles and glued them together then filled the resulting object with water, the water would leak out.

You CAD package can make leaky STL files if it has loosened up the tolerances on the geometry modeling to the point where edges on its surface do not really line up. They trick themselves into accepting this through some hand waving inside their database, and it really is not a problem till you want to do something with the surfaces. Something like make an STL file.

One way to fix this problem is to clean up the original geometry. Run diagnostics on it and see where there are holes. You should do this anyway because in the end, a messy solid will cause problems when you make your drawings, calculate tool paths, or try and do simulation.

If that is not an option, you can use repair software. If you use an RP service provider, they should be able to repair most STL files. But if you constantly need them to do so, you should really look at changing your modeling practices or investing in some repair tools.

If you are doing your own prototyping, you have two good options. The first is free: Meshlab. It is an open source tool for working with faceted geometry and has repair and diagnostic capabilities. It does a lot so the interface can be a bit confusing, but it is free. If you want to save time and probably money in the long run, we recommend that you purchase a copy of SolidView. It is purpose built for repairing STL files and can really cut down on your repair time.

Faceted Geometry

Even if your prototyping tool can read your geometry and make a valid part, it may come out looking all clunky because your geometry is to faceted. As discussed above, the STL file is made up of triangles. If you have too few triangles on a curved surface then it comes out looking all flat and ugly. Here is a simple example:

The key to controlling this is to set the options in your CAD package to create more facets.

This is such an important topic, we actually have a whole posting dedicated to it:

STL File Tolerance: A Short Explanation of Faceting and Chord Height

In the old days we tried to minimize the number of triangles in an STL file because that file had to be uploaded, often via a modem.  But now we can email very large files, so you can make some pretty big STL files. Don’t go crazy, but don’t sacrifice surface quality either.

Degenerate Triangles and Inverted Faces

It is very rare for a CAD tool to create bad triangles, but it happens every once in a while. When trying to create a build from an STL file you might get a “Degenerate Triangle” or “Inverted Faces” error message.  There is not much you can do with this other than try one of the repair tools mentioned above or try and fix your underlying geometry.  If you get this type of error, there is something very wrong with your solid model.

Feature Sizes

Another problem that people often run across is that some of their small features do not show up on their prototype.  This can be because their STL file is not refined enough and that can be solved by tightening up the tolerance on their STL file creation.  If that does not work, the feature may just be too small for the technology.  Take a look at what the true machine resolution is. Make sure that is is smaller than your smallest features.

Make an Investment in Productivity

Having a bad STL file can really slow down the rapid part of Rapid Prototyping.  That is why PADT recommends that you take the time when you create your solid models to make good, robust, water tight solids that can be used down stream.  If you have nasty geometry or a less than precise CAD tool (can anyone say CATIA) you may have to invest in a repair program like Meshlab or SolidView.  Some up-front investment will pay in the long run, especially when you need that prototype first thing in the morning.

12 Things Every Engineer Should Know about Rapid Prototyping

PADT has been providing various forms of rapid prototyping since 1994, focused on providing high quality prototypes to engineers involved in product development. Over that time, we have learned a lot about what our customers need to know in order to get the most out of their rapid prototyping investment. As we launch our new The RP Resource, we think now is a good time to share some of the things we have learned.

1: Know what you are going to use your prototype for

This is the most important thing for any engineer to know when they are using rapid prototyping. A good understanding of how the prototype will be used is critical to making decisions on the technology applied, the material used, the build options set, and the post processing that is carried out. When we look into why a customer who is unhappy with their prototype, nine times out of ten we find out that they did not convey to us what their end use was, so we did not make them the prototype they actually needed.

2: Rapid Prototyping, Direct Digital Manufacturing, 3D Printing: They are all additive manufacturing

The technology may vary from machine to machine, but in the end they all kind of work the same – they build a part one thin layer at a time. This is important because the part you end up getting will be made with layered manufacturing. The strength will be non-uniform, features that overhang may droop a bit if not properly supported, and the surface finish will not be smooth unless you chemically treat it or sand it after the build is done.

3: You will get an exact copy of your STL or CAD file, so make sure it is a good one.

The prototype that you are making is a direct digital copy of the file you ask it to print. None of the processes improve on the geometry you send to them, so it is important that you provide a high quality model. If you are starting with an STL file, you need to make sure that you have enough facets on your model so that they are not visible on the prototype. We like the maximum deviation of the facet from the actual shape (chord height) to be less than 0.001 inches. We recently did a post on this very topic.

The same goes true for “bad” STL files. You may get errors, or the prototyping system may not even be able to build your part. Making sure you have a quality STL or CAD will save everyone a lot of time.

4: Build orientation has a big impact on cost, surface quality, and strength

Remember that you are using a layered manufacturing process. The number of layers and their orientation relative to your part can make a bid difference on cost, the surface quality, and strength.

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In the exaggerated illustration above, you can see the same shape will have different stepping, and a different number of layers depending on how it is oriented. The taller the part, the longer it takes to build. The lower the slope, the more “stair-stepy” the surface.

Something else to take into account is that the parts will be weaker when the layers are put under load that causes them to delaminate. Imagine your prototype was made up of a deck of stacked playing cards with a glue between each card. You want to load it in a way that will not cause those cards to want to pull apart.

5: The amount of material in you part is a big cost driver

One of the biggest drivers of the cost on a prototype is the amount of material used to build the part. This is especially true when you are using some of the more expensive materials.  Take a look at using options in your machine software to more sparsely filled part.  You can also shell your part on your CAD system. If you are working with a service provider, ask them to take a look at this on your prototypes.

6: Part geometry can come from CAD, or a scan

Customers occasionally come to us with an existing part and ask us to make a CAD model of it so they can prototype it. In some cases, it may be easier to just make some soft tooling of the part, skip the prototyping process entirely. But if that does not work, you can use a variety of scanning technologies to get a faceted representation of the real part.

7: Warping and shrinking distortion is above and beyond published machine accuracy

When you look at the published accuracy of a given machine what they show you is the accuracy of the process that traces an outline or sets the thickness of a layer. The accuracy of the mechanisms in the machine itself. Your part may have much less accuracy because most parts warp and shrink slightly during the manufacturing process. Overhangs may also droop if they are not supported correctly.

The key to solving this problem is to really know the machine you are using, or work with a service provider who knows how to plan for and adapt to this reality. Some technologies may just not be suited for your geometry, and you may need to go with a different machine type.

8: Build the full cost or prototyping into your product developments budget

People who use prototyping effectively in their product development always budget for the proper amount to pay for prototyping. Too often this important tool is left out of the budget and when a prototype is needed, funding can not be found or shortcuts are taken that diminish the value of the prototypes. In order to do things right the first time, you should plan for the expense.

9: You are not stuck with the material color that the part is made with

It is fairly easy and affordable to paint or dye most rapid prototyping parts. It does add time to the project because painting or dyeing takes time. Users should be aware that they can get almost any color they need on their part.  A talented technician can also provide almost any surface finish that is needed.

10: Your prototype can be used as a pattern for casting multiple parts

If you need multiple copies of your part, it may be more affordable to only make one additive manufacturing part and then use soft tooling to make copies. This is also a way to get material properties that are not available with any of the additive manufacturing technologies.  In some cases, you can even cast injection molding tooling from a prototype part.

11: The quoted price of the prototype is just part of the total cost of having a prototype made

When looking at cost it is important to calculate the total cost.  When doing rapid prototyping you need to look at the quoted price of having a prototype made, internally or externally, as only one of many costs. Other activities that impact total cost are:  cost of reworking prototypes; shipping/delivery costs; delay in schedule due to build, post processing, and shipping time; time and money spent modifying tests to fit the prototypes shortcomings, time and cost required to deal with prototype failures, etc… 

12: Take some time to learn the strengths and weaknesses of every available technology

Even if you have one particular technology any engineer who needs to do a significant amount of rapid prototyping should invest the time in understanding all of the available technologies. Each has advantages and disadvantages, and if you understand them and you understand what the usage of your prototype will be, you can save yourself and your company a lot of time and money by choosing the proper technology for each prototypes. 

We hope to have some time in the coming months to provide some in depth information on all of the major prototyping technologies, so check this blog for more information.

Rapid Prototyping FAQ

PADT has been providing Rapid Prototyping Services since 1994 to companies around the world, and over that time we have been asked a lot of questions. The lists below present the most Frequently Asked Questions, our FAQ. The list starts with general Rapid Prototyping questions and is followed by questions that are specific to working with the experts at PADT to do your Rapid Prototyping.

If you do not see your specific question, please feel free to contact PADT and we will be happy to answer it directly.

General Rapid Prototyping Questions

What is Rapid Prototyping?

Rapid Prototyping is a manufacturing technology that quickly builds a prototype part. Many different technologies are available that are considered Rapid Prototyping, and many can also be used for production manufacturing. Although most Rapid Prototyping systems use a form of layered additive manufacturing, they can also use a variety of other methods such as high-speed machining, molding, casting, and extruding.

Rapid Prototyping, often called RP, is rapid prototyping when the entire process of going from a computer design to a physical model is faster than more traditional manufacturing technologies. Wikipedia has a good article on the subject.[ http://en.wikipedia.org/wiki/Rapid_prototyping]

What is Rapid Tooling and how is it Different from Rapid Prototyping?

The only difference between Rapid Tooling and Rapid Manufacturing is the end use of the parts produced with the process. Both use rapid prototyping technologies to quickly make a part. But for Rapid Tooling, the part is used in another manufacturing process as a tool.

What is 3D Printing and how is it Different from Rapid Prototyping?

3D Printing refers to a subset of rapid prototyping that goes directly from a 3D computer model to a prototype with very little user interaction other than defining some preferences. The process is designed to be as easy as printing from a computer to paper.

In many ways the name is a marketing label to clearly emphasize the affordability and ease of making prototypes using systems that are labeled as 3D Printers. It is also meant to appeal to a larger, less engineering and manufacturing oriented audience. PADT uses 3D Printing systems as well as Rapid Prototyping and Manufacturing systems.

What are some of the other names for Rapid Prototyping?

3D Printing, layered manufacturing, additive manufacturing, direct digital manufacturing, digital prototyping, digital fabricator, desktop fabricator, desktop manufacturing, desktop prototyping.

People often use the names of various prototyping techniques to refer to rapid prototyping, and even more often the acronyms for those technologies. Examples are Stereolithography or SLA and Fused Deposition Modeling or FDM.

What is Layered Manufacturing and why do most Rapid Prototyping Technologies Use it?

Layered Manufacturing builds parts up, one thin layer at a time. Most traditional manufacturing methods start with a block and remove material, or shapes material using a tool of some kind. Layered manufacturing is often called Additive Manufacturing because it adds material rather than taking it away or molding it.

The best way to visualize layered manufacturing is to think of taking a real part and chopping it into very thin layers. Then stack those layers back up one on top of the other. Layered manufacturing does the chopping in a computer program, and tells a machine how to create each layer.

When and how is Rapid Prototyping used in Product Development?

Rapid prototyping can be used at almost every step in your product development process. At any point where you need a physical part you can benefit from Rapid Prototyping. Examples are:
Conceptualization: concept models, marketing mockups
Initial Design: form, fit, and function testing, visualization
Detail Design: testing, test fixtures, assembly testing, fit, form and function testing.
Production: tooling, mockups for process planning

What are the different types of Rapid Prototyping Technologies and their Advantages and Disadvantages?

Unfortunately there is no one technology that is perfect at everything. The following table is a basic listing of the main advantages and disadvantages.

TECHNOLOGY ADVANTAGE DISADVANTAGE BEST USE
SLA Smooth Accurate Detail Temperature Sensitive, Brittle, Brittles over Time Marketing Models Fit Checks
SLS Durable, Speed on Large Projects Rough Surface, Erratic Accuracy Functional Models
FDM Cost Effective Durable True Plastics Lower Resolution Weak Layer-to-layer Engineering Models Internal Reviews
POLYJET Adjustable Material Properties Speed Fine Layers Weak Material Properties Cost Elastomeric Models Overmold Models
CNC MACHINING Accurate True Materials Long Lead Time Cost Metal Models Precision Work

What is a STL File?

The STL file is a file format developed in the early days of Rapid Prototyping by 3D Systems as a simple and portable format that could be used across CAD systems to define the solid geometry to be made in a Rapid Prototyping machine. It is a triangular facet representation, the surfaces of the solid are modeled as a collection of triangles that share vertices and edges with neighboring triangles. Most CAD tools can output an STL file.

You should also know that there are two types, ASCII (text) and binary. Binary tends to be more compact.

Learn more on Wikipedia. [http://en.wikipedia.org/wiki/STL_file]

My part is about “this” big, how much will it cost to make a prototype of it?

It is very difficult to estimate the cost of a prototype without knowing many different factors. These include the volume of the part, the height in the “up” direction, the process being used, the material being used, and the finishing that is required. The best way to find out the cost is to send a part to PADT for a quote. If you do not have a computer model yet, then sending the basic dimensions and calling our engineers should result in a ball park estimate.

How long does it take to make a Rapid Prototyping Part?

IT can take as little as five minutes and as long as 3 or 4 days depending on the size, the process, and the amount of finishing required. However, most parts can be made within a 24 hour period.

Can I use Rapid Prototyping to make tooling for Injection Molding?

Yes you can. A special process and special materials are required, as is a special mold base. But a low volume injection mold can be made using Rapid Prototyping. PADT can also help find a supplier that can use rapid machining to make molds almost as fast as rapid prototyping.

My buddy has a MakerBot/RepRap/Build-your-Own-3D-Printer. How is that different from these commercial Rapid Prototyping systems?

There has been an explosion of do it yourself RP systems at around 2010-2011. Most of these are based on the fact that the patent for Fused Deposition modeling ran out. The majority of homemade systems, or personal systems, are variations on the systems made for decades by Stratasys. They differ from commercial or industrial systems in two ways: lower cost, and fewer capabilities. In general, the parts made on these systems are not usable for engineering or even visualization models because the material is too soft, the material does not fully harden or bond, there is considerable shrinkage or warping, and the actual precision of the device is low.

What is the most commonly used Rapid Prototyping Technology?

For many years the most commonly used technology is Fused Deposition Modeling. Originally only available from Stratasys, many other providers have adopted the technology. The best way to see how the various technologies stack up is through the Wohlers Report, an annual summary of the industry. [http://wohlersassociates.com]

Is there free software out there that I can use to look at my model before I send it to you? Can I convert a file I made for animation or rendering to a file you can use?

Yes. Meshlab is a tool for dealing with all types of faced data and it works with STL files as well. It can be sued for translating, repair and visualization. [http://meshlab.sourceforge.net/]

MiniMagics is a free STL viewer from Materialise [http://software.materialise.com/minimagics].

PADT’s Rapid Prototyping Services

I need a Quote, How do I get one?

Basically you need to send us a file containing the geometry you want prototyped and let us know what you need your prototype for, or if you already know, what technology you would like us to use. Detailed information can be found on our Rapid Prototyping support page [/support/rapid-prototyping.html]

What Rapid Prototyping Technologies does PADT have in House?

PADT currently has the following Rapid Prototyping technologies in house:

In addition, PADT offers the following related technologies that are often used with Rapid Prototyping:

Which Technology Should I use for my Prototype?

That depends greatly upon the use you have in mind for your prototype and your budget. Each technology has a variety of strengths and weaknesses as well as cost. What sets PADT apart from most Rapid Prototyping service providers is that our engineers have the experience and the expertise to work with you to determine the proper technology for your needs.

What does PADT need to Quote my Rapid Prototyping Job?

At a minimum, an STL or CAD file and a way to contact you. To speed along the process you can provide us with information about any preferred processes or the intended uses for your prototype.

What File Types (formats) does PADT Accept?

The best format to send to PADT is an STL file.

PADT currently has the ability to use the following Native CAD file formats:

  • NX
  • Pro/E or Creo
  • SolidEdge
  • SolidWorks

PADT can also usually work with the following non-native formats:

  • IGES
  • Parasolid
  • SAT (ACIS)
  • STEP

What settings should I use when making an STL file for PADT?

The default settings are generally acceptable for us. We do recommend that you use a “finer” setting if your part is complicated. If we find that your file is not refined enough, our engineers will contact you and let you know how to increase the accuracy for the CAD system you are using.

How do I Send a File to PADT?

We provide multiple methods for sending files to PADT:

Email it to rp@padtinc.com with your contact information.

Put it into a dropbox or secure file sharing location and send us a link via email to rp@padtinc.com.

Upload it to www.padtinc.com/upload

see www.padtinc.com/support/rapid-prototyping.htmlfor details.

I don’t have a CAD file, can you make me one?

Depending on what you need, PADT can quote solid modeling and design services or we can also recommend one of the local companies or individuals that we work with on a regular basis to help people create CAD models of their parts. Please speak with one of our engineers so we can better understand your needs and we will recommend the best course of action.

I don’t know what a CAD file is, or how to get one, what should I do?

Simply contact us at PADT and we will walk you through the whole process. You may also want to visit PADT’s The RP Resource, it contains a wealth of useful information for experienced users and those who are new to the technology.

My design is Confidential, how do I make sure it will stay that way?

PADT has provided prototyping services to over a thousand companies and individuals without a single confidentiality issue. We treat every customer’s part as confidential. If needed, we have a standard 2-way confidentiality agreement that we can sign to provide additional assurance that we will keep your ideas secure.

How precise are the Rapid Prototyping Technologies that PADT offers?

Precision and accuracy are very geometry dependent as well as machine dependent. Below are basic baselines to consider.

TECHNOLOGY ACCURACY
SLA +/-0.005″ plus 0.001″ per inch
SLS +/-0.010″ plus 0.002″ per inch
FDM +/-0.008″ plus 0.001″ per inch
POLYJET +/-0.008″ plus 0.001″ per inch
CNC MACHINING +/-0.003″

Why does PADT have so many different Rapid Prototyping Technologies?

Because each technology has advantages and disadvantages. By having each of the leading technologies, and multiple materials options for each, PADT can meet almost any rapid prototyping need.

The only common technology that PADT does not have is a ZPrinter. Why?

Frankly the parts are too fragile. Although the technology does allow you to print in color, the resulting parts are not robust enough for our customers.

What is the largest part you can make?

The largest part we can make in one run can fit in a 14 x 10 x 10 in volume. But PADT has made parts that are several over six feet long by simply building individual pieces together. We also partner with other service providers that have specialty very large machines.

How small of a part can you make? What is the smallest feature you can replicate?

Small features and thin walls are very geometry dependent as well as machine dependent. Below are basic baselines to consider.

TECHNOLOGY TYPICAL ABSOLUTE BEST
SLA 0.010″ 0.004″
SLS 0.020″ 0.010″
FDM 0.030″ 0.020″
POLYJET 0.010″ 0.002″
CNC MACHINING Material dependent Material dependent

My part needs to look like the final production part, can you do that? Can you paint my part? Can you put a surface finish on it?

Yes, in fact that is a specialty of PADT. Our technicians are true artists that know how to prep, sand, and paint a part so that when they are done, it looks like a final product. We can apply your specified surface finish or paint color.

My product has hard and soft pieces, can you make a prototype with different stiffness? Can you make a flexible part? Can you make a rubber part?

Yes. PADT has multiple technologies available that allow us to make parts that mimic several different soft materials, including over molding on a more rigid part.

My part needs to operate at a high temperature | in water | outside | under pressure | with nasty chemicals | around clumsy people. Can you make me a prototype that will survive?

In most cases we can. Most of our machines have materials that work well with water and pressure. Please contact us with your specifications and we will go over your options with you. For higher temperatures and specific chemicals, we will have to do a little research.

Can I use a prototype as a production part?

Yes. Using parts made on “prototyping” equipment as production parts is becoming more and more common for low volume manufacturing and certain smaller parts that can only be made using an additive manufacturing process.

Can rapid prototyping parts be used for tooling and fixtures?

Yes. In fact, this is one of the fastest growing areas of rapid prototyping: rapid tooling. It is becoming mainstream for many different manufacturing processes because the parts can be made very quickly and, if the proper technology is used, they can be made very strong.

Can you make a part that is clear or a certain color?

Yes. Several of our technologies have a clear material. In addition, several solid material colors are available. And, if needed, PADT can always paint your part any color you need.

I need more than one part, can you make multiple parts? Is there a less expensive way to make copies of my part?

PADT uses soft tooling and prototype injection molding extensively to make multiple copies of a part. Our soft tooling technicians are very experienced and skilled and are able to compete effectively on speed and cost with many other options, including off-shore manufacturing.

Do you do machining, vacuum forming, traditional model making?

In addition to the Rapid Prototyping technologies that PADT has in house, our shop is also equipped with a CNC mill and lathe, a vacuum forming machine, and all of the tools needed to do traditional model making.

Can you make sheet metal prototypes?

This is one of the few prototyping options that PADT does not offer. But if you are looking for a sheet metal prototyping provider, we have several we can recommend.

Can you make metal parts?

We do not offer metal parts at this time unless we use our CNC machining center. But we do partner with several providers that can make metal parts using rapid prototyping technology.

Shopping for a Rapid Prototyping Service Provider

imageThere are a lot of companies out there providing Rapid Prototyping, Rapid Manufacturing and 3D Printing as a service to others.  As of this writing, Wholers Associates lists 98 around the world. That list does not include the smaller providers or companies who offer RP services as a side service.  It certainly does not include the hundreds of people with low cost 3D printers who will make parts for people. 

With so many choices, how do you pick the right one?

Well, the obvious answer is you just pick PADT to be your service provider.  That makes it easy and you can stop reading now.

Didn’t Work? Damn. Well it was worth a try.  So, taking off the PADT marketing hat and putting on the design engineer hat and engineering manager sweater, here is how I recommend that you make a logical decision:

Why are you Making a Prototype?

Before you do anything you need to ask yourself this question and get a good answer.  Sometimes, the real answer is because it is cool and you want to impress your boss or customer. That is OK. Just keep it in mind when you pick a vendor.  Somebody cheep and fast that delivers so-so quality may not be a good choice.

An important part of the question is also what will you use it for?  Most prototypes are made for visualization – a 3D image.  But many are also made to check fit, form, or function. How you plan to use your prototype should impact the technology you use, and the material choices you make for that technology.

Does it need to look like the production part? Does it need to perform as close to the production part as possible?  If the answer to either question is yes, then you need to really look at what post-processing (sanding, surface finish, texturing, painting) your prototype will need and which providers can supply it.

In fact, if your potential RP service provider does not ask what you want the prototype for, you probably are working with the wrong provider.

Establish what is Important to You

Every customer is different, and often every project is different.  A good place to start is to look at these typical priorities, grouped into three classes, and rank them for your company:

  • The Basics:Image
    • Cost
    • Speed
    • Quality
  • The Interaction:
    • Location
    • Responsiveness of Staff
    • Effort Required to Work With
  • The Capabilities:
    • Technologies Available
    • Material Offerings
    • Knowledge and Experience of Staff
    • Post Processing  Available
    • Down Stream Services Available

Too many customers that we see at PADT who have worked with other service providers, and who have had a bad experience, just look at the first two priorities – cost and speed.  The reality is that there are a lot of things that impact the overall effectiveness of your prototyping effort.  Once you know how you will use your prototype, you can better determine what is important to you.

So rank your priorities and evaluate your potential vendors on the important ones.

Assessing the Basics: Cost, Speed, Quality

Cost and speed seem very easy to obtain. You just send your part file to the potential vendors and get quotes with cost and delivery time. But, you have to look at what you get for the cost, and what the total cost and time are.  Do you need to post-process the part yourself?  Will the quality, surface finish, and material strength meet your needs?  A part made on a low cost 3D Printer may only be $50 versus $500 on an SLA machine.  But if it breaks during your test, how much will that cost?

If you have not worked with a provider before, quality can be tough to determine.  Ask for a reference.  If they are local, go see their shop and look at sample parts.  It might be good to have all of your potential vendors make a simple and inexpensive sample part for you so you can compare all of them before you go off and order $12,000 worth of prototypes.  After you get parts from a vendor, make a note of the quality. If you work for a larger company, maybe share that with purchasing so they know who delivers high quality, and who does not.  We all know that a purchasing person will simply go on the transaction cost if you do not give them other factors to work with.

The Price of Interaction

Manufacturing consulting meetingThis is by far the most difficult set of priorities to define and quantify.  This is the fuzzy stuff that deals with the time, money, and emotional capital that is invested by you during the process of getting your prototype quoted, purchased, made, and delivered.  I wish there was a formula, but you just need to make a gut decision on this one.

After you interacted with a vendor, ask yourself if you found the interaction enjoyable and productive?  Did you get the information you needed quickly and efficiently?  Did they call you back or respond to your email in a quick manner? Did you feel that you were working with them, or was it a bit of a battle? 

I consider this important because what we are talking about here is Rapid Prototyping. It is not “I’m way ahead of schedule, have plenty of budget, and can wait to get my part whenever –prototyping.”  You are doing RP because you need a part fast, you need it right the first time, and your whole product development schedule is probably being held up by it.

If your RP partner is hard to work with, when you get into those stressful I-need-it-tomorrow situations, you can not afford the emotional and financial cost of battling our coaxing your provider to help you out. You need to know you have someone on your team that will step up and come through for you in a pinch.  Never under estimate the importance of how hard or how easy it is to interact with your Rapid Prototyping service provider – keep it in mind and let it weigh heavily in your decision.  It will pay off when you get to crunch time.

What does your Vendor Bring to the Table? Capabilities

Image

Novices in the world of 3D Printing or Rapid Prototyping usually start of with the thought that they just “need a prototype.”  What they have yet to learn is that there are literally hundreds of different options – combinations of various technologies, materials, and post-processing steps.  Picking a service provider based upon capabilities is actually easy:

  1. They need to have most of the major technologies available (SLA, SLS, FDM, Polyjet).
    A provider that is focused on only one or two technologies will fit your needs into what they have. They only have a hammer, so whatever you ask for, you will get a nail.
  2. They must offer a wide range of materials for each technology they have in house.
    This is a big one.  Often customers can get a part that is the wrong stiffness or strength because they use a vendor that just does not offer the full range of materials.
  3. They can offer the post processing you need for your prototypes planned usage.
    A vendor that has to go outside for detailed sanding or painting is just not going to work. They need to be able to give you the part, looking like you want it to look, when they are finished and without running around and counting on other providers.  If they tell you that it is easy and you can do it yourself, walk away.
  4. The engineers on staff understand the strengths and weaknesses of each technology, material property, and post-processing option.
    All of the other capabilities are useless if you can not talk to someone who understand them. You need to be able to call or email someone at your vendor, tell them what you want to do with your prototype, and have them give you reasonable options on how to get there.  If they just have people processing your order through a piece of software, you will get burned in the end.

Cliché’s Exist for a Reason: Don’t be Afraid to Shop Around, Ask Questions, You Get What you Pay For

In conclusion, we should all remember what our grandmother probably told us a few times. I know mine did: Don’t be afraid to shop around. If I put my service provider hat back on I cringe at this. We would like all of our customers to stay with us forever and never stray.  But the truth is that it is a competitive market out there, and if you do not shop around, then you may not be getting the best product and we may not be as focused on making sure we keep you as a customer.  So in the end, we all benefit.

And another thing she said: “Eric, ask questions. It doesn’t hurt anyone to ask questions.”  So do that. The answer may not be as important as how a potential provider answers the question. Does it show they can listen, that they know their stuff, and that they care about you?

Lastly, and most importantly: You Get What you Pay For. There is not need to elaborate on that one.

Image

This is a short list, and there is a lot more to think about. Do not hesitate to contact us at PADT to ask more questions and to learn more about how to pick the right Rapid Prototyping service provider.

3D Printing, Rapid Prototyping, Additive Manufacturing? What is the Difference?

imageThe technology called 3D Printing is getting a lot of press lately. Articles like “3D Printing is the New Personal Computer” and “The New MakerBot Replicator Might Just Change Your World” are all over this place in the fall of 2012.  For those of us who have been printing 3D parts since the early 1990’s, this new frenzy can be a imagebit annoying. At every trade show that PADT goes to these days a large number of non-technical people come up and start telling us about 3D Printing and how it is going to “change everything.”  The next question is almost always “Is that a big 3D Printer?” as they point at a nice big FORTUS 400.  “Well, no, that is a digital manufacturing center, which is a rapid prototyping technology that uses similar technology to 3D Printing but it is much more precise, the material…” and by that point their eyes glaze over and they start playing with the model of the USS Enterprise we put out on the table to attract people.

By sorting through branding, media hype, and the confusing array of new low cost technologies, some clarity can be found and direction for those of us who use these technologies for product development. 

Additive Manufacturing

The first place to start is to recognize that we are talking about additive manufacturing technologies.  Taking a part definition and adding material through a variety of methods to make a physical part.  In almost every case, you build a part by adding thin layers of material one on top of another. The additive process differentiates this type of manufacturing from molding, forming, and machining – all of which remove or shape material.

The advantage of additive manufacturing is that you have very few constraints on the shape of your final part and there is no tooling, no programming, and very little manual interaction with the process.  This has huge advantages over the traditional manufacturing methods when it comes to speed.  Although you pay a price in strength, material selection, and surface finish, you can get parts quickly without a lot of effort.

Rapid Prototyping

Additive manufacturing took off in the late 80’s because it allowed engineers to make prototypes of their parts quickly and easily.  Rapidly.  And that is why for almost twenty years, most people who use additive manufacturing refer to it as rapid prototyping.  And to this day, most of the users of additive manufacturing use it for making prototypes as part of their product development process.  RP sounds better than AM, and better describes what you use the technology for rather than the technology. So that name took off and has stuck.

Other Names, Other Uses

As the technology got better, and especially as the materials got better, people started using additive manufacturing for other uses beyond making prototypes.  And, as is the way of companies that are trying to sell stuff, the manufacturers starting coining new names for the applications as users come up with them:

  • Rapid Patterns: making a part that will be used as a pattern in a downstream manufacturing process.  This is very common with jewelry in that the pattern is used in a lost-wax process for casting.  It is also used a lot with soft tooling, where the pattern is used to make a negative mold out of a soft rubber material.
  • Rapid Tooling: Making fixtures and molds using additive manufacturing. Tools can be used as patterns for forming, patterns for casting, or even for making molds for injection molding.
  • Direct Digital Manufacturing:  This is one of my favorite names and abbreviations – DDM.  The difference here is that the additive manufacturing process is used to make a final product, not just a prototype. 
  • Rapid Manufacturing: The same as Direct Digital Manufacturing, but without the alliteration.

3D Printing

According to Wikipedia the term 3D Printing was invented at MIT in 1995 when someone used an inkjet printing head to “print” a binder on to a bed of powder.  They used a printer to do their additive manufacturing, and used the term 3D Printing to describe it. By the way, they went on to form ZCorp, the second most popular additive manufacturing process in the world. 

Even though it started being used to refer to an inkjet printing based approach, the name spread over time. The term really caught on because it is so descriptive. Additive Manufacturing, and even Rapid Prototyping, do not make a lot of sense to non-engineers. 3D Printing makes sense immediately to pretty much anyone.

Those of us who are diehards really want 3D Printing to refer to lower cost, affordable devices that make lower end prototypes.  And if you look at how the name is applied by the manufacturers, that is generally how it was used.  Here is a screen shot of the Stratasys home page, and see how they split their systems into 3D Printers and 3D Production systems:

image

But the name is working so well that we are seeing a shift towards refereeing to additive manufacturing as printing.  3DSystems is going full bore and as of this writing, refers to their whole line as “Printers” and differentiates them by calling them “personal, professional, and production.”

image

What is Old is New Again

So it looks like the trend is towards 3D Printing becoming the new term for an old technology. And those of us who call them RP machines will have to stop doing that, or just accept that we will be met with blank stares when we do.  So next time someone comes up to tell me they just read an article in Good Housekeeping about how they will be able to make replacement parts for their dish washer in the garage with a 3D Printer, I will smile and say “That is great. In fact, we use almost all of the major 3D Printing technologies in house at PADT, and we resell the most popular 3D Printers from Stratasys, Inc.  That includes that big FORTUS 900.  It is a big and accurate 3D Printer”

PADT Medical Receives Support Award from AZBio, and Provides Awards to Others

On October 23rd, 2012 PADT was honored to receive an award at the AZBio Awards event in recognition for our support of Innovation in the Arizona Bio-Technology community.  It is a very cool little guy and is very happy on our awards shelf:

AZBio-15Years-Award-2012

In addition, we were very honored to be asked to manufacture many of the awards that were handed out.  The distinctive double-double-helix design was a big hit again this year, and it was a real honor to know that so many companies, educators, and individuals will have something PADT made in our Rapid Prototyping group on their shelf.

group2

3D Printing Technology Animations

Update: 

We recentlly used these animations for a presentation and realized that this post is so incredibly old that we call everything Rapid Prototyping. In the years since this was written, the industry has shifted to using the terms 3D Printing and Additive Manufaturing.  So we went through and updated it so people can find it easier in search engines. 

Additive Manufacturing has changed a lot since these were made and we do hope to soon update these animations, and add new technologies we did not cover.    – Eric Miller  11/8/2019


Every once in a while we get asked to go out and do presentations on 3D Printing. As part of that, we like to explain the four most common. Additive Manufacturing technologies: SLA, SLS, FDM, and Polyjet. No matter how many hand gestures we use people just don’t seem to get it unless we show an animation.

So we thought it would be good to share those with the community so that they can either learn about the basics of the technology or use these to help educate others. They are crude, we are engineers and not artists.  But they get the point across and should help people understand Additive Manufacturing better.

They are in the form of animated GIF’s, so you can put them on a website or throw them in a PowerPoint and you don’t need a viewer or special software to view them.  Click on the images to get the larger version.  Then right-mouse-button to download to your computer.

Use as you see fit, just remember to mention where you found them: P – A – D – T.

FDM-Animation

PolyJet_Animation

SLA-Animation-3

SLS-Animation