Lighted Speakers show Off Power of 3D Printing


We came across this very cool application that uses a Stratasys Connex 500 spreading like wildfire across the blog-sphere.  We thought we would put our own technical spin on it since we have that same system.  Evan Atherton from Autodesk did the model working with a company called LumiGeek to do the lighting.
Here is a  good video that explains the project:

As you can see, Evan built a very cool 3D model of the speakers then printed them on the Connex 500. That particular system uses an inkjet technology called polyjet to print out a photocurable resin (a plastic that hardens when you expose it to ultraviolet light) in layers. What is special about this application of the polyjet technology is that the machine can print two different materials at the same time. So you can mix those materials as you build a part to change properties. This allowed him to get a mixture of rubber-like and semi-transparent plastic parts to fit into his design.

Once printed they assembled the parts with a programmable LED strip from LumiGeek. And presto – they now have their own custom speakers that blink and shimmy in time with the music they are playing.

Endgadget has a pretty good slide show and a video that shows some of the details.

So What?

As most of the blogers/vlogers point out this is not a way to mass produce speakers.  The material and labor costs are extensive. But it does show how a truly unique idea for a whole new type of product can be quickly and easily visualized using 3D Printing technology. Within a week a full working prototype of a complex product can be produced.

It also shows the power of custom product development. There is a significant market out there for custom applications where people need a unique application like this.  Although the cost of producing these was not small, it is much less than any traditional manufacturing process when you only need one or two copies.  This is another example of how someone can create a new service around taking peoples unique design requirements and creating a stand-out solution in relatively little time.

Plus, they just look cool. That is “what” enough for us.

If you have an idea you want to realize using 3D Printing, contact PADT.  We have the skill, the experience, and the equipment to make it happen.

PADT on Local TV Talking About 3D Printing


The general public’s interest in 3D Printing has taken us all a bit by surprise. We know it is a popular topic but we were shocked when a local TV station (ABC15 – KNXV) called us up and wanted to do some filming of 3D printers in action, answer some questions they had about the technology so they could make sure they got it right in the story,  and talk to someone about 3D Printing.  Tey ended up getting a copy of the reporters head as well. Here is the result:

The List: The Futurist: 3D Printing a beak, a break and something in vain

It is not the first time that PADT has been on TV, but the first time we have made it on beyond background shots or public access.  They edited out all of the brilliant and insightful comments, which is expected.  What was nice is they really did not get anything wrong in the story and they spelled our name right!

Six Things to Do when Shopping for a 3D Printer

Stratasy-Mojo-3D-Printer-in-Shopping-CartPADT has been in this prototyping business for a while, even before we called the machines that make physical parts directly from computer models a 3D Printer.  When we started it was rapid prototyping and we have purchased maybe a dozen machines for our own use, and sold several hundred to our customers.  As the cost of these systems comes down and the number of people interested in having their own 3D Printer goes up, we thought it would be a good time to share our experience with choosing systems with the community.

Here are six things that every person should do when they are shopping for a 3D printer. We even recommend that you write these down and fill out a form before you contact the first vendor.

Thing 1:  Understand What you will use your Parts For

This seems obvious. You would not be looking for a 3D printer unless you knew you needed one and you knew what you needed it for.  But in reality it is very easy to get caught up in how powerful and just plane cool this technology is and you start thinking about what you can do, and you forget what you need to do.  The best way to approach this is to not think about which technology you may end up with, that will point you in one direction or another. Just assume you push a button and a prototype of your part comes out. What would you actually use it for?

The key here is to be honest. If the reality is that your receptionist really likes models of Japanese Anime characters, and you plan on making models of such in an attempt to get her attention, then be honest about that. You need a printer with the detail and perhaps color capability for that. But if you really think about it you probably need one to make patterns for doing custom composite layups, so your use will be very different and the so will the system you need.  She probably will be just impressed with your layup tooling. Well, maybe not but your boss will.


Our experience tells us that customers often get hung up on features that they get excited about, but when you look at the end use of their prototypes, they really do not need some of those features.  We have seen people buy a machine because it was the only one that did this one thing they got fixated on. But in the end, they only make two prototypes that need it a year and the other 137 prototypes they make are kind of sucky.  Make a list of all the uses and put a guess next to them that shows the percentage of parts that fit into that use.  A typical example would be:

  • 35% Mockups for design reviews
  • 25% Models for the machine shop and vendors to help them plan machining
  • 15% Fixtures for testing
  • 10% Consumer testing and marketing mockups for ad campaigns
  • 10% Fit models to build
  •   5% Other

Thing 2: Benchmark the Machines on your Geometry


When we run into someone that is unhappy with their 3D Printer, three out of four timeswe find out that it just does not perform like they thought it would.  And if we dig deeper we find out that when they were shopping for a printer, they just looked at parts that the various vendors gave them. Demo parts. They never made a variety of their own typical parts.  This is especially true if they ended up buying a lower cost machine.

Here is a secret of every person selling a 3D Printer, that probably is no secret to you. They pick the demo parts they show you because those parts look really good on their technology. And if you are not closely familiar with the strengths and weaknesses of each technology, there is no way for you to know that the parts they showed you may be the only parts that actually look good on that technology.


Get four or five parts that are typical parts that you would prototype, and have them made on each technology.  Even if the vendor tells you they can only afford to make one sample part for you (with the cost coming down the margins on these machines is low so few in the business can do a bunch of free parts for every potential sale),  go ahead and pay money to get your geometry made.  You may be shocked by the results, especially on some of the newer low cost machines.

Thing 3: Ignore Hype or the Herd

Any fast growing industry has a lot of hype, and a lot of mob pressure to go with one technology over another.  3D Printing is no different, and in fact it is worse because this technology is so cool and interesting.  The problem with hype and herd mentality is that the company with the best public relations people or with the “hippest” story gets all the attention regardless of the technology. And it feeds on itself. They get more attention because they got more attention.

A case in point is the recent introduction of a hand-held fused deposition modeling system.  Very cool, lots of hype and interest.  But really, who could use that for real work?  Even a hobbyist is going to struggle with making anything useful with a tool like that. But there is a lot of hype around it right now and a huge amount of interest. I’ve had a taxi driver mention it to me when he asked what I do.

It is human nature to want to be part of something big. So it is hard to push that aside and look at each 3D Printer you are evaluating on its own merit. Not what the press is saying, not what other people are touting, not what is the newest and flashiest.  We are talking basic “make me a useable part” here.  Look at it with basic and non-influenced eyes.

Thing 4: Calculate the Total, Long Term Cost

Of all the things listed here, this may be the hardest to do. There are so many costs that go into making prototypes. The initial cost of the machine is small compared to all the other costs. What we recommend you do is make a spreadsheet and list cost items in the first column, and create rows for each 3D Printer you are looking at, then fill it out. We like to put in the cost over three years.

Here are some cost items we recommend people include:

  • System
  • Cleaning system
  • Facility modification costs
  • Build and support material
  • Cleaning materials
  • Maintenance fees
  • Labor to prepare jobs
  • Labor to post process jobs
  • Facility square footage for machines, cleaning equipment, material storage, etc…
  • Scrap rate cost (some systems have a higher scrap rate, you need to include the cost of lost time and material because of that)

Thing 5: Honestly Prioritize the Features you Want and Need

It is always a good idea to make a “want” and “need” list, regardless of what you are purchasing.  When you are dealing with a set of technologies with so much buzz around it, we feel it is doubly important.  Sitting down and making a list, then justifying it to someone else clarifies what you should be looking for more than anything.

We also recommend that you prioritize the list.  Marking things as Want and Need is a first step, then every one of those should also be ranked in order of importance.  You can use a point scheme or you can just put them in order from most to least.  This will help you sort through the gee-whiz stuff and truly understand where the value of your investment in 3D Printing can be found.

Needless to say, it is critical that you finish Thing 1, and refer to it, when completing this step.

Thing 6: Figure Out what is Good Enough, then Ask for More

OK, maybe this one sounds like a sales pitch: “You know what you really want, but really, trust me, you need more.”  Experience tells us that this is actually true. When you are talking 3D Printing we run into customer after customer that felt the system they purchased was “good enough” for their needs then they realize it does not do what they need.  And in most cases it is because they really needed a bigger machine, or they needed a more robust material than they thought.

The last thing you want to do is invest in a 3D Printer then six months later try and turn it in to get one that is bigger, faster, more precise, or that runs a better material.   Now you are still paying for the more expensive system and you wasted money on the less expensive one.  Be honest, upgrade in the beginning to what you really need in the long run not what you think you can get by with in the short run. Because, in the end, you will save money and have better parts.

Doing the Six Things and Getting that 3D Printer

You know you want one. You actually probably need one. We have been doing this for a long time and almost every customer that has made an intelligent investment feels like the investment has been a positive one. And by intelligent investment, we do not want to imply that they bought a system from PADT (although statistically that may be true). What we have found is that these companies took their time, they used some variation of the steps listed above, and they treated their purchase as a long term investment.

You too can make a smart choice and make in-house 3D Printing part of your company, job, or even hobby.  PADT is here ready to help you with that choice.  We can show you the complete line of fused deposition and Polyjet 3D Printers from Stratasys. We can also provide some advice on what we think is a good fit for your needs, and help you capture data for the six things we have outlined here.  And don’t forget, we have a full 3D Printing services offering, with all the major systems and materials. So we can show you the advantages of all of them by providing you with your outsourced parts while you look for an in-house solution.

Stratasys Objet Polyjet Systems

PADT Adds Stratasys Polyjet 3D Printers from Objet to Product Offering


PADT is proud to announce that we are officially certified to resell the full line of Stratasys products, including the newly added Polyjet 3D Printers from Objet.  We were very pleased when Objet and Stratasys decided to merge to become the new Stratasys, and we have been waiting patiently for the legal merger to take place, and then for the two organizations to merge their businesses.  Now that wait is over and PADT just completed our sales and support training for the Polyjet product line and we can offer it to customers in Arizona, New Mexico, Utah, and Nevada.

Here is a family photo of the line:

Stratasys_polyjet_machines_portfolio-500wAs you can see, they start with small desktop systems and work their way up to the monster Objet1000, a true beast of a machine capable of printing parts up to 39 inches long!

Artistic 3D Printed Prototype in Rigid Blue Material
There are two key characteristics that really sets these systems apart: The variety of materials available and the precision of the parts they make.Because the Polyjet systems use ink-jet printer heads, they lay down small droplets of photocurable material.  So the resolution of each layer can be up to 600 dpi, and the layers themselves can be very thin, as thin as 16 microns.The same ink-jet technology also allows for the use of such a wide variety of material.  Over 100 different materials can be made by mixing two different materials during the build.  This allows materials the have the properties of ABS, Polypropylene, rubber, or transparent plastic.  And materials can vary on a given layer or from layer to layer.Another set of ink-jet heads allow for the deposition of a water soluble support material, that is easily washed away to make the post processing of parts made on a Polyjet machine simple and fast.

We cold go on and on about this technology, or you can see it for yourself. As we mentioned, this technology is not new to PADT, so we know a lot about it and are eager to share what we have learned over the years.  If you want to learn more, simply contact us and we will be ready to answer your questions, show you some machines, and help determine if Polyjet technology is the right fit for you.

You can also check out our new Polyjet product pages, where you can find brochures and videos that give a lot more information.

And look for more information on this blog as we share stories, tips, and hints on the use of these systems.

View the official press release here.


3D Printing on “Big Bang Theory”

The thing that gets me about “The Big Bank Theory” is how accurate it is. They seem to always get it right and their treatment of 3D Printing during “The Cooper/Kripke Inversion” last week was spot on. 

Take a look at 7:10 and then 11:06.

BBT-3d-Printing-Whistle“We Printed a Whistle!”

“Amazing! You know these things go for 25 cents a pop at a party store”

“And we made it in only 3 hours!”

So close it hurts!

The 3D Printing Store in Denver

LogoWe are pleased to promote the fact that The 3D Printing Store in Denver is open for business and they have their new uPrint SE Plus up and running.  We are very excited about this new more retail oriented face for 3D Printing bringing the dream of rapid prototyping as a mainstream technology to a huge audience, and we wish the owners great success.  We are very honored to have provided them with their Stratasys uPrint SE Plus printer.

We really feel that before long this location will become a center for invention and creativity and people will find ways to use this technology that were never thought of before.

The store will be holding an open house on February 7th from 3:00 – 6:00 PM.  Click here to learn more.

Retail 3D Printing at the Beginning of 2013

I just came across a posting from Terry Wohlers that he did in December with some interesting observations on the growth of 3D Printing in retail stores:

3D Printing at Retail Stores

I have to agree with Terry’s assessment that these efforts in Africa and Europe to bring this new technology to a mass market through old business models may not click.  Some of the efforts here in the US seem to be a better fit.  Reading the article, and the fact that non-technical people are constantly bringing up 3D Printing around me, got me to thinking about the retail space and where it is headed.

Is Online the Future for Retail 3D Printing?

Shapeways_websiteIn New York, the VC backed experiment at Shapeways seems like a more viable option for mass retail 3D printing.   There was an interesting interview done in December by the Business Insider that sheds some light on how things are going, but does not discuss the business aspect too much.  What I am interested in knowing is what type of margin Shapeways is making on their parts with the prices as low as they are, or are they using their buckets of VC money to build market share in hopes that volume will bring their margins up?  It would be interesting to know.

A French company called Sculpteo has a similar model. I’m sure there are others.

3D Systems, along with buying up as many technologies as they can, has launched their own retail competitor to Shapeways called Cubify.   Their advantage is that they do not have to pay full price for machines or materials.  It is early days and in some ways it looks like a vehicle for promoting their low-end FDM CUBE machines, but the reach of 3D Systems may make a difference.

The Brick and Mortar Store


Although these online based models have the advantage of access to the masses to grow their markets, storefront retail outlets for 3D Printing also seem to be taking off.  Makerbot, the kings of getting media attention for low-end 3D printing, has a showcase store now in Manhattan. This store may be more for marketing than a direct revenue generator, but it starts a trend.   A new startup, 3DEA is also in New York City and they are trying to use similar low-end FDM technology to provide 3D printing to the masses through a corner store, literally.

Here at PADT we are aware of several companies starting the same thing in the west and they seem to have good solid business models that will not only go after the art/accessory/gadget market but they are also looking at other more practical retail applications.  We think this broader and more balanced approach has merit.

Is New York the Center of Retail 3D Printing?

Are you seeing a trend here? Retail 3D Printing in the US seems to be focused on New Your City. There is a store in Pasadena called Deezmaker, but it is more hacker-centric selling more kits than home machines or direct to consumer printed objects.

Is this NYC bias because the market for consumer 3D printing is huge there? Or is it the art community? Or is it a tech-infiriority complex with the west coast?  A “we missed all this computer based stuff, so we are going to lead on this 3D printing thing” effect?

I suspect it has more to do with the proximity to Wall Street and the mass media than anything else.  Which may or may not be good for the additive manufacturing business.  It means cash and exposure for something that really captures the imagination of the general public. But is this a bubble that will grow and pop for the full industry? Or will it just be the retail side?  Only time will tell.

FDM Rules, but not Necessarily Good FDM.

One other take away from this retail trend is the dominance of Fused Deposition Modeling (FDM) technology that is making much of this possible. Although Shapeways seems to use almost all of the technologies, most of the startups that are trying to get the cost down and the volume up are using some sort of low-cost FDM technology. This is reflected in the lower costs and in the poor finished part quality that is seen on most of the websites. It is too bad more are not looking at technology Stratasys, the originators of FDM and producers of machines that make very high-quality parts.

stratasys_mojoI bring this up not only because PADT is a long time Stratasys reseller, but because the poor part quality might result in a black eye for the industry as a whole.  And the concern is not just about aesthetics, but also about part strength.  There is a lot of excitement over making replacement parts for appliances, toys, and consumer electronics.  Delamination in low-cost FDM parts is a real concern.

I also wonder if the merger of Stratasys and Objet might allow for the development of low cost and reliable 3D Printing based on the Objet inkjet printing approach as a compliment to FDM based systems.

What is the Future?

rasputinAnyone that is in the RP business knows that the use of additive manufacturing for prototyping, tooling, and even production is growing and getting better. Machines are faster, more accurate, and offer much better material choices. And the cost of systems that make strong, high-quality parts is coming down. So the non-retail side of this market should see continued strong growth.

The retail side of things is seeing a lot of buzz, a lot of press, and a lot of interest from average consumers.  As with any new market it is hard to guess where it is going.  But history has shown us that something like this that shows the potential of being a disruptive technology will have a big impact, and the market will whipsaw back and forth a few times before the technology finds its place and becomes mainstream.

For the record, just to see how close I get, I predict the following landscape for retail 3D Printing in five to ten years:

  • Two or three large on-line outlets, focused on art, fashion, and accessories as an outlet for small designers.
  • One or two large business supply/service chains that offer 3D Printing alongside traditional printing and copying using high quality FDM technlogy
  • A variety of specialty local almost neighborhood stores that offer duplication using 3D scanning and printers along with part printing.

Hopefully someone will remind me of this post in the future and we can see how far off I am.



Stratasys and Objet Merger Complete


It is now official. Stratasys and Object have completed their merger to form a company worth over $3.0 Billion.  Actually, as we prepare this update it is up to $3.37B.  Obviously the markets thing this merger is a good thing.

And now Stratasys has a new logo and what we think is a great slogan: “For a 3D World”

You can read the press release here.

As a long time Stratasys distributor and a user of Objet’s and Stratasys systems in our rapid prototyping services business, we are very familiar with both product lines and look forward to the synergy of the merger.  These are two truly complimentary product lines.

Right now this merger will have no impact on how we do business with our existing customers for any of the product sales or services we offer, including sales of new systems, maintenance of existing machines, material ordering, or prototyping services with either FDM or PolyJet.  As the two companies combine organizationally we will keep everyone informed.

Learn more about the Stratasys line of Mojo, uPrint SE, Dimension, and FORTUS 3D Printers here.

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.


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.


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.[]

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.

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. []

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. []

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. []

MiniMagics is a free STL viewer from Materialise [].

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 with your contact information.

Put it into a dropbox or secure file sharing location and send us a link via email to

Upload it to

see 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.

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

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.

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.

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

When you are making a prototype of a CAD file, you send an STL file to the software that the machine uses to calculate how to build the part.  An STL file is made up of triangles, called facets, that cover the surface of your part.  Imagine having a a real part and a box full of small triangle. You have to paste the triangles all over the surfaces of the part till you have covered every part of the surfaces.

To illustrate what we are talking about lets start with a simple geometry: a block with a hole:


When we make an STL file the CAD package breaks the surfaces of the part up into triangles.  The result is something like this:


Notice how the surface is made up of triangles.  Triangles are flat so if you don’t have enough, if the triangles are too large, you end up with visibly flat surfaces.  This example shows the default for many CAD tools, and if we make a prototype of it we will see the flat triangle bits, and it will look bad.

To solve this you need to set your tolerance to a smaller number. Each CAD package has a different way of specifying this.  Most of them use some sort of Chord Height tolerance. 



The chord height is the maximum distance from the actual surface (orange) to the facet face (green).  The smaller the Chord Height, the smaller the facets and the more accurate the curvature of the surface is represented.

Here are some examples of our sample part with different tolerances (the hole has a 2” diameter):


0.1” Chord Height


0.01” Chord Height


0.001” Chord Height


0.0001” Chord Height

That last example may be a bit extreme. 

Why not just set your tolerance very small and be done with it?  The problem with that approach is that you force the program to make a ton of triangles, and your STL file gets huge.  So you need to find a nice compromise.  0.001” seems to work well for us and is a good place to start.

if you want to view your STL files, you can usually do so in the software you use to send your parts to your RP machine. If you are using a service provider, you may want to download a tool like Meshlab or MiniMagics.

Using 3D Printing to Make a Clock


If you visit the lobby of PADT’s Tempe office you will notice something very cool on the wall – a large white and black pendulum clock clicking away on the wall.  Its gears are exposed and you can not only hear it tick-toking away, you can see the gears moving, and watch the timing mechanism rock back and forth.  It defiantly attracts the attention of our mechanically minded customers.

imageThe clock was built by our very own manufacturing engineer Justin Baxter based upon a design from a website called Brian Law’s Wooden Clocks (  Brian has a large array of very cool wooden clock designs that he has done for the hobbyist community.  Do take a look at his website to see the very cool designs he has developed. We have our eye on a few more to try out.

To make our clock, Justin took the Clock 1 design and modified it for use with the Stratasys FDM machines that we have in house.  Starting with the free 2D drawings on the website, he created 3D Solids of the assembly making only a few changes. He had to add a bit of thickness to the winding ratchet paul and added some brackets for rigidity because the ABS plastic is more flexible then wood.  It took about 20 hours to build up the CAD model in SolidWorks.


He then set to work building the parts on our fleet of Stratasys 3D Printers and Manufacturing Centers.  To speed things up he spread the job up over three of our machines:  The FORTUS 400mc for the large white parts, the SST 1200es for the small black parts, and a few smaller parts here and there on the Elite.  Black and Ivory ABS was used for all of the parts that were made on the 3D Printers. He then spent about 15 hours post processing the parts.

The post processing was important because he found early on that friction between the ABS parts could be significant.  All of the sliding surfaces needed to be sanded and Acetone-Smoothed to get rid of any ridges that are a natural byproduct of the additive manufacturing process.  This proved to be the most difficult part of the entire process.

Meanwhile, he ordered and fabricated the few metal parts that he needed: the drive shaft (steel rod), the pendulum rod (aluminum tube), and the mass for the weight (stainless steel bar). I strong string was also found that could be used to suspend the weight.  Everything was then assembled and he spent some time tuning the mechanism to reduce as much friction as possible, and to get the timing worked out on the mechanism.  After all was said and done, the material costs were around $700, and the total machine running time was around 60 hours total.

The end result is shown here in this video:


When asked if he had any advice for someone who wanted to make his own clock, Justin replied “Do it, these plans make it quite simple to print one and with a lot more patience and skill you could even make one out of wood as the designer intended. I found making this clock to be a very enjoyable learning experience. “

We hope to have some time to try out some other designs, the PADT Colorado office is already making noise about wanting their own clock.  We will be sure to share the experience with everyone here on The RP Resource when we do.

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


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.


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:


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.”


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”