We were testing out the new Website on different browsers and some smarty-mc-smarty decided to try it on Lynx:
It is not as bad as I thought it would be… Who remembers using Lynx?
It has been a long road but we have finally arrived. You can see it at www.PADTINC.com. Not only is the site new, but we have a new and expanded blog that covers the whole company and not just ANSYS related topics.
Jump right in and take a look, or hang here a bit as we share a little history of how we ended up with the site we have:
About three years ago we decided to redo our website. Several of us tried, but we were just too busy with other things. Or we found we lacked one or two critical skills to get it done. Plus our old site was still doing well with the search engines, bringing in business, and providing information to the community. No one was pushing us to get it done (OK, our sales team was getting pretty frustrated) and it was not easy, so it languished. Still no new website.
So about a year ago, we started looking for a website design company that would work with us the way we wanted to work. This was a more difficult task then we envisioned. We were not looking for someone to make us an online brochure. We were also not looking for someone to set up a content management system that we could upload short bits and pieces to. We also did not want someone that would create a site that we could not get into and mess with. We also ran into a problem with people really not understanding the kind of customer who comes to the PADT website and the type of content they expect. And we wanted it in Adobe Dreamweaver (I know, 2005 called and they want their web design tool back. At least we are not using ColdFusion.)
After looking for a while, we found Newhouse Studios, http://webstrategyaz.com/. They have worked with technical companies in the past, and actually still had people who could use Dreamweaver. They took us through a real design process where different designers (artists really) shot us different look and feel concepts:
We opted for the second one, and the real hard work began. After refining the colors and fonts, we started laying out the site. What a chore! PADT really can be represented on the web as 4 or 5 different companies, and the web needs of each area of the PADT is a bit different. But we did it, lots of multi-color post-it notes all over a big board with arrows going everywhere.
Then we slowed down because we had to write content. And lots of content. Over 90 pages of content. Some were short, some very long, some cut and paste. And each one had to be proofed, optimized for search engines and then formatted properly.
Somewhere in the middle of it all we found we needed some nice images, so we called on DM Photo to put on their commercial photography hat and shoot a bunch of stuff in and around the office. The results were better than we could have hoped for and upped the professional look of the site.
So we just kept on crunching out pages, adding images, and reorganizing as we went.
And in parallel, we launched a new blog hosting server using WordPress, and we expanded the topics for our blog from just ANSYS to all the area that PADT works in. It will also be where we post news, like this posting. So our blog now has: News, The Focus, Product Development, PADT Medical, The RP Resource, and Fun. It is our hope that The RP Resource will become as popular as The Focus. We also hope that the “Fun” page will be fun. That is yet to be proven.
And we worked, and we let other things get in the way, and we dropped a few balls. Nothing unusual for a new website. If you have tried to do this, you know what it is like. But we kept moving forward, and we eventually got there. We are done!
Thank you to everyone who helped out and all of our customers and vendors who put up with the old site. We are pleased with the results and hope you find it useful and entertaining.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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…
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.
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.
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.
|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].
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:
PADT can also usually work with the following non-native formats:
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 firstname.lastname@example.org with your contact information.
Put it into a dropbox or secure file sharing location and send us a link via email to email@example.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.
|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.
|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.
As we gear up for the holidays we think it is very important to prepare our employees for the coming trials. As part of that, we have an annual Turkey Feed the Friday before Thanksgiving. This allows us to spend some time together as a company before the craziness starts, share some food, and be thankful in our own way.
It was a perfect day out there today as we got ready:
The food was from Boston Market. Not great cousin, but hot, on time, and tasty.
We all enjoyed taking some time out of our cubicles and in the sun:
We wish all of you a very Happy Thanksgiving and a joyous and peace filled holiday season.
What is the software tool that us numerical simulation types use almost as much as ANSYS products, maybe even more? Most of you will answer Microsoft Excel. We all use it almost every day for a variety of things. Every time I see someone doing something sophisticated with Excel, I learn something new, a tool I can use to be more efficient.
For this week’s The Focus posting I will be sharing some stuff in Excel, tips and tricks, that ANSYS users should find useful. I am using Microsoft Excel 2010 and the assumption is that the reader is a good user of Excel, maybe not an expert, but good. I have tried to pick things that have a direct impact on user efficiency. You may already know some or even most of these things, but hopefully you will find some of it useful. If you have something to share, please add it to the comments.
I love tables. I’m always getting made fun of because I always convert what I’m working on into tables. Why are they so great?
Making a table is easy:
That give you:
Click on the downward facing triangle icons to filter. Use the options in the Table Tools > Design tab to set the name, remove duplicates, turn on the total row, and change the basic formatting (color). Once you have played with these for a while, you will find you can not live without them and people will ask you why you use tables so often.
One of the ways that we use Excel is to convert some sort of text data in row/column form into a command, mostly MAPDL commands. A key to this is the ability to concatenate text strings and the values of cells. I’ve even seen someone write a NASTRAN to ANSYS translator in Excel.
To do so you create a formula (start with =) and string together the text you want with ampersands: &
As an example, if we want to add a column to the table we used above to create N commands we simply click on any of the cells in the empty column next to our table and enter:
=”n, “&[@N]&”, “&[@X]&”, “&[@[Y ]]&”, “&[@Z]
Because we are using a table, the command uses the column reference [@name] from the tables rather than cells. In a non table the command would look like:
=”n, “&$A6&”, “&$B6&”, “&$C6&”, “&$D6
Either way you are stringing the values in your cells together with text to make a command:
That column can be pasted into a text file, an ANSYS Mechanical code snippet window, or saved to a file.
After tables, the next most useful feature in Excel for the analyst is the ability to convert the text in a column into multiple columns. This is a lot like the text import window that opens up when you open a text file, but it can be used at any time on any column in your spreadsheet. To use it, simply select the column you want to convert:
Then go to the Data tab and click on “Text to Columns”
This will bring up the wizard that steps you through the process:
If you are working with a NASTRAN type input file, formatted with fixed columns, you can chose “Fixed Width” here. If not, choose delimited. Click next.
For fixed, you get a ruler that you can drag the column lines back and forth on till you get what you want. Pretty simple.
For delimited, you get the delimiter screen. Specify your delimiter here. In the example, we will use a comma. But it can be spaces, tabs, or any other character. When you specify the delimiter, it shows you how Excel will break it up.
I usually click finish here because the next screen is formatting and I usually play with that once I have the data in Excel.
That is it. Very simple.
One thing to note, it converts to columns by overwriting columns to the right. So if you have data in those columns, you should insert enough blank columns before you use this command, so you don’t overwrite anything.
Usually you refer to a cell or a range of cells with the old LetterNumber syntax: A3, B7:NN2145, etc… That can be a real pain to deal with and it really doesn’t tell you what the data in that range is. A better way to deal with chunks of information, or critical cells, is to use names.
Creating names is very easy. The simplest is to click on the cell or cells you want to name and then type in the name you want in the input box in the upper left corner:
Now, if you want to know the max value of those numbers, you can use the formula =max(MyData)
If I have a lot of constants I want to define, I can use the “Create from Selection” tool in the Formulas tab:
This command brings up a dialog box and you can tell Excel where to grab your names from. Three or Four clicks and you have named parameters instead of cell locations. This is very useful if you have a group of key parameters you want to use in your calculations. Now when you look at your formulas, the descriptive name of the parameters are there rather than a reference.
Use the Name Manager in the same Formulas tab to view, edit, and delete your names.
A related trick for Excel is creating dynamic ranges. What do you do when you name a range and then the amount of data in that range changes? You have to redefine your range. Nope, you don’t. You can define the range using a formula that changes as the length of the column, or row, changes.
The name can be defined for a column as: =OFFSET(startCell,0,0,COUNTA(column)-1)
Or for a row: =OFFSET(startCell,0,0,0,COUNTA(row)-1)
This may be the most time saving trick I know in Excel.
You put the formula into the “Define Name” dialog box found on the Formulas tab:
Now, no matter how long the column of data is, MyVals will always contain it. A big time saver.
How many times have you gotten data in Excel, or imported data into Excel, where you want to make a small change to every line. But you have several thousand lines. If you do a “Record Macro” that doesn’t work because you have to click down to the next line, then run the macro and repeat that over and over again. Wouldn’t it be great if you could simply record a macro with some sort of relative reference.
For years (maybe decades) I didn’t know you could do that. There is an option under the Developer Tab called “Relative Reference.” Click that before you record your macro and you are good to go.
As an example, take a look at this data. Nodal coordinates on one line, rotations on the second.
I want to grab the rotations, paste them on the same line as the coordinates, delete the rotation line, then move to the next node.
Here is a video that shows the process:
That is all fine and dandy if you have a few dozen lines, but your fingers will get tired CTRL-e’ing that many times. I quick fix is to go into the macro and add a simple loop. First we use CountA() to see how many nodes we have, then we loop on that with a for statement:
Of course you could have done this with *VREAD’s in MAPDL, or python. But sometimes Excel is just faster.
It is a busy time in the world of CUBE computers. We are building our own new cluster, replacing a couple of older file servers we bought from “those other guys” and building a 128 core mini-cluster for a new CUBE customer. We ran out of room in the IT cubicle so we looked around and found that PADT’s clean room was not being used. A few tables and tools later and we had a mini-cluster assembly facility.
With the orders that customers have told us are on the way before the end of the year, this is going to be a busy area through December.
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.
PADT was honored to be invited to come out and see the Formula SAE car that Arizona State University has been working on as part of their Press Day at the Bondurant School of High Performance Driving. The PADT Hat came along and got a picture:
We helped out the team last year by printing them an intake manifold and by offering some assistance to the Aero design team. It was a very nice design and in their first year of competition, they came in 24th out of 80 teams.
Congratulations to all the students involved and we are looking forward to working with them in the coming season.
The CleanTech Open (CTO) is a unique organization in the world of technology startup competitions. As PADT grows our involvement with the CTO, we become more and more enthusiastic about their efforts. I just finished attending our first global awards competition as a sponsor, and wanted to share my thoughts on what makes it so special
The most unique aspect of this competition is the fact that it is more than a competition. When a company applies they immediately enter into a mentoring process that is comprehensive and in depth. Whereas most competitions offer up the ability to chat with a few retired guys, the volunteers that make the CTO so strong are active business, finance, and technology domain experts. Applicants are put through a rigorous training and mentoring process that addresses all aspects of starting and growing a business. So when they get to the actual competition they are much more mature and prepared than we have seen almost any other applicants in other competitions. It is not about winning the pitch, it is about learning.
The other characteristic of the CTO that we find special is that they are focused on companies that are using technology to address real environment problems. Clean water, more efficient energy production, dealing with waste and pollution. Sitting there watching the presentations I realized that the problems we face as a planet are not going to be solved by politicians, laws, treaties, or activism. Like most serious problems that we have faced in history, they will be solved by smart people being creative who apply knowledge and technology. They are working on it.
What a great experience. Thank you to all the volunteers that make it happen and the leadership behind the whole effort. I can’t wait to get involved in the 2013 competition.
When you watch someone work with a tool as complex as ANSYS Workbench, you quickly realize that they use different tools and features than you do. One thing I noticed the other day was someone really using the Files View. So I thought, I should really make sure I know what is there and take advantage of it. In looking into it I found a few things I was not aware of, and I needed an article, so here we are.
Before we get started, you have to realize that the way ANSYS Workbench thinks about files is unique, and you should understand it. The idea originally was that the program itself would manage all your files. You just had to worry about the project file and the directory tree it points to. Therefore the directory structure in that tree is pretty complex, and the user can not change the name of a file being used. That is all managed by the program. Times have changed and there are a lot of programs that run in the Workbench that require the user to know about the files, especially some of the legacy solvers. So we have the Files View to help us with that.
It is very important that you do not go in and rename, delete, or move files around. ANSYS Workbench has no way of knowing that you have done that. You should just use it to find files, edit their content, and deal with files that non-workbench type solvers (FLUENT, MAPDL, Etc…) use that are not managed by the Workbench.
You see your files through view by toggling it on and off. Under the View menu there is Files item. Click on it to turn on the Files View and click on it again to make it go away.
If you see the check and not the view, then use View->Reset Window Layout
As with any window in the ANSYS Workbench GUI you can drag the bar at the top of the view, or click the thumbtack in the upper right corner, to break it out as its own window, and drag it anywhere you want. I have two monitors so I like to do that, and have a full size graphics window.
If you look at what is in the view, there are no real surprises. Like a lot of Workbench applications, the information is presented in a spreadsheet from. If we take a look at each column we can learn some things:
Nothing spectacular here. The icons are kind of nice to let you know what type of file you are dealing with.
This one is kind of handy. It shows you where in your project the file in question is used. This helps with complex models where you have multiple systems. If you don’t change the names on your files, then things get confusing quickly. The Cell ID helps sort it out.
Take a look at the Cell ID and the associated project schematic. You can see that the geometry is used in two systems, and that the material properties are used in the Static Structural system. As you review this, you can see how useful these references can be.
Also notice how some of the files only have a letter for the Cell ID. These are usually solver related files that really apply to the whole system, and not to any one particular cell in the system.
Not much to say here. One nice use is to see if your result files are large enough to indicate a successful solve.
This tells you what type of file you are dealing with, often including the tool that uses it. What is cool about it is that you can sort on it and you can filter on the file type. More on that below.
Always useful for finding out what files were, or were not created and what the most recent work is.
Again, not much to say here. This is where your files are. Sometimes you can tell a bit more about where the file is used by looking at what directory it is in.
You can do some cool stuff in the Files View. The most obvious, is you can click on the upside down triangles and sort by any of the columns: Ascending or Descending.
You can also choose Sort Settings… and specify multiple columns to sort on.
Just add columns and set the Ascending flag as needed. Delete by clicking the X or Remove All.
Notice how the triangle now shows the columns that are being used to sort.
When you are done using the sorting, you can click on any of the columns being used in the sort, and choose Cancel sorting.
If you right mouse button (RMB) on any of the cells, you get two options. They both do what they say: open the folder that contains the file or bring up the File Type Filter.
Note, just because you can open the folder that does not mean you can go messing around with file names and locations. Only do that on files that are not managed by Workbench.
The File Type Filter will list all of your file types and let you turn on or off the visibility of any of them.
This can be very useful for a very complicated project.
So using this tool is not that hard. A better question than how is why? Here are some suggestions:
Finding Output Files
Many of the solvers in the ANSYS family create log, error, journal, and output files. Instead of poking around and trying to find them through the operating system, you can quickly use the type filter and maybe sort by Date Modified to find the files you need. Then open up the folder containing them and view the contents.
Extracting a Solve
Sometimes you need to get into the lower levels of the directory structure and get all the files associated with a particular solve so that you can run them outside of workbench, or give them to a user who does not use Workbench. Using this too, you can quickly sort by directory, find the one you need, then bring up the OS file browser tool.
Managing Macros and Input files
If I’m writing macros or input files, I really don’t want to dig around through directories. So when I’m ready to save my macro, I copy the directory that my solver uses out of the cell in the Files View, then paste it into my text editor’s Save As… dialog.
Making a File Table
Because the information is presented like a spread sheet, you can copy and paste any of the columns you want right into Excel. This comes in handy for reports because you can add a column where you add your own description or notes. To copy hold down the CTRL key and click on the column label of any columns you want.
We recommend that you use the Files View all the time, not just when you have to. The more familiar you are with the files the program is using the better you will understand what is going on when you use the program. Black boxes are fine and dandy when you are learning or in a hurry, but if you are going to be spending a good chunk of your life alone with one of the ANSYS, Inc. products, you should be spending some time looking at what file are created and where it stores them.
PADT Medical has been an established group within Phoenix Analysis & Design Technologies (PADT) for a while now. Over the years it has grown and we have added new employees with new skills and experience. But one “employee” has been a member of the team since the beginning, providing guidance and setting a strong example on a variety of medical device product development projects. Skott Skeleton may not be physically substantial, but his skills are rock solid. If you have been fortunate enough to have toured PADT, you have probably met Skott as he hangs around in the PADT Medical office area.
As we launch this new blog based format for sharing information and news with people interested in what is going on with PADT Medical, we thought it would be a good opportunity to sit down and ask Skott a few questions and learn more.
EM: Skott, why don’t you share with our readers why you decided to join PADT Medical?
SS: I didn’t decide anything. One day I was hanging around with my buddies in a warehouse in China, and someone comes along, shoves me in a box and ships me off to the desert. But once I got here, I really fell in love with the place. PADT is a great company. Everyone here is smart, they have good senses of humor, and they do not judge me because of my body type.
EM: What is your roll within PADT Medical?
SK: Mostly I just watch. I move around in the office and I watch. Everyone knows that I’m there and that I am watching. Another important role that I play is to remind everyone why they are doing what they are doing what they are doing. For many engineers, parts are parts. But PADT Medical works on parts that are used to heal and repair people. There is nothing like a person stripped down to the basics to remind everyone that we are working on devices that can really make a difference in people’s lives. And, if we do it right, a good difference.
EM: PADT has been doing product development for over 15 years, including many Medical Devices, why create a special group and brand it apart from PADT?
SS: After doing a couple of medical projects two things become clear. First, the development process for medical devices is different because of the quality requirements, the material issues, the regulatory environment, and the difficulties in designing things that go inside of or interact with human bodies. Second, medical device customers know that they need specialists. PADT Medical customers know that generalists might be able to do some things very well, but that engineers in this space really need to know what is required for medical devices. So we formed a group dedicated to nothing but medical device product development. And to convey that specialization and focus to people inside and outside of the company, we created the PADT Medical brand.
EM: There are a lot of people out there doing medical device product development, what sets PADT Medical apart?
SS: I’d say their engineering skills and their ability to simply get stuff done. When I’m standing in the corner and no one remembers I’m there, I hear customers talk. The main thing they say over and over again is how impressed they are with the breadth and depth of engineering knowledge within PADT Medical. The other thing they say is that when the PADT Medical team signs on to a task, they get it done. They get it done efficiently and with a minimal amount of delay and floundering, especially with difficult tasks.
I also think there are a few other things that set PADT apart but I could go on and on about it, or you can read the PADT Medical part of the website. Let me list the most important bits:
That is just the tip of the iceberg.
EM: That is very impressive. PADT Medical really seems to have a lot of unique skills, experience and tools. But no group can do everything themselves, what do you do when you can’t do what you need in house?
SS: Ah yes, our vendors. We love our vendors. We have over 350 vendors and 65 are approved for medical device work. You are exactly right when you say that we can’t do everything ourselves. So we have spent a lot of time finding and qualifying lots of different vendors. We use our quality system to make sure they can deliver what our customers need, exactly the way they need it. Then we continually work with them to make things better and more affordable.
I should also add that not the way a lot of companies do it this way. We don’t have a purchasing department that beats up our vendors on price and schedule. Our engineers and technicians work directly with our vendor network as partners to come up with a reasonable win-win-win solution for everyone. We want our customers to win, we want PADT to win, and we want our vendors to win.
EM: I’ve heard that PADT Medical is well known as a team that works very closely with vendors and customers. How close?
SS: So close that sometimes I get wheeled out of my comfortable corner to make room for our customers and vendors to actually move into our space here. Only a few partners end up collocating, but even if they are visiting for a day or a few weeks, we make room, and we work side by side till the project is complete.
EM: Skott, we are running out of time and you probably need to get back to the PADT Medical room. But before you go, is there anything else you would like to share with our readers about PADT Medical?
SS: Wow. That is a tough one. There are so many things that we do here, so many success stories. So many difficult challenges that we have identified and overcome.
When I think about it, I guess the only thing I can say is that if anyone out there is thinking of using PADT Medical for their medical device development project, you should meet with us to really understand all we have to offer. Some of it can be put down on paper or explained in a PowerPoint, but much of the value that PADT Medical adds is intangible. Things like experience, problem solving, perceptiveness, mechanical intuitiveness, and organizational skills. If you want to learn more, let us do a proposal for you, or better yet, let us work on a small project where we can show you first hand.
EM: Well thank you very much Skott. It has been a bit creepy talking with you, but it has been informative. I hope we can do this again soon.
SS: Anytime. I am looking forward to the new blog. I hope to meet some of the readers when they come in for a tour.
[Editors Note: Yes, we know this is a silly way to do an article about what sets PADT Medical apart, but let’s be honest – if I had written an interview with one of the mangers here you would not read it. This way we can have some fun and you might learn a thing or two about what sets PADT Medical apart. Or you will at least get to roll your eyes a few times. Share your thoughts in the comments below. – EM]
The awards are all done and are sitting on Jen’s file cabinet. It is time once again for the Arizona Technology Council’s Governor’s Celebration of Innovation (GCOI) Awards. It does not seem like it could have already been a year since PADT won an award last year. But it has. And we can not wait to celebrate what a great year it was.
Learn more about the event here.
We will be back this year, in our booth before the ceremony, in the audience with everyone else waiting to see who wins, and afterwards at the dinner. Please stop on by and say hello.
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.
The clock was built by our very own manufacturing engineer Justin Baxter based upon a design from a website called Brian Law’s Wooden Clocks (www.woodenclocks.co.uk). 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.
There 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:
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.
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:
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.
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.
This 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.
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:
- 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.
- 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.
- 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.
- 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.
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.