Wednesday, September 29, 2010


This week's posting is by guest blogger, Andy Berlin, Z Corp. Senior Firmware Engineer.

3D printing of appearance models is used to convey visual information. For this project, I explored a non-traditional way in which 3D printing could be used to encode information. I wrote a program that converts an audio file into a printable 3-dimensional model that vaguely resembles a record album, and hacked a record player to generate an audible signal from the printed model.

Before getting started, a quick calculation revealed that for the resulting model to reasonably fit on a record player, the audio file would have to have 8-bit sample depth, limited by the .004” Z-resolution of the printer. And to play the record at 45 rpm, the best sample rate I could hope for out of a 10” diameter record would be about 6 kHz. The resolution would suffer even more as the record played, because the samples towards the center of the record are closer together that those near the outer edge. This might work, but it wasn’t going to be high fidelity.

Version 1 of the program created a monochrome .STL file. The outer edge of each groove is smooth, to provide a surface for the tracking needle to ride along. The inner edge contains peaks and valleys which correspond to the audio data.

In version 2, the program outputs a .ZPR file, where each sample is both coded by color as well as height. High amplitude signals could then be lighter color that low amplitude signals, further enhancing the signal for the optical playback mechanism.

Craigslist provided a cheap, hackable turntable. The tone arm was modified to accommodate a 1” tall printed model. A pin replaced the needle to provide mechanical tracking, and an LED and optical sensor, remarkably similar to the LED/sensor module the ZPrinters use for auto-alignment, provided the playback signal.

While this modern version of a 45 may not be directly useful, perhaps it might inspire other creative or other non-obvious uses for 3D printing.

If you’re wondering whether it was a success, well... if you listen really hard and apply the aural equivalent of squinting, you can just about hear over the noise the Beastie Boys belting out a rhyme from the 21 seconds of ‘Time To Get Ill’ that I printed.

Wednesday, September 22, 2010

Creating a 3D Printed Rattleback

Today's guest post is by Nick Stone, Z Corporation Mechanical Engineer.

I came across this toy in a science museum gift shop when I was a teenager. It's a simple canoe shaped piece of plastic that performs miracles. It's called a rattleback and it has amazed people for thousands of years.
Spin the rattleback one direction and it just keeps going. Spin it the other way and it slows down starts rocking, and then, as if by magic, turns back the other direction. Start it rocking and it will begin spinning. The magic is in the weight distribution. It causes the rattleback to have a preferred spin direction. If you spin it in the other direction the rotational energy converts to rocking energy and then back to rotational energy in the other direction. And frankly that's the best explanation I can give because I really don't get it. Oh well, it's still a lot of fun.

I've wanted to print one for quite awhile now and after a bit of trial and error I got a shape that works pretty well. The great thing about having a ZPrinter at my disposal is that I can run through revisions so quickly. I'd say I went through 20 different revisions before I was happy with it. Because the strength of zp150 parts is so high, for a lot of the early revisions I didn't bother to infiltrate. I just depowdered, gave it a spin, watched it not spin back, and then tossed it in the trash.

This model is about 4 inches long but I've scaled it up to 26 inches and all the way down to 1 inch. It seems to work better the larger it is. The surface finish is important so after a dip in ZBond 101 I smooth the bottom with fine grit sand paper. I get about a half turn back from the 4 inch version. Let me know if you can beat that.

Here's a video of a 26 inch model we printed on a Z810. It actually shakes the table when it starts rocking.

Wednesday, September 15, 2010

Nike's Future Sole Competition

I know Nike uses Z Corporation's 3D printing technology in their shoe development process but I had not heard of their Future Sole Competition. First of all, what a great name for a competition: Future Sole. The name alone makes it worth checking out. The Future Sole Facebook page includes videos, pictures and more. The contest allows high school and college students the opportunity to submit a shoe design to Nike. The designs from each category that make it to the final rounds get to work Nike designers as mentors on a new project. It appears that the final presentation includes a 3D printed model of their shoe printed on a Z Corporation 3D printer. The winners were recently posted on the blog with photos of the winners, their designs and accompanying 3D printed models. Here's some more coverage of the competition by 

What a thrill it must be for a high school or college student to see their winning design as a full size color ZPrinted model. Whether you are into sneaker design or not it’s worth checking out this competition.

Wednesday, September 8, 2010

Inkjet 3D Printing or DLP Plastic Prototyping: How to Choose?

In the traditional design process (concept development>detail design>build/test> manufacture/ship) rapid prototyping has historically addressed the build/test and manufacturing/ship phases of the process, providing necessary form, fit and function testing and verification of designs. 3D printing is widely thought to address only the concept development and detailed design phases of the process, enabling designers to iterate more frequently, resulting in greater innovation.

Today, the previously clear lines between 3D printing and rapid prototyping are blurred. In fact, there’s overlap in the testing phase of the process. Z Corporation’s inkjet 3D printers meet the needs of many customers requiring form, fit and functional testing and verification. Z Corp. uniquely provides both inkjet 3D printers and plastic prototyping systems to meet all phases of the design process.

Many people think that they need plastic because that’s what certain manufacturer’s have led them to believe, when in reality, most people don’t need plastic for their applications, and in fact, they could be saving significant time and money using inkjet 3D printing. However there are times when a plastic DLP system is the right tool for the job. So how do you decide which system, inkjet 3D printing or plastic prototyping, is the best tool for your application?

Over the next couple of months our worldwide channel partners are running free, in-person, interactive seminars that will explain and demonstrate how you choose which type of technology is best for your unique application. The “How to Choose the Right Prototyping System” seminars will include live product demonstrations, reviews of applications, analyses of costs, displays of prototypes you can produce with each technology, methods for making smart device choices, interactive Q&As, and even a contest drawing for a Flip camcorder. These seminars are run by experts who will be happy to answer your questions.

I encourage you to take advantage of this great educational opportunity that could ultimately save you a lot of time and money in your job. For more information on the seminars, including locations and dates, visit:

Employee Appreciation Day

I’m going to change things up a bit this week and talk about a recent company event. Every year in the summer Z Corp. employees spend a day off site at an event call the Employee Appreciation Day. It’s basically a Z Corp. holiday. This year, as in years past, we spent the day at a local private recreation facility that includes a pool, soccer field, volleyball, basketball, mini-golf, and my favorite, batting cages with unlimited pitches.

The day included a continental breakfast and a cookout style lunch. There was no real structure for activities so everyone could migrate to whatever they were most interested in. Throughout the day I would have to say that it every part of the facility was taken advantage of. The food was great and the weather this year was perfect. One of the best things about an event like this other than the fact that we otherwise would have been working hard developing the next big innovation in 3D printing is the opportunity to mingle in a casual non-work environment with people from across the company that you typically don’t interact with on a daily basis.

Z Corp. isn’t the first company that I have worked for that held an event like this. One company in particular used to take the day off, get on a boat, and spend the day at the beach having a lobster bake. But, most have not. What is your experience? Does the company you work for have an Employee Appreciation Day? Let me know what they do and what you think of the event?

Wednesday, September 1, 2010

Todd Grimm's June 2010 3D Printer Benchmark Report - Part II: Cost

A few weeks back I posted a blog about Todd Grimm's 3D printer benchmark report. One topic the study covers is cost. It includes the cost of the prototype, cost of acquisition, and cost of operation. I like this topic because there are many variables that impact cost and I assume people place more or less importance on some of these variables. For instance, when considering a 3D printer do you first consider cost per cubic inch or are you more interested in the purchase price of the equipment? Logic says that a savvy buyer will consider the total cost of ownership which includes all costs over the useful life of the printer. Is that really the most important decision when considering cost?

This is an important topic from an R&D perspective because we made design decisions every day that impact these cost variables. Keeping total cost of ownership the same, let's assume that we could decrease the cost per cubic inch of material used to create a model simply by increasing the cost of manufacturing a printer. The total cost of ownership might stay the same but the cost distribution is different. Here's another example. Assume the cost per cubic inch of material used for a prototype can be cut in half simply by increasing the time it takes to produce the prototype by slowing down the printer. Is that a trade-off you would make? Following this a bit further, what cost would you place on the time it takes to print your part if it is entirely hands-off.

In the real world you can't simply add cost in one area to lower cost in another. But you can influence them in one direction or another. So, considering all costs associated with 3DP, which ones are more important to you? If you produce models every day you may be more concerned with the consumable material cost. If you are an infrequent user you might be most concerned with the price of the 3D printer. But, I'm interested in hearing from you and knowing what you consider important.