Re: Makerbot's layoffs

PREFACE to all of this: My heart goes out to the 20% of Makerbot's workforce - some 100 people - that were laid off this week. 

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I think this - the layoff announcement, the Reddit thread about the layoff announcement, and the eulogies for what Makerbot used to be -  is mostly a sign of the industry (and Stratasys, though to be fair they probably knew this all along) realizing that desktop 3d printing is a relatively small market. Jordan - a colleague at Undercurrent - has this thing about "mean time to kitchen drawer," which is basically a measure of how sticky (or unsticky, if the customer ends up putting it in their kitchen drawer) your product is. I think most people don't use their Makerbots nearly as much as they anticipated, and anyone who uses a Makerbot a *lot* is likely to graduate to something a bit fancier (probably SLA). So the growth really isn't there, and what they're selling is commodity hardware and some really user friendly software, and that type of business can cut operating costs to something less than Makerbot's were while they were approaching the acquisition.

I think there are two ways forward with desktop 3d printing. The first is to drive the cost down as much as possible, which ultimately means reducing R&D and other fixed costs, and also probably paying less for labor by moving it somewhere other than Brooklyn. The second thing is to look *really* hard for the next technology. That CLIP stuff - Carbon3D - is one direction (though I don't think it's the next big thing). Or maybe it's closer to what HP is working on, though I suspect that machine will cost six figures. Regardless, I'm betting *against* FDM being the predominant desktop 3D printing technology in, say, 5 years.

Either way, you cut costs on anything that touches FDM, and invest a *lot* of money in R&D on the technology that will eventually kill it off. Which I suspect is exactly what Stratasys is doing.

3D printing titanium and the bin of broken dreams

Note: What follows here describes my early experiences designing and building metal 3D printed parts. Since this post was published, I've had a number of parts printed successfully; you can read more about the current state of this work in a recent update, here.

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Last December, in an industrial park in Cincinnati, I watched as Dave Bartosik set up a build platform on an EOS M280. The part he was printing is one that I began designing a full fourteen months earlier, before I had any idea of the intricacies of metals 3D printing, nor the complexity in bringing an additively manufactured part from design to prototype.

My part, being sintered from titanium 6/4 powder.

While the consumer 3D printing community has coalesced around openness, the industrial market tends to be opaque. Sure, anyone can design parts with free software. But the process of bringing those designs to life requires hundreds of engineering hours, tens of thousands of dollars worth of software, and millions of dollars worth of tooling — and even then, developing a single working prototype is a long and expensive process.

To many people, 3D printing offers a new manufacturing paradigm. It stands for rapid iteration, customization, and distributed fabrication. But today it’s arduous and costly, and the knowledge base needed to enter the market is concentrated in a select few people.

Here, I’ll share what I’ve learned about 3D printing titanium parts so far — and what other designers should expect out of the process as well.

A primer on 3D printing metal

Within the maker and startup communities, a 3D printer is essentially an extremely accurate, robotic, hot glue gun, capable of making complex plastic parts within a few hours. For some people that means making functional models more quickly, and with less interaction with outside suppliers, than if they were machined or injection molded. For others it means a couple of desk trinkets, and for the really ambitious it provides a peek into a new way of bringing products to market, replete with on-demand, custom-to-order parts, produced just walking distance from where they’re used.

My background is in short-run manufacturing. I spent a few years building custom bicycle frames, and later ran a small prototyping shop, where I designed and tested robotic door assemblies on fast development cycles. When people talk about the need to iterate rapidly, I get it.

For five years, I worked in a shop that could make machined and welded parts on demand. There were always hiccups — prototype development is often more art than science — but in general we could, with a day’s notice and a bit of help from McMaster-Carr, take a 3D model and create a useable part from it. So when I think of 3D printing metal, I keep those kinds of capabilities (which are shared by easily thousands of shops around the US) in mind.

Metals parts are 3D printed in one of three ways:

1. Binder jetting, in which powdered metal is sprayed with glue to get it to stick together — and later infused with a second metal to make the bond permanent. The most common binder jet printers are made by ExOne. In general, binder jetting is used to create prototypes or parts that require low strength.

2. Directed energy deposition, in which metal is sprayed or fed at a part — and melted to that part by electric arcs or lasers upon contact. DED machines vary significantly; see DMG Mori and Sciaky for context. Directed energy deposition is even more niche than binder jetting; its application is mostly limited to repairs and very large aerospace parts.

3. Powder bed fusion, in which a bed of powdered metal is selectively fused (through sintering or melting) by a laser or electric arc. The most common powder bed fusion machine is probably the EOS M280, but Concept Laser, Arcam, and Renishaw (among others) all have their own offerings. Powder bed fusion has a variety of uses in both production and prototyping. It supports a wide range of materials (the most common being titanium, stainless steel, and cobalt-chrome) and with care can be used to create lightweight, strong, and highly customizable parts — just like mine. But the process is far from easy and is definitely expensive.

Though it’s used extensively within the aerospace, medical, and tool & die industries, there are no metal powder bed fusion products on the consumer market today. Which made me think: why not?

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The powder bed fusion process

When it comes to machine design, humans aren’t nearly as creative as you might think. The basic model for milling machines has been around for more than a century, and despite the fact that the process has changed significantly during that time, the overall layout of industrial tooling today is much the same as has been since the Civil War. Today’s powder bed fusion machines are no exception: If you squint just right, they look a lot like CNC vertical mills.

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Powder bed fusion machines consist of three core parts: The build platform, a material source & recoater, and a source of thermal energy.

During operation, a thin layer of powder is spread by the recoater blade across the build platform. Then the heat source — either a laser or an electron beam — scans across the build platform, melting powder selectively as it goes. Where the metal is melted, it fuses to the metal around it, creating a solid part. After one layer is scanned, the recoater blade spreads another layer of powder and the process repeats.

Printing things this way is slow; a part the size of a juice glass might take ten hours. The recoater takes a few seconds to spread each layer, and although the laser is moving incredibly fast, it takes some time to scan the cross section of a part line by line. Add to that the fact that each layer is about eight ten-thousands of an inch thick, and you see how anything larger than a thimble would take a long time to complete.

Although powder bed fusion can be done by both lasers and electron beams, lasers are far more common. Electron beam melting (EBM) is notoriously difficult to control, and although it has some advantages, EBM parts tend to have very coarse surfaces and require more post processing as a result. EBM also suffers from relatively low market penetration; by my count, there are fewer than five service providers for EBM in the US.

By comparison, laser sintering (which I’ll refer to as DMLS, for direct metal laser sintering, though that is technically an EOS trade name) is almost ubiquitous. I’m aware of about seventy US shops offering metal laser sintering in-house, and even consumer-facing providers like iMaterialse offer DMLS. And although EOS sells far more metal laser sintering machines than any of their competitors, the market is still competitive — and that competition is beneficial to the industry as a whole.

Within the aerospace industry, DMLS has a high adoption rate — at least in an R&D context. In fact, my collaborators and primary tour guides to the industry (Dave Bartosik and Dustin Lindley) both began their careers in additive at Morris Technologies, the aerospace DMLS giant that was acquired by GE Aviation in 2012. Between the two of them there’s about as much experience printing titanium parts as anyone else in the world.

But for all the work that has gone into understanding the properties of additively manufactured parts, the process is still very much in its infancy. It is not in any sense a mature technology, and the result is that each new part you design for DMLS — and, indeed, each new copy of the part that you print — is very much an experiment. Small variations in geometry and orientation can have huge effects on the way that a part prints. The laser’s scanning path is a closely studied subject, but much is not yet understood about it. Even keeping those variables constant, it’s often the case that building the same part on a different machine will produce very different results.

All of which is to say that DMLS is anything but plug-and-play. Even when a design has been optimized specifically for the process, it often takes dozens of tries before a functional part comes out of the printer. And the process of troubleshooting a failed build — even at the most advanced DMLS shops in the world — still involves a lot of trial and error.

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Part constraints

In general, parts that benefit from 3D printing tend to have the following traits:

• Benefit from weight reduction

• Benefit from customization

• Complex geometries

• High inventory costs and/or long lead times

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My seatmast topper, in full and half-section views. Note internal cavities in the center neck area.

The part I’m building is a seatmast topper for high end road bicycles. Cyclists want lightweight, custom parts. Custom bicycles are increasingly popular with consumers, and they carry high price tags and long lead times. Broadly, it’s my suspicion that more and more bicycle components will be produced on-demand through 3D printing — if only for the simple fact that within high end cycling, sexy sells.

At about 60 grams, my part is fairly lightweight. It’s also relatively small, and fits easily within nearly every DMLS machine’s build platform. And because of its function (seatmast toppers are used to hold a bicycle saddle onto the frame) its structural requirements are fairly predictable. These factors, plus the fact that seatmast toppers are easy for almost any cyclist to install on their own bike, make it a good candidate for 3D printing.

But that doesn’t mean it’s easy to print. My part consists of two cylinders, oriented 90° apart and joined together by a funneled neck. The part’s wall thicknesses fall between 1mm and 1.75mm — roughly .039"-.068". And it’s critical that these walls not vary much in thickness; if they end up just .010" thinner (for comparison, a sheet of paper is about .004" thick), the part could be unusable.

Harder yet, the inner diameters of both of the cylinders must be accurate and consistent. Again, variations of just .005" can have a big effect here — and if the cylinders end up with oval cross-sections, the part won’t work at all. And the titanium 6/4 that my part will be made of (which is named for its 6% aluminum, 4% vanadium content) is notoriously prone to built-in stresses, meaning that we’ll have to be very careful setting up the build parameters and support structures to prevent the part from turning into a pretzel during the process.

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As with almost all 3D printed metal parts, mine will require some degree of post processing; at an absolute minimum, the clamp bolt threading will need to be tapped. But because of the physical tolerances listed above — and the mechanical and aesthetic properties of DMLS parts, which tend to be rough and unpredictable — it’s likely that extensive finishing will be required on both the inner and outer surfaces of the part.

In short, my part’s manufacturing process chain was always going to include some subtractive steps. There are many feature types that 3D printing simply isn’t intended for, and I knew going in that this part would require more than one process as a result. But until we picked a build orientation — and built parts that passed fit & finish tests — we wouldn’t know for sure what our total process chain would look like.

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Build orientation

My prototyping partner, DRT Medical— Morris, prints titanium parts on an EOS M280 — the workhorse metal 3D printing machine for American job shops. Based on my research, EOS’s market penetration outmatches each of their competitors by five to one. As of November 2014, EOS only lists eighteen service-ready M280s in the US, but their data is clearly incomplete; I wouldn’t be surprised if the real number was triple that. Moreover, the vast majority of DMLS machines are purchased by OEMs, who use them for internal capacity only, and my suspicion is that the proportion of EOS machines behind closed doors is similarly large.

The M280's build platform measures 250mm (x) by 250mm (y), and is has a maximum build height of 325mm (z), including the build plate. My part is about 70mm long (x), 37mm deep (y), and 90mm tall (z).

A common misconception about 3D printing is that the unit cost doesn’t vary much with quantity — that printing one part is just as efficient as printing a thousand. Granted, 3D printing doesn’t require tooling per se, but non-recurring engineering costs are absolutely to be expected. In addition to the time spent determining an optimal build configuration, there are significant changeover costs when a DMLS machine operator goes from printing in, say, titanium to stainless steel — which some low-volume service providers might do on a weekly basis. Moreover, metal 3D printing providers don’t normally print multiple orders in one build. In other words, if I buy a titanium part at the same time as another customers does, they’ll usually run those orders in two separate builds — even if both parts might fit on the build platform at the same time.

The exact math is hard to reverse-engineer, but there are generally four variables that determine the cost of a DMLS part:

• Finished part mass. There are two subcomponents here: Raw material cost, plus the time it takes the laser to sinter the part. Raw powder costs between $300 and $600 per kilogram. My part weighs about 60 grams, which puts the material cost in the neighborhood of $30. But that 60 grams will take about eight hours to sinter, and the cost of sintering time adds up quickly. As a rough guide, expect to spend on the order of $100–200 per hour for part build time.

• Support structure mass. DMLS parts require solid support structures to tie them to the build platform, and those structures are made of the same metal powder that the part is. If your part has a lot of overhanging geometry or requires additional support structures for other reasons, you’ll pay for those (and the time it takes to sinter them) as well.

• Part height. Across all types of manufacturing, capital expenses (tooling, etc.) are paid off over a period of years. In DMLS, part height correlates directly with time spent recoating the platform with new powder, and that in turn equates to a higher tooling cost that the supplier needs to pay off during your build. As a result, designers are incentivized to orient their parts as close to the build platform as possible, to reduce build height and hence reduce recoating time.

• Number of parts per build. Because the setup and powder recoat time can be shared across multiple parts, buying in batches (when possible) will generally be less expensive than buying one-offs.

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Build configuration 1: Part on it side. Ten parts, ~40 hours. Image courtesy DRT Medical — Morris

In my case, those last two factors act directly against each other. If I orient the part on its side, I can fit about 10 parts per platform, with a ~40 hour build time — about 4 hours apiece. But if I orient them vertically (upside-down ends up being more favorable), I can print 24 parts in a ~85 hour build — about 3.5 hours per part.

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Build configuration 2: Part upside-down. 24 parts, ~85 hours. Image courtesy DRT Medical — Morris.

At this point, Dustin and I spent some time thinking through the manufacturing process chains for each of these configurations. It’s very likely that we’ll end up needing to machine the inner diameters of both of the part’s cylinders, and we wanted that process to be straightforward and involve as little custom tooling as possible (post processing DMLS parts often requires extensive custom tooling). As far as we could tell, build configuration 2 was going to be slightly easier — mostly because the long ID could be machined while the part was still on the build platform. But the difference was very difficult to quantify, and in the end our build orientation was determined for a much simpler reason: powder availability.

The DMLS powder market is, like most things in this industry, changing rapidly. Powdered metal is expensive to produce, and the particle size, shape, and consistency are critical to finished part characteristics. And while prices are going down rapidly (double digit percentages year-over-year, I’m told), service providers are still stuck with having a large chunk of money tied up in raw powder powder at any given moment. Add in lead times, and the fact that titanium powder isn’t particularly fun to handle, and you can see why job shops would only want to keep as much powder on hand as they absolutely need.

In the end, we ended up building my part on its side simply because DRT was getting towards the end of a batch of powder, and the taller orientation was going to require more than they had on hand. Which is possibly, given the small quantities these parts will probably be produced in, the right orientation anyway — and was a less expensive build to boot.

At this point, our goals were explicit: Determine the minimum amount of post processing necessary to produce a working part.

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Stress & build failure

It’s critical to remember that 3D printed parts move as you print them. The same is the case with other manufacturing methods as well (injection molded parts shrink as they cool, machined parts warp as they’re cut, etc.), but DMLS creates extreme thermal gradients, and the net effect is that stresses are built into the part layer by layer.

Build orientation affects stresses in *huge* and unpredictable ways. See this paper, by Amanda Wu, a researcher at LLNL, for more.

Predicting built-in stresses is an incredibly difficult task, and is the topic of a lot of basic research. At the moment, the best we can hope is to analyze and understand the stresses that are built into parts once they’re complete; predicting them before they happen is still a long way off.

Despite the fact that stress prediction is very much a dark art, the correlation between laser sintering and welding is not a trivial one; many of the same principles apply to both. But when approaching a new part, it’s almost always the case that the best way to deal with potential problems is through trial and error — and then adding and removing support structures as necessary.

This is a key point: powder bed fusion involves welding your part to the machine while you build it. The build will definitely fail if the part lifts off the build platform (when this happens, the recoater blade strikes the part. In general it doesn’t damage the machine, but I’m told it can be… exciting), so a lot of effort goes into designing clever — and hopefully not too massive — solid and lattice support structures to keep the part where it’s supposed to be.

Even if the build itself doesn’t fail, internal stresses can still render it unusable. This is why most parts are stress relieved (a heat treatment process) after they’re built and before they’re removed from the build plate: doing so allows the crystalline structure to relax, preventing failure later.

Going into the build process, I was warned many times that cylinders oriented parallel to the build plate are notoriously difficult to build. The stress profile around the circumference of the cylinder will tend to vary widely, and the result is that you generally wind up with a big oval. But other than orient the part at a 45° angle to the platform (and risk ovalizing both cylinders), our options on this part were limited. So, we started as simply as possible, and iterated as needed.

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Support structures & Iteration

Once the build is complete and the part is wire EDM cut off the plate, support structures are removed manually.

While I was in Cincinnati, I visited MicroTek Finishing — a major player in the metal 3D printing world. While there I spoke with Tim Bell, who related an anecdote about his time at Morris Technologies, the aerospace 3D printing giant that was acquired by GE in 2012. Tim was a product development leader at Morris, and he talked of a large bin that they had in their shop. It was called the Bin of Broken Dreams, and into it went an endless stream of failed parts.

My part has now been printed in six different build configurations. We (and by we I mean Dave Bartosik, whose creativity and enthusiasm for getting the build to work was inspiring) added solid supports in a number of places, chasing built-in stresses around the part with each iteration. The latest prototype, although nonfunctional, is nevertheless a big improvement on the earlier builds — and the process has taught us a lot about the idiosyncrasies of my design.

To begin, Dave let Materialise Magics (the industry standard for support structure generation software) do its thing with no manual intervention. Magics generates mesh support structures, which are scanned every other layer of powder (solid regions of the part are scanned every single layer). As a result, they’re very easy to chip off the part — but don’t have the same strength that solid supports do. As internal stresses proved to be an issue, Dave added solid supports to keep the part undistorted and tied to the build platform.

Build 1

You can see the saddle clamp cylinder lifted off its support structures.

Build 2

The saddle clamp is firmly anchored to the platform, but the front of the part — including the bolt boss — have lifted off. Some of the support structures have been removed in this photo.

Build 3

The saddle clamp and bolt boss are both anchored, but the center of the part lifted.

Build 4

Shown here heat treated & wire EDM’d off of the build plate. The bottom of the part is distorted & lifted. The purple color comes from the heat treatment process.

Build 5

The bottom rib helped the seatmast clamp distortion, but not fully.

Build 6

The part is basically round, but has a bulge in the middle of the seatmast clamp.

Build 1

In this build, the part is laid on its side and supported only by mesh supports. The build failed at only 15.6mm in the z-direction, when the recoater jammed on the saddle clamp end of the part, which had lifted from the build platform.

Build 2

Here, the seatpost clamp cylinder is firmly fastened to the build plate. But the stresses just concentrated on the other end of the part, pulling the bolt boss and some of the front edge off of the platform at a height of 22.7mm.

Build 3

Both ends of the part — the saddle clamp and the bolt boss — are firmly anchored to the build platform. But this created a complex bending moment, pulling the center of the part upwards; the build failed at 22mm.

Build 4

Here we’ve got solid supports on both the saddle clamp cylinder and the bolt boss, and added an additional solid rib to the middle of the part, tying it down there. This is the first build that completed; all of the others had failed midway through. We’re clearly getting closer, but the bottom of the part has distorted, pulling in and looking like a big “D”.

Build 5

To prevent the bottom of the part from distorting like in Build 4, we added a second solid rib. It helped, but only below the centerline of the cylinder; above that, the wall still pulled in.

Build 6

Build 6 finally produced a part that’s generally round and complete. This was achieved by extending the lower rib up the side of the part, giving external support to the entire bottom edge of the seatmast clamp cylinder. But although the top and bottom of the seatmast clamp are both basically round, the internal stresses still needed to go somewhere — and ended up bulging out the middle of the tube instead.

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Throughout each of these builds, three things have remained consistent. First, the surface finish on the exterior of the part leaves much to be desired; it will definitely need to be finished in a separate step. Second, the surfaces that needed to be EDM cut from their solid supports (the saddle clamp and the bolt boss) are irregular, and will need to be smoothed into the rest of the part. Third, the internal diameters will almost definitely need to be post-processed by machining or EDM — even the saddle clamp, which overall had passable surface finish, was undersized by .020" — about four times the desired variance.

The net effect is that after six build iterations — each of which took almost two full days to set up, build, stress-relieve, and cut off of the build plate — we still don’t have a functional prototype to test.

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Takeaways

What to take away from this? Well, prototyping is hard — but everyone knows that. My primary observations have more to do with the state of the industrial marketplace, and the maturity of metal 3D printing processes, than with the fact that we’ve now put six parts into our own bin of broken dreams.

File processing

As with consumer 3D printing, industrial 3D printers work exclusively from STL files. This produces a total break in the design-to-manufacture process. When I export an STL to send to a manufacturer, all of the underlying feature data is lost; all that’s left is a shape. This is drastically different from the conventional manufacturing world, where parts are regularly built directly from underlying design files.

Tolerances

For the vast majority of machined parts, any single dimension is expected to be accurate to within .005", regardless of size; in other words, a quarter-inch hole should be between .245" and .255", and a one-inch hole should be between .995" and 1.005". For a relatively small cost, designers can specify even tighter tolerances, and the means of achieving them are predictable and not overly complicated. But with additive, tolerances accumulate across the part at a rate .005" for every inch of distance. That’s fine if you’re building a one-inch part (whose dimensions will be between .995" and 1.005"), but larger parts can be problematic; a ten-inch part will be between 9.950" and 10.050" — a decidedly generous tolerance. Moreover, these tolerances don’t always stick; many of our early prototypes didn’t come close to meeting them. And when a part prints out of tolerance, the way to fix the problem is essentially to fiddle with the underlying design and then build it again.

Intellectual Property

Across the metal 3D printing industry, a stream of contract manufacturers told me the same thing. DMLS build processing is hard, they say. And the only way to maintain a competitive edge is to invest countless time and money into R&D — and then guard institutional knowledge vigilantly. On many occasions this is referred to as intellectual property, but the truth is that it’s closer to expertise; what’s being developed is craftsmanship, not patentable tools or methods. But whatever the name, the effect to designers is stifling. Regardless of manufacturing method, the design-to-manufacture process benefits from transparency; if a build fails, then I as a designer want to know the reason — and adjust my underlying design accordingly. Until the additive supply chain opens up to sharing its experience in the design-to-manufacture process, new DMLS products will be few and far between.

Undistributed Manufacturing

Today, 3D printing metal parts via a distributed supply chain is a myth, full stop. And while I’m as excited about that vision as the next guy, distributed manufacturing will continue to be a pipe dream for the foreseeable future. A distributed manufacturing ecosystem can only exist once there’s a robust network of suppliers capable of making parts repeatably. And while it’s my sincere feeling that the most hardworking, intelligent, and visionary people in manufacturing today are working in 3D printing, there simply isn’t currently a rich network of DMLS suppliers. For instance, the closest DMLS-equipped shop to New York City is a 200+ mile drive away. Meanwhile, MFG.com lists 68 machine shops within a 150-mile radius. If distributed 3D printing is to become a reality, the install base must increase by orders of magnitude — and the reliability and repeatability of the processes must improve dramatically as well.

In-Process Monitoring

In conventional manufacturing, parts are checked between operations to ensure that critical dimensions will be met. But the current generation of industrial 3D printers have little in the way of in-process monitoring, with the result that distortion isn’t detected until the build fails altogether. Although there are hints that this may be changing (B6 Sigma has announced some ambitious plans recently, and a lot of primary research is being done on the subject), the fact remains that until we’re measuring and analyzing the factors (thermal gradient, sound, vibration, etc.) that indicate build failure before it happens, trial-and-error will be the only way prototypes are developed.

The Process Chain

3D printing is very, very good for certain things. But it is not a one-stop process. For now and the foreseeable future, additive manufacturing will be a poor method of creating a number of important mechanical features, including many aspects of fastening and articulation. In addition, the surface quality of 3D printed parts will be unacceptable for anything requiring tailored aerodynamic features, and will be similarly poor for products whose fit and finish are of high value for aesthetic reasons. This is not to say that those aspects won’t improve; they will. But while I expect additive manufacturing to be an important part of the way parts are produced in the future, it’ll be a long time before it’s used to produce a wide range of products. And for those products which are well suited for 3D printing, their total manufacturing process chain will include subtractive tools (machining, honing, polishing, etc.) for the foreseeable future.

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Next steps

My part has come a long way. Just having a physical prototype in hand makes a huge difference in understanding its benefits and drawbacks, and I continue to believe that with continued research and prototype development, I will find a way to make it commercially viable and attractive to high end cyclists.

But there’s much work to do. Moving forward, I see three primary directions to explore:

Keep the current build orientation, and continue to iterate on support structures as necessary.

At this point, it’s clear that we need to rethink the way we’ve been mitigating internal stresses. The external ribs are working somewhat, but even if we can add enough of them to make the build work, they leave ugly marks on the outside surface which require additional post-processing. Instead, I plan to experiment with reinforcing the inner diameter of the seatmast clamp cylinder. One thought is to create an internal lattice (like those that Frustum’s software creates), which would provide rigidity during the build and then be removed via machining afterwards.

Change the build orientation

Turning the part so that it’s upside-down on the build platform — with the seatmast clamp on the top — will offer significant advantages. The saddle clamp already has a thicker wall than the seatmast clamp, and is likely to resist distortion more easily. And with the seatmast clamp oriented in the z-axis, it’ll be in much less danger of distortion.

Try EBM

The electron beam melting process preheats the entire build platform to just under the melting point of titanium, and so generates much lower thermal gradients — and as a result less internal stress — than DMLS. EBM also generally requires fewer support structures, which is helpful for part cleanup. However, the surface quality and minimum feature size of EBM is significantly worse than DMLS, so EBM would probably require a longer overall process chain, with more material removal than DMLS would.

Regardless, I’ll be continuing this work over the coming months. These technologies are changing rapidly, and any ambitious product designer would be wise to pay close attention to their development. And only by experimenting with actual parts can anyone hope to keep up.

I believe that functional, engineered consumer products made by additive manufacturing are an inevitability. But as a product manager today the viability of metal 3D printing is totally opaque, and that will only change by careful study of the efficiencies (and inefficiencies) of the additive manufacturing toolchain.

Join me in working to make that a reality.

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Thanks

First, thanks to Dustin Lindley (of UCRI) and Dave Bartosik (of DRT—Morris), without whom all the cool stuff described above would have never happened. Thanks also to Greg Morris (who originally connected me with Dustin, Dave, and Chuck Hansford at DRT), to Clay Jones and Jordan Husney for their creative inspiration and infectious enthusiasm throughout the process, and to Clay Jones and Mike DiGiulio for reading early drafts.

Lastly, thanks to Undercurrent, which is providing critical funding for this project — and which I am proud to call home.

This article originally appeared in three parts on 3D Printing Industry.

Directions in automation adoption

I've been spending a lot of time looking at industrial automation the past few days, and had an idle thought:

So many ppl trying to automate design, sourcing, and assembly. Meanwhile robotics gave up; Kuka & Baxter are programmed literally by hand.

— Spencer Wright (@pencerw) December 2, 2014

I've touched on this before, if only obliquely, when writing about MFG.com's role in manufacturing logistics. Much attention is being paid to companies who want to simplify (or circumvent) some part of the product development value chain. Many of these are companies I admire, and think are doing really valuable things. Take Within, whose 3D design software generates structures that are driven directly from functional constraints (but can't, as far as I can tell, deal well with thin-walled structures). Or Willow Garage's PR2, the really slick research robot (that takes charmingly long - 20 minutes per bath towel - to fold laundry).

Each of these is an incredibly impressive feat, and one that follows an ambitious (and I would argue honorable) line of thinking:

If we can encode all of the information needed to complete a routine yet complex task, then we can use machines to automate the process, freeing up our minds to do other (presumably more important) things.

But consider an alternate proposal:

If we can get machines to mimic a series of behaviors that humans can plan and execute with relative ease, then we can decrease the amount of rote mechanical work that humans need to do.

This is the tact taken seriously by Baxter, the admittedly not-too-serious (but cool nonetheless) humanoid task robot built by Rethink Robotics. Baxter learns by physically training his movements, presumably by the technician who he's "collaborating" with:

Even the traditional robotics companies, like Kuka, are moving in the direction of using robots simply to execute the complex tasks that humans calculate and perform with ease. Here a Kuka robot is trained how to clean a permanent mold by a BMW employee:

Both of these robots' use cases share a key feature: There's still a human doing the "hard" planning and calculation about how the task will be completed. In each case the robot doesn't understand the physical constraints or goals per se. Baxter has some awareness of his surroundings for sure, but all he knows is that his arms hit something; he doesn't have the vision or awareness of why that happened or how to correct for it.

Similarly, the Kuka bot doesn't understand that he's cleaning a mold, or have the facilities to learn how to do better work. He's just repeating a toolpath that he knows a human told him to do. Which, in this case, is good enough - and a hell of a lot faster than waiting for a computer vision expert to give him the intelligence required to do better.

I'm not sure what the implications of this are for the companies working to automate the design and supply chain. But the philosophical difference is striking, and I must say that the more hands-on model is very compelling - and I expect it to be so for the foreseeable future.

Parenthetically: All of the industrial 3D printing market is currently driven off of this same model: An intelligent, experienced technician makes manual edits to 3D CAD data in order to get a part to print within its design constraints. Anyone who suggests that build optimization is "right around the corner" is, in my opinion, *not* to be trusted. We're in a world of basic research still, and an automated design-print-post process chain is many years away.

DMLS in process

This is my seatmast topper being printed from titanium 6/4 powder on an EOS M280 at DRT Medical - Morris.

This video clip is about 1-2mm into the build, so this is the very close to the bottom edge of the part (which, to be clear, is lying on its side). A lot of what's being printed during this clip is support structures & ribs that will help hold the part to the build plate, but you can clearly see the general shape of the part already.

This is 6th iteration on this build. In other words, we printed 5 parts before this one, and each of them failed for one reason or another. We've (and by we I mean mostly Dave Bartosik, the head Additive Technologist at DRT, with me trying to look over his shoulder) made a bunch of modifications to the build to help the part come out within spec, and I'm hoping that today we end up with something that has consistent inner diameters and is more or less useable.

Anyway, what you're seeing here is a 400 watt ytterbium fiber laser in the process of melting 30 micron layers of titanium powder. The recoating arm spreads a thin layer of powder, and then the laser scans a cross sectional slice of the part, and then the process repeats. 

When the video goes into slow motion, notice the smoke that's coming off of the weld pool. The machine has a laminar flow of argon gas that's blown across the build platform (from top to bottom in this video) that pulls the soot away and filters it outside the machine.

More soon.

Initial topper builds

This.

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Today I stopped by DRT Medical - Morris to check out the first builds of my titanium DMLS seatmast topper. I'll be writing up a longer report in the next few days, but the short story is that it's moving forward - but that the process of printing a part is *not* at all straightforward, even when you have some of the most experienced people in the business working with you.

More soon. And - fucking cool, right? This thing started out as titanium powder, and was literally made by laser sintering. Nuts.

Manufacturing logistics wishlist

+1 for breakfast with a smart friend. Always good for taking a step back & seeing a bit of perspective.

I like mass market products a lot. But I want to really love the things that I make, and that's hard to do if you're trying to appeal to a mass audience. Compromises need to be made when you're designing for a diverse customer base; when the market is smaller, it allows the product developer to be a bit more choosy.

I'm excited that making short-run products is getting easier - but there's still a lot to be done. These are a couple of the things that have been bothering me.

Soup to Nuts design toolchain.

As a designer of traditionally manufactured parts, features are specified according to more or less knowable tool properties. When I place a drilled hole, the results will be predictable, regardless of my supplier's equipment or process.

The same is not the case with additive manufacturing, where build orientation and support structures matter a lot. As a designer of these parts, I want to be able to simulate varying configurations myself, so that I can specify the build procedure to my suppliers. Simplifying the CAD/CAM toolchain - ideally with solid/NURBS, T-Splines, topology optimization *and* build plate prep all in one application - will be crucial to lowering the barrier of entry to AM.

Surface finish specs.

When designing a part - especially those used in assemblies - surface finish is often critical. With additive manufacturing, surface finish may vary widely, depending on build orientation and support structures. In some cases it may be possible to reorient a part in order to improve finish.

But today, these determinations are preformed by machine operators whose knowledge of the process is experiential and not publicly available - making it difficult for designers to know precisely what they'll get. Machine manufacturers and job shops should work together to develop design guidelines and detailed surface finish specs, alleviating this uncertainty.

Full service plastics prototyping.

I love Shapeways. But they *need* to offer secondary services, i.e. tapping and tolerancing. 

Advanced Manufacturing 3PSCM.

Again, I love Shapeways. But they *need* to offer assembly, and custom packaging, and small parts that are traditionally manufactured (i.e. bolts). 

3D printing is a cool technology. But so is stamping, and you don't see sheet metal shops selling useful products directly to consumers. Without a supply chain management offering, I believe that Shapeways will be confined to just selling parts - not products.

Industrial supply catalog APIs.

I love McMaster-Carr. But they need an API that can talk to both my e-commerce and the API of my manufacturer. When my customers purchase an assembly from me, my supply chain manager (whether it's Shapeways or somebody else) would automatically place orders through McMaster-Carr and my manufacturing partner(s) - with all parts being shipped to the SCM and assembled just-in-time for shipment.

A word on MFG and Alibaba.

I'm all for services that provide me access to a wide range of manufacturers. But it is critical to the design process that that service be completely transparent. Like it or not, most designers are *not* manufacturing agnostic, and speaking directly to a manufacturer - and preferably to the machine operator who will actually be setting up & running your part - is key to producing successful designs.

Too much effort is being spent trying to disrupt procurement in ways that adds an opaque layer between me and my supplier, and the end result is that I learn little from the process. All I want is for you to put suppliers in front of me and then get out of the way.

Everyone in the supply chain should have a blog.

Why aren't these people talking about their processes? Why aren't they sharing the non-NDA work they've done? Why aren't they showing me the capabilities of the new machines they have? I would gladly pay a premium for a shop that's actively showing me the engineering feats they're accomplishing. Get bloggy - the openness is quite becoming.

I hope it is, at least :)

Thumbrest

Got this back from Shapeways a week or so ago. 

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To recap, this is designed to be installed in the hotshoe of a Sony A7, in order to improve the grip stability & feel.

I still need to do some post-processing & try the part out. I'm excited to put it together.

Unsolved problems

Kegan Schouwenburg's advice to entrepreneurs working in 3D printing, from an interview with Ideas Lab:

Do something that isn’t being done currently. There are so many unsolved problems in 3D printing, and it seems like everybody is focusing on the same one right now, which is basically: Let’s make a cheaper 3D printer. But that problem has been solved. We have that. I think the question now becomes, How do we create products that people want? How do we develop the infrastructure to support that?

ST Clamp

An alumide Shapeways model I had made a month or so ago:

This is an alumide model of a part that I've gotten quoted in DMLS a few times recently. This part probably wouldn't be printed in its current design - at least as anything other than an exercise in showing that it's possible. The shape simply isn't optimized for additive manufacturing, and it would take a lot of re-imagination in order to change that.

Still, it's a start - and because of its volume/mass ratio, it would be an interesting part to explore deeper.

Stay tuned.

"A traditionally cast frame."

Who knew: Tell people you're designing 3D printed bike parts, and *everyone* will send you some variation on this article. Which is great - it's a totally awesome project, and I think Empire and Renishaw are working on absolutely the right thing. 

But I have a little nit to pick, and it's with the specific wording of the following paragraph (ephasis is mine): 

By using additive manufacturing the MX6 saw a marked decrease in weight. In fact, while the original bike frame weighed 2.1 kg, its 3D printed cousin was slimmed down to 1.4kg - a 33% reduction. What’s more, because Empire’s frame was 3D printed analysis showed it to be denser and stronger than a traditionally cast frame.

Here's the thing: frames aren't traditionally cast. Empire Cycles makes awesome stuff - totally crazytown bikes - but there's very little that's traditional about them. In fact, they're almost specifically atraditional - they use alternative methods of manufacturing partly as an exercise in design and manufacturing prowess. 

Okay. Rant over.

I should be clear: I think this bike is awesome. I especially like the photo of the build platform, which must have been a pain to engineer - even after they'd engineered the assembled product. I think Renishaw and Empire are totally onto something here. I'm just being a punk about the details :/

Hario Driver from Shapeways

Got this yesterday: 

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This is a socket bit that can be chucked in a drill and used to grind coffee with a manual burr grinder. I'm toying with the idea of having some CNCd, but this 3D printed steel version will work well for testing.

I don't own the Hario grinder that it's designed for, but I'm hoping to test it this weekend at a friend's house. Expect results soon :)

Shapes

Scott DeFelice, CEO of Oxford Performance Materials, said something in conversation yesterday that I found really prescient. I'm paraphrasing this a bit from my notes, but the feeling is there:

There is a business selling shapes. It's not a new business. Shapeways and MakerBot are doing interesting things with the business model, but it's the same business. 

The business of selling *useful* shapes is totally new.

What Scott's saying here rings true to me: When designers are able to create shapes that are functional in and of themselves, the nature of the product - and its value to the end user - changes dramatically. 

If I'm selling shapes, I want to be selling useful ones.

McKinsey

Two excerpts from a short piece on 3D printing by McKinsey. Emphasis mine:

As of 2011, only about 25 percent of the additive-manufacturing market involved the direct manufacture of end products. With a 60 percent annual growth rate, however, that is the industry’s fastest-growing segment. As costs continue to fall and the capabilities of 3-D printers increase, the range of parts that can be economically manufactured using additive techniques will broaden dramatically. Boeing, for example, already uses printers to make some 200 part numbers for ten different types of aircraft, and medical-products companies are using them to create offerings such as hip replacements.

And:

Design is inherently linked to methods of fabrication. Architects can’t design houses without considering construction techniques, and engineers can’t design machines without considering the benefits and limitations of casting, forging, milling, turning, and welding. While there is a wealth of knowledge around design for manufacturing, much less is available on design for printing. Our conversations with executives at manufacturing companies suggest that many are aware of this gap and scrambling to catalog their design know-how.

Incidentally, I'm not sure that the premise of that second quote is necessarily true, regardless of what I believe *should* be the case.

DMLS Site Visits

Last week, I had the pleasure of visiting two excellent resources in the world of additive manufacturing. What follows is all in relation to my titanium 3D printed bike seatmast topper project.

Within Lab

On Wednesday I sat down in the Brooklyn Navy Yard with Kaveh and Siavash of Within Lab. Within's software takes solid models as input and allows the engineer to convert them to 3D lattice structures in order to reduce mass and build time - and maintain structural integrity. Their software is no joke; it's clear that for engineered mechanical products, Within Enhance is going to be key to making 3D printing a viable manufacturing method.

There were a few key takeaways:

• The base portion of my topper is a thin walled sleeve. I suspect it could be latticed (instead of having a consistent wall), but I don't believe Within's software will generate curved lattice segments. The demos they ran all assumed a thin skin on the ID of the cylinder, but I suspect there's a better way - which would likely require a curved lattice.
• It's possible that many of the theoretical benefits of Within's process will be somewhat tempered by the nature of my relationship (as a designer) with the job shops that will eventually produce the parts. Optimally, the job shop has an intimate understanding of the design intent of the part - both its function *and* the assumed build characteristics. In other words, I would hate to optimize my part for a vertical build orientation, and then find later that my supplier was building horizontally. Big things like that should be easy to avoid, but it'll require a bunch of management and communication on my part.
• I'm unsure whether Within Enhance will be able to find an elegant design for the pinch bolt on the front of the Topper. I'd prefer to eliminate the bolt altogether, but I'm trying to redesign as little of the wheel as possible here. This isn't a criticism of the software itself - just an anomaly of my particular design (and the design of bike parts in general).
• Within's software deals entirely with STLs, which are limited in their portability. I don't think this will be a serious issue, but I was a bit surprised about it.

It's also worth noting that I really need to redesign the saddle clamp if I'm going to take full advantage of the manufacturing process. Again, though, I'll probably hold off for now and just focus on getting one of these made - and on a bike - ASAP.

Incodema

On Thursday, I got a facility tour of Incodema (warning: autoplaying audio on their site!), a job shop in Ithaca NY with DMLS, CNC, stamping, wire EDM, and welding capabilities. I also got a chance to talk in depth with Scott about their DMLS capabilities and the idiosyncrasies of my project.

Some of the parts that Incodema commonly makes.

A few interesting things that I learned here:

• Incodema uses wire EDM extensively for post processing. I had just assumed that part cleanup was either manual or machining, but EDM makes a lot more sense for lots of parts. Incodema keeps a bank of EDM machines, as uses them both for DMLS cleanup and for toolmaking for their stamping shop.
• Incodema is developing a proprietary surface finishing treatment for DMLS parts. I'm aware that this is a hot topic (another supplier bragged of their ultra secretive process), and grumblings continue in the traditional manufacturing world re: DMLS's low (Ra ~400) surface finish. It's unclear where Incodema is with their process, but the first articles I saw were quite pretty.
• After hearing Within's off-the-cuff recommendations about build orientation, Scott and I spent a little while setting up a build platform and support structures for my part. It appears that we could build 20 parts per build with the part oriented roughly upside-down, and we were able to reduce support structures a bit too. We did, however, increase build height significantly, and it's unclear what effect that'll have on the per-part price. (I should have more info on this soon.)

I also got a chance to see a bunch of other DMLS parts in their shop. Most were NDA and couldn't be photographed, but this demo knife blade was pretty cool :)

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It's a little hard to see, but almost everything on the top left side of this image is support structures (the part is built with the blade edge up), which can be snapped off manually. Support structures on parts like this are built with perforations in a couple different dimensions, including along the part edge, so removal isn't too hard. The resulting blank still needs to be post processed pretty heavily, though - this knife will require polishing, probably some tapping, and the blade will need to be sharpened as well. My part had an estimated 1 hour of post processing, which seems really reasonable to me.

Next Up

I need to spend some time reconfiguring my design. It's likely that I strip away a few more features, and possibly redesign the bolt boss as well. I then need to think a bit on how I can prep for support structures, and whether I can remove areas of the part (especially around the saddle clamp tube) in order to reduce build time and mass. It's possible that I'll reduce the offset of the topper as well, as it both increases mass and also requires a lot more support in order to build the part.

I'll be putting a bit more time into this project over the coming week; expect updates.

Seatpost collar

After doing even more research on DMLS pricing (update soon), I played around a bit today with designing a seatpost collar. 

The design here is pretty straightforward. I'm using fairly standard barrel nuts and a M5 bolt (I'll steal these from a Thomson collar I have laying around), and the part profile isn't trying to be innovative either.

I'm getting this printed in alumide (a mixture of nylon and aluminum) for an aesthetic/basic form/function mockup, and will look into pricing on the part too. I suspect that it could be relieved in a bunch of places still (to reduce build time & cost) but for now I don't care too much - I just want to get a functional stainless or titanium part on a bike ASAP.

Updates when Shapeways ships, probably before Valentine's day.

My current feelings on topper

What follows is cross-posted from a discussion on linkedin re: my DMLS seatmast topper. Some of this is specific to a comment I received there, which basically boiled down to "the pricing structure and logistical/engineering benefits of DMLS are poorly suited for bike parts generally, and seatmast toppers specifically." 

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I've done a bit of pricing research and the numbers aren't totally crazy. Sure, the current cost is 2-3x what I'd want it to be, but between redesigning the part, and buying by the build platform (6-10 parts per order), and improvements in the technology (especially multi-laser machines), I'm actually not too far from other ultra-high-end seatposts. Consider that ax-Lightness sells their 2200 post for €467 - over $600. Even without significant drops in DMLS pricing, I can already buy my design at under $500 (at quantities of 6), with almost no overhead or fixed costs, no tooling to amortize, etc... It seems to me that there's an opportunity there somewhere, but I'm probably something else? 

I completely agree that seatmast toppers aren't necessarily the best application of the technology - and moreover, my design is a pretty inefficient geometry to boot. I'm totally open to suggestions on this front - I'd love to test pricing on low mass/volume, high value consumer parts that aren't bicycle related! 

That's really the key for me: To produce consumer products via DMLS. I tend to think that it's an inevitability, given improvements in the technology and a bit of intelligent planning & design. It's totally possible that I'm wrong about that, though - and like I say, it's not as if my planning & design is fully fleshed out either :) 

I'd love to hear more of your thoughts, either here or via email (snwright@gmail). Thanks for the feedback! 

Spencer Wright

Teardown

After doing a bunch of price research on my Topper, I'm embarking on a near full-scale teardown. The reason is, as I noted earlier this week, that I'm not really taking advantage of the technology as much as I could be. My design requires a lot of support structures, and could also be a bit less massive. 

As a result, I'm pursuing a different approach. Early this week I spoke to Sia Mahdavi at Within Labs, and I'm hoping that his company will be able to guide me through this next step - converting what is essentially a hollow tube-like structure into a lattice form.

My first step was to strip my model back down to a primitive shape, which I did this evening. 

By removing a lot of the features I had in the model, I can give Sia and his engineers a clean starting point from which to reimagine the design. Ultimately I may end up reconfiguring the part more significantly (the saddle clamp mechanism is, in some ways, sub optimal) but for now I'm just excited to see what they come up with. Expect updates next week.

DMLS Pricing

Note: Updates on this project can be found here; or sign up for updates by email.

Over the past few weeks, I've collected a handful of quotes for the seatmast topper. All are for DMLS laser sintered titanium. I've had direct contact with 12 potential suppliers and received 9 quotes back. They range from $987 to $2377 for one finished part.

First: Although I posted the part on MFG - and they distributed it to 110 suppliers - I received *no* responses there. In fact, only 8 of those suppliers ever even saw the RFQ. I also posted the file to Elihuu, and later received a personal email from the founder. That RFQ hasn't been live for quite as long; I'm hopeful it develops into something. I also spoke with Jonathan Placa and ProtoExchange, who was able to source me a few competitive quotes.

Separately, I've tracked down DMLS leads around the internet & through personal connections. Both of these channels have been as fruitful as they usually are. My crash course in the economics and availability of DMLS parts has been quite fun, and want to share a few of my findings here. Some of these are obvious, but worth noting anyway.

The number of DMLS suppliers is small; even fewer are printing in titanium.

This became evident when the second shop I sent my files to replied that they had already seen them. Presumably this is because the first shop I contacted had some relationship with them - shared production, engineering, or some supplier/buyer relationship. The deeper I got, the more evident the small size of the industry became - as I asked more experts for the names of qualified job shops, I was often referred back to people I'd already spoken to. This kind of pattern is common in small industries - I had similar experiences when I was looking for inflatable pneumatic seals - but when it comes to larger/more mature industries (e.g. CNC, stamping, etc) there are generally more shops than one person could keep track of.

There are only a handful of machines that print DMLS titanium. 

The firms who were able to produce my part had one of three machines: EOS M280; Concept Laser M2; Renishaw AM250. A few other firms had an EOS M270, which prints only mar-aging steel (though it can be reconfigured to print a special blend of ti with different mechanical properties). All of these has a build volume roughly the size of a 10" cube.

The next generation of machines will be bigger and faster.

In particular, the EOS M400 is closer to a 12" cube and might reduce build times by as much as half (though one supplier seemed suspicious of that claim). It will be released Summer 2014, though, and likely won't be in wide use for a while after that.

Note: As multi-laser machines become available (the M400-4, a 4-laser machine, is scheduled for 2015), one would expect that cost would come down even more - especially as, I hope, more and more parts are being designed for this process.

Speed & build volume aren't everything.

The one supplier that suggested they'd be getting a M400 noted that even if it *does* reduce build times by half, that would still only reduce the cost of the build by something like 20%. Factors like handling time (this is *not* a hands-off process), material mass (titanium powder isn't cheap), and machine cost & maintenance will keep prices high for a while. 

Nobody seems to be making consumer products this way.

Most of these firms' clients are aerospace, manufacturing & biomedical companies. They're often buying up the whole build platform on a machine - running something like $30K - to print a huge part that would otherwise be made up of numerous (and expensive) smaller parts. Mold & die work is a decent part of the industry, where 3D printed internal cooling chambers on complex molds can decrease cycle time for a molded consumer product significantly. 

Excess Capacity isn't built into the current marketplace.

In traditional manufacturing, a significant portion of the cost of the part is fixturing and setup/teardown between different parts. Some advanced manufacturers (think Shapeways & i.materialise) are able to capitalize on 3D printing's lack of tooling, but most of the job shops I talked to aren't operating that way. Instead, they're performing builds per-order. In other words, they don't bundle multiple orders on one build plate - if I order one of my topper, they run a titanium build just for my part. That's hugely inefficient for small parts like mine, but because of the low volume of orders there's not much these shops can do about it. In a few cases, a supplier mentioned that they could set up standing orders for a part, and piggyback those orders into other clients' builds... But that sounded like a bit of a longshot - this particular supplier told me that it's often months between titanium builds.

The main way to decrease price is still to increase quantity.

Because most DMLS shops aren't bundling orders from multiple clients, each client is essentially paying for a bunch of unused build volume. The unused powder is recycled, of course, and the laser isn't running over unsintered parts of the build plate, but the setup/teardown time and material deposition runtime are still allocated to  your job. As a result, a part's price will decrease significantly - perhaps as much as half - by ordering in larger quantities (one supplier quoted me $569 apiece if I ordered in quantities of three, and $491 if I filled his plate with 6 parts).

This is a bit dismaying for single-piece-flow geeks, though I'm sure at some point in the near future it'll start to change. Shapeways, for instance, doesn't operate this way at all, and I expect that as job shops see more orders for DMLS parts, they'll largely follow suit.

The net effect is that the promise of advanced manufacturing - where you don't worry about tooling/setup/teardown costs, and small batch, JIT parts delivery becomes a reality - is still a bit off. 

However.

Consumer-ready DMLS parts are a good bet for a few reasons. First, the quotes I received aren't - if you just squint at them a little bit - all that bad. Sure, three parts at $600 apiece doesn't give me much margin if I'm selling them to consumers for $400, but that was never my intent. Plenty of high end seatposts retail for $300, and this part offers a few distinct features (lightweight; customizable geometry; "cool as shit;" etc.) that those can't.  And if the improved build times of this year's machines result in a price drop of 15%, and if the next two generations of machines - ones built with multiple high-power lasers - cut build times in half one or two times over... Well, all of the sudden I'm looking at a pretty affordable part - at least for high end customers, who tend to exhibit price-elastic spending habits. 

It's also the case that my topper's design doesn't utilize the technology as efficiently as possible. It's still largely a tube-to-tube structure, which just isn't the best use of additive manufacturing. In order to improve its strength:weight ratio and decrease cost, I'll be exploring lattice structures in the next week or two. My hope is that by working with Within Labs, I should be able to reduce cost by an additional 30%.

I've also been working on a few smaller parts. Because of the way most DMLS suppliers are operating, having a variety of differently sized items to fit on a build plate could increase the output of a build significantly without much effect on cost. 

A note on i.materialise.

Honestly, I was shocked at the price they quoted me ($617 per part). It was less than 2/3 the cost of the next lowest quote, which led me to suspect that their process was different in some way. I contacted their support team, who didn't go into specifics but did reply that their "machines are the same as for industrial projects but the approach and handling of the orders in different, which results in a different quality."

Moving Forward.

At the moment, I've got a basic proof of concept (SLA model) and pricing that puts me about 150% over budget. I'll be visiting at least one DMLS shop later this month, and will also be making big changes to the current design. I'd also like to explore the possibility of integrating additional components - saddle clamp parts or (my dream) a lightweight saddle frame - into the topper itself. The more parts I'm able to reduce with my design, the more I expect to close the price gap between DMLS and traditional manufacturing methods. 

Expect updates.

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Thanks to the following people for helping me get this far (in no particular order): Kane Hsieh, Jordan Husney, Clay Jones, Dorian Ferlauto, Scott Miller, Jen McCabe, Shane Collins, Robert Hassold, Duann Scott, Greg Irwin, Jonathan Placa, Siavash Mahdavi, Kaveh Mahdavi.

File conversion woes

This is why dimensioned PDF drawings are so extensively used in procurement. The top photo is from a supplier from MFG.com; the bottom one is the STEP that I originally uploaded to MFG.

This supplier has obviously downloaded my STEP and performed some translation or conversion on it, and in the process has deleted a few faces (you can see the difference in the foreground of the part, and in the areas he's highlighted in red). This is clearly an inexperienced supplier, and one that I would ultimately have a *really* hard time choosing. I'm not sure what he did or how he did it, but the fact that he made this mistake is an indicator that we'd have issues down the road.

(To his credit: the photo came from a message he wrote me saying that he "noticed some missing surfaces on the part file," and asking me to fix them. So he knew that there was a problem, but didn't understand what it was and wasn't able to troubleshoot it himself.)

In traditional manufacturing, 3D part files are created and edited in a program like Inventor or SolidWorks. The parts are then brought into a separate environment in the same application and drawn and annotated in multiple 2D views on a "paperspace." The resulting drawing file (.IDW for Inventor) is a dynamic representation of the original part; if you modify the part file, the drawing will update automatically. 

You *never* submit drawing files directly to a manufacturer. Instead, you export PDFs of the dimensioned drawings, and *optionally* include STEP files (which are essentially cross-platform 3D files) as a courtesy. The STEPs can be used to help the manufacturer set up their CNC machines, but they're for reference only; the PDFs (with all their dimensions and annotations) are what you're buying.

"Organic" shapes - like those that 3D printing is so well equipped to make - don't fit into this process well. Complex surfaces are *really* difficult to define clearly and completely in two dimensions, and so most 3D printed parts are built from solid files. In this case I submitted a STEP, which manufacturers will convert to an STL and then run through a slicer and feed into their machines.

The problem is that STEP files aren't immutable, and the supplier in this case has apparently deleted a feature from the part. In this case the result was obvious, but there are a lot of features that he could modify or delete that would be a lot more difficult for him to detect, and my QC job would be accordingly tricky.

This process should be better. The PDF workflow is inconvenient, but at least it's an effective barrier to issues like this one. 

Also, we need more, and more *good*, DMLS suppliers. 

The Public Radio assembly

A few days ago Zach and I assembled the lids on the newest version of The Public Radio. 

I had spent a bit of time thinking of how we'd streamline the process, and had purchased a round punch and some foam tape to make an adhesive backed spacer for the speaker. For production we'll get these die cut by a job shop, but for prototyping this worked very well.

I was trying out two different varieties of mounting screws for this version. In order to make the lid cost effective, I designed it with countersunk thru holes and am mounting the speaker from above. That meant finding screws that would bite into the plastic speaker body well, and I bought a selection of thread-forming screws for that purpose. They've got cute little torx heads which - if I spend a little more time organizing the speaker perforations - will look pretty nice on a stamped (as opposed to this SLA printed) stainless steel lids.

Overall, the assembly worked very well. Honestly I'd prefer to nix the screws, but that's impractical... it's possible that I would design the lids in two parts (like a clamshell) instead, so that the mounting hardware could be hidden from view.  We'll see :)

We should be receiving new PCBs on Monday, and will be assembling a few v1.1s ASAP. Expect updates.