I realized that I never posted photos of the most recent revision of my dummy headset. Here it is:
The major difference is that I removed a bit more material from the inner diameter of the part. The result is that it's lighter and less expensive to produce, while still holding a fork steerer gently & securely.
The updated version is on Shapeways - please check it out and send any feedback my way!
PS - it's also available in black :) With more colors to come!
After a couple of revisions, my 3D printed dummy headset is on Shapeways!
It still probably needs a few refinements, but I'm hoping to get a little feedback on it before I make them. I did try it out in my shop recently (NYCVelo also has a prototype), and I can confirm that it looks great and works damn well.
The headset is two parts. The top half has two 3.3mm holes "drilled" in it; they need to be tapped M4 in order to make the assembly really work well. I would recommend using brass tipped set screws for aluminum or steel steerers, and nylon tipped set screws for carbon fiber. You can also experiment with thumb screws or plain old socket cap screws if you like.
This may seem like an obscure part, but for anyone who has spent any time handling bike frames & forks, it'll come in *really* handy. If that sounds like you, grab one on Shapeways and let me know how it works!
This is *so* satisfying.
:)
This is modified a bit from last night. Fillets, window dimensions, and a few wall thicknesses are revised. Overall effect is that it's lighter and stronger.
Still more work to go, but it's getting there :)
Oh - and this simulation is 2000 Newtons - about 450 pounds-force.
Made a bunch of changes to the seatmast topper last night.
I ended up rebuilding the entire lofted body, which is basically the whole middle section of the part. Doing so allowed me to modify it down the line, which is really useful when building NURBS surfaces. After making the outside shape, I ended up needing to tweak it a lot to avoid collisions with later features. Accommodating these changes is hard to do, though - you kind of need to know what the part is going to look like before you start. It's a real chicken-and-egg problem. What usually ends up happening is that you don't do it right until you've rebuilt the whole model three or four times, which is about where I'm at here :)
It's hard to describe, but the upper section is hollow. I also spent a while trying to optimize around shared surfaces, so the window upper & lower walls coincide with features that I already needed on the part. The one thing I'm not particularly happy about is the seatmast clamp at the bottom of the part. The details are a little different, but overall it's designed the same way it would be if the part was welded. This part is going to be 3D printed, though, and I'd prefer to find a way to build the feature in a way that directly addresses its manufacturing method.
But overall, the part is definitely forward looking. I'll post a section view later, but for now just take my word that most of the middle of the part would be impossible to make by any other method than additive manufacturing. Also, right now the topper body (just the gold part, not including hardware) comes in at 74g, and I suspect that with a little work I can shave that even more :)
Stopped by NYCVelo today to get design review on a few parts I've been playing with. While there, I tried out the dropout protector I designed on a fork they had laying around. It was the first chance I've had to do so.
The fit is snug, just like it should be - it took a mallet to get the protector in place. There's no chance it's going move around during shipping, but with a little careful prodding I was able to get it back out just fine.
I also left one of my dummy headsets there for them to use on frames around the shop. Brett was pretty excited about it, and it was great to get some feedback on the execution and pricing. I'll probably redesign the part soon and get an injection molded part quoted. In the meantime, the dropout protector is for sale at Shapeways if you want to grab one (or a dozen!) for yourself :)
I like digital prototypes, but I also like physical prototypes. This arrived this morning and will go through another design rev with Clay in the next week or so. And then, at some point... titanium?
The downside here is, I'll eventually need to build a new bike with an integrated seat post :/
Short update on my Dummy Headset project!
First, I took v1 (the non-lightened version) and installed it on a frame I lad lying around. In order to do so, I had to tap threads into the holes that were SLA printed right into the parts, which I did by hand. Shapeways and the other 3D printing houses just won't do secondary operations (this is dumb and will in time change), but it only took a few minutes to do. For mockup purposes I used some cup point set screws that I had in my shop (the final version will have soft tipped set screws). The end result was pretty slick - my frameset now has the fork semi-permanently attached, and the whole thing is totally secure.
Of note: Here's a photo of the original dummy headset that I turned on my late circa 2010. I used little thumb screws on it, which were kind of convenient, but the overall look is too blocky for my eyes.
After mocking the whole thing up and seeing that it functioned as intended, I went ahead and ordered v2 of the parts, which are internally relieved to reduce build mass. They came a week or two ago, and I'm happy to say that I think they'll work just fine. The internal ribs probably aren't totally necessary, but they're kind of a cool feature and would be *impossible* to be made via conventional methods. I may end up removing most of them, but for this version I'm happy to have included them.
I also grabbed a few soft tipped set screws from McMaster, and am looking forward to seeing how they work. The nylon tipped one would be for carbon fiber steerers, which are pretty delicate and don't want a metal screw digging into them. The brass tipped screws would be for steel and aluminum steerers, which are much more durable.
I haven't had time to tap the holes in this version or install them on a frameset yet, but I have no reason to think they'll work anything other than perfectly. At that point I need to determine whether it's worth trying to get them injection molded or CNC machined in bulk. These SLA versions cost me about $20 for the set. If I had to guess, I'd say that they'd run $5-10/set for CNC machined and $2-3/set injection molded (in quantities of 100s, plus $2-3K in tooling and setup).
I spent a little while today optimizing my dummy headset for 3D printing. In subtractive manufacturing, cost can often be estimated by calculating the difference between the mass of the raw material and the mass of the finished object. The more material you need to remove, the more fabrication time and resources you'll consume producing the part, and hence the more expensive (generally) it will be.
The cost structure of 3D printing is totally different. With additive techniques, cost is a largely a function of the mass of the finished object (envelope size also has an effect in production settings, but it's less critical). The cost of a part comes down to how long it takes to make, and production time is limited by the amount of material the machine can spit out in a period of time.
As I noted the other day, my dummy headset is a bit more expensive than I'd like it to be. On the upside, though, I can remove material in a bunch of places! I took the revolved part in Inventor and made a series of revolved cuts on the ID of the part. I left some ribs along the ID to keep the perimeter somewhat intact, and left the areas right around the set screw holes thick.
I was able to shave a *lot* of mass off the parts - more than 45% on the lower part - which means significant cost savings.
I still need to make sure I'm on the right track on clearances in a few locations, but cutting the extra material out should make these parts much more feasible. Keep in mind, my total development cost at this point is probably 2.5 hours of labor and $40 in parts. Were I trying to get this product to market quickly (and who knows, I may try doing so) I could be live in both Shapeways' - and my own - webstore within two weeks.
I can't justify the cost on this, but with some small modifications I could print a lot of them before I hit the price of the molds I'd need to injection mold them.
Most framebuilders, and a lot of bike shops, will have a frameset (that's frame and fork, for the uninitiated) around the shop for some time before the headset is ready to be installed. Optimally, they're able to be kept together and protected - both from things around the shop and from each other - and the natural solution is to temporarily install the fork in the head tube. For a variety of reasons, though, you don't always want to install a headset just yet, and in those cases it's useful to have a dummy that approximates the size and shape of the headset that you're eventually going to use.
When I was building bikes, I made a batch of dummy headsets out of aluminum on my lathe. It was a fun project, but it took a while and the finished thing didn't look at all like the headsets (usually Chris King) that I was installing on the bikes when they were done. Moreover, a lot of small time builders either don't have access to a lathe or don't have the time/energy/gumption to build dummy headsets themselves.
So I spent an hour or two and modeled this one. It's a damn close copy to a King 1-1/8" NoThreadSet, but SLA printed. I included two holes in the top "cup" that I'll tap out and install set screws in. When the dummy is installed on the frameset, the set screws can be tightened down to keep the whole thing together. Because the dummy is plastic, it won't mar the frame, and because it's dimensionally accurate, it could be used to mock up the steering column for use in rack building, component setup, etc.
I need to make a few small changes to reduce printing mass, but in the meantime the design files for these parts are all in a GitHub repo. If I can find a way to get the cost down a bit, I'm hoping to put them up for sale for other folks to use; drop me a line if you're interested.
I think Nick Pinkston has it absolutely right: "3D printing is great, but it's only a small part of the solution." The current hardware revolution is about the workflow from development to manufacturing to distribution. Sure, I'm sure I'll have more and more 3D printed objects in my life in the next 5-10 years. But the effects of product customization (which will be significant) and kanban/just-in-time manufacturing (which I believe will be huge) will far outweigh the designer's ability to neglect draft angles when designing plastic parts. In the near future, I expect we'll be buying more stuff that hasn't been built yet than we have since the industrial revolution. In the next decade, I expect Amazon (or whomever) to be literally building the parts required to fulfill my order the night after I place the order. 3D printing will be a big part of this process, but so will distributed manufacturing and rapid delivery systems. And innovative ways of finding new products (and, on the flipside, innovative ways of finding new customers) will totally change the game.
I tend to recoil at most of the crap that's made with the current generation of FDM machines, but I've spent some time recently trying to think of objects in my life that I would accept being shat out of a MakerBot. A few traits I was looking for:
I'm sure there are better use cases, but one thing I came up with was dropout spacers. When shipping a bike, you usually remove the front wheel and install a dropout spacer into the fork. The spacer protects the dropouts from impact from below and also protects the fork from impacts from the side. Most consumers don't keep dropout spacers around, and wouldn't necessarily think to go to a bike shop to pick some up (most shops give them away) when they're shipping their bike. When the bike is unboxed on the other end, the spacers usually go straight to the trash, and surface finish is totally inconsequential. Plus, the spacer itself isn't very massive, and the dimensional accuracy required is low.
I spent an hour or two modeling, and got Shapeways to print me the result for $13. It's a bit more than I would want to pay for a piece of plastic, but the FDM version would be basically free. The finished version is shown below. I rather like it, and think that things like it will be printed - not in the home, probably, but by brick-and-mortar third party services like Kinkos, or web shopping platforms like Amazon and Shapeways - as a matter of course in the future.
If anyone is interested in printing one of their own, I'd encourage them to grab the model on the Thingiverse. I also published the model and a bunch of other stuff in a GitHub repository.
I often have the urge to cut-and-paste an email I've written onto a blog post. Ideas mull around in my head, and it's often the case that an email chain prompts me to finally compose the thoughts that I've been meaning to get down for months.
This morning, I had cause to write a message regarding the questions I have about 3D printing, and managed to nail down a few points that I've been working through recently.
Note: I would be remiss not to mention the sources of much of my thinking:
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As a hardware product manager, I've sourced 3D printed parts (SLA, mostly) on a few occasions in order to prove out basic functionality. As a prototyping tool, it's been very useful to me (notwithstanding the value that inexpensive CNC prototyping shops like rapidmachining.com offer). As a manufacturing technology, though, I'm a little less impressed with 3D printing, especially because the industry seems most interested in replacing inexpensive injection molded consumer products with their FDM analogs. As SLS/SLA models become more cost effective and - more importantly - easier to procure, I suspect that the cost-benefit will shift, and I'll begin to see more 3D printed objects in my personal life.
But the model for producing those parts is far from settled, and I'm most interested in how the big players (I figure that Shapeways, Kinkos, and Amazon are probably best situated) will integrate the entire manufacturing process:
In short, I'm interested not in 3D printing itself, but in a new paradigm for product development, manufacturing, and distribution. My work background is in traditional manufacturing, where information systems tend to be closed and resistant to change, and I'm particularly interested in hearing people's opinions about how, over what timescale, and by what means these tendencies are likely to change.
this evening, someone named Wen shi Di asked me to answer his question on Quora. i did, and i enjoyed doing so very much. my answer is reposted below.
It's true, the ability to create complex structures - negative draft angles, interlocking parts, voids, etc. - is much touted in the current press surrounding 3D printing. And for some physical product designers (jewelers come to mind), that ability is already having a significant impact on the creative range of printed product. 3D printing frees the designer from manufacturing constraints, and designers that are able to discard those shackles will likely see some creative benefit.
I see a few caveats to this, though, which dilute the net effect significantly.
1. I would question whether "unimaginative" cultures actually produce less creative content than liberal ones. For instance, the electronic music movement allowed for the democratization of music in many ways. Did that discourage the creative output of countries like Japan and Germany?
(It's worth noting here that I'm not even sure how to determine a consensus on which cultures discourage imagination or critical thinking. But compare the number of google results for "germany imaginative" (6.3M), "japan imaginative" (5.4M), and "america imaginative" (11.6M). Similarly: "germany creative" (289M); "japan creative" (310M); "america creative" (608M). Of course, "america" is a bit vague, but "USA imaginative" gets 7.7M and "USA creative" gets 458M, so I think it's safe to say that the English-speaking internet, as crawled by Google, thinks that the US is more creative and imaginative than Germany and Japan.)
2. It remains to be seen whether 3D printing becomes a large scale means of production unto itself, as opposed to a prototyping tool for injection-molded and machined parts. For most consumers, 3D printed objects aren't yet at the quality where they're desirable as home objects. Unless FDM machines improve part quality by an order of magnitude (let's be honest: fused deposition parts look and feel like crap), I doubt they'll ever produce objects that consumers want to be touching or seeing. Even SLA parts lack the strength and weight of most popular injection molded parts (n.b., this is all coming from someone who refuses to put even an injection molded plastic or CNCd aluminum case on his iPhone, so take my comments on user experience with a grain of salt). It's possible that SLS, if production costs can be reduced, could make consumer-ready product in the future, and who knows what other technology is nearby - or what the consumers of the future will regard as "consumer-ready." But as it stands, even the most creative designers are still largely constrained to designing for traditional manufacturing methods, if they want their designs to be produced and distributed with traditional supply channels and to a consumer base that's accustomed to the look and feel of traditionally manufactured parts.
3. Even if the designers in "unimaginative" cultures like Germany and Japan fail to fully utilize the creative freedom allowed by 3D printing, and even if 3D printing does transition into being a source of large numbers of consumer and industrial goods, that doesn't necessarily mean that Germany and Japan will be left at a disadvantage with regard to technology adoption. If SLA and SLS really do take off, there will be more than enough opportunity to go around. Every industry that deals with physical goods will be affected on a massive level, and the inability to think in terms of objects that are solid and have positive draft angles likely won't make a whit of a difference. Because regardless of how much the 3D printed jewelry of today resembles sea sponges, 3D printing needs to (and certainly will) be used for many more traditional uses for the technology to really take off.
