Manufacturing guy-at-large.

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Manufacturing agnosticity

Added on by Spencer Wright.

I came across an interesting quote yesterday in the Wikipedia page for Geometric Dimensioning & Tolerancing (GD&T):

Descriptions of manufacturing methods should be avoided. The geometry should be described without explicitly defining the method of manufacture.

In context, this makes sense. GD&T has the purpose of making a part that fits the intended purpose, and in an ideal world, manufacturing methods are largely irrelevant to that process. But in the conventional design-manufacture cycle, I think this sets up a poor incentive structure, and hinders communication of key information.

It would be my hope that design tools evolve such that intent can be executed directly. But as it stands now, designers are still largely designing features. The result is that manufactured products carry high setup and switching costs, and often require multiple sample iterations in order to get right.

I admire the intent in the quote above (which, it should be noted, seems not to have been taken directly from the ASME standard), but I think it's a bit optimistic. Until we figure out a new way of incorporating intent directly into design, methods of manufacturing will be highly useful in design data transfer. 

3D printing & Material specifications

Added on by Spencer Wright.

I've been working on a few product ideas that would be 3D printed from titanium or stainless steel, and the methods by which 3D printed parts are specified has been on my mind throughout the process. The following passage, taken from the IDA Science and Technology Policy Institute's 2012 report "Additive Manufacturing: Status and Opportunities" sums up my feelings quite nicely. Note: "AM" refers to "additive manufacturing, which is a slight superset to the processes casually described as "3D printing." Emphasis is mine.

AM technology has made significant strides over the past 25 years, but technical challenges related to materials, equipment, and applications remain. Many of the challenges described in this section, which have commonly been discussed in workshops or publications, are the focus of ongoing research in government agencies or industrial organizations. In some cases, the topics may be underfunded by the private sector and could benefit from new or additional Small Business Innovative Research funding. 
Information is needed on material properties for different processes, but who would maintain such a database and which data should be publicly available are unclear. Before the AM industry can fully transition to offering viable manufacturing solutions, specifications are needed that provide mechanical properties data for available materials, as well as more detail on how parts made from these materials perform (Campbell et al. 2011). Engineers and designers cannot design without fully understanding the properties of the materials used to manufacture the parts being designed. If the properties for AM materials are not available, designers will not consider additive manufacturing as a method of manufacturing. With so many AM processes and materials currently available, the creation of comprehensive specifications is a resource-intensive endeavor, requiring the involvement of research organizations and system and material manufacturers (Kinsella 2011). 

Worth noting: despite knowing the difference between yield strength and ultimate tensile strength, I am not an engineer. But having access to full material data - as well as data on how parts made of that material perform - would be incredibly useful, even to a dullard like me.

Feature Requirements: Parts Storage System

Added on by Spencer Wright.

Parts storage has been a key aspect of my product development career, and has consistently frustrated me. A few reasons for my ire:

  • Parts cabinets are expensive. I probably spent $200 on my cabinets, which were mostly used; at my last employer, we spent over $2K on "standard duty" parts drawers, shown here, from McMaster-Carr.
  • Traditional parts organizers are time consuming to organize, and often aren't formatted to hold the size and quantity of parts you need to store.
  • Most management systems don't allow for reorganization without significant amounts of work.
  • Every organization & labeling system I'm aware of is disconnected from the part specs that I usually want to have on-hand when making a selection from physical inventory.
  • Keeping a digital catalog of parts inventory on-hand is time consuming, difficult, and totally disconnected from the location and quantity of the parts themselves. 

In order for the full implications of digital product development, manufacturing and distribution to come to pass, I believe that industry will need to completely rethink how it addresses, organizes, processes and tracks parts inventory. I have a few ideas of what this will look like, but I'd like for now to focus on the requirements for such a system. 

  • Parts should be uniquely addressable. For many of my applications, McMaster-Carr, DigiKey, Sparkfun, and Amazon product numbers would be fine. Ultimately a system like IP would probably be preferable, if only to apply uniformity and allow manufacturers and distributors of all flavors to buy into a single standard. At some point, I wonder about the possibility of addressing not only each brand/make/spec of bolt, resistor, or chip - but also addressing each physical instance of each of those categories. With the enormous addressing capacity of IPv6, this is well within the realm of possibility - we simply need to find an appropriate tracking mechanism. (Side note: IPv6 has an addressing capacity of about 3.4*10^38. In comparison, there are estimated to be on the order of 7.5*10^18 grains of sand on all the beaches in the world. That's a ratio of 4.5*10^19 : 1, in favor of IPv6 addresses.)
  • Physical organization shouldn't need to be hierarchical. Hierarchical systems work fine on dynamic interfaces (e.g. on the web, where they're used in conjunction with tagging and search features), but parts organization is subject to so many other forces - not the least of which is the size and quantity of a given type of item. For example: if the bolts I have on hand vary in length from 5mm to 50mm, finding a single drawer to accommodate all of them will be difficult. Much better to allow locational organization to be loose, and instead encourage browsing through a database. Put a different way: I don't see the need to institute a browsable Dewey Decimal system on my parts; I'll just search for them on my computer, and it'll tell me where I should look.
  • Parts on hand should be treated as a subset of parts in the world. When I'm designing a new assembly and searching for a bolt to use in it, I want to access a single interface that will allow me to search either globally (the entire catalog of uniquely addressable parts in the world), from a single manufacturer/distributor, or only from my in-stock catalog. On the other hand, when I'm physically looking at a particular item in my inventory, I should have easy access to the product specs for replacement parts and compatible mating parts. 
  • Inventory should be tracked in real time. When I remove parts from physical inventory, my database of stocked components should be updated immediately. As sensor technology evolves, it is my hope that this will be possible with minimal user interaction (e.g. via the use of pressure, proximity, or chemical presence sensors within the parts cabinet). In the meantime, the parts cabinet itself (or at the very least a nearby iPad running dedicated software) should offer me the ability to quickly update quantity on hand.
  • Complete part data should be available at the part's physical location. If I'm browsing for a bolt, I should be able to have access to all available part data for that bolt - including specifications, tolerances, 3D models, compatible mates, replacements - right at the parts cabinet. For now, this could be achievable by some user gesture at the parts cabinet (e.g. pressing a tactile switch at the individual part compartment) pushing a notification to a nearby iPad. As interaction hardware evolves, I would hope that this would happen within the parts organizer itself, through the use of haptic/gestural info (picking a part out of a bin) and integrated displays.
  • My purchasing system should know what parts I have on hand. When I order parts, it's almost exclusively through webstores. When I hit the "confirm your order" page, I want my inventory tracking software to scan for similar parts in my database and alert me if I've got anything in stock that would work for what I'm doing. If I'm ordering M4x12 button head cap screws and I have M4x12 socket head cap screws in stock, it's possible that I could save time, money, and inventory space by redesigning my assembly to accept what I have in stock. Conversely: When I place an order, my inventory system should know about it and prepare my parts organizer to accept new inventory.
  • Everything should have a 3D model. This is a bit of a pet peeve of mine. It blows my mind that many PCBs are designed without a digital visual check for interferences, and the situation is even crazier when you consider integrating PCBs into mechanical assemblies. I've spent a lot of time modeling off-the-shelf components for my own use, and have begun posting them on GrabCAD  for others to use. It's my hope that this type of thing catches on, and that manufacturers find ways to support/help the effort.
  • No paper. My previous parts organizers relied heavily on sticky notes and Sharpies, as I suspect most contemporary systems do. This is absurd. What happens when you run through stock of a particular part, and decide not to reorder? Well, you spend ten minutes scraping a crusty old label off of the bin, or taping over it with a new one. Adhesives fail over time, and pen-and-paper just isn't modular enough for the rapid changes in direction that modern product development shops go through. My bins should be unlabeled. Instead, I'll identify parts by comparing them to their 3D models (viewable in my parts organizer's interactive display), or - better  yet - by my parts organizer knowing what I'm doing (through whatever gestural interaction it uses) and telling me what I'm looking at.

What I've described here is huge, but not that conceptually complex. It also has the capacity to be expanded recursively, to apply to all kinds of physical and digital objects. A cohesive, consistent system for tracking and managing parts will allow for improvements in innovation and distribution techniques to reach their full potential. And I worry that without such a system, the benefits of rapid prototyping, just-in-time manufacturing, and distributed, adaptive supply chains will be highly constrained.

GitHub for 3D Design

Added on by Spencer Wright.

In the past, I've used Autodesk Vault for version tracking & backup of 3D design files. I was using Inventor for work at the time, and was a part of a group that sometimes (though not often) shared files. It was useful but totally inconvenient, and I'm happy to now be setting up GitHub for my own 3D design file sharing, version control & backup. 

Not being fluent with GitHub in the past, I'm still a little hazy on the terminology and process. Over the past few months, I've cobbled together a system or organizing 3D part and assembly files from SolidWorks and Inventor. For some reason, I set up separate folders  (named "SolidWorks" and "Inventor") in the "Documents" folder of my hard drive. Inside each of those folders is a bunch of separate project folders. When I create a new project, I choose a two-letter shorthand for the project; the project folders have been named, e.g., "CS Cycles Parts". Inside is a bunch of part and assembly files, and usually a subfolder called "Static Exports" which contains STLs, STPs, PDFs and JPEGs.

I'm doing this all from Windows 7 on Boot Camp, so I downloaded the Windows GitHub client and got started. First, I tried creating a new repository on the GitHub web interface and then adding existing files to it, but I couldn't for the life of me figure out the dialog. Then I realized that I could drag and drop a directory from my hard drive into the desktop GitHub client, but for some reason it kept wanting to reassign the repository to .../Documents/GitHub/. Also, it complained about special characters, so I removed all the spaces from my directory names and replaced them with underscores.

Finally I just created new repositories in the desktop client, but named them the same as the existing project directories. GitHub kept wanting me to put them in the /Documents/GitHub directory, but this time I could change the location to be /Documents/Inventor/ - the parent of the existing repository directory that I was trying to set up. 

My first commits all just had titles like "First Posting," and I published the commits immediately. To my immense pleasure, I'm now able to see the contents of those directories in GitHub, and a bunch of the files in the "Static Exports" directories display in Git's STL viewer within the browser

I'll be interested in seeing how GitHub fits into my design workflow. For now it's - at the very least - a great backup system. I hope it becomes a collaborative tool for me in the near future. 

If anyone has tips for how to use GitHub to host design projects, I'd love to hear them. 

3D Printing: One part of a New Paradigm

Added on by Spencer Wright.

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: 

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 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: 

  • Design (cf. Quirky; the current proliferation of hardware crowdfunding & acceleration programs)
  • 3D printing (SLA/SLS, and *limited* FDM) 
  • Secondary operations (namely drilling/tapping)
  • Assembly (monolithic consumer objects are boring; it'll only be once 3D printing is integrated with fasteners, wiring, electronics, etc. that it becomes really interesting)
  • Distribution (ten days to ship a Shapeways model just isn't sustainable)

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.