FROM STEEL: The Making of a Soulcraft from michael evans on Vimeo.

Filmmaker Michael John Evans sets out to visually portray “the zone” which one enters when their craft is honed. Sean Walling, owner of Soulcraft, builds top notch custom steel bicycle frames. This short film documents Sean’s fabrication methods: a well choreographed dance of experience and muscle memory producing a seemingly effortless ode to process. From Steel: invites the viewer into Sean’s machine shop for an up close and personal look at the work that results in yet another awesome Soulcraft.

• Uniform wall thickness
• Radii on the corners
• Sufficient draft
• Bosses
• Ribs
• Choice of parting lines
• And many more

Learning how to design a perfect injection molded part can take a long time and could require years of learning lessons the hard way. There are many books on the subject, but sometimes a great resource is the downstream vendors themselves. I’ve said it before, and I’ll say it again, it never hurts to work closely and early with vendors when designing custom parts. They’ll be designing the tooling and controlling the process parameters, so they can help you understand what works best.

ProtoMold is a rapid injection molder – they turn soft-tools and injection molded parts around quickly. To help designers make the most out of their services, they’ve provided a Design for Moldability reference with a few of the most fundamental concepts discussed. While their capabilities are slightly limited to provide such quick turn-around, their guidelines provide several sound ways to improve an injection molded part, resulting in less expensive tooling and a better performing component. (Registration required to view the document)

Disclaimer: Key Tech is not connected in any way with ProtoLabs or their affiliates and was not compensated in any way for pointing out this guide to you. We just like their work.

In this video, Atul starts off with an interesting explanation of how a skyscraper is built. In the old days of construction, a master builder was the central control with thorough knowledge about each detail of the building and responsibility for coordinating every operation.  Modern buildings have gotten so complex that it becomes impractical for a single person to attain that amount of knowledge.  Instead, today buildings are built by a team of skilled craftsmen; involved in up to 16 trades.  The project manager would rarely know much about any of the trades involved.  Atul asked the question, how is it that a group of specialists with a manager who isn’t an expert in any of these fields can build a complex structure and meet a very strict safe code.  It’s interesting to find out that the secret lies in two checklists, which are essential in the success of the construction business.  One checklist details every task that needs to be done in the short term for scheduling and coordination.  Another checklist involves the necessary parties required to communicate when problems arise.  Problems arise in construction just like in any other fields and the problems are always unexpected, otherwise, they wouldn’t be problems to start with.  The second checklist doesn’t try to make cookie-cutter solutions, but simply makes sure that the appropriate parties are involved when problems arise.  As a result, dynamic group decisions can be obtained for each problem based on inputs from all shareholders.

Atul further goes on to talk about the “Miracle on the Hudson” an emergency landing made by US Airways Flight 1549 last January.  He argued that the real miracle in this case was the entire crew acted as one and followed procedures (another word for checklists) in this situation.  Sure, luck was on their side, but by following procedures and going through the checklists designed for such situations, the crew ensured the best survival chances.

Atul finally went on to discuss his experience of implementing a checklist in the OR at 8 different hospitals around the world.  The result is significant.  By following a simple 19-step list, some steps being as simple as introducing surgeons and nurses, teams who followed the checklist was able to reduce complications by 30% overall.

Come to think about it, it made intuitive sense.  A checklist enforces the user to be regimented and diligent about the process and thus, has the effect of minimizing human errors when these regiments are implemented.  Another example that I can think of where a checklist is vital is during space shuttle launches.  I’m sure everyone has heard those familiar announcements such as “T minus 10: heater control exit; T minus 9: pressurize first tank; … T minus 0: blastoff”.  What NASA does is follow a monster checklist to ensure that every aspect of a shuttle launch has been checked.  If the rocket scientists think checklist is worth using, Atul might be onto something here.

The video is a bit long (74 minutes), but I’d recommend it since it provides food for thought.  Have you read the Checklist Manifesto?  Do you agree with Atul?  What other scenarios do you recognize that benefit from using a checklist?

The Scale

We chose an Acculab 210.4 scale because it was accurate enough (.0001 gram resolution, which is about a tenth of a microliter for room temperature water) and because it has a serial interface that we can call from Visual Basic to easily collect data and put into a spreadsheet. The data stream is limited to about 8Hz, but it was fast enough for our purposes.

Scales with more resolution often come with damping mechanisms to keep them stable. Although the glass cover keeps the air movement down, this one didn’t have a means to damp vibrations, so we needed to isolate the scale ourselves. We used a small table with some rubber feet as the foundation. Then we used one of those heavy engineering textbooks we have so many of on some thick foam and put the scale on top. Considerate use of flexible beams, soft materials, and masses meant the scale was rock-steady without any software averaging required.

The Fluid Connection

To get the fluid onto the scale, we attached tubing with a luer-lock fitting to a long needle inserted into the scale cover through a hole in the top plate and held in place with a thumb-screw. By using a needle instead of just inserting the tubing into the container, we eliminated any contact with the container or scale. we found that any such contact threw the scale out of whack, especially when the fluid flowed through the tubing with momentum.

The question came up as to whether the needle should be above the water-level or below it. If the needle is below the water-level, surface tension on the needle can reduce the weight of the water. However, if the needle is above the water-level, a drop can form at the tip instead of depositing the small volume onto the scale. We needed fine-resolution flow-rate data, so we opted to ignore the surface tension, which we found to be below the resolution of the scale.

Evaporation of the Water

Over the duration of a test, water will evaporate. The rate is dependent upon temperature, relative humidity, and the surface area of the container. Many suggest adding mineral oil to the water to create a barrier layer to supposedly eliminate evaporation of the water. Data showed that the oil layer did reduce the rate of evaporation (from 0.13 g/hr to 0.08 g/hr), although the oil ruined the plastic connections of the tubing by making them brittle and causing them to leak and break. Instead, we drilled a 1/4” hole into the cap of the container for the needle to fit through, which dropped the rate of evaporation by two orders of magnitude. We collected data for various configurations of the water, oil, and lid and plotted them below. So, without using any oil, we were able to drop the rate of evaporation from 0.127 g/hr to 0.002 g/hr.

Volume and Flow Rate

So, how does a measure of weight relate to volume and flow-rate? Well, the density of water is pretty well defined based on temperature (and weight / density = volume). Accounting for the error of this density value, as well as errors in the scale resolution and time resolution provided excellent measurement results by which to evaluate the devices.

When progress slows or I’ve hit a roadblock, it can be frustrating. Maybe I overlooked something critical or my assumptions were wrong. Maybe my prototype is based on a component that just ran out of stock. Whatever the case, when I need some fresh ideas, it’s time for a distraction.

Ideas rarely occur to me when I’m straining to think of them. Instead, they pop into my head when I’m doing something else. I might be driving my car, taking a walk, or reading my kids a story. It’s not always an “Ah, HAH!” moment, but it’s often worth remembering.

But, I’m supposed to be working. I need an idea now! I can’t think of anything! THINK HARDER!

Relax. I can’t force an epiphany. Can I encourage it? When I get stuck on something, one of the best ways for me to get unstuck is to change my environment. I “unplug” – walk away from the computer and iPhone. I get some ice-cream from the market or walk to Federal Hill Park and listen to the leaves blow in the wind. In the quiet, my mind, usually struggling to keep up with my Inbox, Voicemail, and cell phone, starts to race with ideas. I’m flooded with new possibilities.

But, wait. Isn’t that the exact opposite of “making progress” or “working”? Perfect.

Key Tech outsources for prototype components and then assembles, details, and tests in-house. Prototyping capabilities are full service, including SLA, SLS, thermoforming, urethane, epoxy and silicone casting, polyjet, CNC machined parts, full electrical prototyping including microprocessor selection (in-house), board design (in-house), population and testing, user interface screen mock-ups with display software, and more.

Read more about the symbiosis of modeling and prototyping (PDF) for designing microscale parts in an article I wrote that was published in MICROmanufacturing Magazine this month, page 33 (Jan/Feb 2010, Volume 3, Issue 1).

• How can this be cleaned?
• Is it going to be dropped?
• What if someone sticks a finger in here?

As an engineer, it’s a good skill to have. But, is asking the right questions something that can be taught, or do you have to be born with this twisted skill?

If you’ve spent any time around young kids, you know that asking questions comes naturally. At that stage, “Why?” is one of the most common words in our vocabulary. We’re born with so many questions, and every answer simply creates more questions.

At some point, though, we have to refine this line of questioning, if only to get to sleep. Experience and intuition can help determine which answers are productive and which are just interesting. Draw the line. Give users some amount of responsibility, some amount of credit to their intelligence, and create some limit to the amount of abuse a product can take. Otherwise, the next handheld medical device will have a steel shell, cost ten times as much as it should, and take twice as long to get out the door.

Photo credit: arte_ram

Thanks to Jessica Hagy at Indexed for inspiring the format. Some ideas are just better depicted graphically.

You’d probably like to hear that Key Tech has already built a product just like yours, but if that were true, you might not end up with much competitive advantage in the marketplace. Instead, we go to great lengths to hire and retain talented engineers who seek out new challenges. Our idea of fun is the process of designing something new and solving the unique challenges that arise along the way. Our portfolio includes numerous medical and industrial electro-mechanical devices that incorporate complex technologies such as shape memory alloys, microfluidics, and acoustic ultrasound. We are constantly leveraging our problem solving and product development experience to help you meet your goals, and we really hope you’ll challenge us along the way.

Key Tech is fortunate to be a busy company, even in the current economic downturn.  We remain focused on finding engagements and relationships where we can bring value and have a real impact.  We will be very straightforward with you regarding which engagements are a good fit for us, and we won’t waste your time with those that aren’t.