More is Better?

Posted on January 13, 2021 by george

When you are choosing materials to create a chiller block- more heat conductivity is better. Beryllium copper has 5 times the heat conductivity of H13. Fast freezing of the aluminum creates the crumbly shut off that makes chill vents work. Somewhat messy as the leading crumbs fill the casting machine pit. When choosing the main insert material, more heat conductivity may not be better. Most customers do not wish to buy crumbly parts. Otherwise we would make all of the inserts out of beryllium copper. Fortunately H13 has poor conductivity. It makes it possible to get the molten metal to the far side of the mold before it freezes. Interestingly a thermocouple drilled into a H13 insert to 6mm from molten metal does not rise in temperature until almost one full cycle time has elapsed.

A few proponents of conformal cooling have chosen to over simplify. A die does not run faster simply because more is better. Quickly making good quality parts occurs when proper choices are made. In a 390 alloy (740C cast temp) valve body heat is a problem. An Anviloy ( 3 times the conductivity of H13) roto pocket sub insert proved to be more effective than a conformal cooling sub insert. ( Having tried both) The scale in the water passages of the Anviloy sub insert could be drilled out each run such that the casting quality did not deteriorate with die age.

However I believe more is better when it comes to the Nanaimo bars that my Canadian wife makes for me. I can even put up with the fact that they crumble.

Take Off

Posted on November 19, 2016 by george

plane -waiting for take off

Every time I visit an airport I marvel that it is possible to lift 100 tons of metal into the air. As an engineer I also know that in most cases the engines are operated during take off at 110% of the power output that they can deliver on a continuous basis. This extra power is needed to accelerate the plane to flying speed in a reasonable runway length. When I fly it is comforting to know that this is not the first time that the plane successfully managed a take off. I am also not surprised that flegling aircraft are tested on much longer runways so that the pilot can choose to abort and try again if the indicators are not favorable.
The same approach is used to get a business to take off. Yes, it is going to take much more effort to get it started than will be expended keeping it going. As “The Lean Start-up” teaches us, we will need to abort some take off attempts and pivot to new strategies. This is why venture capitalist describe the cash flow of a start-up business using a J Curve. Most successful start-up companies will require input capital to fund these aborted take off attempts

Private Equity Start-up J-Curve graph
by URBANRENEWAL

Even though the concepts taught in “The Lean Start-up” were honed in the software community they have relevance within the manufacturing community. In manufacturing it is less possible to obtain the same rapid customer input and testing that is enjoyed by software creators. Just because it might not be possible to evolve as fast, improving time to market has major benefits. The advent of tools like 3D printing and computerized finite element testing have made it possible to substantially shorten the time to pivot to more acceptable customer offerings. Historically the 3D CAD designers could work at a leisurely pace because they were faster than the down stream tooling builders. In the emerging new economy the leaders have discovered that they can get a jump on their competition by putting the systems in place to accelerate the creation of 3D CAD definition.

Dot to Dot

Posted on October 16, 2016 by george

We all learned to create
pictures by connecting the dots.

A simple child’s task like connecting the dots matches a computer’s capability. This was especially true in the early days when computer numeric controls had a lot less intelligence. It was a stretch for the computer to perform a simple 2 dimensional connect the dot task. Even todays CNC (Computer Numerical Control) is based on connecting dots with straight lines.
We began the computer controlled manufacturing revolution by using simple 2 dimensional dot to dot. In the very beginning there were long distances between the dots. The parts that were CNC manufactured had facets like you see on diamonds. As Moore’s law has given us more computer memory and horsepower we use ever greater numbers of dots to the point where the facets caused by straight line connecting of the dots are perceived as a smooth blend. A simple 2 dimensional approximation of a circle using a ring of dots connected by straight lines has evolved into a the chain of connected dots that has lengthened to stretch many miles.

A string of connected dots, many miles in length guides the path of a cutter used to make a mold

As we acquired more computer horsepower we wanted to expand into three dimensional objects. We again looked for the simplest way. A straight line connecting two dots was evolved into a set of three dots connected by straight lines defining a plane in three dimensions. Computer defined three dimensional objects look a lot like geodesic domes

Tyranny of numbers came to get us. Whereas we were able to manually program CNC machining G-code and moon landings by creating the travel path dot by dot, it simply was not humanly possible to define all of the little triangles needed to define an object shape. The STL (STereoLithography) data format we created for the task actually is capable of defining just about any shape that we can conceive. It was the early 90’s before any version of CAM (Computer Aided Manufacturing) software could generate a complete enough STL shape definition to be commercially useful. It was the turn of the century before any CAD (Computer Aided Drafting) software caught up to the same level. The underlying issue is that most of the part shapes that we use are not pure cubes,cylinders or spheres. In the classic example, three different radii meet at a corner. What is the shape at the corner? Turns out the computer does not know either.

The historic solution to the three different radii meeting at corner, was to instruct the pattern maker to do a blend. The digital solution started out in a very similar fashion. The STL file was manually adjusted by a person. This time consuming and costly step is one of the impediments slowing the adoption of 3D printing. The incredibly slow 3D printing speed is fast compared to the time need to clean a STL data file triangle by triangle. Moore’s Law keeps advancing. Each generation of software and 3D printing hardware opens the door for new affordable uses. Even though 3D printing theoretically has the ability to create any shape, in the near term it will have economically imposed shape limitations like any other manufacturing process

Lights Out Manufactuing

Posted on June 10, 2016 by george

It is hard to imagine a life before we used electric lights

The introduction of bright plant lights made 3 shift operations possible. Sufficiently bright lighting is interpreted by the workers internal clocks as sunlight. In most 24 hour settings it is important that the off shift workers are alert and attentive. This is only possible if their internal systems think that it is time to be awake. You would not want everyone to be asleep if you arrive at the hospital emergency room at 3:00 am.
Times when we are without lights turn into events in our lives. I can still remember one evening when we were having a boxed murder mystery party with friends. In the middle of the game our house lights went out. This looked suspicious because of a lack of bad weather and the neighbors houses with lights on that were visible through our windows. ” OK, How did you do it?” My friends know that I am an engineer.

Even though I was the murderer in our game, the loss of lights was the local utility company transformer giving up the ghost.
Lights out manufacturing is one of those “overnight” revolutions that have been in the works for more than 20 years. In the 90’s there were very few pieces of manufacturing equipment that you could trust to run overnight unattended. Electrical Discharge Machining (EDM) was one of the first manufacturing processes to be used in a lights out fashion. Yes, we did need to add automatic halon fire extinguishers just in case.

The highest precision manufacturing processes like EDM occur at slow speeds

This process is heavily used in mold making. It was a natural for unattended operation because some of the cuts can take days to accomplish. Many mold shops run their expensive EDM machines unattended overnight and over the weekend.
Lights out manufacturing has emerged from the bowels of tool and die manufacturing. A couple factors are responsible because implementing lights out manufacturing is not as simple as running over to the electrical breaker panel and snapping off the lights. ( Usually chaos ensues when the lights fail while people are working.) First our control systems are more reliable. Second, we can include more sensors to handle adjustment or shutdown if we are not present. Third we have adopted more slow speed manufacturing processes like 3D printing which take long periods to accomplish.

Photo courtesy of i.materialize.com

A good modern example of lights out manufacturing is the Amazon (Kiva) robots that happily operate in a dark warehouse because they are part of a system that was initially set up to operate in that fashion. Welding robots are another good example because they have the sophisitcated controls the enable then to run unattended. Welding robots can finish the job they are on after everyone goes home because of proper engineering design.

Sophisticated computer controls allow welding robots to run unattended

Laser and water jet cutting machines for sheet material can operate in a lights out manufacturing environment. The usually means that the jobs are packaged into full sheet set-ups so that sufficient time is gained by finishing jobs after everyone goes home.
We all remember the fairy tales of our youth where the elves came and did our work while we slept. It is more than a fairy tale. I still find it amazing seeing the progress that occurred while I slept when I arrive at work in the morning. Manufacturing will come back to North America. Some of it will come back as lights off manufacturing. Innovators in the manufacturing space have discovered that it is necessary to implement the latest manufacturing techniques and equipment to make a profit at an attractive selling price.

Virtual

Posted on August 21, 2015 by george

William Shatner and Julie Newmar of Star Trek by NBC television

Being a Star Trek fan, I remember the original episode that incorporated film footage from the first pilot. In that pilot, the Star Trek team encounter an advanced race that inserted illusion into their minds with such precision that it replaced reality. The stuff of science fiction except for the fact that we are beginning to have that technology. Google with others have invested a billion dollars or so into a Florida Start-up named Magic Leap. They are in a technology category called augmented reality but they like to call it “cinematic reality”. Unlike some of the other virtual reality technologies. their method of projecting light directly at the eye is a lot less likely to make you sea sick. The images that it creates are so convincing that you think that your hand is the illusion when you try to touch the projected images. Before you dismiss this technology as a video game, be aware that there are commercial uses for a technology that can display activity beyond the vision of your eyes.

Full flight simulator by
Super Jet International (uploaded by russavia)

The next time you are flying, it will be comforting to know that the potentially new pilot flying the plane is not using this flight as a training tool to hone his ability to land the aircraft under all kinds of adverse conditions. Modern virtual reality in the form of flight simulators allows pilots to practice landing at many of the airports of the world. We are happy to know that the pilot flying the plane has practiced landing enough times to react instinctively to the turbulence around him. Other things, we would like to “see”, are hidden inside opaque objects, occur too fast or slow, are not our scale, lack contrast, or have other mismatches. In the molding industry the filling process is occurring inside an opaque mold at extremely high speed. As we adjust the shapes to improve the part quality it is helpful to have a virtual testing tool to guide our efforts. This technology reduces the amount of expensive trial and error mold changes needed to achieve a commercial yield from the mold.

Mold fill simulation software of the “brain” of a Ford Transmission by Magmasoft

In the emerging mass customization era, we do enough part set-ups that we can no longer afford to tie up the production equipment to train the robots. The availability of 3D models for the parts and equipment makes offline pre-programming of the robot path commonplace. This matches the Japanese SMED (Single Minute Exchange of Die) strategy invented by Segeo Shingo. Job shops who employ welding robots are the heaviest early adopters of this virtual technology. It is easy to more than double the through-put of a robot welding cell when you can minimize the time that it is not burning
the arc

Robot motions can be taught remotely

Display

Posted on July 17, 2015 by george

In the future hologram
displays will be commonplace

Indicator lights- The earliest computers borrowed from the machine control heritage and
included lots of indicator lights. These lights were mostly used to determine which vacuum tube had burned out and needed to be replaced. We are all familiar with the usefulness of indicator lights. The message displayed by these lights has become more sophisticated as we can afford more computing horsepower to embed decision logic behind the light

Indicator lights have been at the backbone of computers from the beginning
Univac Buffer by Travellerva
US Robotics Modem by Bortzmeyer

WYSIWYG- What you see is what you get- The first thing that you notice when you pick up a robot teach pendant is that there is no display screen. Once you are actually controlling the robot, there is no need to substitute a virtual display. Shigeo Shingo (Japanese manufacturing methods pioneer) would approve of the software that does use a screen display that allows preprogramming of robot tasks ahead of time without consuming robot operating time. Based on my experience, I can assure you that most pre-programmed routines will require touch up where the robot itself is the display.

The robot itself displays the command inputs

UX- user experience- Speedometers started as mechanical devices run by a rotating cable connecting to the drive shaft. A digital display was implemented when the dash was computerized. The automotive engineers wanted to advertise this conversion by creating a dash panel display that showed the speed as a digital number. This style of display was disliked by the buying public and a simulated bar style analog speed display emerged as the user preferred choice. Not every car design group has learned to utilize UX. You can make your own decision as to the sum of factors that resulted in the Fiat 500 flop in the marketplace. The digital speedometer shown is just one candidate. A joke applies. Two hikers in the woods hear a bear behind them. One opens his pack and puts on his tennis shoes. The other tells him “You can’t outrun a bear” He replies “I don’t have to. I only need to out run you” In true world class competitive fashion the pendulum will swing such that different auto manufacturers are the ones struggling to keep up. I remember when Lee Iacocca brought European front wheel drive back to America after test driving some Fiats.

Fiat 500X Speedometer
by Karlis Dambrans

Trends – The embedded computers can inform you with 100% certainty that your car is having a problem when you are stranded at the side of the road. Not very helpful. Those of us who spent a chunk of our lives inventing the advance warning systems, wanted to have the voice reminder system say “I told you so” when the car stopped because the user ignored the warnings we created. Not very helpful either. Our ability to predict impending failure is the combination of big data analysis of all 200,000,000 cars that have on board diagnostics and the ability to watch data trends within the ¼ petabyte of data each car generates in real time. At the other end of the big data spectrum is a one-of-a-kind control like I just finished installing. As a one-of-a-kind there is not a pool of experience to predict failures. However, this does not stop us from displaying the trends in graphic overlay format to maximize the visibility of impending issues. This allows the user to simultaneously digest data that would occupy many table pages.

The best HMI displays like the Visi-trak shown can overlay process data in real time

Context- Before we had modern CAD and Virtual reality, it was necessary to use sketches to communicate concepts. Having a better than average sketching ability, I occasionally got into trouble because I could make something that was impossible look like it would work. Many of the displays we use come to us from the game industry. Even though 3D CAD enables the average person to visualize the detail parts that we draw they lack the context of what they are used for. This is especially true for novel approaches. I use Carrara which is a video game software to combine my 3D equipment models with the surroundings so that it becomes possible to explain how they work.

Video game creation software can combine
3D model with a background to show context

Emerging displays. We are watching the evolution of even more powerful displays. Remote piloting of drones is even easier when the pilot has the same visual input as an on board pilot. This silicon valley driven technology will grow to even wider use when some of the flicker and headache causing instablity has been overcome by even more computing horsepower.

3D virtual reality glasses are an emerging display form.

Kludge

Posted on July 4, 2015 by george

Treasure is camouflaged in the digital jungle

kludge
[klooj]
noun – Computer Slang
1. a software or hardware configuration that, while inelegant, inefficient, clumsy, or patched together, succeeds in solving a specific problem or performing a particular task.

*definition from Dictionary.com

Whoever came up with this term must have been assigned to marry legacy IoT (Internet of Things) digital controls. Lots of ones and zeros show on the logic analyzer, with obscure or forgotten protocols for interpreting what they mean. In the arms race to stay ahead of the newest start-up, many of the companies who built the previous generation equipment with embedded internet communication no longer exist. However, even the first internet connected device is still a part of our IoT infrastructure. At the blinding communication speed of two bits per week, the transmitter shuts off the water feed pump every Sunday when the water tower is full.

We take running water out of our taps for granted

I used to worry about terrorists gaining control of our infrastructure using the internet. It is theoretically possible to inflict some serious damage and injury. My concern was based on the fact that early IoT devices have very little access protection. Now that I have integrated some legacy systems I realize the lack of standardization will be our saving grace. It is next to impossible to apply experimentally the right combination of ones and zeros without a guide.
I was discussing the evolution of CNC position encoders with the technician who was upgrading the control on one of our CNC machining centers. In mold making, the cutter path software that converts 3D models (3D printing) into physical shapes, originally used a layer by layer contour line approach. We would like to use the more modern climb milling software because it eliminates the contour lines. (and the hours of hand draw polishing to remove them) The upgraded control will position X Y and Z at high speed instead of just X and Y which is all the contour line method requires. The embedded computer in each axis position encoder sends a high speed serial data stream including error correcting bits back to the control. This is a far cry from the first GE (now Fanuc) CNC control retrofitted to a Buffalo milling machine that I first programmed – yes, there is still a lot of legacy stuff in operation out there. This control also had position encoders without the local embedded computer. It only lost about 2500 count per shift (about 1/4 inch of position) and it came with a switch to shut off the Z axis so that you did not mill too deep. We evolved through resolvers and glass scales and back to a smart encoder. Don’t expect to do “big data” analysis of this type of IoT real time data stream. Bad things happen if the transmission of position is interrupted.

Who will bridge the genetation gap?

On the hardware side it is very convenient to connect the 10/100 port of my laptop to the ethernet switch. In my latest control I added ethernet cables so that it can be used in convenient locations without exposing it to the open internet. The generation gap became painfully obvious on the software side. The desire of the Windows operating system coders to download daily changes exceeds the ability of any custom low volume application software creator to keep up. We are finding that the latest version of custom application software is obsolete before it is sold. In the short term we will keep the systems synchronized by isolating them from the internet once we solve the inter-connectivity issues. This solution does not work for every IoT software mismatch issue. In my mileage trakker www.mileagetrakker.com IoT connected car application, it is necessary to have a staff who continuously monitors the functionality of the links and keeps up with interfacing with each model and car maker as they evolve. This becomes part of the monthly charge which enables our trakkers to obtain a couple thousand dollars in annual savings. Many of my mileage trakker competitors have gone out of business because they got caught continuously rewriting their cell phone based code in order to keep up with a rapidly changing software platform.
The IoT is evolving like the power grid. New IoT applications emerge based on the cost and performance drivers. Each implementer chooses a variation that matches the application without regard for the broader inter-connectivity issues. This will generate employment for the people with the STEM skills to link users to the vast data pool.

3D Niche

Posted on June 21, 2015 by george

Most 3D printed materials have porosity like swiss cheese
Emmentaler Switzerland PDO Cheese image by Dominik Hundhammer

The first successful applications for 3D printed materials tolerate the porosity in the part. Materials from nature such as quartz are essentially porosity free because they were formed over millions of years. This is why we like quartz for kitchen counter tops because bacteria does not have any place to hide. I suspect that man could create porosity free materials if we are willing to wait a million years or so. Given that our life span is a lot shorter than that, pretty much all man made materials contain porosity. With that as a preamble, I am not surprised that 3D printed materials have significant porosity. One of my active 3D printing projects is a two piece case for electric controls. Normally this would be made as an injection molded plastic which is reasonably water tight. I was hoping that the Stereolithography process which uses a photo catalyzed liquid plastic would also be liquid tight. It turn out that only one side has a water tight skin as my 3D printing service company discovered by making custom chocolate candy molds. This matches my experience with other materials. We all get frustrated if the porosity in the case of a transmission causes a big puddle on our driveway. Having made a multritude of transmission cases, I can report that only the skin of the case is liquid tight.

A Transmission + A Seive for a Case = A Driveway Puddle
Oil Stain picture by Christopher Sessums
Seive by DaveMontPhotography
Automatic Transmission by Vestman

When we actually need reasonably porosity free materials it is currently necessary to apply the 3D printing process to creating the mold. We successfully manufacture low volume metal parts by 3D printing a mold made from glued sand. The surface tension of the molten metal retains the metal even though the sand mold is 20% air. A similar strategy is used by Invisalign to make retainers where the high density sheet is vacuum formed over 3D printed molds.

Vacuformed orthodontics are shaped over 3D printed molds by Smikey lo

It is possible to post process a part with porosity. One of my clients makes aftermarket automotive air conditioning compressors. Freon is a gas and is very difficult to contain. Most car owners would be happy if they never had to refill freon in their car AC system. Even though zero leaks is impossible, as a manufacturer it is our goal. Freon is also used to prevent explosions in high voltages switch gear. When a switch in Downtown New York lost its freon and an killed a hundred or so people ABB enlisted my client to solve their leakage problems because the impregnation cell I set up for them is best in class. Even with that level of impregnation talent, I doubt that the anaerobic sealer we use, can fix 3D SLS (Selective Laser Sintered) metal parts because the pores are too big. Other techniques such as burnishing can be used to create a local skin.

The Burnishing process can increase density
and make a pressure tight skin
Burnished bearing race picture by Jean-Jacques Milan

Burnishing is a cold working process. We use other cold worked materials like cold rolled steel because this process closes the gaps between the grain boundaries to make them pressure tight. The CNC machining centers ability to burnish in addition to cutting is not widely known, but that does not stop me from using this very useful technique.
Invisalign, SpaceX, and GE have discovered that there are niche 3D printing applications. Engineering the product as match to 3D printing, combined with choosing an application that is not affected by material properties such as density, has enabled their marketplace success

Additive Manufacturing

Posted on June 19, 2015 by george

Your morning coffee delivered in a cup made using additive manufacturing

The value of additive manufacturing has long been known to the human race. Early civilization discovered the benefits of layering clay to create the pottery containers that we use for every day life. Most of us do not give a second thought to the pottery cups that deliver our morning coffee. Linking a coffee cup to additive manufacturing might not be obvious even if you work in the factory that makes coffee cups. A coffee cup factory is all about making an identical copy for everyone. After a coffee cup is designed using additive manufacturing, it is given to the pattern makers. Their precision wood patterns capture the shapes and serve to guide the creation of molds and tooling. This became the backbone of industrial manufacturing until the 1990s when the mathematics within the CAD and CAM programs evolved to replace wood patterns.

Wood patterns have been replaced by 3D CAD models.

Some of the bits of craftsmanship such as the “S” shaped gear spokes that keep the gear round during casting cooling have been lost from modern designs. The STEM skills required for the shape definition task are unchanged even though the practitioners are now called CAD modelers instead of pattern makers. The commercially useful shapes still require corner radii and fillets. Fits, blends, dimensional accuracy and finishes are even more important. As we evolve to a mass customization marketplace more people with this skill will be required.
Convergence is a term used to describe the effect that advancements in computer technology is having on the communications industry. The line between telephone, television broadcast, radio, paging, security, satellite, cable, and internet companies is blurring. The same is happening in additive manufacturing. A robot arc welder heats material fed as a wire and fuses it in a predetermined position controlled by a multiaxis CNC control. Interestingly enough, this is the exact description of what happens in filament style 3D printing.

ROBCAD Offline teaching welding
001 by KOMATSU Ltd
Airwolf 3D printer by Neon Tommy

As we evolve away from one size fits all, it will become possible to manufacture locally the items that we want. Computer controls will add the necessary flexibility to the production equipment that we own and recognize.

Packaged 3D

Posted on May 31, 2015 by george

A chocolate assortment in a vacuformed tray by Evan-Amos

Life could be a box of chocolates. The challenge in this era of mass customization is that the assortment of flavors that we want to buy changes with the wind. If you look at the picture carefully you will discover that the pockets match the shape of the chocolates. This means that if you want to change the assortment you require a new mold. The associates filling the box also find it hard to adapt to continuously and randomly changing customer order. It would also be helpful if the vacuum molded tray had some visual management labels to guide in the fulfillment activity.
Enter 3D printing. Invisalign pioneered the use of 3D printed molds to shape plastic sheet.

Vacuformed orthodontics are shaped over 3D printed molds by Smikey lo

Since every retainer created is different, the 3D printing process also molds into each item identification information. Why did Invisalign choose plastic sheet?
From the earliest blacksmiths shaping swords, the engineering community has discovered that it is possible to increase material strength if the application does not need the high strength in all directions. The bio-compatible plastic used by Invisalign actually works as a retainer, whereas the 3D printed plastic used to make the mold is too brittle and you would not catch me sticking it in my mouth because it still contains active plastic precursors. Other plastic composite sheet can be even stronger because reinforcing fibers can be laminated into the mix

Fibers add strength to plastics and rubber by PerOX

For example pneumatic car tires must have embedded fiber reinforcement to withstand the applied forces. Airplane manufacture is a logistic nightmare. About 100,000 parts must be manufactured and gathered together in the right order to make a plane come together. The Boeing engineers joke that FISH (first in still here) has replaced FIFO (first in first out) as their accounting system. Boeing in their Moonshine Project determined that staged delivery to the assembly floor is more that sending the parts. The parts themselves are useless without the matching tools to install them. In their historic system workers spent much of their working day traveling back and forth to the tool cabinets around the working area. As we gain engineering control, the implementation of molded tool trays on 3d printed molds is an effective shadow board so that it becomes possible visually to determine in the warehouse that all of the required tools are sent with each cart of parts.

747 airplane parts and tools are delivered together by Jeff McNeill from Chiang Mai, Thailand

Some of the solution for the shortage in transportation capacity has to come from efficiency. It would be easier if the marketplace didn’t want mass customization at the same time. I can picture us evolving to 3D print to order shipping trays so that full density skid size loads can be assembled upstream enabling fast loading and less unprofitable empty space in transit.

The Lean Innovator

Lean Engineering Solutions to Improve Profitability in the Areas of Manufacturing, Material Handling and 3D

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