Author: Mary-Jane Owen

It was, perhaps, inevitable that the success of Just-In-Time production would find its way to the CNC machining process.  Suppliers and wholesalers have for decades now shown the incredible benefits of JIT inventory control.  There was an inexplicable disconnect between being able to restock consumer electronics in a day and having to wait months for custom products or parts.  On-demand production has emerged as the answer.

CNC machining on demand begins and ends with the customer’s needs.  Tight integration between the customer and Macfab is tailored to boost customer profitability and satisfaction.  If you’ve ever tracked a package, you know the frustration of seeing it sitting for a day in a warehouse not far away, knowing it will be tomorrow before you receive it.  On-demand manufacturing is all about eliminating that kind of pointless delay.

Integration is the Key

Cloud-based integration with your manufacturer is at the heart of on-demand manufacturing.  Once you find a dependable full-service CNC on-demand manufacturer like Macfab, you’re ready to roll.  Your designs can be uploaded through an encrypted connection rather than email.

Evaluation can begin immediately rather than waiting for someone to open the email and decide what to do with it.  Questions can be fielded and decisions made largely through an AI-driven process that saves huge amounts of time.

Moving Through the Stages

Designs can be optimized to take advantage of raw stock dimensions.  Materials choices can be made from readily available stocks, or orders placed if suitable stock isn’t immediately available or castings are called for.  The required CNC machining processes can be identified and the necessary machines, tools, manpower, and time arranged.  Changes determined by our engineers or your designers’ feedback on the system and adjustments are made accordingly at all levels of the manufacturing plan.

The CNC machining on demand goes on to include inspections and all necessary QA reporting, cleaning, assembly, packaging, and shipping.

Parallel Planning

Just as building construction often begins before a design is finalized, on-demand manufacturing with its AI underpinning maintains the flexibility that wasn’t possible that long ago.  Overseen by our engineers and managers, our on-demand capabilities incorporate Kanban, lean manufacturing, and integrated inventory control.  Changes are mapped ahead as soon as they’re introduced to your product.  The goal is to avoid the scenario of your product sitting and waiting for some machine to be free or some time to be opened up like your package sitting in a terminal somewhere.

Our low-volume / high-complexity manufacturing model allows us to focus on manufacturing runs of the size you need.  We aren’t in the business of being a high-volume manufacturer.  From prototypes to finished products, we tailor our output to your needs.

Prototypes actually play a critical role in your on-demand experience.  MacFab can produce a prototype very quickly.  In fact, your testing of the prototypes may be the longest part of the on-demand manufacturing process.  Whether you run incremental prototypes or test them to failure to determine what features need to be adjusted, the bulk of your production run remains active in our on-demand system.  As soon as you give the green light, manufacturing begins.

Stripping out the dead time in the manufacturing process saves you money by optimizing the time you have to invest in your products.  It makes us profitable by keeping our shop schedule at peak efficiency.  In other words, there are very good reasons for everyone to utilize CNC on-demand manufacturing.

 

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There’s a real Renaissance happening in medicine today, and Advanced CNC Machining is playing a part.  When COVID-19 hit in 2020, the first vaccine was rolled out in a matter of months thanks to years of research into mRNA.  Prior to that point, the fastest vaccine development had been four years.

Putting Advanced CNC Machining to Work

At that same time, the government issued a call for the manufacture of ventilators to help save lives.  Macfab was brought in by our client in the medical industry to help produce components for a new ventilator.  They designed and rolled out the ventilator in a record-shattering six months, winning Gold at the 2020 International Design Awards.

Macfab was also brought in recently by another client.  They are tackling sepsis infections.  So-called “blood poisoning” can be caused by a host of different pathogens.  Patients face life-threatening symptoms that advance quickly.  Every hour lowers a patient’s chances of survival.  With our help, they are able to develop and release a self-contained testing system that can identify over 90% of sepsis pathogens in under an hour.

We worked with cancer and genetics research client when they were developing their hematology analyzers.  These units allow doctors to get complete blood counts in as little as a minute.  Of course, to do something that revolutionary requires some revolutionary technology, including channels through which blood can pass only one cell at a time.  These machines not only count and differentiate different types of cells but can monitor for certain types of blood disorders.

As the range of medical devices continues to grow, there is more and more need for high-precision advanced CNC manufacturing.  The level of detail that these new medical techniques take advantage of requires an equally refined mechanical interface.

Advanced CNC Machining When You Need Precision

Along with advanced CNC machining, 3D printing is also being tasked with creating new devices with designs that could only be imagined only a few years ago.  Some of this 3D printing takes the form of organ models surgeons use to prepare for surgery.  Others are more permanent.

Macfab has found itself working with companies that bring in 3D-printed parts requiring post-printing refinement.  The printed parts may require a smoother surface finish or higher detail than can be produced in the printer.  We can treat the printed part much like casting and mill it to the level of precision called for by their designs.  This can take the form of threading holes, shaping curves, or making other cuts that would create problems if they were produced directly in the printer.  We can also etch in serial numbers.  You could say this makes 3D printing the newest tool to advance CNC machining.

Our new machines are faster, more energy efficient, and more precise than all of our previous machines.  One of our mills performs a tool change in 0.7 seconds.  They all provide tighter tolerances than ever.  Systems like our new 9-axis Swiss turning machine are effectively two mills that can work on a given part simultaneously.  The speed and precision are beyond anything else on the market.  Our new metrology equipment, too, allows us to verify to a ridiculous extent how accurate we are at any given point on a part.  Advanced CNC Machining is the gold standard for the development of complex medical devices.

Macfab has a long history of working with the medical industry.  It’s the type of business that allows us to push ourselves and our abilities to the limit.  When lives are on the line, you find a new focus in your work.  Not every CNC machine shop can produce the accuracy, cleanliness, and consistency that Macfab does.  It’s something we take great pride in.

 

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Manufacturers talk a lot about quality.  Everyone wants to be known for putting out quality products.  “Quality is our job.” “No one beats our quality!”   Well, “Quality” is a great buzzword, but how can you tell what they mean -if they mean anything?

In the realm of CNC machining, there are a couple of common ways to gauge quality -quality assurance and quality control.  Together they constitute a quality improvement.  The way to determine if a company is actually committed to quality improvement should be easy -just look at what they invest in quality improvement tools and how they use them.

In the Beginning: Quality Control

At Macfab, Quality control starts at the beginning of the manufacturing process.  Measurements are taken when setting up raw stock or castings, even before machining begins.  Then throughout CNC machining, quality control steps are included.

The operators (or often the CNC mills themselves) will pause to take measurements of the part in progress, confirming that specific features meet specifications before proceeding.  This can be vital in some situations. Tensions in the material may cause a part to warp as it’s milled and structures become thinner.  These tensions may be caused during the production of the raw stock or casting, or from heat from the CNC milling process itself.  Features may have been in spec earlier but may shift as the part is shaped further.  Monitoring the details of a part’s shape at various stages of machining allows us to spot where warping is being introduced.  With that knowledge, we can determine how best to handle the situation.

All of those measurements are recorded, most of them automatically, in another quality tool -our ERM software.  Not only does this provide our customers with QC data on their products, but we can use it internally.  If we see similar failures happen on different projects using the same raw stock, that can inform us that our supplier may have a problem with that particular commodity.  Or we may discover that we need to use a different milling bit or different cooling in some circumstances.  Watching for and analyzing failures is vital to genuine quality control.

In the End: Quality Assurance

Once the shaping is finished on a part, quality assurance takes over.  The part is placed into one of our component measuring machines, and every aspect of it is checked again.  The features are compared against the design drawings and the specified tolerances.  Screw holes, curves, surface finishes, recesses, flanges -Macfab’s CMM machines measure it all as part of their quality tools.  Every single measurement winds up in our ERM software and is provided to the customer in an easy-to-read format.

There is one last component to Macfab’s Quality Improvement: our people.  Everyone here is crucial for the continued success of our quality improvement efforts.    Nothing can replace the senses of the operators, who can often spot issues before any measurement system would.  The engineers who design and maintain our ERM software work out how to use the data to monitor systemic problems.

Most of our customers are answerable to their customers for quality assurance.  Macfab provides ample documentation to satisfy the most exacting requirements.  In the end, that’s how you can gauge a company’s commitment to quality improvement.  It’s not one thing, but a culture of attention to detail that permeates an operation as you’ll find at Macfab.

 

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Environmental sustainability isn’t the first thing that springs to mind when someone mentions CNC machining, but Macfab has made environmental responsibility a key component in our business philosophy.  As we see it, doing what we can to promote sustainable manufacturing makes sense for us and our customers.

Our operations are tightly integrated.  We use the principles of Kanban to provide a seamless service to our customers.  Lean manufacturing helps keep our costs down.  And sustainable machining benefits both us and our customers.

Planning for Sustainable Manufacturing

Designs can be worked on digitally by their designers in conjunction with our engineers.  Aside from the mountains of paper and travel that saves, it also allows us to influence designs with an eye toward efficient use of raw stock.

Minimizing waste begins before materials are even purchased.  Our engineers can also recommend material options that are available locally, avoiding shipping.  If machining is going to be too wasteful, they can look at the possibilities of cutting nested parts out of the raw stock or using castings to avoid waste.  Our CRM software allows us to manage inventory for many of our customers and can control stock levels automatically to avoid both outages and leftover components after a product is dropped.

Sustainable Machining on the Shop Floor

CNC machining is fundamentally greener than old-school metal working.  Gone are the giant motors spending half their energy running Rube Goldberg mazes of gears and worm drives.  Modern CNC machines have digital stepper motors tuned to the requirements of their specific jobs.  Properly tooled, they run more efficiently than operators, as well.

Some CNC machines are capable of running completely unattended, or what’s called “Lights Out”.  If a Swiss turning machine can be left to produce parts overnight, it can use electricity at off-peak hours, when there’s little if any energy being put into maintaining a comfortable environment in the shop.

It’s the nature of precision CNC machine shops that we have to be fastidious about our surroundings.  Chips and swarf can’t be allowed to collect.  Macfab has a robust recycling program for shop cuttings of all materials.  We are also heavily invested in coolant systems for the various machines.  Along with keeping parts and bits cool, those fluids wash away cuttings from the milling area.  We use environmentally friendly coolant fluids.  We have also recently purchased a filtration and management system that allows us to remove the contaminants for recycling and use the coolant for far longer.

At Macfab we see sustainable manufacturing as a win-win.  We save time and money by minimizing waste.  Our customers save money as a result.  We also know our customers appreciate working with companies that keep an eye on sustainability -it’s good for their bottom line and it’s something investors look for, as well.  We all live in this environment.  We all have very real motivations for keeping our communities clean and healthy.  At Macfab, we try to incorporate that into everything we do.

 

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You can’t escape stories about artificial intelligence these days.  The Internet is blowing up with tech’s drive to roll it out and tales -from humorous to frightening- about early results.  But rest assured; artificial intelligence is coming.

AI is not new in itself.  Early systems have been in use for years.  These are not the general-purpose language models being rolled out today, but specialized AI algorithms designed for specific tasks.  Fields like industrial design have been taking advantage of AI to optimize product designs.

AI systems can effectively be told to produce a device that does this set of tasks and can be held in one hand, for example.  The algorithm then runs through iterations of designs quickly until it comes to what it believes to be a good design that meets the stated goals.  Engineers then assess the work and feed changes back into the design as needed.  Weeks can be shaved off a design process.

AI Applications in Manufacturing Today

CNC machines get smarter and more capable all the time, so it would be naive to think they wouldn’t be affected by AI.  CNC mills and lathes are effectively part of the Internet of Things at this point.  Current machines are networkable, allowing them to report CMM measurements into our inspection and reporting software, but there’s more to it than that.  AI Software maps out the machining sequences, tool selection, spindle speeds, and feed rates.  CNC mills have tool load monitoring, which they can use to detect a broken bit.

AI modeling now allows analysis of tool load and vibration to watch for damaged bits.  AI can decide if it needs to check the accuracy of its work and automatically insert a step into its program to use its CMM probe to verify the feature it just cut.  It will catch a damaged bit and swap out for a new bit before continuing with the milling program. That same ability allows it to take another pass over a feature to see if it can be cleaned up, or to reject the part without wasting further time on it.

Macfab uses AI in our CRM software.  We provide inventory management for some of our clients.  We monitor their use of inventory parts and production runs are slated accordingly to ensure inventory levels are always where they need to be.  This technology saves managerial time by automating orders.  It also saves inventory costs.  The AI can spot trends and automatically manipulate inventory levels up or down according to usage.

One of the most revolutionary features of CNC machines was freeing up the operators to a degree.  Milling no longer required the operator’s full attention as it had since the start of the Industrial Revolution.  Operators in some cases could run two or three machines at once.  It was a monumental change.  AI is the next iteration of that same process.

Self-calibration, measuring spindle run-out, checking the bed for flatness, spotting unacceptable backlash in head movements, and catching issues like dry bearings are either here or coming.  Using in-built sensors and AI logic will allow us to be proactive on machine maintenance, which can be a huge cost-saving measure.   The AI will be able to determine the least disruptive time, schedule a machine for downtime, and reassign its production to others while it’s down for maintenance.  If CNC machines can police themselves, operators will be freed up even further to address the genuinely complicated tasks.

Some people fear advancements like this. Some fear automation like this kills jobs.  History has taught us repeatedly that jobs don’t go away; they merely change.  Advancements like AI are the next step in freeing people up from the most mundane and repetitive portions of their jobs.  They get to be more creative and have more variety in their work with fewer “chores”.  Macfab is excited by the changes AI is bringing to the world of CNC machining.

 

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AI in cnc machining

Macfab is both pleased and humbled by the opportunities we’ve been given over the last 35 years.  There’s no mistaking that it’s been difficult work.  There have been challenges, and we’ve faced each one head-on.  At year’s end, it’s traditional to look back with gratitude and forward with expectation.  This year, though, we have a special reason to be thankful.  Aerospace and Defense Review is the business and technology magazine for the aerospace and defense industry.  They have just named Macfab as a Top Canadian Defense Technology Company in 2022.

Growth and Change

It’s amazing to think back to the state-of-the-art technology when we started.  We’ve witnessed the introduction and maturation of new technology in several fields.  Machining has become synonymous with CNC mills, and lathes.  Digital (and then computer) control of machines revolutionized machine shops.

That runaway success led to a revolution in engineering.  Paper gave way to screens as we were getting started, and CAD/CAM software gave designers the tools to create devices of unprecedented complexity.  Along with accuracy, new technology brought the speed.  CNC mills and lathes began to have multiple axes of operation, meaning they can shape parts from various angles, often with multiple spindles.  Deep recesses, fine protrusions, and thin walls -all with precise surface finishing- have become our bread and butter.  These technologies also mean these products can often be produced without repositioning the part during machining.  That’s a huge time-saver.

The Next Steps

New developments don’t end with machining, either.  Cleaning and measuring have kept up with the needs of engineering, too.  Macfab’s cleanroom facilities and metrology investments have kept us at the forefront of our industry.  Thorough inspections and intense cleaning regimens are generally required for the parts we produce today.  Whether we’re cleaning and packaging components for a customer or we take those parts to our cleanroom for assembly, the level of care required is hard for most people to grasp.

The cleanroom facilities and our attention to eliminating surface contamination down to the microscopic level set us apart from most CNC machine shops.  Our component assembly facilities enable us to make sure that delicate parts are handled safely.  We are often tasked with assembling individual components into larger parts because our customers know they can trust us to do the job properly, and we can test the functionality of the finished assemblies before sending them to the customer.  Our work eliminates surprises on their manufacturing line or in the finished product.

Thank You, and We Look Forward

We’ve grown a lot over the years.  We’re going to keep growing, too.  Just this year we invested several millions of dollars in new machines, including vertical and horizontal mills, 5-axis turning centers, and Swiss turning machines.  The range of materials we encounter continues to expand to include new alloys and new plastics.  Each of those brings its own machining strengths and weaknesses, and we have to adapt to all of them.  It all comes back to the customer’s needs.

Both aerospace and defense industries face new challenges, whether it’s cube sats for the burgeoning private space industry, critical designs for long-distance surveillance in military actions, or new capabilities for the front lines.  We’re very happy to be recognized for our work, and we’re excited to see what 2023 is bringing.

 

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The old adage is “measure twice; cut once”.  It’s as true today as it ever was, only in the world of quality CNC inspection, we measure a lot more than twice.  The complex shapes, delicate features, and tight tolerances of precision CNC machined parts demand higher accuracy than ever before.  It’s those once-impossible designs that are at the heart of once-impossible machines.

Pressures to minimize devices and maximize performance means squeezing more into less.  Less material is more highly engineered, leaving very little on a given part that isn’t critical.  Instead of having a simple, flat back plate, the back of a part is likely to be the front of another part with its own features.  That means accounting for more surface finishes, more details, and more dimensions.

Innovation Leads to Complexity

When the engineers design these parts, they have to make sure every part fits and everything works together.  When Macfab’s engineers get involved, they must respect all those requirements while laying out how to hold the parts in the CNC machines so they can be shaped with the fewest moves.  They also have to consider the material being milled and the limitations of the very precise (but rather bulky) machines.

Operators will take multiple measurements of parts during the milling process.  The CNC mill can swap out a bit for an inspection probe and check the dimensions.  The first parts of a production run when the CNC programming is being fine-tuned get special attention.  These in-process measurements won’t cover every aspect of the part, but the most critical points are checked during shaping.

CNC Inspection Machines and Extreme Reporting

Metrology is where we really get down to measurements.  Vision systems with their video cameras and computers can scan newly machined parts, checking for any defects or missed tolerances.  Touchless laser micrometers can at the extreme check dimensions down to 0.00001mm, or a hundredth of a micron -that’s smaller than a light wave.  Coordinate Measurement Machines are the workhorses, checking all dimensions and features on a three-dimensional part.  All of these and more go into our quality control and the reporting we deliver to customers.

With our metrology instruments fully integrated with our new reporting software, First Article Inspection Reports are more detailed and easier to read than ever before.  Balloon diagrams showing every feature on every part are generated automatically.  They’re easy to read and provide engineers with measurements and dimensions at every important point.  Network connectivity eliminates inspectors having to transcribe readings and the possibility of mistyped numbers.  Our customers receive more accurate data on their products, both in precision and in reliability.  Our new reports ensure that we provide our customers with exactly what they need, so their parts will perform precisely as they’re supposed to.

As they continue to improve our ability to manufacture to finer and finer standards, they’ll also keep producing systems to measure those standards.  Macfab will be right there with them, staying on top of the state of the art.  When you have parts that are critically important, bring your designs to Macfab, and let us show you what quality CNC inspection looks like.

 

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When you organize your CNC machine shop to reduce waste, downtime, and inefficiencies, that’s called lean manufacturing.  The underlying principles of lean manufacturing were formed almost a century ago at Toyota Motor Works.  In the years since, countless books and papers have been written on the topic and it has become the dominant system in manufacturing.  Like so many things, the key is how you implement it.

The Focuses of Lean Manufacturing

It can be harder than it sounds (which is why so much effort goes into discussing it).  Inefficiencies creep into any system over time as the products change, new machines are introduced, and new people come in.  It’s almost axiomatic that whatever system was set up ten years ago is less efficient today just due to tiny system changes.  The CNC machining processes now run much faster because of the new mills, so the operator has downtime he didn’t use to have.  Instead of taking finished parts here for inspection, he now must take them across the shop to the new CMM machines.  That eats time.  Non-productive time is created by one change.  Another change comes along and uses up that spare time, but typically not in a productive way.  Lean manufacturing is concerned with those little gaps in actual productivity.

These “just-in-time” principles extend to inventory control as well.  The idea is to have the parts needed on hand as they’re needed.  Part shortages or surpluses equally point to inefficiencies in productivity.  Our clients rely on us to get parts to them, but they don’t want to warehouse huge quantities.   That puts the onus on us to work closely with them and plan well ahead to ensure they stay properly stocked -and no more.

Lean Manufacturing on the Shop Floor

Macfab has long used the ideas underlying lean manufacturing.  Back in the day, a CNC operator could run a mill or a lathe -one machine at a time.  Machining a part demanded the operator’s full attention.  With the advent of the CNC machining processes, operators wound up with spare time on their hands.  If a mill is going to take 5 (or a hundred) minutes to carry out operations on a piece, the operator has time to do other things.  He can get another job set up on another CNC machine, pull finished work off a machine, or run tests on the piece just finished.  Depending on the job, one operator may be able to keep several CNC machines busy.  That’s a principle of lean manufacturing.

If you want to reduce non-productive time and want operators to run more than one machine, those machines need to be set up so the operator can move from one to another easily.    They need to be arranged so it’s easy for raw stock, castings, tools, etc. to be delivered where needed.  That typically means the stock room and tool crib should be somewhat centrally located.

Lean manufacturing also calls for careful monitoring of workflows.  Ideally, we try to make sure as few people as necessary are involved as a specific part moves through the CNC machining processes.  That saves time, improves consistency, and avoids confusion during the completion of the part.

Lean Manufacturing in the Offices

Lean manufacturing doesn’t begin (or end) on the production floor.  Our ERP software monitors customer inventories for low levels or new jobs that come in, triggering orders for raw stock or castings.  If it’s an item that we stock for a client, that stock is delivered, and production begins to replenish our inventory.  The volumes of parts at each production step are monitored, watching for bottlenecks in the manufacturing process.  We go beyond tracking inventories of consumables, looking for anomalies.  Are more end mills wearing out on a particular CNC machine than any other?  Is that a function of the jobs it’s doing, do the milling parameters need to be adjusted, or does it indicate a problem with the machine itself?

Diligence is Always Due

We’ve learned if we’re consistent about watching for these inefficiencies, we can prevent them from becoming real headaches.  Just because an issue seems trivial doesn’t mean we shouldn’t focus on it.  A worn part on a CNC machine today will become an additional worn part if it’s not replaced.  Lean manufacturing is the key to catching those issues while they’re manageable and keeping downtime to a minimum.

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CNC machining summons images of strangely shaped aluminum plates or steel gears being formed by spinning bits. The machines are huge and complex. But precision production has a softer side, too with plastic machining.

We’ve all seen metal parts replaced with engineered plastics to save money or weight. It’s easy to think that they just shoot molten plastic into a mold and out pop a gear. True enough, a lot of plastics are cast in molds. However, some plastic pieces are machined just like a metal part would be.

Engineering Plastic to Get It Right

Sometimes plastics are used in place of metal for testing purposes. A particularly unusual design might be milled in plastic just to ensure it can be produced by the machine. This prototype often isn’t functional but serves as a proof of concept. Machined plastic parts like this can be used to test the fit with other components. Plastics are cheaper than metal, and they can be machined much more quickly since the CNC mills can take much larger cuts in comparatively soft plastic.

There is, however, a sector of the manufacturing industry that deals specifically with engineering plastics. These parts may be milled from thermoplastics like Nylon or Delrin, or thermoset materials like printed circuit boards.

Plastic Machining is Harder Than It Looks

Engineering plastics is actually more difficult than engineering metal. Plastics melt at very low temperatures, by comparison, making the heat of machining a huge problem. Oil-based coolants are typically off the table because oils can have serious effects on plastics. Chips from machining plastics also pose unique problems. They tend to adhere to everything due to static electricity, so collect in the work area. If chips get into the bit, they can cause gouges in the part or partially melt and fuse to the part. Water-based coolants are used, but strong air jets are more common.

Many plastics used today are infused with glass or fiberglass. This is particularly hard on bits, and diamond-coated bits are often used. Thermosets like G7 are commonly used for electrical insulation, especially in high-temperature settings. This plastic is a silicone/glass cloth laminate, which accounts for its high dielectric properties. It’s not unheard of for CNC machine shops to designate mills for plastic milling only. This ensures that metal dust from previous jobs can’t make its way into the plastic parts and compromise their performance as insulators. Plastics laminated with glass cloth are also prone to delamination during milling -another problem metal fabrication doesn’t have to deal with.

Then there’s the issue of tolerance. Plastics are generally designed to a tolerance of five-thousandths of an inch, as opposed to two thousandths for metal working. Some designers, though, will specify plastic parts with much tighter metal tolerances. We have worked out ways to achieve those tighter tolerances in many circumstances, but it does slow down machining and drives up costs.

The Future of Engineered Plastics is Bright

Macfab handles a lot of plastic machining. Our work in the medical industry requires it. Today’s medical care is replete with single-use medical devices, as well as pumps and sensors that benefit from plastic components. Engineered plastics are also finding a home in prosthetics, saving weight that can then be devoted to robotic functions in the limb.

If anything, the field of plastics is growing faster than metallurgy. Plastics are a perfect complement to metal components in spacecraft. Metal parts will often fuse together in the vacuum of space. Plastics are used as bearings to prevent metal parts from touching, as well as serving a host of other functions. Plastics also provide tremendous weight savings, which is critical for spacecraft. No matter where you look, advancements in engineered plastics are growing, and MacFab is growing right along with it. Look to us when your next machining tasks come up, no matter what materials you intend to use.

 

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For decades, manufacturing process R&D has been an integral part of shaping MacFab’s service capabilities and technological advancements. Our lessons learned include “what not to do” as well as “what to do”. Although many of our research projects were, at the time, product specific, the knowledge and experience gained were transferable to a variety of other product challenges.

A client came to us this year with a complex problem producing susceptible portable detectors. We love the hard cases, and we recognized that this project requires advancement in physical chemistry, material science, and engineering. The following are some of those lessons learned from recent and not-so-recent research projects. You can see how they informed our research into solving his problem.

These detectors have been manufactured from aluminum but machining the air manifolds from magnesium would make them considerably lighter. Aluminium is a rather inert metal, not so magnesium. Sniffer detectors like this work with parts per billion. That means the air absolutely cannot handle being exposed to contaminants once it enters the machine.

“Normal” Parts Cleaning Won’t Work

The normal procedure is to wash the parts first with water-based cleaners, followed by a solvent, then bake them to drive off any residue. That works for aluminum, but magnesium begins to anneal at typical baking temperatures. Not only will it deform slightly from the heat, but tiny features like the screw threads in tapped holes will weaken. We knew that typical wasn’t an option, so we needed to find an alternative.

Cooling

We knew CNC machining magnesium means no water-based coolants. CNC machining magnesium is always exciting because the metal catches fire easily, and once it ignites it’s very difficult to extinguish. It burns hot enough to melt steel. Machining it without coolant can overheat it to the point of ignition. Machining magnesium also means taking every step to avoid fine cuttings, as those are the most flammable. We had to develop cost-effective, customized micro-fixturing to facilitate component manufacture and assembly. We even had to avoid high humidity and only handle them with clean nitrile gloves to avoid moisture.

Cleaning

Acids could clean the contaminants but would eat away the surface of the magnesium parts. Ultrasonic cleaners will cause microscopic surface pitting. Because of their intended use for sniffing out explosives and drugs, we had to avoid halogens in the cleaning regimen. Even traces of chlorine or fluorine would render them useless. Commonly used cleaning solvents like alcohols and ketones were also out of the question. The entire drying/ baking process had to be carried out in a vacuum. Newly cleaned parts then have to be packaged immediately to protect them from contamination and humidity.

Testing, Research, and More Testing

Macfab’s clean room facilities were invaluable for this project, like many before it. The procedure we developed for this project included prohibiting anyone from touching the parts unless they have been specifically trained. Each part had to go through the ultra-cleaning process after each handling. Cleanliness inspections required microscopes as high as 40X and unique borescope inspections for internal surfaces with all inspection and packaging processes have to be carried out under a laminar flow hood with particle-free compressed air.

The Value of Quality CNC Machining

All of our experience has gone into the development of a rigorous manufacturing regimen covering every aspect of producing components from start to finish. It did in fact involve many different talents, from designing the micro-fixtures to environmental control to cleaning and cleanroom protocols. Every step has had to be tailored for this project, and the end result is a development not many CNC machine shops could produce.

This is the work we love. The projects that others have said couldn’t be done or have hit walls in their attempts provide us with the opportunities to push ourselves. That’s why we invest heavily in facilities like our clean room and the incredibly sensitive testing equipment. We love advancing the state of the industry. Our research and discoveries on this project will inform future demands, which are always evolving to push past our current state of knowledge.

 

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