Machining watch parts. Design Considerations for Machined Parts: 13 Design…

How to design parts for CNC machining

In this complete guide to designing for CNC machining, we’ve compiled basic advanced design practices and tips to help you achieve the best results for your custom parts.

• What is the CNC machining process?
• What are the main restrictions of CNC design?
• CNC design guidelines
• CNC machine setups and parts orientation
• What is 5-axis CNC machining?
• CNC machining undercuts
• Drafting a technical drawing
• What are Hubs’ best practices for CNC machining?

There are a few easy steps you can take to optimize your designs for computer numerical control (CNC) machining. By following design-for-manufacturing (DFM) rules, you can get more out of CNC machining’s broad capabilities. This can be challenging though, as industry-wide specific standards do not exist.

In this article, we offer a comprehensive guide to the best design practices for CNC machining. To compile this extensive up-to-date information, we asked for feedback from industry experts and CNC machining service providers. If you are optimizing for costs, check out this guide to designing cost-effective parts for CNC.

Did you know we offer local sourcing for CNC machining?

What is the CNC machining process?

CNC machining is a subtractive manufacturing technology. In CNC, material is removed from a solid block using a variety of cutting tools that rotate at high speed—thousands of RPM—to produce a part based on a CAD model. Both metals and plastics can be CNC machined.

CNC-machined parts have high dimensional accuracy and tight tolerances. CNC is suitable for both high-volume production and one-off jobs. In fact, CNC machining is currently the most cost-effective way of producing metal prototypes, even compared to 3D printing.

What are the main restrictions of CNC design?

CNC offers great design flexibility, but there are a few restrictions. These limitations relate to the basic mechanics of the cutting process and mainly concern tool geometry and tool access.

Tool geometry

Most common CNC cutting tools (end mill tools and drills) have a cylindrical shape and a limited cutting length.

As material is removed from the workpiece, the geometry of the tool is transferred to a machined part. This means, for example, that the internal corners of a CNC part always have a radius, no matter how small a cutting tool was used.

Tool access

To remove material, the cutting tool approaches the workpiece directly from above. Features that cannot be accessed in this way cannot be CNC machined.

There is an exception to this rule: undercuts. There’s a section on undercuts towards the end of this article.

We recommend aligning all your model’s features (holes, cavities, vertical walls, etc.) to one of the six principal directions. However, see this rule as a recommendation and not a restriction, as 5-axis CNC systems offer advanced workpiece-holding capabilities.

Tool access is also an issue when machining features with a large depth-to-width ratio. To reach the bottom of a deep cavity, for example, you need tools with extended reach. This means a wider range of motion for the end effector, which increases the machine chatter and lowers the achievable accuracy.

It will simplify production if you design parts that can be CNC machined with the tool that has the largest possible diameter and the shortest possible length.

CNC design guidelines

A challenge that frequently comes up while designing a part for CNC machining is that no industry-wide specific standards exist. CNC machine and tool manufacturers continuously improve the technology’s capabilities, expanding the limits of what is possible. The table below summarizes recommended and feasible values for the most common features encountered in CNC machined parts.

Cavities and s

Illustration of cavities and s

Recommended cavity depth: 4 times cavity width

End mill tools have a limited cutting length (typically 3–4 times their diameter). Tool deflection, chip evacuation and vibrations become more prominent when cavities have a smaller depth-to-width ratio.

Limiting the depth of the cavity to four times its width ensures good results.

If larger depths are required, consider designing parts with a variable cavity depth.

Deep cavity milling: Cavities with depths greater than six times the tool diameter are considered deep. A tool diameter-to-cavity depth ratio of up to 30:1 is possible using specialized tooling (maximum depth: 35 cm with a 1-inch diameter end mill tool).

Internal edges

Illustration of internal edges

Vertical corner radius

Recommended: ⅓ times cavity depth (or larger)

Using the recommended value for internal corner radii ensures that a suitable diameter tool can be used and aligns with guidelines for the recommended cavity depth.Increasing the corner radii slightly above the recommended value (e.g. by 1 mm), allows the tool to cut following a circular path instead of a 90 angle. This is preferred as it results in a higher quality surface finish. If sharp 90-degree internal corners are required, consider adding a T-bone undercut instead of reducing the corner radius.

Floor radius

Recommended: 0.5 mm, 1 mm or no radiusFeasible: any radius

End mill tools have a flat or slightly rounded lower cutting edge. Other floor radii can be machined using ball end tools. It is good design practice to use the recommended values, as it is preferred by the machinists.

Thin walls

Minimum wall thickness

Recommended: 0.8 mm (metals), 1.5 mm (plastics)Feasible: 0.5 mm (metals), 1.0 mm (plastics)

Decreasing the wall thickness reduces the stiffness of the material, which increases vibrations during machining and lowers the achievable accuracy. Plastics are prone to warping (due to residual stresses) and softening (due to temperature increase), so a larger minimum wall thickness is recommended. The feasible values stated above should be examined on a case-by-case basis.

Holes

Recommended: standard drill bitFeasible: any diameter larger than 1 mm

Holes are machined using either a drill bit or an end mill tool. The size of the drill bits is standardized (in metric and imperial units). Reamers and boring tools are used to finish holes that require tight tolerances. For high-accuracy holes with a diameter smaller than 20 mm, using a standard diameter is recommended.

Maximum depth

Recommended: 4 times nominal diameterTypical: 10 times nominal diameterFeasible: 40 times nominal diameter

Holes with a non-standard diameter must be machined with an end mill tool. In this case, the maximum cavity depth restrictions apply and the recommended maximum depth value should be used. Holes deeper than the typical value are machined using specialized drill bits (with a minimum diameter of 3mm). Blind holes machined with a drill have a conical floor (135-degree angle), while holes machined with an end mill tool are flat.There is no particular preference between through holes or blind holes in CNC machining.

Threads

Illustration of threads

Thread size

Minimum: M1 (and lower, in some cases)Recommended: M6 or larger

Threads are cut with taps and external threads with dies. Taps and dies can be used to cut threads down to M2. CNC threading tools are common and are preferred by machinists, as they limit the risk of tap breakage. CNC threading tools can be used to cut threads down to M6.

Thread length

Minimum: 1.5 times nominal diameterRecommended: 3 times nominal diameter

The majority of the load applied to a thread is taken by the few first teeth (up to 1.5 times the nominal diameter). Threads longer than 3 times the nominal diameter are thus unnecessary.

For threads in blind holes cut with taps (i.e. all threads smaller than M6), add an unthreaded length equal to 1.5 times the nominal diameter at the bottom of the hole. When a CNC threading tool can be used (i.e. threads larger than M6), the hole can be threaded throughout its length.

Small features

Illustration of small CNC features

Minimum hole diameter

Recommended: 2.5 mm (0.1 inches.”)Feasible: 0.05 mm (0.005 inches.”)

Most machine shops can accurately machine cavities and holes using tools down to 2.5 mm (0.1 inches) in diameter. Anything below this limit is considered micro-machining. Specialty tools (micro-drills) and expert knowledge are required to machine such features because the physics of the cutting process change with this scale. Unless absolutely necessary, the recommendation is therefore to avoid them.

Tolerances

CNC Tolerances illustration

Typical:.0.1 mmFeasible:.0.02 mm

Our tolerances are either 2768 medium or fine. If tolerances are not specified, manufacturing partners will use the selected 2768 grade.Tolerances define the boundaries for an acceptable dimension. The achievable tolerances vary according to the base dimension and the geometry of the part. The values above are reasonable guidelines.

Text and lettering

Recommended: font size 20 (or larger), 5 mm engraved

Engraved text is preferred over embossed text, as less material is removed. Using a minimum size of.20 sans.serif font (e.g. Arial or Verdana) is recommended. Many CNC machines have pre-programmed routines for these fonts.

CNC machine setups and parts orientation

Tool access is one of the main design limitations in CNC machining. To reach all surfaces of the model, the workpiece has to be rotated multiple times.

Whenever the workpiece is rotated, the machine has to be recalibrated and a new coordinate system has to be defined.

While designing, it is important to consider machine setups for two reasons:

• The total number of machine setups affects the cost. Rotating and realigning the part requires manual work and increases total machining time. This is often acceptable if the part needs to be rotated up to three or four times, but anything above this limit is excessive.
• To achieve maximum relative positional accuracy, two features must be machined in the same setup. This is because the new calibration step introduces a small (but non-negligible) error.

What is 5-axis CNC machining?

A 5-axis CNC machine moves cutting tools or parts along five axes at the same time. Multi-axis CNC machines can manufacture parts with complex geometries, as they offer two additional rotational axes. These machines eliminate the need for multiple machine setups.

What are the advantages and limitations of 5-axis CNC machining?

Five-axis CNC machining allows the tool to remain constantly tangential to the cutting surface. The tool paths can be more intricate and efficient, resulting in parts with better surface finish and lower machining times.

That said, 5-axis CNC has its limitations. Basic tool geometry and tool access limitations still apply (for example, parts with internal geometries cannot be machined). over, the cost of using such systems is higher.

CNC machining undercuts

Undercuts are features that cannot be machined using standard cutting tools, as some of their surfaces are not accessible directly from above.

There are two main types of undercuts: T-slots and dovetails. Undercuts can be one-sided or double-sided and are machined using special tools.

T-slot cutting tools are made of a horizontal cutting blade attached to a vertical shaft. The width of an undercut can vary between 3mm and 40mm. We recommend using standard sizes for the width (i.e. whole millimeter increments or standard inch fractions), as it is more likely that an appropriate tool is already available.

For dovetail cutting tools, the angle is the defining feature size. Both 45- and 60-degree dovetail tools are considered standard. Tools with an angle of 5-, 10- and up to 120-degree (at 10 degree increments) also exist but are less commonly used.

Undercut design for CNC machining

When designing parts with undercuts on internal walls, remember to add enough clearance for the tool. A good rule of thumb is to add space equal to at least four times the depth of the undercut between the machined wall and any other internal wall.

For standard tools, the typical ratio between the cutting diameter and the diameter of the shaft is 2:1, thereby limiting the cutting depth. When a non-standard undercut is required, it is common practice for machine shops to manufacture their own custom undercut tools. This can add to lead time and cost, so avoid it if possible.

Drafting a technical drawing

Technical drawings are sometimes used by engineers to communicate specific manufacturing requirements to the machinist. If you are interested in the topic, read this article about how, when and why to use technical drawings.

Uploading a technical drawing with your Hubs quote

We don’t usually require a technical drawing for orders on our platform, but in some cases, they can add valuable context to a quote request. Certain design specifications cannot be included in a STEP or IGES file. For example, you’ll have to include a 2D technical drawing if your model includes threaded holes or shafts and/or dimensions with tolerances tighter than the selected 2768 grade.

If you add a technical drawing, please make sure it matches the specifications of the files uploaded. If the technical drawings do not match the files uploaded or the quote specifications:

• The quote specifications are considered the point of reference for the technology, material and surface finishes.
• The technical drawings are considered the point of reference for the thread specifications, tolerance specifications, surface finish details, part marking requests and heat treatment specifications.
• The CAD file is considered the point of reference for the part design, geometry, dimension and feature locations.

What are Hubs’ best practices for CNC machining?

Have parts you need CNC machined? Upload your designs and our DFM tool will suggest optimizations and provide instant pricing.

resources for engineers

How do you deal with sharp corners in CNC machining? Designing with the machinist in mind

Have you designed your parts with sharp corners? They may look good on paper, but they’re a nightmare to manufacture with CNC machining. In this article, learn how and why to avoid sharp corners in your designs. It’ll reduce lead times, cost and potential headaches for machinists.

What is GDT? How to reduce manufacturing errors and improve quality

What is Geometric Dimensioning and Tolerancing (GDT) and how is it used? This article explores the basics of how and when to use GDT to get the best results out of custom part manufacturing.

What is design for manufacturability (DFM)?

Design for manufacturing (DFM) means taking a design-first approach to manufacturing. In this article, we look at the overall DFM process, the necessary steps for a successful outcome, examples of DFM done right and how to get the most out of your own processes.

What is anodizing and how does it work?

What is anodizing? Anodizing is key to finishing parts made from aluminum and other metals. Learn how anodizing works and why it is an important part of CNC machining and manufacturing.

What are the different types of threads for manufacturing? Practical tips for engineers

What are the different types of threads for manufacturing? In this article, learn how to correctly design threads to reduce lead times and cost for your next CNC machining production run.

Standard blank sizes for CNC machining (sheets rods)

Tables of the standard blank sizes (sheets rods) commonly used in CNC machining.

What is heat treatment and how does it improve CNC-machined parts?

What are the different types of heat treatment and how do they affect CNC-machined parts? This article explores how heat treatments can be applied to many metal alloys to drastically improve key physical properties like hardness, strength and machinability.

How do you select the right materials for CNC machining?

This comprehensive guide compares the 25 most common materials used in CNC machining and helps you choose the right one for your application.

How to prepare a technical drawing for CNC machining

How do you prepare technical drawings for CNC machining and why are they important? Technical drawings are widely used in manufacturing to improve the communication of technical requirements between the designer and engineer and the manufacturer.

How to design parts for CNC machining

In this complete guide to designing for CNC machining, we’ve compiled basic advanced design practices and tips to help you achieve the best results for your custom parts.

14 proven design tips to reduce the cost of CNC machining

Make the most of CNC machining by optimizing your design and making the right material choices. Read these 14 design tips to help you reduce CNC-machining costs and create the perfect parts for your project.

How do you deal with sharp corners in CNC machining? Designing with the machinist in mind

Have you designed your parts with sharp corners? They may look good on paper, but they’re a nightmare to manufacture with CNC machining. In this article, learn how and why to avoid sharp corners in your designs. It’ll reduce lead times, cost and potential headaches for machinists.

What is GDT? How to reduce manufacturing errors and improve quality

What is Geometric Dimensioning and Tolerancing (GDT) and how is it used? This article explores the basics of how and when to use GDT to get the best results out of custom part manufacturing.

What is design for manufacturability (DFM)?

Design for manufacturing (DFM) means taking a design-first approach to manufacturing. In this article, we look at the overall DFM process, the necessary steps for a successful outcome, examples of DFM done right and how to get the most out of your own processes.

What is anodizing and how does it work?

What is anodizing? Anodizing is key to finishing parts made from aluminum and other metals. Learn how anodizing works and why it is an important part of CNC machining and manufacturing.

What are the different types of threads for manufacturing? Practical tips for engineers

What are the different types of threads for manufacturing? In this article, learn how to correctly design threads to reduce lead times and cost for your next CNC machining production run.

Standard blank sizes for CNC machining (sheets rods)

Tables of the standard blank sizes (sheets rods) commonly used in CNC machining.

What is heat treatment and how does it improve CNC-machined parts?

What are the different types of heat treatment and how do they affect CNC-machined parts? This article explores how heat treatments can be applied to many metal alloys to drastically improve key physical properties like hardness, strength and machinability.

How do you select the right materials for CNC machining?

This comprehensive guide compares the 25 most common materials used in CNC machining and helps you choose the right one for your application.

How to prepare a technical drawing for CNC machining

How do you prepare technical drawings for CNC machining and why are they important? Technical drawings are widely used in manufacturing to improve the communication of technical requirements between the designer and engineer and the manufacturer.

How to design parts for CNC machining

In this complete guide to designing for CNC machining, we’ve compiled basic advanced design practices and tips to help you achieve the best results for your custom parts.

14 proven design tips to reduce the cost of CNC machining

Make the most of CNC machining by optimizing your design and making the right material choices. Read these 14 design tips to help you reduce CNC-machining costs and create the perfect parts for your project.

Design Considerations for Machined Parts: 13 Design Features That Can Reduce Your Lead Times and Costs for Machined Parts

Sometimes, engineers and designers need machined parts cut and ready to go as fast as possible. Even at top speed, the goal is minimal cost for production without sacrificing quality. At Modus Advanced, Inc., we understand those CNC machining needs. Our goal is to produce world-class machined parts as quickly and affordably as possible every day.

Designers can help us further this goal while saving yourself some money and time in the process, thus leads us into our design rules for CNC machining series. If you implement these 13 design considerations for machined parts, you can reduce your lead time and costs for them. To discuss your unique needs with Modus Advanced, contact us today.

The information below is taken from a webinar hosted by Brian Beck, our Director of Engineering. You can watch the full webinar or read on for more information about how to reduce lead times and manufacturing costs for your CNC machining project and machined parts.

Go for Large Inside Corner Radii

Another design consideration for CNC machining is to keep in mind that inside corners are difficult to machine square. CNC machines commonly use a cylindrical cutting tool. Sharp inside corners can add a lot of lead time because they may require electrical discharge machining (EDM). EDM and specialized tools that create sharp inside corners also add to your total cost.

In general, the larger the inside corner radius, the better for your lead time. Larger inside corner radii allow for a larger-diameter tool that can run faster, reducing both cost and lead time.

Don’t Make s Too Deep

Deep s aren’t necessarily a good thing when it comes to machined parts. A deep is considered to be six times the tool diameter and can impact tool access. The deeper the in your design, the longer the cutting tool to cut the inside corners of that will need to be. A smaller corner radius inside the will call for a smaller, more specialized cutting tool to create those inside corners.

To reduce lead time and costs for your machined parts, keep your depths to around three times the depth of the tool diameter to simplify tool access. When possible, keep inside corner radii as large as you can to allow for a faster run with the tool. Smaller is always possible, but it costs you cycle time and actual costs for the part itself.

Pay Attention to Pre-Drill Tapping Depth

The drilling depths in your design for CNC machining must be deeper than the tapping depths. When you’re designing, keep in mind that every tap on the market has a certain amount of thread lead-in :

• Bottoming tap: 1 to 1.5 thread lead-in
• Plug tap: 3 to 5 thread lead-in
• Taper tap: 8 to 10 thread lead-in

You can avoid production hangups by ensuring that you’ve allowed for enough tapping depth and the drill depth necessary to produce full threads to the required thread depth.

If you are having trouble accommodating the necessary depth, consider making it a through-hole that allows us to drill straight through. This saves on time and cost.

Avoid Side Work in Multiple Orientations

Designs aren’t always simple, but simplicity is key when you need a part in 24 hours. One big way to save on time and costs is by keeping your side work as simple as possible.

Parts that have side work on opposing faces, or faces that are 90 degrees from each other, require an additional setup to machine the part. It’s possible, of course, but it’s one extra setup to program, validate and execute on the CNC machine.

Give Tapped Holes Some Wall Clearance

Check the location of the tapped holes in your design. Are any close to the inside of a ? This creates a high likelihood that the tapped hole will break through the inside wall when the part is machine made. Breakout will cost time and money to fix.

You can avoid breakout by creating more wall clearance between the tapped hole and the inside wall. Move the hole further from the side wall or use a smaller thread to create a tapped hole with a smaller diameter to machine.

Prefer Specified Edge Breaks Over Modeled Chamfers

Specifying your edge breaks can prevent machine operator errors during the CNC machining process that can cost a lot of money and time.

When you model the chamfer without specifying your edge breaks, it’s possible for the tech to select the wrong edge break when presented with multiple options.

For Heatsinks, Go Wide

Heatsinks are usually no problem, but you can reduce lead times and costs for these parts if you keep a few design priorities in mind. If possible, avoid tall fins spaced very closely together. This kind of heatsink design adds a lot of cutting time and forces us to use a tool with a tiny diameter on multiple finishing passes to get the right surface finish on the CNC machine. Avoiding a rounded top corner on the fins can also save multiple finishing passes of the tool.

The best time and cost saving practices for heatsink designs are making fins as short as possible, providing space between the fins and avoiding rounded top corners.

Design with Gasket Width in Mind

Avoiding gasket overflow is key to preventing problems with circuitry and avoiding longer lead and inspection times. If your housing’s wall thickness or the width of the dispensed gasket don’t match up, the fluid being dispensed can spill over the thin wall into the cavity, potentially causing shorting issues with whatever you are trying to shield.

When possible, a wider wall is better than a thin wall, so try to design your housing with your gasket widths squarely in mind. The minimum recommended wall thickness for metal is 0.8mm and 1.5mm for plastics. Aim for consistent wall thickness to make it easier to dispense the gasket in the center and across the entire wall.

Compression Stops Over Grooves to Control FIP Gasket Height

We see a lot of form-in-place (FIP) designs come through with a gasket intended to be dispensed within a groove. This creates a number of potential issues.

First, if fluid is being dispensed into the groove and the groove is relatively narrow, the fluid may contact the groove wall and cause the gasket to cure toward one wall rather than symmetrically in the center of the groove. This creates inconsistent compression forces and maybe even ineffective sealing.

How do you prevent this problem and save on inspection time and redesign costs? By designing with compression stops instead of grooves.

Instead of Small O-Ring Grooves, Use an FIP Gasket

If possible, try to use an FIP environmental gasket in your design instead of small O-ring grooves. Very small O-ring grooves take a lot of time to produce, which increases costs and total lead time.

Instead of O-ring grooves, you could incorporate a flat surface with compression stops on which an environmental gasket could be dispensed. That could take your CNC machining time from over an hour to less than a minute.

Keep Hardware to a Minimum

Extra hardware in your design means extra costs and time during CNC machining. While helicoils and similar hardware are usually readily available, some more specialized hardware can take a long time to acquire. A few helicoils in a design is usually manageable, but a design with more than 50 might take much longer to machine. On CNC machine, it’s much faster to tap a hole than to set up and validate a helicoil. To reduce your lead time and costs of CNC machining, keep extra hardware to a minimum.

For Quality Inspection Requirements, Be Specific

If certain dimensions in your design are going to be critical during the quality control inspection stage, specify those dimensions in your design. That gives us notice to FOCUS on those. That is not to say, of course, that we will not be accurate with other dimensions, but we may not have to generate an inspection report for them, which can save on lead time for you.

When Setting Tolerances, Go Big When Possible

A lot of designs will incorporate boilerplate tolerance ranges on the title block. This is generally not a problem in the CNC machining phase, but if it’s possible for your design to use a larger tolerance, that’s preferable if you want to reduce lead time and manufacturing cost.

Larger tolerances make it easier for us to prove out the process, maintain stability and, ultimately, get the part back to you faster. Always choose the largest possible tolerance that still meets design requirements

Modus Advanced Machined Parts: Less Lead Time, Quality

With Modus Advanced machined parts, you don’t have to sacrifice quality for speed. You don’t have to bust your budget either. You can control your lead times and costs by implementing the above design features and speaking with our team of experts. To reach Modus Advanced, call 925-960-8700 or contact us online today.

MANUFACTURED IN AUSTRALIA

In 2016, Nick and Josh Hacko made the decision to begin the process of building an in-house manufacturing facility for their watches. In 2020 NHW has the capability to make up to 85 per cent of their watches in house.

In 2021, NH Micro, the contract manufacturing arm of NHW was started, catering to parallel precision industries, as well as offering parts manufacturing for other watchmakers, locally and internationally!

BAR TURNING

Our Citizen R04 CNC lathe was the first machine we purchased in 2016. We use this machine to manufacutre the very small cylindrical components, such as the screws, pins, stems and pinion blanks that go in our watch. The maximum turning diameter is 4mm, meaning all the parts are smaller, in diameter, than 4mm! We specialise in cutting various materials, such as brass, tool steel and titanium.

CNC MILLING

Our Kern Pyramid Nano, 5 axis Ultra precision milling machine is the core of our manufacture. We use this machine to manufacture all the flat, large components, such as mainplates, bridges, dials, as well as large variety of smaller parts, such as gears, springs, and small plates.

GEAR HOBBING

Gear hobbing is the manufacturing method in which the gear teeth are generatively cut onto gear blanks. This method of manufacture is extremely accurate, and very stable. We are very proud to use our Affolter AF90 CNC gear hobbing machine to produce our in-house gears. Only a select few manufacturing facilities employ this process, manufacturing your own gear train is a mark of true independence.

WIRE EDM

Our Makino U32J wire EDM machine is our newest CNC machine. Electrical Discharge Machining (EDM) is a form or erosion based machining widely used in the Tool and Die and Medical sectors. We use this machine to cut prototype parts for our watches, as well as to cut extremely fine parts such as springs and gears. This type machining is quite new to the watch industry, as it trades low machining force and accuracy for long cutting times. We also use this machine to service our in-house tooling for our watchmakers and manufacturing facility.

Watchmaker manufactures small parts with a high-precision machine tool

Exclusive watches. “made in Australia?” Absolutely, thanks to Nicholas Hacko, a talented watchmaker who opened a small factory making high-quality timepieces in Sydney a few years ago. To be flexible and competitive, he invested in a high-precision 5-axis machining center from Kern Microtechnik, enabling him to reliably produce the micron-accurate parts, which are the basis for his business today.

Originally from Europe, the Hacko family has a long tradition of watchmaking. In 1992, when Nicholas Hacko emigrated to Australia, he already was in the third generation of his family who all succeeded in the watchmaking industry.

NH Watches has been designing and producing its own watches since 2016—watches made in Australia. Photos courtesy of Kern Precision

In 2011, Hacko took his first step towards making his own watches by founding his own small business called “Nicholas Hacko Watchmaker” – in short NH Watches. Initially, he repaired watches and manufactured replacement parts. Inspired and motivated by the high precision of traditional watch manufacturers and by using his expertise in high-quality workmanship and flawless assembly, five years later Hacko created his first entirely self-designed and developed watch.

Since then, the Australian has been living his dream and enjoying significant commercial success. He produces exclusive, unique timepieces in the price range from USD 1,200 to 11,000. As Hacko explains, he has already surpassed his original goal of making 100 watches per year: “Thanks to a long waiting list of enquiries from interested parties, we have already sold more than 600 watches after only three years. And the huge demand from Australia, Europe and Asia is still going up.”

In 2017, Nicholas Hacko invested in a used Kern Pyramid Nano: “This 5-axis machining center still has the same tremendous precision as it did at the beginning of its life. It produces each part exactly the way we program it—faultless.”

Producing microparts with μm precision

Besides its founder’s creativity and entrepreneurial spirit, Hacko believes that two additional factors are crucial for the success of the brand. First of all, of course, his employees, seven highly motivated people and three of them are apprentices learning the watchmaker’s trade. And then he underlines the importance of his equipment and introduces the Kern Pyramid Nano, a high-precision 5-axis machining center he has been using since 2017. “This machine mills very small gears, bridges, pallets, mainplates and other micro parts with greater precision than is actually necessary,” Hacko said.

Or, to put this into numbers: Hacko typically needs a production accuracy of between 6 µm and 10 µm to ensure his watches keep perfect time throughout their life. In exceptional cases, XY pitch accuracy of just /-2 μm must be met when drilling and interpolating holes in metal plates. The Kern Pyramid Nano, developed for ultraprecise production by Kern Microtechnik GmbH, Eschenlohe, Germany, reliably achieves a machining accuracy of less than 1 μm—throughout the entire service life of the machine.

NH Watchmaker reliably produces micron-accurate parts using the Pyramid Nano.

This outstanding level of performance is the result of numerous technical refinements that were incorporated into the machining center’s development. While Matthias Fritz, head of development at Kern, is not prepared to reveal all of the Pyramid Nano’s secrets, he is happy to name a few key factors: “We’ve equipped the Kern Pyramid Nano with complex, hydrostatic guides and drives that are not subject to any mechanical wear. In addition, our hydrostatics dampen any vibrations, so even high rates of acceleration have no effect on the machining accuracy.” The result is a machining center in which productivity and precision go hand in hand.

This is just one of the reasons why Kern machining centers are in widespread use throughout the watchmaking industry—the Australian watchmaker had long had his eye on a machine made by the Bavarian precision experts. At the AMB trade fair in 2016 in Stuttgart, Germany, he saw a Kern machine in action for the first time, which only confirmed his opinion: “I was convinced that a machining center of this type would be ideal for my needs.”

Udo Reinwald, Kern sales director Asia, invited NH Watches to Germany in February 2017 to discuss some options at the company’s machine engineering factory in Eschenlohe, including the possibility of purchasing a used machine. The result was that Hacko found what he was looking for. In the summer of 2017, when a Swiss luxury watch company replaced a Kern Pyramid Nano with a new Kern milling center, Hacko immediately decided to buy the used machine.

During a training course in Eschenlohe, Germany, a small team from NH Watches learned how to operate the Kern Pyramid Nano. From left to right: Christopher Soto, Tyler Hailwood and Josh Hacko with Kern TC-leader Thomas Mauer.

A used Kern machine with flawless precision

After inspection and maintenance by the Kern service department, the transaction was soon completed—Hacko can now personally confirm Kern’s claim that the machine’s performance and precision remain unchanged throughout its service life. “It’s just like my watches,” he beams, before expressing his satisfaction with the usability of his 5-axis milling center: “We took a small team from our company to Eschenlohe, Germany, where we received excellent training in the Kern Training Center.”

During their visit, the Australians learned all the skills needed to reliably produce high-quality parts, including programming with Heidenhain conversational code, using the right tools and setting up the milling center.

The machine’s final adjustments and commissioning in Sydney also went very smooth. With on-site support from a Kern service technician, it was ready for use in early March 2018. It has been running with the help of Kern’s teleservice support ever since and “produces each part exactly as we program it. It simply doesn’t make any mistakes,” says Nicholas.

If required, the 5-axis machining center can mill parts with sub-1-μm precision.

Thanks to its investment in the Kern machine, NH Watches can now serve its customers much faster and further increase its sales. In the past, the company had no choice but to purchase the required small parts externally and, being a minor customer, was not always high on the supplier’s priority list. In addition, because the plates, gears and other parts required by NH Watches were primarily produced overseas, the parts deliveries were sometimes subject to unforeseeable delays. Interesting side effect: The raw materials used to produce these parts, such as brass in the mainplates and bridges were originally mined and exported from Australia to Korea. They were machined in Korea and were reimported back to Australia as processed bar material. A logistical odyssey that is no longer needed.

High-precision microparts, such as these boards and gears, ensure that the watches stay tuned.

Contract manufacturing as a new business area

Recently, NH Watches has found another way to utilize its new production capacity—as a contract manufacturer for industrial companies that need highly precision parts. With no significant competition for this service in Australia, Hacko is now expanding his business and already supplies several companies in the medical and moldmaking industries. He sees significant potential for the future in this area.

“It’s a great feeling to be the only entrepreneur in Australia with a high-precision machining center of this type, Hacko said. I’m sure this gives us a lot of growth potential and I’m looking forward to being able to buy more Kern machines in the future.”

centers

Cone-shaped pins that support a workpiece by one or two ends during machining. The centers fit into holes drilled in the workpiece ends. Centers that turn with the workpiece are called “live” centers; those that do not are called “dead” centers.

machining center

CNC machine tool capable of drilling, reaming, tapping, milling and boring. Normally comes with an automatic toolchanger. See automatic toolchanger.

milling

Machining operation in which metal or other material is removed by applying power to a rotating cutter. In vertical milling, the cutting tool is mounted vertically on the spindle. In horizontal milling, the cutting tool is mounted horizontally, either directly on the spindle or on an arbor. Horizontal milling is further broken down into conventional milling, where the cutter rotates opposite the direction of feed, or “up” into the workpiece; and climb milling, where the cutter rotates in the direction of feed, or “down” into the workpiece. Milling operations include plane or surface milling, endmilling, facemilling, angle milling, form milling and profiling.

milling machine ( mill)

Runs endmills and arbor-mounted milling cutters. Features include a head with a spindle that drives the cutters; a column, knee and table that provide motion in the three Cartesian axes; and a base that supports the components and houses the cutting-fluid pump and reservoir. The work is mounted on the table and fed into the rotating cutter or endmill to accomplish the milling steps; vertical milling machines also feed endmills into the work by means of a spindle-mounted quill. Models range from small manual machines to big bed-type and duplex mills. All take one of three basic forms: vertical, horizontal or convertible horizontal/vertical. Vertical machines may be knee-type (the table is mounted on a knee that can be elevated) or bed-type (the table is securely supported and only moves horizontally). In general, horizontal machines are bigger and more powerful, while vertical machines are lighter but more versatile and easier to set up and operate.

sawing machine ( saw)

Machine designed to use a serrated-tooth blade to cut metal or other material. Comes in a wide variety of styles but takes one of four basic forms: hacksaw (a simple, rugged machine that uses a reciprocating motion to part metal or other material); cold or circular saw (powers a circular blade that cuts structural materials); bandsaw (runs an endless Band; the two basic types are cutoff and contour Band machines, which cut intricate contours and shapes); and abrasive cutoff saw (similar in appearance to the cold saw, but uses an abrasive disc that rotates at high speeds rather than a blade with serrated teeth).