How to Adapt the Fixture & Jigs to Intelligent Manufacturing
Recycling of chips and scrap metal is a matter of course for most machine shops; sending this material off to a processor is a way to reclaim some of the capital invested in stock that cannot be used otherwise. But what happens to that metal once it is out of sight? Is there a way to not just recycle, but upcycle, that material into something even more valuable?
This is part of the vision of 6K Additive, a materials processor based in Pennsylvania that has developed a way to turn various types of metal into high-value, infinitely flexible powders that can be applied in 3D printing. The technique can be used to refurbish leftover powder from the laser powder bed fusion (LPBF) process; refine oversized powder produced through gas atomization; or transform metal chips, grindings and even full parts into usable powder.
6K Additive has developed a process that cleans and mills metal chips like these turnings (left) into a mechanically sized powder (center), which is then passed through microwave plasma to be densified and spheriodized into metal powder suitable for additive manufacturing (right).
6K Additive uses a two-step process to do this. First, the feedstock material is cleaned and mechanically milled down to the desired size. Then, the particles are passed through a column of microwave plasma using one of the company’s UniMelt reactors. The plasma melts each particle just enough to densify and spheroidize the material into powder suitable for additive manufacturing (AM). Each pre-milled particle remains distinct during this step and cools quickly, so that the final powder can be collected soon after.
One of the UniMelt reactors at 6K Additive’s Pittsburgh-area plant. Read more about the company’s material processing technique.
By separating the sizing of powder from its densification and shaping 6K Additive has been able to overcome some of the challenges of gas atomization, a common means of producing metal additive manufacturing feedstock. In gas Cemented Carbide Inserts atomization, large amounts of metal are melted and dropped through a stream of gas to produce spherical particles; once cooled and solidified, the entire lot of material is then sieved and sorted into various grades, which can result in waste when powder that is too large or too small results.
In contrast, because the UniMelt reactors use material that is already pre-milled down to size, it is nearly a 1-to-1 process. Without the need to melt large amounts of material, it does not need to produce a large batch in order to be economical (and may be more energy efficient). The mechanical step can also support the production of alloys that would not be possible otherwise.
Thanks to mechanical milling and an efficient microwave plasma process, 6K Additive does not need Carbide Turning Inserts to produce large batches of powder which can make new alloys and unusual materials more accessible.
But the potential of this technique extends beyond 6K Additive and even beyond additive manufacturing all together. A process that can make use of existing material rather than requiring virgin feedstock not only provides a home for scrap like machining chips, it also keeps valuable material local.
Consider that the United States has no domestic source for mining of titanium; like many other alloys, most of the stock comes from China so virgin titanium must be imported. Yet with an efficient recycling strategy, the U.S. could mine its own chip bins and aircraft boneyards and more for titanium feedstock. (6K Additive even envisions a future where large OEMs might have their own UniMelt reactors to convert scrap right on site.) And once converted into feedstock for additive manufacturing, the potential applications might be limitless.
Learn more about UniMelt and 6K Additive in this feature article on AdditiveManufacturing.Media.
An example of when traditional manufacturing goes wrong
The chatter in machining occurs in almost all manufacturing processes. The heavy machines used in manufacturing generate a high amount of vibration, resulting in poor surface finish and a decline in dimensional accuracy.
Machinists must deal with this undesired vibration in different processes like CNC turning, milling, or drilling. However, understanding machining chatter and its causes and knowing how to avoid it would be helpful as it helps to prevent downtime, which is terrible for businesses.
This article discusses the chattering definition, types of chattering, its consequences, and how to avoid it.
What is Chatter in Machining?
Chattering in machining is the unwanted vibration that occurs when cutting or drilling parts. The chatter is due to the vibration imbalance of the workpiece and tool repeatedly moving relative to each other. The vibration occurs when the machined part and the cutting tool move in opposite directions, causing the machining tool’s varying cutting load per rotation.
This may be due to improper design for manufacturing or inadequate tooling. The chattering usually produces loud noises and visible waviness on the surface of the machined components. Machining chatter is in two forms, namely:
- Resonate vibration
- Non-resonate vibration
Non-resonate vibration occurs as a result of using unequally worn tools on workpieces. This vibration is often constant throughout the machining cycle and due to mechanical causes that are easy to examine.
On the other hand, resonate vibration occurs at specific stages in the tool path, like machining concave corners.
Types of Chatter in Machining
There are two major types of chatter that you can encounter in CNC machining. They include the following:
Tool Chatter
Generally, CNC milling cutters vibrate during cutting operations. They begin trimming while transferring the vibration to the workpiece they add various features. As a result, the tool and the workpiece begin to slip against each other, causing the chatter to increase significantly.
Workpiece Chatter
Sometimes, when you fix the workpiece on the milling machine’s worktable incorrectly, it may result in some offsets and vibrations. Consequentially, the workpiece’s thin wall may begin to vibrate while it transfers to the cutting tool.
It is important to note that some chatters are often unavoidable. If the vibration that occurs during machining is more than 100μm, your workpiece may suffer scratches on the surface. However, it would be best if you considered doing something about the tool and workpiece chatter for the quality of your product. We will discuss how to avoid chatter below.
What are the Consequences of Chatter in Machining?
Machining chatter, if left uncontrolled, can result in various detrimental effects, such as lowering machining efficiency. Here are some of them:
Reduced Tool Life
Cutting tools cannot handle the vibrating impacts of the tools chattering against the workpieces. These jarring effects can chip and blunt the cutting tool, damaging the surface quality of the cut parts. Also, it reduces the tool life and cutting efficiency, and the tooling replacement is expensive.
Reduced Machine life
The machine tool used in different machining components comprises various parts such that when there is vibration, these components vibrate at the same frequency. The spindle and other essential members producing the different axes of motion may begin to wear out faster than supposed. As a result, machine chatter puts machine components under undue stress, and if left unchecked, it can reduce machining efficiency and cause downtime.
Poor Surface Finish
Chattering in machining affects the workpiece’s aesthetic properties and can diminish its tolerances in extreme situations. One of the most APKT Insert apparent consequences of machine chatter is poor surface roughness. The chattering causes visible waviness on the surface, which compromises the quality and durability of the part.
Reduced Dimensional Accuracy
When a cutting tool chatter during CNC machining, it derails from its CAM-initiated path. This deviation, however, can cause the parts to have ill-fitting. These parts may be too tight, too long, too short, or too loose due to inaccurate dimensions.
How to Avoid or Minimize Chatter in Machining?
Manufacturing companies employ different methods to minimize the chatter in machining operations and ensure that both workpieces and cutting tools are in good condition. Here are some of these steps on how to reduce chatter during CNC machining:Carbide Inserts
Optimize Machining Strategy
The degree of cutter engaging the workpiece varies with conventional milling. Excess force is regularly exerted on the milling cutter as it moves along the path. Therefore, the best way to reduce the chatter is to attain a regular engagement toolpath. You can reduce the depth of the cut as an alternative.
Also, try to reconsider the configuration of the spindle. For instance, if resonate chatter is the cause of the machining vibration, increase or reduce the machine’s RPM by 5%, and it will minimize the resonance vibrations occurring. Note that some CAM software has features that allow you to vary spindle speeds consistently. Most manufacturers adopt this feature due to its versatility.
Adopt the Right Work Holding
Balanced machine tools feature better adjustment. Several factors, such as incorrect positions and fixings, are the leading causes of chattering in CNC machining. However, the tool holder with end face and tape contact helps to ensure maximum rigidity during machining. As a result, the surface quality of components is not compromised at the lowest RPM.
You also need to check whether the machinist vice, vacuum table, chuck, or other workholding device applies adequate pressure to the workpiece to keep it firm and stationed.
When considering employing jigs and fixtures to exert clamping pressure as required, however, do not clamp only one end of an extended, thin workpiece. It is rather difficult for thin-walled parts to absorb shock. As a result, filler materials enhance their overall stiffness and reduce chattering. A tailstock or similar form of stable rest frame is an ideal option for such components.
Use the Right Cutting Tool
Using the right cutting tool helps to avoid machining vibration. Some cutting tools generate more vibrations than others. It isn’t easy to eliminate tool chatter as that of a workpiece. As a result, you should consider the following factors in any tool of choice:
- Coating of a tool
- Correct substrate geometry
- The aspect ratio of a tool
Machinists and engineers often utilize the largest machine tool that fits well if it meets the technical specifications. The more solid a cutter is, the less it is likely to chatter. Long or thin tools often deflect. Hence, consider choosing shorter tools with the largest diameter.
However, combining various tools with varying groove shapes is the most effective way of minimizing chatter in machining. Additionally, consider reducing the tools protruding from the holder and fixing them tightly. Machine chatter is less likely to occur after doing this.
Ensure that your cutters have sharp blades that minimize the cutting force of CNC milling machines. You should always consider the stability of the processing environment and prompt maintenance of the cutter. Likewise, it is crucial to apply proper and consistent tool pressure so that the chip load is regular.
Determine the Ideal Tool Path
CNC milling operations are of two types – upward milling and downward milling. If you exert the cutting force in the same direction as the clamping direction, it can reduce the chattering of bent parts. It is often an essential aspect of cutting that needs consideration.
Generally, CNC mills have pre-installed ball screws which aid the efficiency and precision of CNC machine technology. As a result, you can employ a vertical machining center to prevent chattering during the cutting process.
Machine Setting and Maintenance
As expected, your CNC machine should be installed on a concrete floor without any cracks, deformities, or discontinuities. You should know that the arrangement of your machine plays a crucial role in minimizing the chattering that occurs during machining.
It is because elastic, soft, or damaged flow may increase the trembling of a CNC entity. Therefore, you should consider utilizing anchors and adjusting feet to keep the CNC unit firm and steady to minimize chatter.
WayKen Helps Provide Effective Machining Solutions
It is always difficult to avoid various small problems in machining operations, such as chatter, which can affect the final result. That’s when you need to have a CNC machining expert to help you deal with it.
At WayKen, with over 20 years of machining experience, our machinists are ready to respond and solve any machining challenges. From simple to complex shaped parts, we are always able to provide effective machining solutions in a cost-effective manner. As a result, you can be confident that you will get the product you want. Just upload your CAD file today and get a free quote and DfM feedback.
Conclusion
Chattering is a machining effect that causes a substantial decline in productivity. It affects machine performance, workpiece quality, cutting tool, and machine tool life. Various factors contribute to its occurrence ranging from where the machine is installed to the toolpath.
However, whenever you experience severe vibration, inspect the occurrence thoroughly. Ensure that the tool and the workpiece are held correctly and the configured machining options are correct to mitigate this chattering efficiently.
FAQs
What are chatter marks in machining?
Chatter marks are irregular surface defects left by a wheel that is out of turn in grinding or regular mark formed when turning a long workpiece on a lathe due to machining vibration.
What causes chatter in machining operations?
The cutting forces created during the cut will increase significantly if your machine tool has excessive wear. Increased cutting force usually results in chatter while cutting rigid substrate.
What causes vibration in rotating equipment?
The most common causes of chattering or vibration in rotating equipment include misalignment, imbalance, wear, and looseness. The imbalance of a heavy region within a rotating component will result in vibration when the unbalanced weight sins around the machine’s axis, generating a centralized force.
How can I identify chatter in machining?
CNC machine chatter is usually audible. Hence, an experienced machine operator can successfully identify when chatter occurs using its distinctive sound. Also, machining chatter makes visible wave marks on the surface of a workpiece.
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CAD is a term that stands for Computer-Aided Design. It is the process of using computer software to create three-dimensional models of proposed products. This type of software is used by many industries in order to create drafts and models. It can be used to design both two-dimensional drawings and three-dimensional models with precise measurements.
If you are reading this article, probably you are seeking to know the benefits of CAD over manual hand drawing and/or its importance in rapid prototyping and computer-aided manufacturing. It is important to realize the crucial role of CAD in design and how it is simplifying the product development workflow, especially in this era, in which remote working is becoming the new normal.
Contents hide I What is Computer-aided design Design (CAD)? II What Advantages Does CAD Have Over Manual Drafting? III Industry Applications of CAD IV CAD and CAM (Computer Aided Manufacturing) V CAD in Rapid Prototyping and Manufacturing VI Conclusion VII FAQWhat is Computer-aided design Design (CAD)?
The origin of computer-aided design software trace back to 1963, when Ivan Sutherland developed Sketchpad and Dr. Patrick J. Hanratty introduced Automated Drafting and Machining (ADAM) in 1971.
Since then, computer-aided engineering and design software has come a long way and become more advanced as computer system improves by introducing an automated set of features and design tools making the design workflow easy and pleasant. Prior to the development of CAD, designers use pencils, rulers, compasses, drawing boards, set squares, etc. to create 2D drawings.
CAD is an abbreviation standing for Computer-Aided Design, which is the use of computer software for 2D and 3D modeling of products and structures in engineering, architecture, and industrial product design. It is more than a replacement for paper and pencil sketching as it has brought a whole new level of possibilities for engineers, designers, technicians, and architects.
What Advantages Does CAD Have Over Manual Drafting?
CAD provides a number of advantages over manual drawings that make it an essential tool in the design market today. These advantages help the contemporary engineer or product designer in a number of ways.
1. Productivity
CAD programs are continually evolving by adding various tools and features that boost the productivity of the designing process. These tools help cut the time of product development which in turn reduces production costs and reduces error by leaving fewer rooms for mistakes which also improves the quality of the product.
With manual hand drawing, if changes were required, sketches should be thrown away and started entirely from scratch. Digital drawings can be edited far easily using a CAD design program and an infinite number of modified variations can be made without having to redraw them from the beginning. Different parts of a single model can be made drawn separately by different designers and get assembled in CAD.
And, almost all CAD systems have a set of standard components (for example fasteners like bolts, screws, nuts, etc.) from which the designers can pick their suitable size and assemble it. 2D drawings, sectional views, detailed CNMG Insert drawings, and auxiliary views can be generated from 3D models in the preferred standard convention.
2. Accuracy
Manual drafting is not competent with CAD drafting in creating precise technical drawings. CAD programs have features and tools that are developed as per design and drawing conventions and standards which helps designers reduce error percentages. And, complex features of design which will be extremely difficult with a manual drawing can be made far easier in CAD.
3. Legibility
Manual drawings may get unclear sometimes which will not be the case in CAD drawings. Even if the model is highly complex, having a lot of parts and features, CAD programs have to hide and show tools to eliminate temporarily unimportant parts and focus on the specific detail of the rest which is not totally Carbide Aluminum Inserts possible with paper and pencil drawing.
Further, the availability of 3D isometric and section view in CAD designs enhances visibility and understanding as they make turning and slicing possible respectively which is again very time-consuming work in manual designing.
4. Presentation
It is easy to influence your customer and fellow workers by presenting your design with virtual models without having to manufacture a prototype as you can simulate movements, show internal parts by sectioning and show it from different sides. You can even communicate the function and aesthetics of your design to a layman with no engineering background easily with a rendered 3D model in which different parts have different colors.
5. Subsequent Operations
?Other than creating drawings, CAD software has the capability of engineering computation and analysis with mathematical equations. For instance, the product designer can calculate geometrical properties (area, volume, the center of gravity, etc.) and mass properties (mass, density) of the model usually with a single click in CAD programs.
Further, a lot of CAD programs support motion study and simulation, parametric modeling, structural, thermal, fluid, etc. finite element analysis which help designers analyze and enhance their model strength, functionality, and other properties prior to manufacturing.
Sharing and Collaboration
Another huge advantage of CAD drawing over manual drawing is that one designer can make a model and send it to another even if they are on the opposite side of the world. The receiver can view the model history, see exactly how it is designed, and edit it. ?This is too difficult with manual drawing.
Most CAD systems are continually making collaboration easy for remote working by adopting cloud sharing and automated data management tools that enable engineers to edit the same design simultaneously in real time from anywhere and on any device.
6. Documentation
After modeling, linear and angular dimensions and measurements of parts, assemblies and sub-assemblies, and bills of materials are digitally recorded and saved for future reference and use. In the case of traditional manual drawing, the sketch paper should be shelved which is prone to damage and deterioration.
Industry Applications of CAD
Nowadays, commercial CAD software packages are a must to have design tool in factories, design offices, and academics as it saves time, and ensure good collaboration and seamless integration with other computer-aided production systems like CAM.
A lot of industries; including factories, architecture, product design offices, etc. utilize CAD as it optimizes the design workflow and delivery of the final product. CAD enhances collaboration within the firm and across industries and concurrent engineering works.
CAD and CAM (Computer Aided Manufacturing)
In addition to creating models just as imagined, CAD is used in tandem with digitized manufacturing in a process called CAD/CAM. When combined with CAM, CAD assists in the entire phases of producing a product, including process and production planning, scheduling, production management, and quality control.
In CAD/CAM, the design and production processes are blended together as the electronic output file of CAD software is used in part production processes. This allows changes to be made at any part of the workflow and reduces the time to go from raw materials to finished products.
CAD software makes it possible to perform structural, thermal, vibration, motion steady-state, and transient simulations to investigate and diagnose problems. This helps to make small changes by iterating the design parameters and seeing improvements.
CAD in Rapid Prototyping and Manufacturing
In rapid prototyping, designers can bring their imagination and innovative ideas to physical life right the first time without having to make multiple iterations. This gives an incredible opportunity for communicating your ideas with colleagues, customers, or even end-users visually and with hands-on experience and getting feedback and design concept proof.
Rapid prototyping minimizes time and waste, and promotes the creative design process, especially for companies offering custom and complex products. Almost all rapid prototyping methods rely on Computer-Aided Design to create prototypes, and hence we can say CAD is the heart of rapid prototyping. So, let’s briefly look at how CAD automates both machining and additive manufacturing rapid prototyping techniques.
1. CAD with CNC Machining
CNC prototyping comprising precision multi-axis milling, turning, EDM, wire EDM, and grinding is a subtractive process in which the prototype is made by removing a bulk of the material. The broad range of engineering materials that are difficult to shape with other prototyping methods can be made with CNC machining. Most CNC machines work with G-codes which dictate the cutting tool direction, cutting speed, feed rate, and depth of cut. And G-codes can be obtained from the DXF format of CAD files.
2. CAD with 3D Printing
CAD software provides users with the tools they need to create a 3D model from scratch. This model can then be processed, sliced, and sent to a 3D printer for printing. Creating a 3D model is the first step in making a physical, real-world replica of an object or concept.
With CAD software, you can export your model to a file format compatible with slicing software. This slicing software translates the model into G-code instructions that can be interpreted by a 3D printer. Once the printer has these instructions, it can create a physical replica of the original digital model.
3. CAD with Vacuum Casting
Vacuum casting uses silicone molds to make high-quality plastic and rubber components under vacuum. The master pattern used for mold making is made with a 3D CAD model and manufactured with one prototyping technique.
Conclusion
There are a number of advantages to using CAD in rapid prototyping as well. CAD software is constantly evolving and becoming more user-friendly, making it easier for those with little experience to create complex models. Additionally, CAD-created prototypes can be easily modified and tested, allowing for a more efficient design process.
Already have a CAD file and are worried about how to bring your ideas to life? WayKen is always here to help you.
We are a leading rapid prototyping manufacturer with an outstanding track record for producing high-quality prototypes and machined parts. With our years of machining experience and approaches, we can handle a variety of processes, including CNC machining service, 3d printing, injection molding, etc. So, Upload your CAD file today, and we will take your CAD blueprints and bring them to life in the best way possible.
FAQ
Which software is used for CAD?
The popular CAD software is, AutoCAD, CATIA, Fusion 360, Inventor, SolidWorks, Onshape, and Solid edges.
What are the advantages 3d over 2d cad drafting？
?The 3D model has better visualization for a person with no knowledge of engineering drawing. It has more satisfaction than 2D when the designer looks at it. Of course, we can generate 2D views from 3D models
What is the limitnation of CAD?
Sometimes a designer can have a fancy imagination in mind which can be modeled in CAD but is costly for physical realization. A CAD user needs the training to use each commercial CAD programs
