China Shenzhen Perfect Precision Product Co., Ltd. company news

What is CNC milling? Although the methods of removing materials are different, first of all, CNC drilling and milling machines and CNC lathes remove materials to produce a part. A machining center usually combines two methods and multiple tools on one machine. All of these have a multi axis motion function to guide the cutting tool around and through the workpiece to create the exact shape required. The basic difference between the two methods is that the milling machine uses a rotary tool to cut the workpiece, while the lathe rotates the workpiece and the engagement is completed by the tool. How does CNC milling work? Before the introduction of computer numerical control (CNC), milling machines and lathes were operated manually. As the name implies, CNC automates this process, making it more accurate, reliable and fast. Now, a trained operator encodes the G code (representing geometric code) into the machine, usually through software. These control milling machines, each controlling stroke and speed, so that it can drill, cut, and shape materials to meet specified dimensions. There are many different types of CNC milling machines. The most common is a 3-axis machine tool, which moves on the X, y and Z axes to provide tools for 3-dimensional manufacturing. The three-axis machine tool can produce more complex features by rotating and resetting the workpiece to allow access from multiple angles. On a five axis machine tool, this capability is optimized by adding motion in two directions, i.e., rotation around the x-axis and the y-axis. It is an ideal choice for producing complex and precision parts. However, the disadvantage is that using this technology will break your budget, because complexity increases costs. Believe it or not, you can define any 3D geometry with 5 motion axes. However, it is unrealistic to hold the workpiece and rotate freely in all directions. This would be a machine with 6, 7 or even 12 axes. However, unless you need extremely complex parts, you are unlikely to need such a machine -- because the investment is huge, and the size of the machine is also the same! What is the next step in CNC machining? As you can see, the development of more and more complex CNC milling machines requires more and more professional knowledge to operate, which requires a lot of time. Even if you outsource numerical control processing, the cost of this complexity will be higher, because professional manufacturers must recover their investment. If you have an extremely complex part that requires incredible accuracy and requires a lot of use, you may be able to justify the investment. For most jobs, 3-axis or up to 5-axis machining is more than enough. After all, there is always more than one way to solve a problem -- for example, it is much better and cheaper to design two or more less complex parts and then bolt, weld or connect them as part of the secondary assembly process than to try to process an extremely complex single part. So why do so many people pay attention to developing new expensive and huge machines, and the profits generated by these machines are getting smaller and smaller? It's a bit like a Microsoft office. Most of us use word, but in fact we may only use 20% of the content it provides. However, Microsoft continues to add new features, most of which we may never need, use or even know. Instead of gradually improving the process, we think it is better to improve the process itself. This is where we can make real gains. Process automation Let's go back to the beginning and study the process of making a part. All this begins with the designer designing the required parts or components on his CAD system. In general, an experienced person is responsible for G code programming of computer aided manufacturing (CAM). However, once the design is in place, why add another step? The good news is that you can use many CAD packages to convert your CAD into G code -- but we need to go back one step. Once you have designed your part, how do you know that it can be manufactured by CNC machining and meet the tolerance you require? Your CAD should be a digital line connecting everything with little or no human intervention. After all, with industry 4.0, we should all live in an interconnected world. Most of the work of NC machining still depends on experienced machinists. When you send your design, there is usually a person to check whether it can be made with a known process. If not, I need to tell you so that you can redesign or optimize the design. At protolabs, we have automated this process. Once you send your CAD data, our software will check its feasibility and generate a quote. If the proposed modifications are necessary, they will be displayed to your CAD in the feasibility report automatically generated by the software. Once you agree to design and manufacture, our software will create the code required for processing as specified in the quotation. Faster and more cost-effective This makes the process faster and more cost-effective, which can have a real impact on the prototype design and testing of small and medium-sized work or new parts. Thanks to the automation, this service is the same for everyone, regardless of the size of the project. It is understandable that traditional engineering companies will give priority to projects that can make them more money -- whether it is due to the scale of work or the complexity of the components required -- of course, it depends on their ability. The automation of the process makes the competitive environment more fair. Therefore, for prototyping or requiring a small or medium number of parts, you can still benefit from the same speed and quality of service. Because all this information is generated and collected from the beginning, we can cut and deliver customized CNC milled plastic and metal parts in just 24 hours. If you are not in a hurry, you can choose a later delivery date and reduce your costs - so you can even set the terms yourself. This process starts with your CAD, which means that after you design your parts, we have a digital line that we can use in the whole CNC processing process - from your computer to delivery. Automation is not only a problem of CNC milling and turning. It includes everything from design. This is the future of CNC milling. This is the real industry 4.0 action.

The main advantages of the full-automatic drilling machine are as follows: 1. The mechanical operation is simple and convenient: the operator only needs a brief understanding, and one person can control 4-5 machines, greatly reducing the labor cost. 2. High power: generally, an automatic drilling machine can complete the operation requirements of hundreds to thousands of workpieces in an hour according to the size of workpieces. A full-automatic drilling machine can operate continuously, stably and quickly for many hours, improve the output power, and the transmission system is precise and simple. The equipment consumption is low, the operation is more stable, the failure rate is extremely low, the maintenance is more convenient, and the replacement fixture is convenient. It can be used for a variety of similar products to share this equipment, And the production cost can be saved. 3. Intelligent transformation: all actions are controlled by software, equipment parameters are set flexibly, technology is advanced, and function adjustment is convenient. It is the main content of the use and management of CNC equipment. Main advantages of full-automatic drilling machine: 1. The mechanical operation is simple and convenient: the operator only needs a brief understanding, and one person can control 4-5 machines, greatly reducing the labor cost. 2. High power: generally, an automatic drilling machine can complete the operation requirements of hundreds to thousands of workpieces in an hour according to the size of workpieces. A full-automatic drilling machine can operate continuously, stably and quickly for many hours, improve the output power, and the transmission system is precise and simple. The equipment consumption is low, the operation is more stable, the failure rate is extremely low, the maintenance is more convenient, and the replacement fixture is convenient. It can be used for a variety of similar products to share this equipment, And the production cost can be saved. 3. Intelligent transformation: all actions are controlled by software, equipment parameters are set flexibly, technology is advanced, and function adjustment is convenient. Hebei CNC drilling machine automatic drilling machine usually uses German advanced motor to match the operation of multiple gears, which makes the equipment run smoothly and reduces the error. The layout of the automatic drilling machine is suitable for the factory environment. A common reason for selecting PLC is that it can work normally in the factory environment. However, most PLCs are installed in the nematic box. However, in such an environment, the additional cooling equipment of the PXI channel, the consolidated external appearance and the enhanced impact and oscillation resistance target all make the system as reliable as PLC. The automatic drilling machine has a strong expansion function: engineers expect to use a flexible automation system to meet the needs of continuous updating, so they require the control system to be modular, sensitive and flexible. Because PLC system is constrained by I / O, it can only be flexible in digital and motion. PAC not only has the flexibility of PLC, but also you can add vision, modular instruments or high-speed analog I / O to the system. It is also possible to use multiple PCs via Ethernet and add or reduce the number of PCs as required. In order to process qualified parts on the full-automatic drilling and tapping machine, firstly, according to the accuracy and calculation requirements of the part drawing, analyze and determine the process flow, process parameters and other contents of the parts, prepare the corresponding NC processing program, and specify the NC programming code and format. Attention must be paid to the specific CNC system or machine tool of the full-automatic drilling and tapping machine, and the programming shall be carried out in strict accordance with the provisions of the machine tool programming manual. However, in essence, the instructions of the CNC system of each fully automatic drilling and tapping machine are set according to the actual processing technology requirements. Whether it is a CNC lathe or a machining center, it is very important in the machining industry. If you need a full-automatic drilling and tapping machine, please call us and let us solve your processing problems! The automatic drilling machine has a variety of processing dimensions, which can meet the processing requirements of various industries. Draw inspection grid or inspection circle: after the line is drawn and the inspection is qualified, the inspection grid or inspection circle with the hole center line as the symmetry center shall be drawn as the inspection line during trial drilling, so as to check and correct the drilling direction during drilling. Proofing and punching: carefully proofing and punching shall be carried out after the corresponding inspection grid or inspection circle is drawn. First make a small point, and measure it in different directions of the cross center line for many times to see if the punching hole is indeed hit at the intersection of the cross center line, and then punch the sample punch with force to correct, round and enlarge, so as to accurately cut and center. Clamping: clean the machine table, fixture surface and workpiece reference surface with a rag, and then clamp the workpiece. The clamping is flat and reliable as required, and it is convenient for inquiry and measurement at any time. Pay attention to the clamping method of the workpiece to prevent the workpiece from deforming due to clamping. Although the automatic drilling machine is more expensive than the general drilling machine, it is a one-time investment. Drilling and tapping machine The imported modular solid-state relay with self maintenance function, which is the world's leading technology, is used for circuit control, and the original imported components are matched to make the machine function stable.

When designing 3D printed parts, one of the most important considerations is wall thickness. Although 3D printing makes prototyping easier than ever in terms of cost, speed and DFM (Design for manufacturing), you cannot completely ignore DFM. Therefore, the following provides some guidelines for 3D printing wall thickness to ensure that your 3D printing is actually printable and has a reasonable structure. Therefore, you can design prototypes, produce 1 quantity, and finally produce 100 or more than 10000. Wall thickness recommendation The thickness of part features designed for 3D printing is limited. The following table lists the minimum thickness of each material we recommend, and the minimum thickness. We have successfully printed the parts to our ultimate minimum thickness, but we can only guarantee that the parts can be successfully printed to our recommended minimum thickness or above. According to our recommended minimum value, the thinner the part, the higher the possibility of error during printing. Anything below the limit minimum is actually not printable. Why are there restrictions During and after printing, a variety of constraints need to be considered. During printing The 3D printer prints one layer of parts at a time. Therefore, if a feature is too thin, there is a risk of the resin deformation or peeling, which means that there is not enough material contact to connect it with the rest. In addition, just as you need a solid foundation to build a stable structure, if the part is being printed but the wall is too thin, the resin may bend before drying or curing. Therefore, the thin wall will bend, resulting in warpage of the part. After printing Even if thin-walled parts are successfully printed, fragile parts still need to be cleaned and the supporting material removed before they can be considered successful. The cleaning method includes spraying water and removing residues, so many thin parts break at this stage. In addition, in order to print such thin walls, additional support materials are usually required. After cleaning, the supporting material disappears and the components will become more fragile. Minimum wall thickness and resolution We often see some confusion about the difference between the minimum wall thickness and the resolution. Sometimes we are asked, "if the resolution of a material is so high, why can't the wall be so thin?" As long as there is enough thickness to provide structural support, the detail and accuracy of the design depends on the resolution. The resolution is regarded as the precision that the part is designed for printing, which is very similar to the dimensional tolerance. Take a hollow sphere as an example. The minimum wall thickness determines the thickness of the housing so that it can be printed without collapsing under its own weight. Resolution determines the smoothness of curvature: low resolution will show visible "steps" and roughness, while high resolution will hide these aspects.

The medical device industry continues to grow around the world. With the development of the industry, 3D printing of medical device prototypes and production parts is also developing. Medical 3D printing is no longer something in science fiction. Additive manufacturing (AM) is now used in everything from surgical implants to artificial limbs, even organs and bones. Advantages of 3D printing for medical use Why 3D printing is very suitable for the medical market? The three main factors are speed, customization and cost-effectiveness. 3D printing enables engineers to innovate faster. Engineers can turn ideas into physical prototypes in 1-2 days. Faster product development time allows companies to allocate more time to receive feedback from surgeons and patients. In turn, more and better feedback will lead to better performance of the design in the market. 3D printing has achieved an unprecedented level of customization. Everyone's body is different, and 3D printing allows engineers to customize products according to these differences. This increases patient comfort, surgical accuracy, and improves outcomes. Customization also allows engineers to be creative in a wide range of applications. With the application of 3D printing technology in thousands of flexible, colorful and solid materials, engineers can put their most creative vision into practice. Most importantly, 3D printing can generally realize customized medical applications at a lower cost than traditional manufacturing. 3D printing technology for medical treatment Metal and plastic 3D printing technologies are suitable for medical applications. The most common technologies include melt deposition modeling (FDM), direct metal laser sintering (DMLS), carbon direct photosynthesis (DLS), and selective laser sintering (SLS). FDM is a good process for early device prototypes and surgical models. Sterilizable FDM materials include ppsf, ULTEM and ABS m30i. Metal 3D printing through DMLS can be completed with 17-4PH stainless steel, which is a sterilizable material. Carbon fiber is a new process that uses custom resins for various end-use medical device applications. Finally, SLS can produce strong and flexible parts, which is the best process to use when creating bone replicas. Use 3D printing in the medical industry 3D printing is changing almost all aspects of the medical industry. 3D printing makes training easier, improves patient experience and accessibility, and simplifies implant procurement and implantation process. Implants: 3D printing is not only a part of our physical world, but also a part of many people's bodies. Cutting edge technology now allows 3D printing of organic matter, such as cells for tissues, organs and bones. For example, orthopaedic implants are used for bone and muscle repair. This helps to improve the availability of the implant. 3D printing is also good at making fine lattices that can be placed outside surgical implants, which helps reduce the rejection rate of implants. Surgical tools: especially effective in the dental field, 3D printing tools conform to the unique anatomical structure of patients and help surgeons improve the accuracy of surgery. Plastic surgeons also often use guides and tools made by 3D printing. Guides are particularly useful in knee arthroplasty, facial surgery, and hip arthroplasty. The guides for these procedures are usually made of a sterilizable plastic pc-iso. Surgical planning and medical training mode: future doctors often practice on 3D printed organs. 3D printed organs can better simulate human organs than animal organs. Doctors can now print out exact copies of a patient's organs, making it easier to prepare for complex operations. Medical equipment and tools: traditionally manufactured using subtraction technology, many surgical tools and devices that now use 3D printing can be customized to solve specific problems. 3D printing can also produce conventionally manufactured tools such as clips, scalpels and tweezers in a more sterile form and at a lower cost. 3D printing also makes it easier to quickly replace these damaged or aging tools. Prosthetics: 3D printing plays a key role in making fashionable and easy-to-use prosthetics. 3D printing makes it easier to develop low-cost prosthetics for communities in need. Prosthetics are now being used for 3D printing in war zones such as Syria and rural areas in Haiti. Due to the limitation of cost and accessibility, many people did not have such equipment before. Drug dosage tool: you can now 3D print pills containing multiple drugs, and the release time of each drug is different. These tablets make dose compliance easier and reduce the risk of overdose due to patient errors. They also help to solve problems related to various drug interactions. Customized manufacturing of medical device companies Since the cost of high-end SLS, DMLS and carbon 3D printers may be as high as $500000 or more, many medical companies outsource their production to manufacturing as a service companies such as xometry. 86% of Fortune 500 medical companies rely on xometry's 3D printing services and medical injection molding as part of their innovation process. We help the world's largest and fastest-growing companies move faster from ideas to prototypes to production, thereby increasing their chances of success in the market. Since the cost of high-end SLS, DML and carbon 3D printers may be more than US $500000, many medical companies are handing over the production to speedup. We help medical device companies move faster from conception to prototype to production, which increases their chances of success in the market.

One of the goals of rapid injection molding is to rapidly produce parts. The correct design helps to ensure that good parts are produced in the first run. It is important to determine how the part will be placed in the mold. The most important consideration is that the part must remain in the mold half containing the ejection system. Cavity and core In a typical injection molding machine, one half (a side) of the mold is connected to the fixed side of the press, and the other half (B side) of the mold is connected to the moving jig side of the press. The clamp (or b) side contains an ejector actuator that controls the ejector pin. The clamp presses side a and side B together, the molten plastic is injected into the mold and cooled, the clamp pulls side B of the mold apart, the ejection pin is started, and the parts are released from the mold. Let's take the mold of plastic drinking cup as an example. In order to ensure that the parts and the ejection system are kept in half of the mold, we will design the mold so that the outer part of the glass is formed in the mold cavity (side a) and the inner part is formed by the mold core (side B). As the plastic cools, the part will shrink from side a of the mold and onto the core on side B. When the mold is opened, the glass will be released from side a and stay at side B, where the glass can be pushed out of the core through the ejection system. The a side (cavity) and B side (core) of the mold are represented by ejector plates and pins placed on the B side. If the mold design is reversed, the outside of the glass will shrink from the cavity on side B to the core on side a. The glass will release from side B and adhere to side a without ejector pins. At this point, we have a serious problem. Rectangle example Let's consider a rectangular shell with four through holes. The outer part of the shell is the cavity on the side a of the mold, and the inner part is the core on the side B. However, the design of holes can be handled in two different ways: they can be drawn toward side a, requiring a core on side a of the mold, but this may cause parts to stick to side a of the mold. A part with four through holes and a tab leading out to side B. A better method is to draft the core to side B to ensure that the parts adhere to side B of the mold. Similarly, any lug or strip from the part or across the internal hole should be pulled to side B to prevent sticking to side a and bending or tearing when the mold is opened. Of course, the design should also avoid the appearance of heavy texture on the outside of the part without sufficient draught, as this may cause the part to stick to side a.

Heat treatment can be applied to many metal alloys to significantly improve key physical properties such as hardness, strength, or machinability. These changes are due to changes in the microstructure and sometimes due to changes in the chemical composition of the material. These treatments include heating the metal alloy to (usually) extreme temperatures followed by cooling under controlled conditions. The temperature to which the material is heated, the time to maintain the temperature and the cooling rate will greatly affect the final physical properties of the metal alloy. In this paper, we review the heat treatment related to the most commonly used metal alloys in CNC machining. By describing the impact of these processes on the final part properties, this article will help you choose the right material for your application. When will the heat treatment be carried out Heat treatment can be applied to metal alloys throughout the manufacturing process. For CNC machined parts, heat treatment is generally applicable to: Before CNC machining: when it is required to provide ready-made standard grade metal alloys, CNC service providers will directly process parts from inventory materials. This is usually the best choice to shorten the lead time. After CNC machining: some heat treatments significantly increase the hardness of the material, or are used as finishing steps after forming. In these cases, the heat treatment is performed after CNC machining, because high hardness reduces the machinability of the material. For example, this is the standard practice when CNC machining tool steel parts. Common heat treatment of CNC materials: annealing, stress relief and tempering Annealing, tempering and stress relief all involve heating the metal alloy to a high temperature and then slowly cooling the material, usually in air or in an oven. They differ in the temperature at which the material is heated and in the order of the manufacturing process. During annealing, the metal is heated to a very high temperature and then slowly cooled to obtain the desired microstructure. Annealing is usually applied to all metal alloys after forming and before any further processing to soften them and improve their workability. If no other heat treatment is specified, most CNC machined parts will have material properties in the annealed state. Stress relief includes heating the parts to a high temperature (but lower than annealing), which is usually used after CNC machining to eliminate the residual stress generated in the manufacturing process. This can produce parts with more consistent mechanical properties. Tempering also heats parts at a temperature lower than the annealing temperature. It is usually used after quenching of low carbon steel (1045 and A36) and alloy steel (4140 and 4240) to reduce its brittleness and improve its mechanical properties. quench Quenching involves heating the metal to a very high temperature, followed by rapid cooling, usually by immersing the material in oil or water or exposing it to a cold air stream. Rapid cooling "locks" the microstructure changes that occur when the material is heated, resulting in extremely high hardness of the parts. Parts are usually quenched after CNC machining as the last step of the manufacturing process (think of blacksmith immersing the blade in oil), because the increase in hardness makes the material more difficult to process. Tool steels are quenched after CNC machining to obtain extremely high surface hardness characteristics. The resulting hardness can then be controlled using a tempering process. For example, the hardness of tool steel A2 after quenching is 63-65 Rockwell C, but it can be tempered to a hardness between 42-62 HRC. Tempering can prolong the service life of parts because tempering can reduce brittleness (the best results can be obtained when the hardness is 56-58 HRC). Precipitation hardening (aging) Precipitation hardening or aging are two terms commonly used to describe the same process. Precipitation hardening is a three-step process: first, the material is heated to a high temperature, then quenched, and finally heated to a low temperature (aging) for a long time. This leads to the dissolution and uniform distribution of alloying elements initially in the form of discrete particles of different compositions in the metal matrix, just as sugar crystals dissolve in water when the solution is heated. After precipitation hardening, the strength and hardness of the metal alloy increase sharply. For example, 7075 is an aluminum alloy, which is usually used in the aerospace industry to manufacture parts with tensile strength equivalent to that of stainless steel, and its weight is less than 3 times. The following table illustrates the effect of precipitation hardening in aluminum 7075: Not all metals can be heat treated in this way, but compatible materials are considered as superalloys and are suitable for very high performance applications. The most common precipitation hardening alloys used in CNC are summarized as follows: Case hardening and carburizing Case hardening is a series of heat treatment, which can make the surface of parts have high hardness while the underlining material remains soft. This is generally better than increasing the hardness of the part over the entire volume (e.g., by quenching) because the harder part is also more brittle. Carburizing is the most common case hardening heat treatment. It involves heating low carbon steel in a carbon rich environment and then quenching the parts to lock the carbon in the metal matrix. This increases the surface hardness of steel, just as anodizing increases the surface hardness of aluminum alloy. How to specify heat treatment in your order: When you place a CNC order, you can request heat treatment in three ways: Reference manufacturing standards: many heat treatments are standardized and widely used. For example, T6 indicators in aluminum alloys (6061-T6, 7075-T6, etc.) indicate that the material has been precipitation hardened. Specify the required hardness: This is a common method for specifying the heat treatment and surface hardening of tool steel. This will explain to the manufacturer the heat treatment required after CNC machining. For example, for D2 tool steel, a hardness of 56-58 HRC is usually required. Specify heat treatment cycle: when the details of the required heat treatment are known, these details can be communicated to the supplier when placing the order. This allows you to specifically modify the material properties of your application. Of course, this requires advanced metallurgical knowledge. Rule of thumb 1. You can specify the heat treatment in the CNC processing order by referring to specific materials, providing hardness requirements or describing the treatment cycle. 2. Precipitation hardening alloys (such as Al 6061-T6, Al 7075-T6 and SS 17-4) are selected for the most demanding applications because they have very high strength and hardness. 3. When it is necessary to improve the hardness in the whole part volume, quenching is preferred, and only surface hardening (carburizing) is performed on the part surface to increase the hardness.

In order to make full use of the ability of CNC machining, designers must follow specific manufacturing rules. But this can be a challenge because there is no specific industry standard. In this article, we have compiled a comprehensive guide with best design practices for CNC machining. We focus on describing the feasibility of modern CNC systems, ignoring the related costs. For guidance on designing cost-effective parts for CNC, please refer to this article. CNC machining CNC machining is a subtractive machining technology. In CNC, various high-speed rotating (thousands of RPM) tools are used to remove materials from solid blocks to produce parts according to CAD models. Metal and plastic can be processed by CNC. CNC machining parts have high dimensional accuracy and strict tolerance. CNC is suitable for mass production and one-time work. In fact, CNC machining is currently the most cost-effective way to produce metal prototypes, even compared to 3D printing. Main design limitations of CNC CNC provides great design flexibility, but there are some design limitations. These limitations are related to the basic mechanics of the cutting process, mainly related to tool geometry and tool access. 1. Tool geometry The most common CNC tools (end mills and drills) are cylindrical with limited cutting length. When the material is removed from the workpiece, the geometry of the tool is transferred to the machined part. This means that, for example, no matter how small a tool is used, the internal angle of a CNC part always has a radius. 2. Tool access In order to remove the material, the tool approaches the workpiece directly from above. Functions that cannot be accessed in this way cannot be CNC processed. There is one exception to this rule: undercut. We will learn how to use undercuts in design in the next section. A good design practice is to align all features of the model (holes, cavities, vertical walls, etc.) with one of the six main directions. This rule is considered a recommendation, not a limitation, because the 5-axis CNC system provides advanced workpiece holding capability. Tool access is also an issue when machining features with large aspect ratios. For example, to reach the bottom of the deep cavity, a special tool with a long axis is required. This reduces the stiffness of the end effector, increases vibration and reduces achievable accuracy. CNC experts recommend designing parts that can be machined with tools with the largest possible diameter and the shortest possible length. CNC design rules One of the challenges often encountered when designing parts for CNC machining is that there is no specific industry standard: CNC machine tool and tool manufacturers constantly improve their technical capabilities and expand the range of possibilities. In the following table, we summarize the recommended and feasible values of the most common features encountered in CNC machining parts. 1. Cavity and groove Recommended cavity depth: 4 times cavity width The cutting length of the end mill is limited (usually 3-4 times its diameter). When the depth width ratio is small, the tool deflection, chip discharge and vibration become more prominent. Limiting the depth of the cavity to four times its width ensures good results. If a greater depth is required, consider designing a part with a variable cavity depth (see the figure above for an example). Deep cavity milling: a cavity with a depth greater than 6 times the tool diameter is considered as a deep cavity. The ratio of tool diameter to cavity depth can be 30:1 by using special tools (using end mills with a diameter of 1 inch, the maximum depth is 30 cm). 2. Inner edge Vertical corner radius: recommended ⅓ x cavity depth (or greater) Using the recommended value of the internal corner radius ensures that the appropriate diameter tool can be used and aligned with the guidelines for the recommended cavity depth. Increasing the corner radius slightly above the recommended value (e.g. by 1 mm) allows the tool to cut along a circular path instead of a 90 ° angle. This is preferred because it can obtain a higher quality surface finish. If an internal angle of 90 ° sharpness is required, consider adding a T-shaped undercut instead of reducing the angle radius. The recommended bottom plate radius is 0.5mm, 1mm or no radius; Any radius is feasible The lower edge of the end mill is a flat edge or a slightly round edge. Other floor radii can be processed with ball head tools. It is a good design practice to use the recommended value because it is the first choice of the machinist. 3. Thin wall Recommended minimum wall thickness: 0.8mm (metal) and 1.5mm (plastic); 0.5mm (metal) and 1.0mm (plastic) are feasible Reducing the wall thickness will reduce the stiffness of the material, thereby increasing the vibration in the machining process and reducing the achievable accuracy. Plastics tend to warp (due to residual stress) and soften (due to temperature rise), so it is recommended to use a larger minimum wall thickness. 4. Hole Diameter recommended standard drill size; Any diameter greater than 1mm is acceptable Use a drill or end mill to machine holes. Standardization of drill bit size (metric and English units). Reamers and boring cutters are used to finish holes requiring strict tolerances. For sizes less than ▽ 20 mm, standard diameters are recommended. Maximum depth recommended 4 x nominal diameter; Typically 10 x nominal diameter; 40 x nominal diameter where feasible Non standard diameter holes must be processed with end mills. In this case, the maximum cavity depth limit applies and the recommended maximum depth value should be used. Use a special drill (minimum diameter 3 mm) to machine holes with a depth exceeding the typical value. The blind hole machined by the drill has a conical bottom plate (135 ° angle), while the hole machined by the end mill is flat. In CNC machining, there is no special preference between through holes and blind holes. 5. Thread The minimum thread size is m2; M6 or larger is recommended The internal thread is cut with a tap, and the external thread is cut with a die. Taps and dies can be used to cut threads to m2. CNC threading tools are common and preferred by machinists because they limit the risk of tap breakage. CNC thread tools can be used to cut threads to M6. The minimum thread length is 1.5 x nominal diameter; 3 x nominal diameter recommended Most of the load applied to the thread is borne by a few first teeth (up to 1.5 times the nominal diameter). Therefore, no more than 3 times the nominal diameter of the thread is required. For threads in blind holes cut with a tap (i.e. all threads smaller than M6), add a non threaded length equal to 1.5 x nominal diameter at the bottom of the hole. When a CNC thread tool can be used (i.e. the thread is larger than M6), the hole can run through its entire length. 6. Small features The minimum hole diameter is recommended to be 2.5 mm (0.1 inch); 0.05 mm (0.005 in) is feasible Most machine shops will be able to accurately machine cavities and holes using tools less than 2.5 mm (0.1 inch) in diameter. Anything below this limit is considered micromachining. Special tools (micro drills) and expert knowledge are required to process such features (the physical changes in the cutting process are within this range), so it is recommended to avoid using them unless absolutely necessary. 7. Tolerance Standard: ± 0.125 mm (0.005 in) Typical: ± 0.025 mm (0.001 in) Feasible: ± 0.0125 mm (0.0005 in) Tolerances define the boundaries of acceptable dimensions. The achievable tolerances depend on the basic dimensions and geometry of the part. The above values are reasonable guidelines. If no tolerance is specified, most machine shops will use a standard ± 0.125 mm (0.005 in) tolerance. 8. Words and lettering The recommended font size is 20 (or larger), 5mm lettering Engraved characters are preferably embossed characters because less material is removed. It is recommended to use sans serif fonts (such as Arial or Verdana) with a size of at least 20 points. Many CNC machines have pre programmed routines for these fonts. Machine settings and part orientation The schematic diagram of parts that need to be set several times is as follows: As mentioned earlier, tool access is one of the main design limitations of CNC machining. To reach all the surfaces of the model, the workpiece must be rotated several times. For example, the part of the above image must be rotated three times in total: two holes are machined in two main directions, and the third enters the back of the part. Whenever the workpiece rotates, the machine must be recalibrated and a new coordinate system must be defined. It is important to consider the machine settings in design for two reasons: The total number of machine settings affects costs. Rotating and realigning parts requires manual operation and increases the total processing time. If the part needs to be rotated 3-4 times, this is generally acceptable, but any exceeding this limit is redundant. In order to obtain maximum relative positional accuracy, two features must be machined in the same setup. This is because the new call step introduces a small (but not negligible) error. Five axis CNC machining When using 5-axis CNC machining, the need for multiple machine settings can be eliminated. Multi axis CNC machining can manufacture parts with complex geometry because they provide 2 additional rotational axes. Five axis CNC machining allows the tool to always be tangent to the cutting surface. More complex and efficient tool paths can be followed, resulting in better surface finish and lower machining time. Of course, 5-axis CNC also has its limitations. The basic tool geometry and tool access restrictions still apply (for example, parts with internal geometry cannot be machined). In addition, the cost of using such systems is higher. Design undercut Undercuts are features that cannot be machined with standard cutting tools because some of their surfaces cannot be directly accessed from above. There are two main types of undercuts: T-grooves and dovetails. Undercut can be single-sided or double-sided and processed with special tools. The T-groove cutting tool is basically made of a horizontal cutting insert connected to a vertical axis. The width of the undercut may vary between 3 mm and 40 mm. It is recommended to use standard dimensions for widths (i.e., full millimeter increments or standard inch fractions) as tools are more likely to be available. For dovetail tools, the angle defines the feature size. 45 ° and 60 ° dovetail tools are considered standard. When designing parts with undercuts on the inner wall, remember to add enough clearance for the tool. A good rule of thumb is to add at least four times the undercut depth between the machined wall and any other inner wall. For standard tools, the typical ratio between the cutting diameter and the shaft diameter is 2:1, which limits the cutting depth. When non-standard undercut is required, the machine shop usually makes customized undercut tools by itself. This increases lead times and costs and should be avoided as much as possible. T-shaped groove (left), dovetail groove undercut (middle) and unilateral undercut (right) on the inner wall Drafting technical drawings Note that some design criteria cannot be included in step or IGES files. If your model contains one or more of the following, 2D technical drawings must be provided: Threaded hole or shaft Tolerance dimension Specific surface finish requirements Instructions for CNC machine tool operators

In the design experience of many people, sometimes they design perfect parts without knowing the correct process of manufacturing them. For designers, the more they know about how things are made, the better they are at designing new parts. This is why thermoforming can be a huge asset in the toolbox when planning production designs. Thermoforming is sometimes masked by the more common injection molding, which is a unique process and can even provide the opportunity to create detailed geometry. Before we understand the basic principles of thermoforming, let's start with the basic principles and see how thermoforming works. Basic knowledge of thermoforming Thermoforming begins with heating and molding. A piece of thermoplastic is heated and stretched on a mold to make a part. Generally, the heat generated by the machine is not enough to completely melt the plate, but the temperature should be such that the plastic can be easily formed. The mold can be either a female mold or a male mold, which is made of a variety of materials, and then the thermoplastic is made into a shape. Once the sheet has cooled on the mold, it can be trimmed to leave the required parts. There are two main types of thermoforming: vacuum thermoforming and pressure thermoforming. Vacuum forming removes the air between the part and the mold to make the material as close as possible to the surface. Pressure forming adds air pressure to the upper surface of the part to push it toward the mold. When selecting materials for thermoforming, all kinds of thermoplastics can play a good role. Some more common materials include hips, pet and ABS, but other materials such as PC, HDPE, PP or PVC can also be used. Plates of different thicknesses can be formed. When to use thermoforming Immediately, it is easy to compare thermoforming and injection molding because they have a certain correlation. Injection molding uses molten plastic or rubber and injects it into the cavity, while thermoforming uses flat materials and stretches them into parts. Compared with other processes, size is the biggest advantage of thermoforming because it can make larger parts. For example, if you have a very large part with uniform thickness, thermoforming is a potential option. For large molds using injection molding, more force is required to close them. However, for thermoforming, this is not a problem. It is also good at making thin gauge parts. Thermoforming is widely used in the packaging industry. It can easily manufacture disposable cups, containers, covers and pallets with high cost efficiency. Thin materials also allow more room for maneuver and undercut. Precautions for thermoforming Although thermoforming sounds great, there are a few things to note when preparing for forming. First, it is important to pay attention to the corners and their possible changes during the molding process. Try to keep the radius at the corners and edges so that these areas do not become thinner during molding. Also consider the depth of the cavity. It cannot exceed a limit because the material must be stretched to create each feature. If the stretch is too large, the material will be too thin to form a shape. A certain pulling modulus is also required to ensure that the part can be demoulded from the mold. If one side of the part needs higher dimensional accuracy than the other, it is important to specify this as early as possible, because the use of male and female molds can help achieve this.

Anodizing is one of the most common surface treatment options for CNC aluminum. It occupies a large proportion in the market share of anodized parts. This process is very suitable for aluminum parts made by various manufacturing processes, such as CNC machining, casting and plate forming. This article will guide you to the design considerations of anodizing. Introduction to anodic oxidation Anodic oxidation is the process of converting metal surface into oxide layer through electrolytic process. Through this process, the thickness of this natural oxide layer is increased to improve the durability of parts, paint adhesion, component appearance and corrosion resistance. The following figure shows some parts that have been anodized and then dyed into different colors. The process uses an acid bath and current to form an anode layer on the base metal. In short, it is to create a controlled and durable oxide layer on the component, instead of relying on the thin oxide layer formed by the material itself. It is similar to bluing, phosphating, passivation and other surface treatments of steels used for corrosion resistance and surface hardening. Type of anodizing In this paper, anodic oxidation is divided into three categories and two categories. The three types are as follows: Type I: Type I and IB – chromic acid anodizing Type IC – non chromic acid anodizing instead of type I and IB Type II: Type II - conventional coating in sulfuric acid bath Type IIB - non chromate alternatives to type I and IB coatings Category III: Type III - hard anodizing There are specific reasons for each type of anodization. Some of these reasons are: 1. Type I, IB and II are used for corrosion resistance and a certain degree of wear resistance. For fatigue critical applications, type I and type Ib are used because they are thin coatings. One example is the highly fatigued structural components of aircraft. 2. When I and IB need non chromate alternatives, type IC and IIB shall be used. This is usually the result of environmental regulations or requirements. 3. Type III is mainly used to increase wear resistance and wear resistance. This is a thicker coating, so it will be superior to other types of wear. But the coating may reduce the fatigue life. Type III anodizing is commonly used for firearm parts, gears, valves and many other relatively sliding parts. Compared with bare aluminum, all types of adhesives contribute to the adhesion of paint and other adhesives. In addition to the anodizing process, some parts may need to be dyed, sealed or treated with other materials, such as dry film lubricants. If a part is to be dyed, it is considered to be class 2, while an unstained part is class . Design considerations So far, you may have been prompted to consider some key factors when designing anodized parts. These are easily (and often) overlooked in the design world. 1. Size The first factor we need to consider is the dimensional changes associated with anodized components. On the drawings, the engineer or designer may specify to apply the size after processing to compensate for this change, but for rapid prototyping, we rarely have drawings, especially if we use the fast turning service that relies on solid models. When parts are anodized, the surface will "grow". When I say "growth", I mean that the outer diameter will become larger and the hole will become smaller. This is because the anode layer grows inward and outward from the surface of the part when the aluminum oxide is formed. It can be estimated that the size increase is about 50% of the total thickness of the anode layer. The following table details the thickness range of different types of coatings according to Mil-A-8625. These thicknesses may vary depending on the specific alloy and process control used. Shielding may be required if the designer is concerned with controlling the growth of high-precision features. In some cases, such as thicker type III coating, the parts can be lapped or polished to the final size, but this will increase the cost. Another dimensional consideration is the radius of the edges and inner corners because the anodic coating cannot be formed on the sharp corners. This is particularly true for type III coatings, where the following corner radii for a given type III thickness are recommended in accordance with Mil-A-8625: For thinner coatings, edge fracture in the range of 0.01-0.02 is sufficient, but it is better to consult the process engineer of speedup to verify this. 2. Wear resistance Considering the increase in the hardness of the anode layer, we know that the surface hardness increases. The hardness of the actually specified coating is not typical due to the interaction between the softer base metal and the hard anode layer. Mil-A-8625 specifies wear resistance tests to meet these challenges. As a reference frame, the hardness of 2024 aluminum base material is in the range of 60-70 Rockwell B, wherein the hardness of type III anodizing is 60-70 Rockwell C. The following figure shows one of my CNC clamping clamps, which has been anodized and dyed red. Although hardwood, engineering plastics and non ferritic metals have been difficult to apply in high vibration environment, the surface has hardly worn. 3. Coloring with dye As described above, the anodized film can be stained. This may be done for a variety of reasons, such as aesthetics, reduction of stray light in the optical system, and part contrast / identification in the assembly. When it comes to anodizing, some challenges to discuss with your suppliers are: Color matching: it is difficult to obtain true color matching with anodized parts, especially if they are not processed in the same batch. If an assembly consists of several anodized parts of the same color, a special control device is required. Fading: anodized film exposed to UV or high temperature may fade. Organic dyes are more affected than inorganic dyes, but many colors need organic dyes. Dye responsiveness: not all anodizing types and coatings can use dyes well. Type I anodizing will be difficult to achieve true black because the coating is very thin. In general, although black dyes are used, the parts will still appear gray, so color dyes may not be practical without special treatment. When the coating thickness is high, the type III hard coating may also appear dark gray or black on some alloys, and the color selection will be limited. Some thinner type III coatings may accept multiple colors, but if aesthetics is the main driving force, type II coatings are the best choice for color options. These are not comprehensive, but they will give you a good start when making the required parts for the first time. 4. Conductivity The anode layer is a good insulator, although the base metal has conductivity. Therefore, if the chassis or components need to be grounded, it may be necessary to apply a transparent chemical conversion coating and cover some areas. A common method to determine whether aluminum parts have been anodized is to use a digital multimeter to test the surface conductivity. If the parts are not anodized, they may be conductive and have very low resistance. 5. Composite coating The anodized part may also be subjected to secondary processing to coat or treat the anodized surface to improve performance. Some common additives for anodic coatings are: Paint: the anodic coating can be painted to obtain a specific color that the dye cannot achieve, or further improve the corrosion resistance. Teflon impregnation: type III hard coating can be impregnated by Teflon to reduce the friction coefficient of bare anodizing. This can be done in the mold cavity as well as in the sliding / contact parts. There are other processes that can be used to change the performance of the anode coating, but they are less common and may require specialized suppliers. Main precautions: 1. The thick anode coating may reduce the fatigue life of components, especially when they use type III process. 2. Geometric changes of any part to be anodized need to be considered. This is critical for type II and III processes, but may not be required for some type I processes. 3. When processing multiple batches, color matching may be very difficult. When cooperating with different suppliers, color matching may be very difficult. 4. For adequate corrosion protection, it may be necessary to seal the holes of the anode layer. 5. When the thickness approaches and exceeds 0.003 inch, the wear resistance of type III hard coat may decrease. Different alloys may respond to the anodic oxidation process in different ways. For example, compared with other alloys, alloys with copper content of more than 2% or higher generally have poor wear resistance when subjected to mil specification tests for class III coatings. In other words, the type III hard coating on the 2000 series aluminum and some 7000 series aluminum will not be as wear-resistant as the 6061 hard coating.

There are many reasons why aluminum is the most commonly used non-ferrous metal. It is very malleable and malleable, so it is suitable for a wide range of applications. Its ductility allows it to be made into aluminum foil, and its ductility allows aluminum to be drawn into rods and wires. Aluminum also has high corrosion resistance because when the material is exposed to air, a protective oxide layer will naturally form. This oxidation can also be artificially induced to provide stronger protection. The natural protective layer of aluminum makes it more resistant to corrosion than carbon steel. In addition, aluminum is a good heat conductor and conductor, better than carbon steel and stainless steel. (aluminum foil) It is faster and easier to process than steel, and its strength to weight ratio makes it a good choice for many applications that require strong, hard materials. Finally, compared with other metals, aluminum can be recovered well, so more chip materials can be saved, melted and reused. Compared with the energy required to produce pure aluminum, recycled aluminum can save up to 95% of energy. Of course, using aluminum has some disadvantages, especially compared with steel. It is not as hard as steel, which makes it a bad choice for parts with higher impact force or extremely high bearing capacity. The melting point of aluminum is also significantly lower (660 ℃, and the melting point of steel is about 1400 ℃), so it cannot withstand extreme high temperature applications. It also has a very high coefficient of thermal expansion. Therefore, if the temperature is too high during processing, it will deform and it is difficult to maintain strict tolerance. Finally, aluminum may be more expensive than steel due to the higher power demand in the consumption process. aluminium alloy By slightly adjusting the amount of aluminum alloy elements, countless kinds of aluminum alloys can be manufactured. However, some compositions have proven to be more useful than others. These common aluminum alloys are grouped according to the major alloying elements. Each series has some common attributes. For example, 3000, 4000 and 5000 Series Aluminum Alloys cannot be heat treated, so cold working, also known as work hardening, is adopted. Main aluminum alloy types 1000 series Aluminum 1xxx alloy contains the purest aluminum, with an aluminum content of at least 99% by weight. There are no specific alloying elements, most of which are almost pure aluminum. For example, aluminum 1199 contains 99.99% aluminum by weight and is used to manufacture aluminum foil. These are the softest grades, but they can be work hardened, which means they become stronger when repeatedly deformed. 2000 series The main alloying element of 2000 series aluminum is copper. These grades of aluminum can be precipitation hardened, which makes them almost as strong as steel. Precipitation hardening involves heating the metal to a certain temperature to precipitate other metals from the metal solution (while the metal remains solid), and helps to improve the yield strength. However, due to the addition of copper, the corrosion resistance of 2XXX aluminum grade is low. Aluminum 2024 also contains manganese and magnesium for aerospace parts. 3000 Series Manganese is the most important additive element in aluminum 3000 series. These aluminum alloys can also be work hardened (which is necessary to achieve a sufficient hardness level because these grades of aluminum cannot be heat treated). Aluminum 3004 also contains magnesium, which is an alloy used in aluminum beverage cans, and a hardening variant thereof. 4000 series The 4000 series aluminum includes silicon as the main alloying element. Silicon reduces the melting point of 4xxx grade aluminum. Aluminum 4043 is used as a filler rod material for welding 6000 series aluminum alloy, and aluminum 4047 is used as a thin plate and a coating. 5000 Series Magnesium is the main alloying element of the 5000 series. These grades have some of the best corrosion resistance, so they are usually used in marine applications or other situations facing extreme environments. Aluminum 5083 is an alloy commonly used for marine parts. 6000 Series Magnesium and silicon are used to make some of the most common aluminum alloys. The combination of these elements is used to create the 6000 series, which is generally easy to process and can be precipitation hardened. 6061 is one of the most common aluminum alloys and has high corrosion resistance. It is commonly used in structural and aerospace applications. 7000 series These aluminum alloys are made of zinc and sometimes contain copper, chromium and magnesium. They can be the strongest of all aluminum alloys by precipitation hardening. 7000 is commonly used in aerospace applications because of its high strength. 7075 is a common brand. Although its corrosion resistance is higher than that of 2000 series materials, its corrosion resistance is lower than that of other alloys. This alloy is widely used, but is particularly suitable for aerospace applications. These aluminum alloys are made of zinc and sometimes copper, chromium and magnesium, and can be the strongest of all aluminum alloys by precipitation hardening. Class 7000 is usually used in aerospace applications due to its high strength. 7075 is a common grade with lower corrosion resistance than other alloys. 8000 Series 8000 Series is a general term that is not applicable to any other type of aluminum alloy. These alloys may include many other elements, including iron and lithium. For example, 8176 aluminum contains 0.6% iron and 0.1% silicon by weight and is used to make electric wires. Aluminum quenching and tempering treatment and surface treatment Heat treatment is a common conditioning process, which means that it changes the material properties of many metals at the chemical level. Especially for aluminum, it is necessary to increase hardness and strength. Untreated aluminum is a soft metal, so in order to withstand certain applications, it needs to undergo some adjustment process. For aluminum, the process is indicated by the letter designation at the end of the grade number. heat treatment 2XXX, 6xxx and 7xxx series aluminum can be heat treated. This helps to improve the strength and hardness of the metal and is beneficial for some applications. Other alloys 3xxx, 4xxx and 5xxx can only be cold worked to increase strength and hardness. Alloys can be given different letter names (called tempering names) to determine which treatment is used. These names are: F indicates that it is in the manufacturing state or the material has not undergone any heat treatment. H means that the material has undergone some work hardening, whether or not it is carried out simultaneously with the heat treatment. The numbers after "H" indicate the type of heat treatment and hardness. O indicates that aluminum is annealed, which reduces strength and hardness. This seems like a strange choice - who wants softer materials? However, annealing produces a material that is easier to process, possibly stronger and more ductile, which is advantageous for some manufacturing methods. T indicates that the aluminum has been heat treated, and the number after "t" indicates the details of the heat treatment process. For example, Al 6061-T6 is solution heat treated (maintained at 980 ° F, then quenched in water for rapid cooling) and then aged between 325 and 400 ° F. surface treatment There are many surface treatments that can be applied to aluminum, and each surface treatment has the appearance and protection characteristics suitable for different applications. There is no effect on the material after polishing. This surface treatment requires less time and effort, but is usually not sufficient for decorative parts and is best suited for prototypes that only test function and suitability. Grinding is the next step up from the machined surface. Pay more attention to the use of sharp tools and finishing passes to produce a smoother surface finish. This is also a more accurate machining method, usually used to test parts. However, this process still leaves machine marks and is not usually used in the final product. Sandblasting creates a matte surface by spraying tiny glass beads on aluminum parts. This will remove most (but not all) of the machining marks and give it a smooth but granular appearance. The iconic appearance and feel of some popular laptops come from sandblasting before anodizing. Anodic oxidation is a common surface treatment method. It is a protective oxide layer that will naturally form on the aluminum surface when exposed to air. In the process of manual machining, the aluminum parts are suspended on the conductive support, immersed in the electrolytic solution, and direct current is introduced into the electrolytic solution. When the acidic solution dissolves the naturally formed oxide layer, the current releases oxygen on its surface, thereby forming a new protective layer of alumina. By balancing the dissolution rate and the deposition rate, the oxide layer forms nanopores, allowing the coating to continue to grow beyond the range of natural possibilities. After that, for the sake of aesthetics, the nanopores are sometimes filled with other corrosion inhibitors or colored dyes, and then sealed to complete the protective coating. Aluminum processing skills 1. If the workpiece is overheated during processing, the high thermal expansion coefficient of aluminum will affect the tolerance, especially for thin parts. To prevent any negative effects, heat concentration can be avoided by creating tool paths that do not concentrate on one area for too long. This method can dissipate heat, and the tool path can be viewed and modified in the cam software that generates the CNC machining program. 2. If the force is too large, the softness of some aluminum alloys will promote the deformation during processing. Therefore, a specific grade of aluminum is processed according to the recommended feed rate and speed to generate an appropriate force during processing. Another rule of thumb for preventing deformation is to keep the part thickness greater than 0.020 inch in all areas. 3. Another effect of the ductility of aluminum is that it can form composite edges of material on the tool. This will mask the sharp cutting surface of the tool, blunt the tool and reduce its cutting efficiency. This accumulated edge can also cause poor surface finish on the part. In order to avoid accumulated edges, the tool material is used for the test; Try to replace HSS (high speed steel) with cemented carbide inserts, and vice versa, and adjust the cutting speed. You can also try to adjust the amount and type of cutting fluid.