Introduction to 5-Axis CNC Machines
- 1. Introduction of Universal 5-Axis CNC Machines
- 2. Contents •1) Introduction to CNC •2) Construction of CNC •3) Advantages and Disadvantages of CNC •3) 5-Axis CNC •4) Difference between 3+2-Axis and 5-Axis •5) Advantages and application of 5 axis •6) Types of machine configurations for 5-axis machining •7) Manufacturers of 5-axis CNC Machines •8) Specification of a 5 axis CNC machine
- 3. Introduction of CNC Numerical control (NC) is the automation of machine tools that are operated by precisely programmed commands encoded on a storage medium, as opposed to controlled manually. Most NC today is computer numerical control (CNC), in which computers play an integral part of the control. In modern CNC systems, end-to-end component design is highly automated using computer- aided design (CAD) and computer-aided manufacturing (CAM) programs. Here is an overview of the basic CNC Process: I. First, the CAD model is converted into a series of commands that can be interpreted by the CNC machine (G-code). This is usually done on the machine by its operator, using the provided technical drawings. II.A block of material (called the blank or the workpiece) is then cut to size and it is placed on the built platform, using either a vice or by directly mounting it onto the bed. Precise positioning and alignment is key for manufacturing accurate parts and special metrology tools (touch probes) are often used for this purpose. III.Next, material is removed from the block using specialized cutting tools that rotate at very high speeds (thousands of RPM). Several passes are often required to create the designed part. First, an approximate geometry is given to the block, by removing material quickly at a lower accuracy. Then one or more finishing passes are used to produce the final part. IV.If the model has features that cannot be reached by the cutting tool in a single setup (for example, if it has a slot on it back side), then the part needs to be flipped and the above steps are repeated.
- 4. After machining, the part needs to be deburred. Deburring is the manual process of removing the small defects left on sharp edges due to material deformation during machining (for example, the defects created as a drill exists the far side of a through hole). Next, if tolerances were specified in the technical drawing, the critical dimensions are . The part is then ready to use or post-process. Most CNC systems have 3 linear degrees of freedom: the X, Y and Z axis. More advanced systems with 5 degrees of freedom also allow the rotation of the bed and/or the tool head (A and B axis).5-axis CNC systems are capable of producing parts with high geometric complexity and may eliminate the need for multiple machine setups.
- 5. Advantages of CNC CNC machines can be used continuously and has Reliable Endurance It consistently executes huge quantities and affords flexible scalability. CNC machines generally do not require much service other than to change the cutting implements at the proper interval and do some light cleaning.Low Maintenance CNC machining requires fewer personnel to execute the production tasks.Less Labor Intricate detail machining.Improves machining accuracy The collective result of high speed, efficiency, specialization, precision and most of all, fewer labor hours, all add up to a better bottom line for your business which is Lower Costs
- 6. Disadvantages of CNC CNC machines are more expensive than manually operated machines, although costs are slowly coming down. The CNC machine operator only needs basic training and skills, enough to supervise several machines. In years gone by, engineers needed years of training to operate centre lathes, milling machines and other manually operated machines. This means many of the old skills are been lost. Less workers are required to operate CNC machines compared to manually operated machines. Investment in CNC machines can lead to unemployment. In case of breakdown a highly skilled professional is required to solve the problem
- 7. 5-Axis CNC In the simplest terms, 5-axis machining involves using a CNC to move a part or cutting tool along five different axes simultaneously. This enables the machining of very complex parts, which is why 5-axis is especially popular for aerospace applications. A machine that is capable of 5-axis design can move the tool-path in the X, Y, and Z directions as well as rotate in the A and B (or C) axes – thus the term 5-axis machining. Having those two extra axes compared to traditional 3-axis machining allows for greater flexibility in part design and more fluid movements for the tool head However, several factors have contributed to the wider adoption of 5-axis machining. These include: •A push toward single-setup machining (sometimes referred to as “Done-in-One”) to reduce lead time and increase efficiency •The ability to avoid collision with the tool holder by tilting the cutting tool or the table, which also allows better access to part geometry • Improved tool life and cycle time as a result of tilting the tool/table to maintain optimum cutting position and constant chip load.
- 8. Axes of 5-Axis CNC Machine Tool
- 9. 3+2-Axis and 5-Axis CNC It’s important to distinguish between 5-axis machining and 3+2-axis machining. The 5-Axis machining also called continuous or simultaneous 5-axis machining.It involves continuous adjustments of the cutting tool along all five axes to keep the tip optimally perpendicular to the part. In contrast, the 3+2 Axis machining is also called 5-sided or positional 5-axis machining which involves executing a 3-axis program with the cutting tool locked at an angle determined by the two rotational axes.
- 10. The main advantage of continuous 5-axis machining over 5-axis indexed is speed, since the 5-sided machining necessitates stopping and starting between each reorientation of the tool whereas the former does not.However, it should be possible to produce the same results whether using continuous or indexed 5-axis. It’s also worth noting that with the speed advantage comes more moving parts, which leads to increased wear and tear as well as a greater need for part crash detection. This is one of the reasons continuous 5-axis machining is more difficult from a programming standpoint.
- 11. Adv. and App. Of 5-Axis CNC 3-axis machines require multiple setups, which may result in incorrect alignments, higher costs, and other errors. With 5-axis machining, you have the ability to machine complicated shapes with a single setup. 5-axis machining enables you to use shorter cutting tools because you can lower the head and orient the cutter appropriately. This helps achieve higher cutting speeds without putting too much pressure on the cutter. 5-axis machines have less vibration, you’ll see a better surface finish. It ensures great precision with regard to the pieces, since they’re only worked on at one workstation. It is used for machining of complex three dimensional profiles It is used for manufacturing of impellers, turbine blades. It is also used for deep cavity mould making.
- 12. M/C Config. Of 5-Axis CNC To understand machine configurations, it’s important to understand the basic terminology of 5-axis machining centers. If you think in terms of a 3-axis machining center, it has an X-axis, Y-axis, and Z-axis. With a 5-axis machining center, the additional rotary axes will rotate about two of those three primary axes. The axis that rotates about or under the Z-axis is called the C-axis. The axis that rotates about the Y-axis is called the B-axis. The axis that rotates about the X-axis is called the A-axis. A 5-axis machine’s specific configuration determines which two of the three rotational axes it utilizes.They are three types of machine configurations.They are: 1) SWIVEL HEAD WITH ROTARY TABLE 2) INTEGRATED TRUNNION TABLE 3) TRAVELING COLUMN
- 13. Swivel Head with Rotary Table A swivel-rotate-style machine operates with traditional 3-axis along with B-axis (rotating about the Y-axis) and a C-axis (rotating about the Z-axis).Rotary table rotates along C- Axis and Swivel head rotated along the B-Axis The benefits of using the 5-Axis swivel head rotary table design is: 1)Heavier Parts: Because the table is stationary, the swivel head/rotary table machines are used with heavier parts. 2)Versatility. You can add a vise for greater versatility because of the large table size. Use the extra space to finish the sixth side of the part or do 3-axis work. 3)Minimizes tool interference Because the swivel head tilts the tool, you don’t need to worry about tool interference with the machine’s spindle head. 4)Better chip control With the swivel head/rotary table configuration, you can run the machine horizontally and gain better chip control.
- 15. Integrated Trunnion Table A trunnion-style machine operates with traditional 3-axis along with A-axis (rotating about the X-axis) and a C-axis (rotating about the Z-axis).Rotary table rotates along C- Axis and Turnnion table rotates along the A-Axis. The benefits of using the 5-Axis Turnnion table design is: Better undercut capability The trunnion rotates -30/+110 degrees versus +92 degree rotation on a swivel head/rotary table design. Larger work volume Compared to the swivel head rotary table 5-axis machine, the trunnion style facilitates larger work volume because you don’t have to compensate for the space used by the swivel head with tool attached. 3 to 5 transition The integrated trunnion table is the most popular configuration for 3- axis shops that convert to 5-sided machining because the approach to the part is similar in that you are simply machining more sides at one time in a linear fashion.
- 18. MANUFACTURERS OF 5-Axis CNC HURCO TARUS CMS north America OKUMA CNC TAKANG Taiwan maximart corporation YCM (YEONG CHIN MACHINERY INDUSTRIES CO., LTD)