There are several steps involved prior to reaching a final machined piece. The most common processes within the CNC machine shop are the planning of materials, creating CNC programs, the actual manufacturing process, as well as the quality control of parts that are machined. The process that is used to create the parts manufacturing will greatly impact the price and quality and quality customized CNC Machining.
Here is a thorough and concise explanation of the processes involved in machining custom-designed parts.
1. Pre-Machining Making Preparations
Prior to beginning machining, the preparations should be made. To ensure an effective custom CNC Machining, the key elements that must be prepared include the raw Materials, CNC Program, Cutting tools, as well as part holding fixtures. If these initial steps are properly executed, will result in the smoothest machining.
Raw Materials
There are numerous varieties of materials that you can choose from when you are the machining process. It is crucial to ensure that their mechanical characteristics of the materials to the specifications required for the particular piece. Plastic materials come in a variety of types of compositions and distinctive properties to meet every requirement. The most commonly machine-able plastics are Delrin, HDPE, Nylon and many others. However metals can be processed prior to machining to create the desired strength of a part. The most popular procedure prior to machining the raw metal is the process of annealing.
CNC Program
Creating the CNC program is among the most essential steps involved in CNC machine machining. The CNC program will control the bulk of the manufacturing process. The process of programming for the fabrication of custom components involves analyzing two major aspects, namely the parameters for machining and the correct sequencing of various manufacturing processes.
Making sure you have the right manufacturing parameters directly affects how well the piece being manufactured. The right parameters are established for various materials and the various parts features are accomplished. It is crucial to stick to the traditional method of calculating feeds and speeds in addition to the cut's depth. Setting the parameters is an essential aspect to consider as it can prevent items like a poor finishing of the surface, tools pull-outs breaking of the tool and unscheduled stops on spindle spindles.
It is vital to develop the program to create an item with the lowest amount of work. As the complexity grows the amount of operations is also increasing. A proper sequence of machining operations within a program can help create a part from a perspective of machining.
Cutting Tools
The cutting tools influence the CNC machine's performance since they are the primary participants in subtraction of material. These tools are employed to remove specific materials from the workpiece in order to create an individual piece. Different cutting tools must have a high level of strength and hardness, toughness and wear resistance in order to withstand the extremes encountered during the cutting process.
There are a variety of cutting tools that are suitable to every material. The most important aspects to consider when choosing the best cutting tool to use for customized CNC cutting are:
Take note of the geometric shapes that would best suit a particular application. (e.g. depth of cutting, angle of rake number of teeth or flutes and Helix angle, bandwidth, etc.)
Choose the right tooling grade to the material that will be cut (tooling material coating insert grade, etc.)
Prepare the tools that are suitable to the processes you have defined.
Choose the appropriate accessory holders for your tool that's sturdy enough for the machining process.
Make sure you match the proper length of the tooling gauge with it's CNC Program.
Part Holding Fixtures
Fixtures are essential elements that aid in the creation of the end product, particularly when custom-designed parts are required where unusual elements must be developed. Fixtures for holding work help the workpiece adjust to specific constraints or limitations that a machine CNC has regards to working with the piece. A few of the fixtures commonly that are used in fabrication shops include Mandrels and CNC jaws drives, centers levels plates, sine plates drill fixtures and milling tools and numerous other.
2. Machining Operation
The ideal time to go to the process of machining is after all the necessary required preparations and prerequisites are completed.
Making a custom-made part requires several machining procedures. There are certain features of the part that are created by each of the kinds of machining techniques. From a fundamental perspective the two main actions in the machining process are turning and milling. The difference between them is that milling is the workpiece is stationary and the tool is rotated; in contrast turning is a rotational workpiece as well as a stationary tool.
There are many different manufacturing processes for custom CNC parts. Below are the most popular:
- OD turningThis is a procedure that takes place by turning (lathe) which removes material from the surface to produce the desired external feature.
- Boring This is a procedure that is carried out by turning (lathe) that expands the hole that is already present using the single-point cutting tool.
- GroovingThe process of groovingThis is accomplished by the turning process (lathe) in which the work piece is made to form a groove on the surface. The groove can be made on the inside diameter, the external diameter, and also on the surface.
- FacingThe process is described asThis procedure is described as subtracting material in order to cut the flat surface. Facing can be performed by turning or milling.
- Profile milling Like the name implies it is a procedure that produces a profile of the work piece using the end mills.
- Slot milling or pocket milling It creates slot or pocket area on a part by using an endmill.
- DrillingDrilling This is the process of creating dimensionally controlled holes by twist drills.
- Threading- This method creates a threaded hole within the work piece using tapping or thread mills.
- Reaming This is carried out on a hole that is already in place to produce a precisely measured dimension of as much as +\-.0001 inches.
- grinding- This procedure involves using an abrasive that removes material from the workpiece at an extremely precise rate.
EDMEDM It is a machining technique which makes use of electric discharge to melt or erode material from the work piece. EDM are a common process for precision slot machining and precision cutting.
3. Quality Inspection
Quality inspection is crucial for custom parts as components made through machining have an important role to play in the accuracy as well as precision. It is essential to manufacture the component according to the dimensions and specifications according to the print specifications of the customer. The main metrics that are inspected in the manufacturing process are typically precision in dimensional accuracy, surface finish, as well as structural quality.
Dimensional accuracy
The accuracy of dimensions is crucial before distributing machined components to clients. Typically , during the process the dimensions of each feature are checked after the machining procedure is finished. To ensure quick inspection using gauges to measure the dimensions are usually attribute gauges (go or no-go gauges) or variable gauges (calipers micrometers, micrometers, and measurement of height). In the end, a coordinate measurement machine (CMM) is utilized for the final and thorough quality check before delivering the completed machines to customers.
Finishing the surface and Structural Integrity
For precise custom-made machined parts the last attributes that are inspected in the machined component are the surface finish as well as the structural quality. Surface finish can be typically assessed using profilometers. However structural integrity is assessed using non-destructive methods that look for cracks or voids within the material that could be present during the process of machining.
