Even with modern cutting tools, it can be difficult to produce parts with high accuracy and precision in the absence of a fixture. Jigs help hold parts in place during machining. From milling lathes to jigs and fixtures, many clamping options are available.
However, the type of material you are working with and the number of pieces you want to produce play an important role in determining the most practical method. This article explains the different fixing solutions available, their positioning and the factors you need to consider before choosing a fixing method.
What is part clamping in machining?
A workholding is a tool or device that prevents a part from moving from its original position during a machining operation. More specifically, clamping a part performs two basic tasks: positioning and clamping.
Positioning allows the part to be better aligned with the cutting tool. Clamping, on the other hand, holds the part firmly enough to withstand the cutting force, preventing deformation of the workpiece holder and the part.
Furthermore, in the CNC machining process, a CNC fixture holds a part while a CNC fixture controls the movement of the cutter. Although a machining jig does not perform a cutting operation, it is valuable and represents the most important non-cutting tool.
Why should you choose a robust part clamping method?
Choosing a sturdy CNC fixture is just as important as choosing the right cutting tool for your part. Properly used part accessories allow the CNC machine to utilize its full performance and produce high-quality parts. A stable workpiece clamping device is important for the following reasons:
Greater immobility of the part
For high accuracy and precision, the entire cutting process must be stable and motionless. The CNC machine, the cutting device, the part and the clamping method used contribute to the rigidity of the machining process. Even slight movement during the machining process can result in errors that require parts to be reworked. With a strong clamping method, you can minimize the time and cost associated with machining.
Protect it against the forces of editing
During machining, some forces are created that can affect the position of the part and the subsequent accuracy of the process. As a result, the workpiece prevents the workpiece from moving, locking it in place. This is particularly important when machining structures with sharp internal corners or when working with CNC techniques such as milling and turning that produce high torque.
Ensure security
Operator and workpiece safety depend on the strength of the workpiece clamping device. Although the CNC machine holds the part firmly, this is not always the case. If the workpiece clamping device is not strong enough, the workpiece or cutting tool parts may fly off. Therefore, the workpiece must remain stationary to ensure the safety of employees.
Examples of part clamping solutions you can use in part production
Below are examples of fixtures that you can use to hold your workpiece during cutting operations.
milling lathe
This is the most popular part clamping solution. The most commonly used milling lathe is the machine lathe. A machine lathe holds a part with its jaws while the cutter rotates through it.
You can clamp the workpiece between fixed and movable jaws. Because these vises are typically made from soft materials, they may not work with all technical materials.
However, you can use any milling lathe to hold plastics, steel, aluminum, and other materials. Additionally, the shape and thickness of the material affect its use. If you use milling lathes, set them up appropriately to produce accurate parts.
Plates and clamps
Plates and clamps are used for the CNC milling machine. The simplest part holding device is a clamp, which can be customized to the needs of a specific part and is suitable for working with all types of metals, including aluminum, cast iron, brass and steel.
A clamp is a type of lever that works like all levers. Part of it firmly holds the surface of the workpiece. Since the plates and clamps are made of steel that can be additionally hardened, they are very wear-resistant and can be reused.
Soft cheeks
Soft jaws are made from soft metals such as aluminum. You can hold pieces with complex shapes and reuse them if the pieces have the same design. However, because soft jaws are not very wear-resistant, they may not be useful when handling a large number of parts. In this case, you can opt for hard jaws.
Although soft jaws are useful in CNC machining operations, they can be difficult to manufacture. Fastening tools do not directly increase company profits. Therefore, the manufacturing process must be designed to be cost-effective.
Staggered Clamps
Stepped clamps allow you to access the surface of a part as you work. This reduces interference with the cutting tool. Staggered clamps hold a part in place by pressing against its sides. Furthermore, this device works well in both manual milling and CNC machining.
Clamping jaws offer a secure way to clamp a workpiece. However, they have some disadvantages. Not only do they need to be reconfigured before each use, but the configuration also takes a relatively long time.
Fixing plates
Jig plates use multiple threaded holes to hold parts while working. Typically, the screws that fit into these holes act as protection and can be removed if you want to use a specific hole.
Jig boards are popular because they can hold most materials, including large, complex, and unusually shaped pieces. Additionally, maintenance costs are low and they can perform specialized tasks.
Positioning for workpiece clamping devices
A clamping method consists of two main components: the clamping device and the tool used to position it. Below are some tools you can use to configure tensors.
T-Slots
A T-slot is a workpiece fixture with a T-shaped recess used to secure workpieces to the machine bed. It is the most commonly used device for configuring and positioning part clamping solutions. They are reliable and easy to use. However, with T-slots, it can be difficult to reposition the fixture. The accumulation of debris and dirt also limits its use.
Device subcards
Fixture base plates provide flat, stable surfaces for positioning part fixtures during machining operations. Fixing subplates come in various shapes and materials. These boards are easy to use and you can place them vertically or horizontally for precise positioning.
Tool plates
It is similar to fixing subplates. Tool plates have holes that precisely position the part's accessories. This precise positioning allows a part to meet machining tolerances.
Modular devices
A modular accessory may be the best option to save costs. These devices perfectly hold the workpiece clamping devices and you can use them multiple times. Modular fixing systems can be supplied with grid holes or T-slots. Systems with grid holes are more stable and can be better positioned.
COB devices
Tenon jigs are ideal for automated applications such as CNC machining. The device can be set up in minutes and uses locating pins to quickly position workpiece fixtures. With threading devices you can be sure of consistency from batch to batch.
Tombstones
Using chuck turrets with more compact equipment is better than using bulky equipment like milling lathes. Clamping turrets are a reliable and efficient positioning tool for CNC machining operations. Most importantly, most voltage towers are already equipped with grid caps. This speeds up cleaning and minimizes chip formation.
Tool Column
Tool columns are made of aluminum or cast iron. For this reason, they are extremely resistant to wear and tear and can be used multiple times. Tool columns are becoming increasingly popular because they provide surfaces for mounting and positioning fixtures and work pieces.
CNC Fixture Configuration Considerations
The configuration of a CNC fastening solution depends on the type of material, point of contact and other factors. This section explains the factors and ways to configure the part clamping solution:
Material Type
The material you work with has a big impact on the strength of your tensioner. There are many technical materials with different textures. As a general rule, the harder the material, the greater the force required to hold it in place. For example, because milling vises are made of soft materials, they are more suitable for soft materials such as plastic and aluminum. On the other hand, hard jaws can work with both hard and soft materials.
Material size and shape
This is another important factor that allows you to limit tensioning options. An irregularly shaped piece may require special attention. For example, if you are milling a large part with complex shapes and geometries, you will need a more robust fixture that can withstand the force of the milling process. Additionally, you can use a simple clamping device if the part is small and has a flat surface.
Contact point
You also need to consider the point of contact between the fixture and the workpiece. Do you want your fixture to grip the sides or surface of the workpiece? Does the surface need to be easily accessible during the editing process? These are some of the questions you need to ask yourself to choose the ideal fixing solution for your part.
number of pieces
The choice of fastening solution should depend on the number of parts you want to produce. Jigs for small batch production differ from those for large volume production because they wear out over time. While you can stop and change them during the editing process, it can be time-consuming. Therefore, considering the number of parts you want to make will help you narrow down your options when choosing the right jigs for your project.
Get custom parts with Wayken fastener solutions
From prototyping to full production, the success of each operation depends on the fastening solution used. That's why choosing the ideal tool for your project is crucial. The ideal fastening solution not only needs to be durable and reusable to reduce costs. It also needs to be easy to set up to save time and increase productivity.
From design to part production, our engineers can support you at every stage of manufacturing to produce high-quality parts and reduce time to market for your product. And what else? We can help you with all your machining needs, including CNC machining services, 3D printing, quick tooling, etc. Simply upload your CAD files today and get started!
University Degree
A good fixture can expedite rapid production while ensuring that all parts in the batch meet specifications. You should know that there is no standard solution for choosing the best design method. You can consider the versatility of the piece's accessory. This is because manufacturing aims to reduce costs while producing high-quality parts.
Common questions
What are the characteristics of good part fixation?
A good clamping must not only hold the part and position it in relation to the cutting tool. It must also withstand the force associated with the machining process.
Is there a difference between soft and hard jaws?
The main difference is the material they are made from. The hard jaws are made of hardened steel. Soft jaws, on the other hand, are made from softer metals such as aluminum or cast iron.
What are workpiece fixtures and fittings?
Jigs and fixtures do not perform the same function. A support holds the part in place. The jigs not only hold the parts but also guide the cutter.
