Are you looking for the notes on Jigs and Fixtures? Yap, you are landed in the right destination.
So today we will study the Definition, Types, Advantages, Disadvantages, Application, and also the Difference between Jigs and Fixtures.
Also at the end of the article, I will give a PDF downloadable link so that you all can download the PDF and read about Jigs and Fixtures offline.
Let me start with the definition of Jigs and Fixtures.
Definition of Jig:
A jig is a work-holding device that holds, supports, and locates the workpiece and guides the one or more tools to perform a specific operation.
In other words, this can also be defined as, used for holding the tools and also guiding the cutting tools.
The main purpose of a jig is to provide repeatability, accuracy, and interchangeability in the manufacturing of products.
Some important points to remember about Jigs:
- It is used in uni-dimensional machining processes like drilling, tapping, and reaming, etc.
- This system is found to be light and has a complex shape.
- Gauge blocks are not necessary and the cost of jigs is higher.
- Jigs are not fixed to the machine table until a large operation has to be performed.
Definition of Fixture:
Fixtures are the work holding device, which holds, supports and locates the workpiece but not guides the cutting tool to perform a specific operation.
In other words, the fixtures are only the work holding device that holds, supports and locates the workpiece in the desired position to perform any operation.
The main purpose of the fixtures is to hold and locate the workpiece during any machining operation and to provide repeatability, accuracy, and interchangeability in the manufacturing of products.
Some important points about fixtures:
- Fixtures are used in multi-dimensional machining like milling, grinding, turning, etc.
- This system found to be heavy in weight, have simple designing.
- Gauge blocks provided for effective handling and the cost is average.
- Fixtures are having specific tools that use particularly in the milling machine, shapers and slotting machines.
- Fixtures are fixed to the machine table.
Jigs vs Fixtures:
Both the jigs and the fixtures are used to reduce the nonproductive time of any mass production process.
The principle of location or the 3-2-1 principle, CAD tools (like ProE), and FEA tools (like ANSYS) are used for the design of the jigs as well as the fixtures.
The jig is used for guiding the cutting tool (like a drill bit), and for doing so, jigs have components like a bush, which comes in contact with the cutting tool.
On the other hand, a fixture never comes into direct contact with the cutting tool.
Fixtures assure the position and alignment of the workpieces for getting the required machining operation done.
Factors to be Considered Before Designing a Jig or Fixture:
These are the factores should be considered before designing a jig or fixture:
- Study of the component.
- Study of locating elements.
- Type and capacity of the machine
- Loading and unloading arrangement.
- Clamping arrangement.
- Study of power devices for operating and clamping element and also a safety arrangement device.
- The clearance between a jig and the component.
- Study of tool guiding, cutter setting elements, rigidity and vibration problems.
- Fool-proofing arrangement.
- Study of ejecting devices, table fixing arrangement, and the indexing device.
- Swarf removal arrangement.
Types of Jigs and Fixtures:
There are several types of Jigs and Fixtures available in the market. Also, you can create a Jig and Fixture by yourself to do an operation easily. it is up to you. Although these are some available Jigs and Fixtures in the market.
Types of Jigs:
Here are some simple drill jigs:
- Template jig
- Plate jig
- Diameter jig
- Channel jig
- Ring jig
- Box jig
- Leaf jig
- Angle plate jig
- Indexing jig
- Trunion jig
You can check this slide to get an idea about this.
Types of Fixtures:
These are some Fixtures available in the market:
- Plate fixture
- Angle plate fixture
- Vise-jaw fixture
- Indexing fixture
- Multistation fixture
- Profile fixture
Difference between Jigs and Fixtures:
Here is the difference between Jigs and Fixtures:
|It holds and locates the work as well as guides the tool.||It holds and locates the work but does not guide the tool.|
|These are lighter in construction and clamping with the table is often unnecessary.||These are heavier in construction and bolted rigidly on the machine table.|
|Used for holding the work and guiding the tool in drilling, reaming or tapping operation.||Used for holding the work in milling, grinding, turning or planning operation.|
|Gauge blocks are not necessary.||Gauge blocks may be provided for effective handling|
|The cost is more.||The cost is less as compared with the jigs.|
|Their designing is complex.||Their designing is simple as compared to jigs.|
Why should we use Jigs and Fixtures?
Let's see some advantages of Jigs and fixtures:
- It eliminates the setting time required before machining.
- It increases the machining accuracy and also increases production capacity.
- Requires less skilled operation.
- They reduce the production cost.
- Increases machine and labor utilization.
- They simplify the work handling.
- Increases the quality of production in the industry.
- They enable the quick setting of a tool and the proper positioning of the work.
Although there are so many advantages by using Jigs and Fixtures, but also there are some disadvantages too.
Disadvantages of Jigs and Fixtures:
- Can wear away over time.
- Another one is the high initial set up costs (and time).
- And can use a lot of material and be bulky.
Applications of Jigs and Fixtures:
There are various fields where we can use Jigs and Fixtures and those are:
- Mass production of automobile parts.
- Inspection of parts in continuous production in manufacturing industries.
- Cutting the ingots in the steel plant.
- In the refrigeration industry.
- Pump assembling process
- For drilling the flanges and drilling holes to any required angles.
- For multi-spindle machining.
- Jigs used for mass drilling, reaming and tapping.
- For guiding the tools for machining contours.
- Fixtures used for milling, mass turning, and grinding operations.
The Material used for Jigs and Fixtures:
These are the following material is used for making Jigs and Fixtures:
- Grey cast iron
- Hardened steel
- Epoxy resins
- Low melt alloy steels
- Stainless steel
Jigs and Fixture is an essential element in Manufacturing Technology. There are several factors you should consider to make jig and fixtures. By using these you can save a couple of production time.
Here in this article, I covered all the important points regarding Jigs and Fixtures. I hope you understand everything.
Now I want to hear from you, if you have any queries or doubts about the lathe machine tool, you can ask me in the comment section and also you can join our facebook group. I will love to hear from you and glad to help you. Till then enjoy rest your day. Cheers.