Milling operation on a workpiece can be done in two ways – the first one is conventional milling and the second is climb milling.
Climb milling is also known as down milling and conventional milling is also known as up milling.
Both milling processes climb milling and conventional milling has its upside and downsides.
Knowing the right milling process for your project is important to complete the milling process efficiently and with minimum cost.
If the wrong milling process is selected, there will be a lot of defects in the process and money will also be wasted.
Conventional Milling is a traditional process and Climb Milling is the process used in the present day.
There are some of the key differences between climb milling and conventional milling which are discussed below.
In this article, we will discuss the differences between climb milling and conventional milling which will help to decide which will help in choosing the right milling process in different situations.
Here are some of the differences between climb milling and conventional milling:
1) Direction of rotation of milling cutter:
# In the case of conventional milling, the feed of the workpiece is in linear motion and the rotation of the milling cutter is in opposites direction.
# In the case of climb milling, the rotation of the milling cutter is in the direction of the feed of the workpiece.
2) Surface Finish:
# The surface finish quality in the case of conventional milling or up milling is lesser than that in the case of climb milling or done milling. As convention milling does not provide a good surface finish so conventional milling is used for rough cutting operations.
# The surface finish in the case of climb milling or down milling is much better than that of conventional milling or up milling as this milling operation is free from backlash error. As climb milling provides a good surface finish so climb milling is used for smooth cutting operations.
3) Direction Of Chip:
# In conventional milling, The milling cutter carries the cutting chips in an upward direction. This is the reason it is called up milling.
# In climb milling, The milling cutter carries the cutting chips in a downward direction. This is the reason it is also called down milling.
3) Chip Thickness:
# In the case of conventional milling, chip thickness increases as the milling process proceeds i.e chip thickness increases from minimum to maximum.
# In the case of climb milling, chip thickness decreases as the milling process proceeds i.e chip thickness decreases from maximum to minimum.
4) Heat diffusion:
# During the conventional milling process, the heat diffuses in the workpiece because of which the properties of the workpiece change. So a high-quality cutting fluid is needed in the case of conventional milling and this cutting fluid is hard to use.
# During the climb milling process, the heat diffuses in the chips so there is no change in the properties of the workpiece. As the heat does not diffuse in the workpiece so there is no need for high-quality cutting fluid, so a simple cutting fluid can be used which is easier to use than high-quality cutting fluid.
5) Tool wear and Tool Life:
# In conventional milling more tool wear occurs as the milling cutter rotates opposite to the feed of the workpiece. So due to more tool wear the tool life of the milling cutter is less in this process.
# In the climb milling process tool wear is very much less than in the conventional milling process as the cutting tool rotates in the same direction as the workpiece feed. as the tool wear is less in the milling process so the tool life of the milling cutter is more as compared to the conventional milling process.
6) Direction Of force applied by milling cutter and fixture required:
# In conventional milling the milling cutter applies force to the workpiece in an upward direction due to which the workpiece lifts up from the work table. So a high-strength fixture is required to hold the workpiece in the work table and these high-strength fixtures are expensive too.
# In the case of climb milling the milling cutter applies force to the workpiece in a downward direction so the workpiece does not lift up from the work table. So a high-strength fixture is not needed in climb milling, a normal fixture is enough to hold the workpiece in the climb milling process.
7) Cutting Force Required:
# In conventional milling more cutting force is required as compared to climb milling and the forces act in an upward direction.
# In the climb milling process less force is required than in conventional milling to remove the material from the workpiece and the force acts in the downward direction.
7) Dragging workpiece towards cutter:
# In conventional milling, there is no tendency to drag the workpiece toward the cutter.
# Climb milling process tends to drag the workpiece toward the utter
8) Tool Deflection:
# In conventional milling, the direction of reactive forces is almost parallel to the tool feed due to which there is very less tool deflection. As there is low tool deflection, the possibility of error is lower and control over the process is higher.
# In climb milling, the direction of the reactive force is almost perpendicular to the tool feed due to which there is high tool deflection and even the workpiece moves which affect the accuracy of the results.
8) When to use:
# Convention milling is recommended when the workpiece material is brittle like ceramics.
# Climb milling is recommended when the workpiece material is not brittle.
9) Use in the present time:
# Conventional milling is a traditional way to cut workpieces.
# Climb milling is non-traditional and is used more in the present time than the conventional milling process to cut workpieces.
Generally, everyone thinks that climb milling is better than conventional milling but conventional milling has its own advantages. There are some cases where conventional milling will perform better than climb milling.
So we can say that both milling process has their own advantages and disadvantages and should be chosen based on the application and specific requirement of the project.