As a BS-Mechanical Student in a well-known university and an incoming 5th year student, I am well knowledgeable on machining. Knowing how to make a design and manufacture it once it is done is a must for us BS-ME student and one machine that can do amazing machining is the Milling Machine.
Intro
Milling is a metal cutting operation in which the excess material from the work piece is removed by the rotating multipoint cutting tool called the milling cutter. Milling is a process of breaking solid materials into small pieces by crushing and Milling came from a root word mill which means to grind or to crush something.
The Versatile Machine : Milling Machine
Milling Machine is a power operated machine tool in which work piece mounted on a moving table and is machined to any various shapes and sizes when it is moved under a slow revolving serrated cutter. It is a machine that is made to machine things like metal,wood, and other solid materials what exist. This machine can also be adjusted and positioned in any orientation may it be vertical and horizontal, to carve on materials based on designs.
Principle Of Milling
Up-milling (Conventional Milling)
Up-milling is a principle of milling where the feed direction of the cutting tool is on the opposite to its normal rotation, and the chip thickness starts at the value of zero and slowly increases towards to the end of cut. The force of cutting tends to push the work piece and the cutter away from each other.
Down-milling (Climb Milling)
Down-milling is a principle of milling where the feed direction of the cutting tool is on its rotation, and the chip thickness is advantageous. The force of the cutting tool tends to pull the work piece into the cutter and holding the cutting edge in the cut.
Comparison Between Up-milling and Down-milling
| Slot No. | Up-milling (Conventional Milling) | Down-milling (Climb Milling) |
|---|---|---|
| 1 | Work piece fed in the opposite direction that of the cutter. | Work piece fed in the same direction that of the cutter. |
| 2 | Chips are progressively thicker. | Chips are progressively thinner. |
| 3 | Strong clamping is required since the cutting force is directed upwards and tends to lift the work. | Strong clamping is not required since the cutting force is directed downwards and keep the work piece pressed to the table. |
| 4 | Gives poor surface finish. | Gives good surface finish |
| 5 | Used for hard materials. | Used for soft materials and finishing operations. |
Major Parts of Milling Machine
- Base - Is the stronghold of the machine and contains the coolant reservoir plus a pump which is used during the operation of the machine process.
- Column - Is also a part that supports all other parts of the machine and it contains an oil reservoir and pump which lubricates the spindle.
- Spindle - Is a part of milling machine where is used to hold and also drives the cutting tool(s) of the machine.
- Overarm - Overarm or the Overhanging arm is a part where its function is to fasten the arbor support, It also consists of one or two cylindrical bars that slides through holes in the column.
- Saddle - it is located on the knee and supports the table, It slides on horizontal way on the knee and dovetail is kind of parallel to the axis of spindle.
- Worktable - Is used to hold the work piece and the working devices. It is a rectangular plane which is located on the top of the saddle. It can be operated by hand or by the use of power.
Horizontal Milling Machine
Is a type of milling machine that has a x-y table though the cutters were placed on place with the horizontal arbor diagonally to the plane or table. Most of the horizontal milling machines do features like +15/15 degrees of the rotary plane on which allows the mills to its shallow angles.
Vertical Milling Machine
Is a type of milling machine that has a Y-axis slide, knee and also the base. The spindle of the axis leans vertically and the cutters are held to the spindle then rotates afterwards within the axis. Spindles can be normally extended and tables can also be raised and lowered at your desire, allowing the effect that cuts and drills the materials.
If you happen to reach until the end of this blog, I sincerely thank you for sharing your time on reading. If you have some concerns and thoughts about this please do not hesitate to leave a comment and I will surely be glad to respond :)
Ciao! @thonnavares
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