Milling Machine MILLING MACHINERY Guide For Manufacturing To Save Cost

C-Axis

2008-04-08T19:38:00.001-07:00

Short video of 360 degree rotation with aggregate flex head

C-Axis

2008-04-08T19:38:00.000-07:00

Short video of 360 degree rotation with aggregate flex head

K2 CNC - Steel rule die - wood cutting - Mach 3

2008-04-08T19:36:00.000-07:00

This is a K2 cnc router cutting wood for steel rule die. The cnc router cuts through .5 thick plywood. The cnc router uses a special tappered/straight bit to achieve .035 inch diameter cut throught. Wow over 100 inch per minute with such a small diameter bit

CabMaxx SF Nested Side Panels

2008-04-08T19:34:00.001-07:00

Nested Based Manufacturing of cabinet side panels on Andi CabMaxx SF CNC router.

Small Solid Wood Part Machining

2008-04-08T19:34:00.000-07:00

Small solid wood part machining on a Anderson S... (more)
Added: December 26, 2006
Small solid wood part machining on a Anderson Stratos SUP CNC router

Mastercam's High Speed Machining

2008-04-07T19:27:00.000-07:00

A compilation of CNC cutting using Mastercam's (more)
Added: August 28, 2007
A compilation of CNC cutting using Mastercam's high speed machining toolpaths.

Muratec Murata MW400 CNC Lathe

2008-04-07T19:26:00.000-07:00

Muratec Murata MW400 CNC Lathe
Muratec Murata MW400 CNC Lathe in action. Large capacity, high quality, high volume state of the art turning technology.

mach3 mach cnc software artsoft machinery cad cam

2008-04-07T19:23:00.000-07:00

Retro fitted B&S late home built 8 station turret. Thanks to the great plans from Ron Kliewer

home made probe digitizing 2d shape

2008-04-07T08:46:00.000-07:00

home made probe digitizing 2d shape

DRILL - CNC - MACH 3 Milling and drill machine

2008-04-07T08:43:00.000-07:00

DRILL - CNC - MACH 3 Milling and drill machine

Pot Filler Faucet

2008-04-07T08:42:00.000-07:00

Pot Filler Faucet

Wet Dry Vacuum Cleaners

2008-04-07T08:41:00.001-07:00

Wet Dry Vacuum Cleaners

Masking Tape

2008-04-07T08:40:00.000-07:00

Masking Tape

How to Cut Ceramic Tile

2008-04-07T08:37:00.000-07:00

How to Cut Ceramic Tile

Home Design Software

2008-03-11T05:44:00.001-07:00

Home Design Software

Wood Router

2008-03-11T05:41:00.000-07:00

Wood Router

Testing whilst setting up and tuning my d.i.y CNC Router

2008-03-11T05:38:00.000-07:00

Testing whilst setting up and tuning my d.i.y CNC Router

Homemade CNC milling machine

2008-03-11T05:33:00.000-07:00

Homemade CNC milling machine

CNC Converted Harbor Freight Mini-Mill

2008-03-07T13:21:00.000-08:00

Benchtop mini-mill converted to CNC keeping man... (more)
Added: April 14, 2007
Benchtop mini-mill converted to CNC keeping manual function. This cuts metal!

CNC milling - first aluminium test

2008-03-07T13:19:00.000-08:00

Homemade CNC milling machine

2008-03-07T13:14:00.000-08:00

I made this machine from a Harbor Freight milli... (more)
Added: February 24, 2007
I made this machine from a Harbor Freight milling machine, an old computer and some new stepper motors & electronics

milling machine

2007-12-22T16:29:00.000-08:00

A milling machine is a machine tool used for the complex shaping of metal and other solid materials. Its basic form is that of a rotating cutter or endmill which rotates about the spindle axis (similar to a drill), and a movable table to which the workpiece is affixed. That is to say, the cutting tool generally remains stationary (except for its rotation) while the workpiece moves to accomplish the cutting action. Milling machines may be operated manually or under computer numerical control (see CNC).

Milling machines can perform a vast number of complex operations, such as slot cutting, planing, drilling, rebating, routing, etc.

Cutting fluid is often pumped to the cutting site to cool and lubricate the cut, and to sluice away the resulting swarf.

Types of instruction CNC

2007-12-22T14:41:00.000-08:00

A line in a G-code file can instruct the machine tool to do one of several things.

Movements

The most basic motion for a controller is to move the machine tool along a linear path from one point to another.^[1] Some machine tools can only do this in XY, and have to accept changes in Z separately. Some have two further axes of rotation to control the orientation of the cutter, and can move them simultaneously with the XYZ motion. Lately 4, and 5 axis machines have become popular. The 2 additional axies allow for the work surface or medium to be rotated around X and Y. For example, a 4-axis machine can move the tool head in XY and Z directions, and also rotate the medium around the X or Y axis, similar to a lathe.This is called the A or B axis in most cases.

All motions can be built from linear motions if they are short and there are enough of them. But most controllers can interpolate horizontal circular arcs in XY. See CNC circular arc motions for further details.

Lately, some controllers have implemented the ability to follow an arbitrary (NURBS) curve, but these efforts have been met with skepticism since, unlike circular arcs, their definitions are not natural and are too complicated to set up by hand, and CAM software can already generate any motion using many short linear segments.

Tool changes

Originally there would be a G-code instruction telling the machine tool to stop so that a human operator could remove the cutting tool from the chuck and insert a new one. Modern machine tools have a magazine of different tools which they can change themselves pneumatically, hydraulically, and electromechanically.

On newer models of CNC Machines such as Mori Seiki designs, depending on which tool would be used, assuming it's tool 4 the procedure for an idle machine tool change would be;

MDI,

T4; M6;

There are related instructions such as setting the spindle speed, and turning on or off the coolant.

Drilling

A tool can be used to drill holes by pecking to let the swarf out. Using a special tapping tool and the ability to control the exact rotational position of the tool with the depth of cut, it can be used to cut screw threads.

Drilling cycles

A drilling cycle is used to repeat drilling or tapping operations on a workpiece. The drilling cycle accepts a list of parameters about the operation, such as depth and feed rate. To begin drilling any number of holes to the specifications configured in the cycle, the only input required is a set of coordinates for hole location. The cycle takes care of depth, feed rate, retraction, and other parameters that appear in more complex cycles. After the holes are completed, the machine is given another command to cancel the cycle, and resumes operation.

Parametric programming

A more recent advancement in CNC interpreters is support of logical commands, known as parametric programming. Parametric programs incorporate both G-code and these logical constructs to create a programming language and syntax similar to BASIC. Various manufacturers refer to parametric programming in brand-specific ways. For instance, Haas refers to parametric programs as macros. GE Fanuc refers to it as Custom Macro A & B. While Okuma refers to it as User Task 2. The programmer can make if/then/else statements, loops, subprogram calls, perform various arithmetic, and manipulate variables to create a large degree of freedom within one program. An entire product line of different sizes can be programmed using logic and simple math to create and scale an entire range of parts, or create a stock part that can be scaled to any size a customer demands.

Parametric programming also enables custom machining cycles, such as fixture creation and bolt circles. If a user wishes to create additional fixture locations on a work holding device, the machine can be manually guided to the new location and the fixture subroutine called. The machine will then drill and form the patterns required to mount additional vices or clamps at that location. Parametric programs are also used to shorten long programs with incremental or stepped passes. A loop can be created with variables for step values and other parameters, and in doing so remove a large amount of repetition in the program body.

Because of these features, a parametric program is more efficient than using CAD/CAM software for large part runs. The brevity of the program allows the CNC programmer to rapidly make performance adjustments to looped commands, and tailor the program to the machine it is running on. Tool wear, breakage, and other system parameters can be accessed and changed directly in the program, allowing extensions and modifications to the functionality of a machine beyond what a manufacturer envisioned.

CNC

2007-12-22T14:00:00.000-08:00

The abbreviation CNC stands for computer numerical control, and refers specifically to a computer "controller" that reads G-code instructions and drives the machine tool, a powered mechanical device typically used to fabricate metal components by the selective removal of metal. CNC does numerically directed interpolation of a cutting tool in the work envelope of a machine. The operating parameters of the CNC can be altered via software load program.

NC was developed in the late 1940s and early 1950s by John T. Parsons in collaboration with the MIT Servomechanisms Laboratory. CNC was preceded by NC (Numerically Controlled) machines, which were hard wired and their operating parameters could not be changed. The first CNC systems used NC style hardware, and the computer was used for the tool compensation calculations and sometimes for editing.

Punched tape continued to be used as a medium for transferring G-codes into the controller for many decades after 1950, until it was eventually superseded by RS232 cables, floppy disks, and finally standard computer network cables. The files containing the G-codes to be interpreted by the controller are usually saved under the .NC extension. Most shops have their own saving format that matches their ISO certification requirements.

The introduction of CNC machines radically changed the manufacturing industry. Curves are as easy to cut as straight lines, complex 3-D structures are relatively easy to produce, and the number of machining steps that required human action have been dramatically reduced.

With the increased automation of manufacturing processes with CNC machining, considerable improvements in consistency and quality have been achieved. CNC automation reduced the frequency of errors and provided CNC operators with time to perform additional tasks. CNC automation also allows for more flexibility in the way parts are held in the manufacturing process and the time required to change the machine to produce different components.

In a production environment, a series of CNC machines may be combined into one station, commonly called a "cell", to progressively machine a part requiring several operations. CNC machines today are controlled directly from files created by CAM software packages, so that a part or assembly can go directly from design to manufacturing without the need of producing a drafted paper drawing of the manufactured component. In a sense, the CNC machines represent a special segment of industrial robot systems, as they are programmable to perform many kinds of machining operations (within their designed physical limits, like other robotic systems). CNC machines can run over night and over weekends without operator intervention. Error detection features have been developed, giving CNC machines the ability to call the operator's mobile phone if it detects that a tool has broken. While the machine is awaiting replacement on the tool, it would run other parts it is already loaded with up to that tool and wait for the operator. The ever changing intelligence of CNC controllers has dramatically increased job shop cell production. Some machines might even make 1000 parts on a weekend with no operator, checking each part with lasers and sensors.

Milling machine tooling

2007-12-22T13:51:00.001-08:00

There is some degree of standardization of the tooling used with CNC Milling Machines and to a much lesser degree with manual milling machines.

CNC Milling machines will nearly always use SK (or ISO), CAT, BT or HSK tooling. SK tooling is the most common in Europe, while CAT tooling, sometimes called V-Flange Tooling, is the oldest variation and is probably still the most common in the USA. CAT tooling was invented by Caterpillar Inc. of Peoria, Illinois in order to standardize the tooling used on their machinery. CAT tooling comes in a range of sizes designated as CAT-30, CAT-40, CAT-50, etc. The number refers to the Association for Manufacturing Technology (formerly the National Machine Tool Builders Association (NMTB)) Taper size of the tool.

An improvement on CAT Tooling is BT Tooling, which looks very similar and can easily be confused with CAT tooling. Like CAT Tooling, BT Tooling comes in a range of sizes and uses the same NMTB body taper. However, BT tooling is symmetrical about the spindle axis, which CAT tooling is not. This gives BT tooling greater stability and balance at high speeds. One other subtle difference between these two toolholders is the thread used to hold the pull stud. CAT Tooling is all Imperial thread and BT Tooling is all Metric thread. Note that this affects the pull stud only, it does not affect the tool that they can hold, both types of tooling are sold to accept both Imperial and metric sized tools.

SK and HSK tooling, sometimes called "Hollow Shank Tooling", is much more common in Europe where it was invented than it is in the United States. It is claimed that HSK tooling is even better than BT Tooling at high speeds. The holding mechanism for HSK tooling is placed within the (hollow) body of the tool and, as spindle speed increases, it expands, gripping the tool more tightly with increasing spindle speed. There is no pull stud with this type of tooling.

The situation is quite different for manual milling machines — there is little standardization. Newer and larger manual machines usually use NMTB tooling. This tooling is somewhat similar to CAT tooling but requires a drawbar within the milling machine. Furthermore, there are a number of variations with NMTB tooling that make interchangeability troublesome.

Boring head on Morse Taper Shank

Two other tool holding systems for manual machines are worthy of note: They are the R8 collet and the Morse Taper #2 collet. Bridgeport Machines of Bridgeport Connecticut so dominated the milling machine market for such a long time that their machine "The Bridgeport" is virtually synonymous with "Manual milling machine." The bulk of the machines that Bridgeport made from about 1965 onward used an R8 collet system. Prior to that, the bulk of the machines used a Morse Taper #2 collet system

CNC milling machines or machining centers

2007-12-22T13:48:00.000-08:00

Most CNC milling machines or machining centers are computer controlled vertical mills with the ability to move the spindle vertically along the Z-axis. This extra degree of freedom permits their use in engraving applications, and also allows to create 2.5D surfaces such as relief sculptures. When combined with the use of conical tools or a ball nose cutter, it also significantly improves milling precision without impacting speed, providing a cost-efficient alternative to most flat-surface hand-engraving work.

Five-axis machining center with rotating table and computer interface

CNC machines can exist in virtually any of the forms of manual machinery, like horizontal mills. The most advanced CNC milling-machines, the 5-axis machines, add two more axes in addition to the three normal axes (XYZ). Horizontal milling machines also have a C or Q axis, allowing the horizontally mounted workpiece to be rotated, essentially allowing asymmetric and eccentric turning. The fifth axis(B-Axis) controls the tilt of the tool itself. When all of these axes are used in conjunction with each other, extremely complicated geometries, even organic geometries such as a human head can be made with relative ease with these machines. But the skill to program such geometries is beyond that of most humans. Therefore, 5-axis milling machines are practically always programmed with CAM.

With the declining price of computers, free operating systems such as Linux, and open source CNC software, the entry price of CNC machines has plummeted. For example, Sherline, Prazi, and others make desktop CNC milling machines that are affordable by hobbyists.

Milling machine variants

2007-12-22T13:42:00.000-08:00

Box or column mills are very basic hobbyist bench-mounted milling machines that feature a head riding up and down on a column or box way.
Turret or Vertical ram mills are more commonly referred to as bridgeport-type milling machines. The spindle can be aligned in many different positions for a very versatile, if somewhat less rigid machine.
C-Frame mills are larger, industrial production mills. They feature a knee and fixed spindle head that is only mobile vertically. They are typically much more powerful than a turret mill, featuring a separate hydraulic motor for integral hydraulic power feeds in all directions, and a twenty to fifty horsepower motor. Backlash eliminators are almost standard equipment. They use large NMTB 40 or 50 tooling. The tables on C-frame mills are usually 18" by 68" or larger, to allow multiple parts to be machined at the same time.
Knee mill refers to any milling machine that has a vertically adjustable table.
Bed mill refers to any milling machine where the spindle is on a pendant that moves up and down to move the cutter into the work. These are generally more rigid than a knee mill.
Ram type mill refers to a mill that has a swiveling cutting head mounted on a sliding ram. The spindle can be oriented either vertically or horizontally, or anywhere in between. Van Norman specialized in ram type mills through most of the 20th century, but since the advent of CNC machines ram type mills are no longer made.
Jig borers are vertical mills that are built to bore holes, and very light slot or face milling. They are typically bed mills with a long spindle throw. The beds are more accurate, and the handwheels are graduated down to .0001" for precise hole placement.
Horizontal boring mills are large, accurate bed horizontal mills that incorporate many features from various machine tools. They are predominantly used to create large manufacturing jigs, or to modify large, high precision parts. They have a spindle stroke of several (usually between four and six) feet, and many are equipped with a tailstock to perform very long boring operations without losing accuracy as the bore increases in depth. A typical bed would have X and Y travel, and be between three and four feet square with a rotary table or a larger rectangle without said table. The pendant usually has between four and eight feet in vertical movement. Some mills have a large (30" or more) integral facing head. Right angle rotary tables and vertical milling attachments are available to further increase productivity.

Floor mills have a row of rotary tables, and a horizontal pendant spindle mounted on a set of tracks that runs parallel to the table row. These mills have predominantly been converted to CNC, but some can still be found (if one can even find a used machine available) under manual control. The spindle carriage moves to each individual table, performs the machining operations, and moves to the next table while the previous table is being set up for the next operation. Unlike any other kind of mill, floor mills have floor units that are entirely movable. A crane will drop massive rotary tables , X-Y tables , and the like into position for machining, allowing the largest and most complex custom milling operations to take place.

Portical mills It has the spindle mounted in a T structure where 2 or 3 combined travels can be made depending if the work table is static or cross moved; The choice for one type or other in this case depends mostly on the part to be machined i.e. on its weight. Therefore the "ap" or "stepdown" needed on the average work done, should be considered, to watch for the torque on the moving axis;

Types of milling machines

2007-12-22T13:26:00.000-08:00

There are two main types of mill: the vertical mill and the horizontal mill. In the vertical mill the spindle axis is vertically oriented. Milling cutters are held in the spindle and rotate on its axis. The spindle can generally be extended (or the table can be raised/lowered, giving the same effect), allowing plunge cuts and drilling. There are two subcategories of vertical mills: the bedmill and the turret mill. Turret mills, like the ubiquitous Bridgeport, are generally smaller than bedmills, and are considered by some to be more versatile. In a turret mill the spindle remains stationary during cutting operations and the table is moved both perpendicular to and parallel to the spindle axis to accomplish cutting. In the bedmill, however, the table moves only perpendicular to the spindle's axis, while the spindle itself moves parallel to its own axis. Also of note is a lighter machine, called a mill-drill. It is quite popular with hobbyists, due to its small size and lower price. These are frequently of lower quality than other types of machines, however.

A horizontal mill has the same sort of x–y table, but the cutters are mounted on a horizontal arbor across the table. A majority of horizontal mills also feature a +15/-15 degree rotary table that allows milling at shallow angles. While endmills and the other types of tools available to a vertical mill may be used in a horizontal mill, their real advantage lies in arbor-mounted cutters, called side and face mills, which have a cross section rather like a circular saw, but are generally wider and smaller in diameter. Because the cutters have good support from the arbor, quite heavy cuts can be taken, enabling rapid material removal rates. These are used to mill grooves and slots. Plain mills are used to shape flat surfaces. Several cutters may be ganged together on the arbor to mill a complex shape of slots and planes. Special cutters can also cut grooves, bevels, radii, or indeed any section desired. These specialty cutters tend to be expensive. Simplex mills have one spindle, and duplex mills have two. It is also easier to cut gears on a horizontal mill.

A more complex form of the milling machine is the Universal milling machine, in which the rotating cutter can be oriented vertically or horizontally, increasing the flexibility of the machine tool. The table of the universal machine can be swiveled through a small angle (up to about 15 degrees), enabling the axis of the spindle to coincide with the axis of a helix to be milled with the use of a gear driven indexing attachment.

Metal Cutting Speeds

2007-12-22T13:24:00.000-08:00

There are three parameters that define how fast material is removed:

Surface Speed: Rate at which metal comes into contact with the tool at the cutting point. Usually expressed in SFM: surface feet per minute.
Feed Rate: Rate at which the cutting point moves transverse to the stock, like an autofeed rate.
Cut Depth: How much material is being removed in a given pass.

The chart of cut rates will make more sense after reading the following.

Surface Speed
Surface speed is how fast the metal comes into contact with the tool at the cutting point. On a lathe, it is the rate at which the surface of the stock passes the cutting tool. This takes into account the diameter of the stock. On a mill, it is the rate at which the end-mill, for example, moves past the stationary stock. This takes into account the diameter of the endmill. Surface speed is usually measured in Surface Feet per Minute (SFM).

For example, turning a piece of 1" stock on a lathe at 260 RPM yields a 68.0 SFM (surface feet per minute) surface rate:

The general formula for a surface speed is as follows:

where
D = diameter of stock (lathe) or diameter of cutting tool (mill), in inches
RPM = speed of the rotating part or tool, in revolutions per minute

Note: when facing a part on a lathe, to maintain a uniform surface speed, the RPM would need to go to infinity. When facing, select the speed based on the diameter at the outside surface. This will yield a slower speed than a diameter measured halfway through the stock, or at the center(!).

Feed Rate
Feed rate is how fast the tool moves relative to a fixed, stationary part. It is the autofeed rate when autofeed is used, and is usually measured in inches per minute on a mill, or inches per revolution on a lathe.

To translate between from inches per revolution to inches per minute on a lathe feed rate, multiply the inches per revolution by the spindle speed in RPM

Cutting Speed

2007-12-22T13:15:00.000-08:00

Cutting speed is the term used to express the velocity of the tool (SFM = surface feet per minute) as it cuts a specific material. Each material has an optimum range for its machinability with each cutting tool material (i.e. H.S.S. vs. carbide, etc.)

Use the following formula to compute a tool's cutting speed:

Where:

- SFM = surface feet/minute
- D= tool diameter in inches
- RPM = revolutions/minute

Rotabroach Cutter

SFM = .262 x diameter x RPM

Conventional Drill

SFM = .262 x diameter x RPM

Rotabroach Cutters provide a nearly constant tooth pitch. This pitch provides consistent tool life patterns for the entire range of diameter sizes in terms of lineal inches (inches of drill penetration).