CNC MACHINING::IS IT TIME TO AUTOMATE?

Machine shops seeking a more cost-effective method of CNC-machining should look to automation as a potential solution - and timing is everything.

Professionals in the automated CNC machining field suggest that automation can improve quality of machined parts, decrease setup time, stop fluctuations in production rates and raise the average percentage of functional machine tools in a shop from 65 percent to more than 85 percent.

However, before making the move to automation there are a few things to consider. First, the machining process selected for automation should be a reliable one from the onset in order to ensure the quality of automatically machined parts. Second, in order to ensure that the switch to automation will be cost effective, the price of automating each spindle should be less than $50,000 or about 50 percent of the cost of a spindle.

As the technology becomes more affordable, robotic vision seems to be the next frontier for CNC automation. One day soon, perhaps, machines equipped with vision technology will be able to guide themselves rather than having to rely on a fixture that holds a part to be machined in a specific orientation so that robots know where to pick it up. This will make it possible for operators to place an object on a conveyor within an accuracy of one inch and the robotic arm will seek, acquire and grip the part for loading.

CNC M-CODES

BELOW U CAN FIND ALL TYPES OF M-CODES THAT ARE USED IN CNC MACHINE PROGRAMMING.  M codes chart
M00	Program Stop
M01	Optional (Planned) Stop
M02	End of program
M03	Spindle CW
M04	Spindle CCW
M05	Spindle OFF
M06	Tool change
M07	Coolant #2 ON
M08	Coolant #1 ON
M09	Coolant OFF
M10	Clamp
M11	Unclamp
M12	Unassigned
M13	Spindle CW & Coolant ON
M14	Spindle CCW & Coolant ON
M15	Motion +
M16	Motion -
M17	Unassigned
M18	Unassigned
M19	Oriented spindle stop
M20-M29	Permanently unassigned
M30	End of tape
M31	Interlock bypass
M32-M35	Unassigned
M36-M39	Permanently unassigned
M40-M45	Gear changes if used, otherwise unassigned
M46-M47	Unassigned
M48	Cancel M49
M49	Bypass override
M50-M89	Unassigned
M90-M99	Reserved for user

CNC G CODES

CNC Machine Language
G-Code List

G-Code is one of a number of computer code languages that are used to instruct CNC machining devices what motions they need to perform such as work coordinates, canned cycles, and multiple repetitive cycles. Industry has standardized on G-Code as its basic set of CNC machine codes.

G-Code is the most popular programming language used for programming CNC machinery. Some G words alter the state of the machine so that it changes from cutting straight lines to cutting arcs. Other G words cause the interpretation of numbers as millimeters rather than inches. Some G words set or remove tool length or diameter offsets.

Below is a complete listing of current codes.

G-Code	Description
G00	Rapid Linear Interpolation
G01	Linear Interpolation
G02	Clockwise Circular Interpolation
G03	Counter Clockwise Circular Interpolation
G04	Dwell
G05	High Speed Machining Mode
G10	Offset Input By Program
G12	Clockwise Circle With Entrance And Exit Arcs
G13	Counter Clockwise Circle With Entrance And Exit Arcs
G17	X-Y Plane Selection
G18	Z-X Plane Selection
G19	Y-Z Plane Selection
G28	Return To Reference Point
G34	Special Fixed Cycle (Bolt Hole Circle)
G35	Special Fixed Cycle (Line At Angle)
G36	Special Fixed Cycle (Arc)
G37	Special Fixed Cycle (Grid)
G40	Tool Radius Compensation Cancel
G41	Tool Radius Compensation Left
G42	Tool Radius Compensation Right
G43	Tool Length Compensation
G44	Tool Length Compensation Cancel
G45	Tool Offset Increase
G46	Tool Offset Decrease
G50.1	Programmed Mirror Image Cancel
G51.1	Programmed Mirror Image On
G52	Local Coordinate Setting
G54 - G59	Work Coordinate Registers 1 Thru 6
G60	Unidirectional Positioning
G61	Exact Stop Check Mode
G65	Macro Call (Non Modal)
G66	Macro Call (Modal)
G68	Programmed Coordinate Rotation
G69	Coordinate Rotation Cancel
G73	Fixed Cycle (Step)
G74	Fixed Cycle (Reverse Tapping)
G76	Fixed Cycle (Fine Boring)
G80	Fixed Cycle Cancel
G81	Fixed Cycle (Drilling / Spot Drilling)
G82	Fixed Cycle (Drilling / Counter Boring)
G83	Fixed Cycle (Deep Hole Drilling)
G84	Fixed Cycle (Tapping)
G85	Fixed Cycle (Boring)
G86	Fixed Cycle (Boring)
G87	Fixed Cycle (Back Boring)
G88	Fixed Cycle (Boring)
G89	Fixed Cycle (Boring)
G90	Absolute Value Command
G91	Incremental Value Command
G92	Work Offset Set
G101	User macro 1 (substitution) =
G102	User macro 1 (addition) +
G103	User macro 1 (subtraction) -
G104	User macro 1 (multiplication) *
G105	User macro 1 (division) /
G106	User macro 1 (square root)
G107	User macro 1 (sine) sin
G108	User macro 1 (cosine) cos
G109	User macro 1 (arc tangent) tan
G110	User macro (square root)
G200	User macro 1 (unconditional branch)
G201	User macro 1 (zero condition branch)
G202	User macro (negative condition branch)

CNC LATHE

CNC Lathe and turningCNC lathes are rapidly replacing the older production lathes (multispindle, etc) due to their ease of setting and operation. They are designed to use modern carbide tooling and fully utilize modern processes. The part may be designed by the Computer-aided manufacturing (CAM) process, the resulting file uploaded to the machine, and once set and trialled the machine will continue to turn out parts under the occasional supervision of an operator. The machine is controlled electronically via a computer menu style interface, the program may be modified and displayed at the machine, along with a simulated view of the process. The setter/operator needs a high level of skill to perform the process, however the knowledge base is broader compared to the older production machines where intimate knowledge of each machine was considered essential. These machines are often set and operated by the same person, where the operator will supervise a small number of machines (cell). The design of a CNC lathe has evolved yet again however the basic principles and parts are still recognisable, the turret holds the tools and indexes them as needed. The machines are totally enclosed, due in large part to Occupational health and safety (OH&S) issues. With the advent of cheap computers, free operating systems such as Linux, and open source CNC software, the entry price of CNC machines has plummeted. For example, Sherline makes a desktop CNC lathe that is affordable by hobbyists. Most CNC Swiss style lathes today utilize two spindles. The main spindle is used with the guide bushing for the main machining operations. The secondary spindle is located behind the part, aligned on the Z axis. In simple operation it picks up the part as it is cut off (or parted off) and ejects it into a bin, eliminating the need to have an operator manually change each part, as is often the case with standard CNC turning centers. This makes them very efficient, as these machines are capable of fast cycle times, producing simple parts in one operation in as little as 10-15 seconds. This makes them ideal for large production runs of small diameter parts.

CNC ROUTERS

A router is a woodworking tool used to rout out (hollow out) an area in the face of a piece of wood. It was a tool particularly used by pattern makers and staircase makers and consisted of a broad-based wooden hand plane with a narrow blade projecting well beyond its base plate gaining it the nickname Old Woman's Tooth. Since about 1960, it has been replaced by the modern spindle router, which was designed for the same work, although the first electric hand routers appeared in the years just after World War I. Further refinement produced the plunge router, invented by Elu (now part of deWalt) in Germany in the late 1940s. This is even better adapted for many types of work. Today, traditional hand-powered routers are often called router planes. Modern routers are often used in place of traditional moulding planes or spindle moulder machines for edge decoration (moulding) of timber. Related to the router, is a smaller lighter version designed specifically for trimming laminates. It can be used for smaller general routing work. For example with an appropriate jig it can be used recessing door hinges and recessing lock faceplates etc. A wood CNC Router is similar to a metal CNC mill with the following differences:The wood router typically spins faster — up to 24,000 RPM It typically uses smaller tools — typical shank size 20 mm or at most 25 mm. It typically uses smaller toolholders MK2 (Morse taper #2 - on older machines),ISO-30, HSK-63 or the tools just get held in a collet tool holder affixed directly to the spindle nose. ISO-30 and HSK-63 are rapid-change toolholding systems. HSK-63 has begun to supplant the ISO-30 as the rapid change standard in recent years Some wood routers have multiple separate heads that can come down simultaneously or not. This design is generally not as easy as a toolchanger with ISO-30 or HSK-63, though it is easier to maintain. A wood router table is controlled in the same way as a metal mill, but there is a lot of CAM software specifically for wood routers. Wood with different grain must be approached with unique strategies, and wood CAM software is less likely to need to have hog-out strategies than the metal ones. Wood routers are frequently used to machine other soft materials such as plastics at high speed.