CNC Machines
In order to understand where CNC Machining first appeared, it is important to note that the said machine’s advent can be traced back to the invention of the NC (numerical controlled) machine made by John T. Parsons during the 1940s-1950s. The NC was a breakthrough invention that led the way towards modern automated machines.
CNC mills have very little differences with its predecessor in terms of its concept. The modern CNC mill still functions in machines to produce outputs in three dimensional directions: X and Y axes, and depth. Examples of CNC systems applied in various industries include laser cutting, welding and ultrasonic welding among others.
CNC Motors
CNC motors are the heart of any CNC machine. The size and type of motor can define a CNC routers precision, speed, and accuracy. There are two primary classes of motors used on CNC machines, stepper motors and servo motors. Within these two classes there are several types.
Stepper motors
stepper motors are used on small to
mid-sized CNC mills & milling machines, CNC lathes, Pick-n-place machines, Laser Engravers and Laser Cutters, Vinyl Sign Cutters, CNC Plasma Cutters, and CNC Foam Cutters. These motors have been used in precision telescope positioning systems and robots.
Block Diagram of CNC Machine
MACH3 CNC Controller
Mach3 turns a typical computer into a CNC machine controller. It is very rich in features and provides a great value to those needing a CNC control package. Mach3 works on most Windows PC’s to control the motion of motors (stepper & servo) by processing G-Code. While comprising many advanced features, it is the most intuitive CNC control software available. Mach3 is customizable and has been used for many applications with numerous types of hardware.
Here are some of the basic features and functions provided by Mach3:
- Converts a standard PC to a fully featured, 6-axis CNC controller
- Allows direct import of DXF, BMP, JPG, and HPGL files through LazyCam
- Visual Gcode display
- Generates Gcode via LazyCam or Wizards
- Fully customizable interface
- Customizable M-Codes and Macros using VBscript
G-Code and M-Code list of CNC Machines
| G-Code List Machining Centers (Common for most machines) |
(G-Codes vary from machine to machine)G00 positioning (rapid traverse)
G01 linear interpolation (feed)
G02 circular interpolation CW
G03 circular interpolation CCW
G04 dwell
G07 imaginary axis designation
G09 exact stop check
G10 offset value setting
G17 XY plane selection
G18 ZX plane selection
G19 YZ plane selection
G20 input in inch
G21 input in mm
G22 stored stroke limit ON
G23 stored stroke limit OFF
G27 reference point return check
G28 return to reference point
G29 return from reference point
G30 return to 2nd, 3rd & 4th ref. Point
G31 skip cutting
G33 thread cutting
G40 cutter compensation cancel
G41 cutter compensation left
G42 cutter compensation right
G43 tool length compensation + dir
G44 tool length compensation - dir
G49 tool length compensation cancel
G45 tool offset increase
G46 tool offset decrease
G47 tool offset double increase
G48 tool offset double decrease
G50 scaling OFF
G51 scaling ON
G52 local coordinate system setting | G54 work coordinate system 1 select
G55 work coordinate system 2 select
G56 work coordinate system 3 select
G57 work coordinate system 4 select
G58 work coordinate system 5 select
G59 work coordinate system 6 select
G60 single direction positioning
G61 exact stop check mode
G64 cutting mode
G65 custom macro simple call
G66 custom macro modal call
G67 custom macro modal call cancel
G68 coordinate system rotation ON
G69 coordinate system rotation OFF
G73 peck drilling cycle
G74 counter tapping cycle
G76 fine boring
G80 canned cycle cancel
G81 drilling cycle, spot boring
G82 drilling cycle, counter boring
G83 peck drilling cycle
G84 tapping cycle
G85,G86 boring cycle
G87 back boring cycle
G88,G89 boring cycle
G90 absolute programming
G91 incremental programming
G92 programming of absolute zero point
G94 per minute feed
G95 per revolution feed
G96 constant surface speed control
G97 constant surface speed control cancel
G98 return to initial point in canned cycle
G99 return to Ref point in canned cycle |
| STANDARD G CODE CHART FOR LATHES |
(G-Codes vary from machine to machine)G00 positioning (rapid)
G01 linear interpolation (feed)
G02 circular interpolation CW
G03 circular interpolation CCW
G04 dwell
G07 hypothetical axis interpolation (sine curve)
G09 exact stop
G10 offset value setting
G20 G70 inch data input
G21 G71 metric data input
G22 stored stroke limit ON
G23 stored stroke limit OFF
G27 reference point return check
G28 return to reference point
G29 return from reference point
G30 return to 2nd, 3rd & 4th reference point
G31 skip cutting
G32 G33 thread cutting
G34 variable thread cutting
G36 automatic tool compensation X
G37 automatic tool compensation Y
G40 tool nose radius compensation cancel
G41 tool nose radius compensation left |
G42 tool nose radius compensation right
G50 G92 programming of absolute zero point maximum spindle speed setting
G65 user macro simple call
G66 user macro modal call
G67 user macro modal call cancellation
G68 mirror image for double turrets ON
G69 mirror image for double turrets OFF
G70 G72 finishing cycle
G71 G73 stock removal in turning
G72 G74 stock removal in facing
G73 G75 pattern repeating
G74 G76 peck drilling in Z axis
G75 G77 grooving in X axis
G76 G78 thread cutting cycle
G90 G77 G20 cutting cycle A
G92 G78 G21 thread cutting cycle
G94 G79 G24 cutting cycle B
G96 constant surface speed control
G97 constant surface speed control cancel
G98 G94 per minute feed
G99 G95 G95 per revolution feed
G90 absolute programming
G91 incremental programming
|
| STANDARD M-CODES |
(M-Codes vary from machine to machine)M00 program stop
M01 optional stop
M02 end of program (no rewind)
M03 spindle CW
M04 spindle CCW
M05 spindle stop
M06 tool change
M07 mist coolant ON
M08 flood coolant ON
M09 flood coolant OFF
M19 spindle orientation ON
M30 end program (rewind stop)
M98 call sub-program
M99 end sub-program |
DIY Small CNC
Designing A CNC machine from scratch is a good idea and a enjoyable hobby but a Time consuming and patient job.
What type of machine you are going to design its depend your application, job size and of-course your pocket weight and volume.
But it is always desirable to start with a small one and you can built a bigger one once you get idea and familiar with all the equipment and controller .If you are agree let's start to design the machine.
What you need
3/4" thick wood planks, 1/4 threaded screw,some brass bushes, 3 nos of stepper motors,
one old PC (equipped with OLD LPT1 printer port)Loaded MACH3 software,Stepper motors driver board, High speed DC motor for spindle drive and power supplies.
