Norton Grinder with Centroid T400 CNC

Startup

  1. Press Emergency Stop
  2. Switch the cabinet rotary switch on. After about one minute, the control will prompt for CYCLE START to home.
  3. Release Emergency Stop
  4. Press CYCLE START. The machine will home the X axis to the back, then set Z home wherever it sits.

The control starts up in Incremental jog mode. In order to jog the axes in continuous movement, you need to press the INCR/CONT key to switch from incremental to continuous jog mode.

Idle Periods

  1. Press Emergency Stop to remove power from the servos.
  2. To resume normal operation, release Emergency Stop.

Shutdown

  1. Press F10/Shutdown
  2. Optionally, press F1/Park and press CYCLE START. This will move the X axis back until it is just in front of its home/limit switch, and move the Z axis to the location it was at when you set home on the last power-up.
  3. Press Emergency Stop
  4. Press F2/Poweroff. After about 15 seconds the console screen will go blank.
  5. Switch the cabinet rotary switch off.

Managing Part Programs

To load an existing CNC program

  1. From the main control screen, press F2/Load.
  2. Use the arrow keys to highlight the name of the program you want to load.
  3. Press F10/Accept.

To edit the current CNC program

  1. Press F6/Edit.
  2. Make any changes you need.
  3. Press Ctrl-S to save your changes.
  4. Press Alt-F4 to quit.

To edit the current CNC program, then save it as a new program

  1. Press F6/Edit
  2. Press Alt-F for the File menu
  3. Arrow down to "Save As" and press Enter
  4. Type the new program name. You can use numbers, letters, hyphens ("-") and underscores ("_"). Do not use blank spaces, quotes, slashes, or other punctuation. Do include a standard file extension on the end of the name: for example, ".cnc" or ".txt". Press Enter to save under the new name.
  5. Make any changes you need.
  6. Press Ctrl-S to save again, with the new name.
  7. Press Alt-F4 to quit and return to the Centroid control screen.
  8. Press F2/Load.
  9. Highlight the new program name.
  10. Press F10/Accept.

To write a new CNC program

  1. Press F6/Edit.
  2. Choose File -> New to create a new file.
  3. Type the codes you want
  4. Press Ctrl-S to save.
  5. Type the new program name. You can use numbers, letters, periods, hyphens ("-") and underscores ("_"). Do not use blank spaces, quotes, slashes, or other punctuation. Do include a standard file extension on the end of the name: for example, ".cnc" or ".txt". Press Enter to save under the new name.
  6. Press Alt-F4 to quit and return to the Centroid control screen.
  7. Press F2/Load.
  8. Highlight the new program name.
  9. Press F10/Accept.

Optionally, you can plug in a USB mouse and use it to navigate the program text and the menus in the text editor.

Part Programming

General Guidelines

The Intercon conversational programming feature will not be useful for writing Cylindrical Grinder programs. You will need to write your programs in CNC G codes.

The X axis moves the grinder in and out, determining the diameter of the part.

The Z axis moves the carriage left and right, along the length of the part.

Every program should start with a G98 code before any feedrate movement. This will select feed-per-minute feedrates. Feed-per-revolution is not available on this machine because it lacks a spindle encoder.

Use X and Z to command the axes to move to specified positions, measured from the part zero position you have set.

Use U and W to command the X and Z axes to move incremental distances, from wherever the previous move left off, without regard to the part zero position.

Use G1 and a feedrate to do straight-line feedrate movement to a specified position or by a specified distance.

Use G0 to do rapid positioning moves.

Use M105/Z P1 to move the Z axis in the minus direction (carriage right) until it trips the minus shuttle switch.

Use M106/Z P2 to move the Z axis in the plus direction (carriage left) until it trips the plus shuttle switch.

Use M3 and an S value to start the workpiece spindle rotating at the requested RPM. Use M5 to stop the workpiece spindle.

Use M13 to start the grinder spindle. Use M15 to stop the grinder spindle.

Use M41 through M48 to select the speed of the grinder spindle, in 8 steps. M41 is the slowest available speed; M48 is the fastest available speed.

Use M8 to start the coolant. Use M9 to stop it.

Use G28 U0 to move the X axis all the way back, without having to know what X coordinate that may be.

Aux1 and Aux2

The Aux1 and Aux2 keys and LEDs in the the upper right section of the jog panel can be used for program control. You can turn the LEDs on and off by pressing the keys. You can also turn the LEDs on and off with programmed M functions (to choose a default mode). You can use IF/THEN and GOTO commands in the part programs to perform different operations depending on whether an LED is on or off.

The suggested use is to have Aux1 select infeed while grinding, and to have Aux2 indicate that the part or feature is finished. Programs would generally check the state of the Aux LEDs at the ends of the part, before turning around.

Use M61 to turn on Aux1 in a program (enable the infeed request).

Use M60 to turn off Aux1 in a program (cancel the infeed request).

Use M63 to turn on Aux2 in a program (enable the end request).

Use M62 to turn off Aux2 in a program (cancel the end request).

Manual Keypad Controls

Workpiece Spindle

The workpiece spindle is controlled by the Spindle Control keys in the upper left section of the jog panel.

Switch between Automatic control using M codes (LED on) and Manual control using the keypad.
Start workpiece spindle
Stop workpiece spindle
Increase speed
Set speed to middle of range (26 RPM)
Decrease speed



Grinder Spindle

The grinder spindle is controlled by Aux keys in the upper right section of the jog panel.

Increase speed
Set speed to middle of range
Stop grinder spindle Start grinder spindle Decrease speed

Coolant

Coolant is controlled by the coolant keys across the middle of the jog panel.

Switch between Automatic control using M codes (LED on) and Manual control using the keypad (LED off).
In Manual mode, turn coolant on and off


MPG Electronic Handwheel

The MPG handwheel pendant can be used to jog the axes during setup operations, and it can also be used to "offset" the X axis during a program cycle.

  To use the MPG in a normal jogging mode (not affecting the offset amount for the X axis), turn the jog panel Aux4 selector off.

With Aux4 off, you can use the MPG to move the X and Z axes as needed for setup and preparation. Turn the axis selector on the MPG pendant to "X" or "Z" as needed, and turn the increment selector to "x1", "x10", or "x100" as needed.

The x1 increment is for fine slow movement (0.0001" per click, or 0.010" per revolution). The x100 increment is for coarse fast movement (0.010" per click, or 1.0" per revolution).

  To use the MPG in an Offset mode during a program cycle, turn the jog panel Aux4 indicator on and turn the axis selector to "X", before you start the program cycle.

In the Offset mode (moving X, with Aux4 turned on) MPG handwheel movement adds to a hidden offset value which is added to programmed X axis position. The X axis will, therefore, move to whatever positions it was programmed to move to, offset by the additional amount set with the MPG handwheel.

The MPG Offset amount affects all X axis movement, even after the program cycle ends. The only ways to remove the MPG X Offset amount are to dial the offset back to zero, or to shut down, power off, and power back up.

To dial the X Offset amount back to zero:

  1. Using the yellow jog keys, or the MPG in normal mode (Aux4 off), move the X axis well clear of the part.
  2. Read the X axis position displayed on the DRO.
  3. Pick a convenient whole-inch position near the current position. For example, if the DRO reads X8.2345 with the wheel well clear of the part, then use 8.0000.
  4. Press F3 for MDI.
  5. Turn the Feedrate Override knob down to 10% or so.
  6. Enter the chosen position (e.g. "X8.0")
  7. Press CYCLE START. The grinder carriage will move in or out, until it has reached the chosen position plus the current offset amount. For example, after you tell it to move to X8.0000, it might end at X7.4355. That would mean that the current MPG offset amount is -0.5645".
  8. Press ESC to cancel the MDI prompt.
  9. Turn on the jog panel Aux4 indicator.
  10. Use the MPG handwheel to move the X axis until the DRO reads the exact target position (e.g. X8.0000). the offset amount is now zero.
  11. Turn off the jog panel Aux4 indicator.

If, when you try to do the MDI move to a chosen position, the control reports "907 X axis travel exceeded", it means that the control cannot move to that position (plus the offset) without going beyond the axis travel limits. This probably indicates an unusually large offset amount. Try smaller numbers until you find one that works.

Program Examples

These programs use local variables and various advanced macro features.

The variables allow a single program to cut parts with different dimensions, simply by editing the dimensions at the top of the program (above the double line).

The IF/THEN and GOTO features are used to repeatedly loop back and forth across the part, and provide for optional infeed.

Manual infeeds can be done with the jogging keys and/or MPG handwheel, but only while the control is waiting at a programmed M0 (pause and wait for CYCLE START).

Straight, with infrequent manual infeed

This program grinds a straight diameter, with optional manual infeed at each end. It assumes that there will be several back-and-forth passes between infeeds, so it automatically cancels the Aux1 infeed request after each use.

; Straight_1.cnc
; Program to cut a straight roll with manual infeeds
; Stop for infeed only when Aux1 LED is on
; Z0 is right-hand end of part
#119 = 20.0 ; Spindle RPM
#120 = 28.0 ; length of part
#122 = 50.0 ; feedrate (inches/minute)
;=====================================================;
G98
M03 S#119
#112 = 60.0/#119 ; dwell time (seconds per revolution)
N1
G1 Z-#120 F#122
; Check Aux1 light.
; If LED is off, just dwell and reverse.
; If LED is on, wait for CYCLE START
IF #61059==0 THEN G4 P#112
IF #61059==1 THEN M0
M60 ; cancel Aux1 request
G1 Z0 F#122
IF #61059==0 THEN G4 P#112
IF #61059==1 THEN M0
M60 ; cancel Aux1 request
; Check Aux2 light.
; If Aux2 is off, go back to start and do cycle again
; If Aux2 is on, part is finished: retract X and end
; also end program if in graph mode instead of running (#4201==1)
IF #61060==0 && #4201==0 THEN GOTO 1
G1 F20 U.05 ; X incremental .025" away from part

Straight, with frequent manual infeed

This program grinds a straight diameter, with optional manual infeed at each end. It assumes that there will be an infeed at every turnaround, so it automatically enables the Aux1 infeed request at program start, and leaves it on. The operator can cancel it by pressing the Aux1 key when he wants to "spark out".

; Straight_2.cnc
; Program to cut a straight roll with manual infeeds
; Stop for infeed at each end, unless Aux1 LED is off
; Z0 is right-hand end of part
#119 = 20.0 ; Spindle RPM
#120 = 28.0 ; length of part
#122 = 50.0 ; feedrate (inches/minute)
;=====================================================;
M61 ; set Aux1 LED to start out
G98
M03 S#119
#112 = 60.0/#119 ; dwell time (seconds per revolution)
N1
G1 Z-#120 F#122
; Check Aux1 light.
; If LED is off, just dwell & reverse
; If LED is on, wait for CYCLE START
IF #61059==0 THEN G4 P#112
IF #61059==1 THEN M0
G1 Z0 F#122
IF #61059==0 THEN G4 P#112
IF #61059==1 THEN M0
; Check Aux2 light.
; If Aux2 is off, go back to start and do cycle again
; If Aux2 is on, part is finished: retract X and end
; also end program if in graph mode instead of running (#4201==1)
IF #61060==0 && #4201==0 THEN GOTO 1
G1 F20 U.05 ; X incremental .025" away from part

Cosine crown, with optional automatic infeed

This program grinds a cosine crown, with optional pre-programmed infeed at each end. It assumes that there will be an infeed at every turnaround, so it automatically enables the Aux1 infeed request at program start, and leaves it on. The operator can cancel it by pressing the Aux1 key when he wants to "spark out".

; Cosine.cnc
; Program to cut a cosine crown with automatic infeeds
; Do infeeds if Aux1 LED is on
; Skip infeeds if Aux1 LED is off
; Z0 is middle of part (high point of crown)
#119 = 20.0 ; Spindle RPM
#120 = 28.0 ; length of part (overall)
#121 = 28.0 ; measured crown face (MCF)
#122 = 70.0 ; cam rotation, degrees
#126 = 0.06 ; crown amount (diameter amount)
#127 = 50.0 ; feedrate (inches/minute)
#128 = 0.10 ; step size (between points along length)
#129 = 0.001 ; automatic infeed amount (at each end)
;=====================================================;
M61 ; set Aux1 LED to start out
G98
M03 S#119
#108 = 0.0 ; accumulated X infeed
#109 = #121/2.0 ; half of MCF
#110 = #120/2.0 ; half length of part
#111 = COS[#122] ; cosine of cam rotation
#112 = 60.0/#119 ; dwell time (seconds per revolution)
N1
#100 = #110 ; Z position, starting at plus end
N2
#113 = #109-ABS[#100] ; distance from crown face
#114 = #122 * [1-2*#113/#121]
#115 = COS[#114] - #111
#116 = #115 / [1-#111]
#101 = #126 * #116 - #108 ; X position at this Z station
G1 Z#100 X#101 F#127
#100 = #100 - #128
IF #100 >= -#110 THEN GOTO 2
; dwell for one turn
G4 P#112
; Check Aux1 light.
; If LED is on, do infeed
; If LED is off, skip infeed
IF #61059==0 THEN GOTO 3
G1 U-#129 F1.0
#108 = #108 + #129
N3
#100 = -#110 ; Z position, restarting at minus end
N4
#113 = #109-ABS[#100]
#114 = #122 * [1-2*#113/#121]
#115 = COS[#114] - #111
#116 = #115 / [1-#111]
#101 = #126 * #116 - #108
G1 Z#100 X#101 F#127
#100 = #100 + #128
IF #100 <= #110 THEN GOTO 4
G4 P#112
; Check Aux2 for program end, then Aux1 for optional infeed
IF #61060==1 || #4201==1 THEN GOTO 99
IF #61059==0 THEN GOTO 5
G1 U-#129 F1.0
#108 = #108 + #129
N5
GOTO 1
N99
G1 F4 U.05 ; X incremental .025" away from part