RotCvt

CNC program conversion utility for rotary fourth axes.
Version 1.01
www.cncsnw.com

Installation

If you received the software via an e-mailed or downloaded ZIP file, unpack the ZIP file and place its contents on a floppy disk or USB flash drive.
Insert the disk or flash drive in the control
Press F7/Utility
Press F2/Update
If prompted for a location to update from, browse to the floppy drive or USB drive.
When installation is complete press ESC to return to the main screen. There is no need to cycle the power.

RotCvt should appear as the next available key on the F5/CAM menu (usually F3, F4 or F5).

Operation

Press F2/Load and load the XYZ program you wish to convert.
Press F5/CAM
Press the F key for RotCvt
Make any changes you need to the conversion options:
1. The name of the input file (the one you want to convert). By default this is the currently loaded job.
2. The name of the output file (where you want to put the resulting converted program). By default this is the same as the input file name, but with the file extension changed to .CYL.
3. The diameter of the cylinder you want to wrap around.
4. Scale factors to apply to each axis before converting. For example, you could enter 0.2 for the Z axis scale factor if you wanted Z depths to cut 20% of what was in the original program. Leave the scale factor at 1.0 if you want to cut full size.
5. XY Plane rotation to apply before converting. You may optionally choose to rotate the part CW or CCW 90°.
6. Press F10 to run the conversion.
On Linux-based controls, press F2/Load to load the converted program. On DOS-based controls the converted program should be automatically loaded (check the name shown in the upper right corner to be sure).
Verify X and Z movement on the F8/Graph screen, noting that Y axis movement will no longer be shown at all.
Run!

Limitations

The program to be converted must not use Cutter Diameter Compensation (G41/G42)
Units-of-measure (G20, G21) or coordinate system changes (G54-G59, G52, G92) in the midst of converted feedrate cuts will cause incorrect feedrates.
M functions with '/' arguments after them (M26, M91, M94, M101, M105, etc.) may not convert correctly.
Mathematical expressions and macro argument references (e.g. "G1 Z[#101*0.5]") are not supported.

Configuration

Default values for the cylinder diameter, scale factors, and plane rotation, as well as several options not presented on the screen, are contained in the ROTCVT.INI file which is located in the same directory as the program (/cncroot/c/cnc10 on Linux controls; C:\CNC7 on DOS controls). You can edit ROTCVT.INI from the command prompt.

Press Alt-F6 in Linux, or Ctrl-Alt-X in DOS, for a command prompt.
Open the file with the command:
edit rotcvt.ini
Change values as needed
Press Alt-F, then X to exit
Press Y when prompted to save your changes
In Linux, close the command prompt with the command:
exit
In DOS, restart the the control software with the command:
CNC7M4

Options in the ROTCVT.INI file include the following:

Cylinder diameter: Default cylinder diameter. You can change this value on the screen when you run RotCvt.
Axis to replace: The linear axis to be replaced with rotary movement (e.g. X or Y)
Rotary axis: The letter for your rotary axis (e.g. W or B)
Reverse rotary?: Whether to reverse the direction (plus/minus) of the rotary axis. Use this to correct an unwanted mirror image.
Move replaced axis to zero?: Whether to add a move at the beginning of the program to bring the replaced axis to zero (usually over rotary centerline).
Include spaces?: Whether to include spaces between values in the G codes. Spaces improve readability, but make the resulting file longer.
Require decimals?: Whether to require a decimal point in position and feedrate values (i.e. to output "X1." instead of "X1"). This is not required on any Centroid control, but could be needed on some other controls.
Chord tolerance: The tolerance for arc conversions: i.e. how close must we stay to the original arc when we break it into straight lines. Smaller values yield smoother arcs, but also larger files.
X axis scale factor Y axis scale factor Z axis scale factor: Default scale factors for the linear axes. You can change these values on the screen as you run RotCvt.
Plane rotation: Default Plane rotation. You can change this value on the screen as you run RotCvt.

Offline Use

You can also run the DOS version of RotCvt offline (for example, on a desktop computer running Windows). The best way to do that is to make a Windows shortcut to ROTCVT.EXE, then drag and drop your input file onto the shortcut. When run this way, RotCvt will not look for the Centroid control's setup file to find the input job name; it will instead use the one it received on the command line, through the Windows shortcut. The output job name will be the same as the input file, but with the extension changed to ".CYL".

Legalese

I make no warranty, express or implied, with respect to their quality, performance, or fitness for a particular purpose. They are provided "as is", and you assume all risk associated with their use.

You should use all available means to verify that the job will run safely before you press the CYCLE START button. These include, but are not limited to, the F8/Graph and F6/Edit features of your control.

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