ROTABLE.EXE
                                  
ROTABLE is a proglet for calculating the settings of a simple rotary 
table, as commonly used on milling machines, for producing equal divisions of 
a circle. This enables a normal rotary table to be used as a dividing head.

It is a DOS programme that should run satisfactorily under Windows on an IBM 
compatible PC.

On entering you need to enter 3 values:

1. Gear ratio of table (Number of turns of handle for 1 of table)
   This is typically 36, 60, 72 or 90.

2. Number of divisions required per rev. of table
   Must be a whole number between 1 and 1000

3. Current reading of table's rim angle
   For the initial cut it may not be convenient to set the angle of the table 
   so that the rim pointer is at 0  degrees. This entry, which may be a 
   decimal value between 0 and 360, allows you to make the first cut with the 
   rim pointer set to any angle. Note that the dial reading should always be 
   set to 0 for the first division.
   
   
On completion of the third entry the programme computes and displays the 
results. If the number of divisions is greater than the screen permits then it 
pauses after each full screen.

The results are displayed in three columns.  The first is the division number, 
the second is the approximate rim angle and the third is the dial setting 
expressed as turns, degrees, minutes and seconds.

In practice the turns count can be ignored: to move to the next division the 
knob is simply rotated slightly less than the number of turns per division and 
then is advanced until the correct degrees, minutes and seconds (if 
applicable) are shown on the dial. Once that has been done check that the rim 
angle corresponds with that shown on the display.  With a 90:1 gear ratio one 
turn of the dial is 4 degrees so it will be immediately apparent if you are 
one turn of the dial out of position.

It is not practicable to print the results from within ROTABLE as it is a DOS 
programme which will normally be run under Windows. The results can be saved 
to a file (ROTABLE.TXT) which can then be opened with any text editor or word 
processor e.g. Notepad or Word.  If it is opened with a proportional spaced 
font such as Arial then the font needs to be changed to fixed e.g Courier or 
Fixedsys. Note that ROTABLE.TXT is always created in the folder/directory 
where ROTABLE.EXE exists.

When the results for all divisions have been displayed you are asked if you 
want to save them to file. If you respond affirmatively then ROTABLE checks 
for the existence of ROTABLE.TXT and, if it finds it, then it gives you the 
option of over-writing it or quitting.

ROTABLE is freeware so you may do what you like with it. There is no guarantee 
that it produces correct results so it is up to you to check them before 
cutting metal.

Both negative and positive comments as well as bug reports or suggestions for 
improvement are welcomed.

         Bob Kellock       bob@chainganger.co.uk      December 2005