Basic view of Helical External Design Module.

Left side of the screen contains input fields on top, gear graphics on the bottom.
Right side shows output fields on top and modification graphs on the bottom.

The bar graphs give an instant feedback on whether the gear is undercut and what minimum modification is required to avoid undercut. The graph also displays the modification value where the gear tooth becomes pointed.

Every time you change an input parameter and press the ENTER key, the changes are immediately reflected in gear graphic as well as the bar graphs.