A worm gear pair is defined by 7 independent parameters:

1

Module

m_{x} or m_{n}

2

Number of starts of worm

z_{1}

3

Number of teeth of wheel

z_{2}

4

One of the following quantities

d_{a1}, d_{1}, q, γ

5

Center distance

a

6

Worm length

b_{1}

7

Face width wheel

b_{2}

Input with following dialog box:

Input or change of one parameter followed by pressing the Tab key, triggers a calculation with actual input: the user can
see the effect of latest input.

Note that for the worm there is a choice for input of one as independent quantity out of the following quantities:

Tip diameter worm

d_{a1}

Reference diameter worm

d_{1}

Diameter quotient

q

Lead angle

γ

Input of one quantity as independent and pressing the Tab key causes the others to be calculated as dependent quantities.
The lead angle γ can be entered as sexagesimal or decimal degrees.
Input of center distance a is optional, on no entry the center distance is considered as dependent quantity.
Alternatively, the profile shift coefficient for wormwheel x_{2} can be entered, the center distance is then
considered as dependent quantity. The application calculates the minimum and maximum applicable center distances.
The minimum and maximum profile shift coefficients in function of the flank form are displayed in the dialog box.

Still required input: face width at root of wormwheel b_{2} and crown width of wormwheel b_{c2}
and some other design dimensions for the wormwheel crown. This is all done with the following dialog box:

Mean normal backlash and backlash tolerance

The application allows the backlash to be apportioned over the worm with a scale from 0 to 100 %. Selection is done
by means of a trackbar. The rest percentage is then apportioned to the wormwheel.
Table with geometry calculation results looks like: