English Deutsch

Info Letter No. 62 - July/August 2000

Copyright by HEXAGON Software 2000

by Fritz Ruoss

ZAR4 - Variable Spur Gears

The new ZAR4 software designs involute spur gears of any shape.

The operating pitch curve may be selected as ellipse, sine, or sine-linear shape.

Or you can freely define the pitch curve, by input of up to 10 mathematical formulas, that are valid for a specified section (0 .. 360).

The calculation of gears from self-defined formulas is very time consuming, a Pentium III is recommended therefore.


Pressure angle, number of teeth, and face width are entered then. The module changes with the pitch radius (mn = d/z). Addendum and dedendum coefficients of tool can be selected from database.

ZAR4 calculates center ditance and operating pitch curve of the driven gear. Transmission ratio, speed and acceleration are displayed at diagrams.

Animation allows you to discover meshing errors, when the gear rotates on the screen.

As no special calculation method is available for variable gears, ZAR4 calculates strength according to DIN 3390 by means of equivalent round gears.

ZAR5 Import/Export

If you used ZAR1+ to calculate planet gears in two steps (sun-planet and planet-ring gear), the *.zar files can be imported by ZAR5. Otherwise, you can export the complete ZAR5 planet gear calculation to 2 *.zar files.

FED3+ 3D-Drawing

A 3-dimensional centerline of the torsion spring can be exported as DXF- or IGES-file. Or it can be displayed isometric on screen.

FED2+ Self-defined Loop

A self-defined loop can be entered, if you select "others". But the description has not been transferred to output, this was changed now. Thanks to Mr. Wilke of Federn-Brenne.

ZM1 - Torque, Speed, Power

Similar than at ZAR1+, you have the choice between two values of torque, power and speed when entering load data. Thanks to Mr. Gerber of Rotzler for his suggestion.

SR1 - New Material Data

The database with clamping plate materials was extended by the new materials of VDI 2230 (draft 1998). The width between flats was added to the output, and a problem when inserting, deleting or modifying clamping plates was solved. Thanks to Mr. Stoll of Siemens Duewag and Mr. Hölscher of WABCO for material data and suggestions.


Dbf files can be extended and modified by the user. But if you get an update delivered with new dbf files, you must decide:

  1. Use of user-extended database
  2. Use of new database delivered with the update
  3. Append new records of the update database to your current dbf files.

You can use our DBFCOMP software to put together two dbf-files with same structure. DBFCOMP compares records of original database and update database. If it finds differences, you will be asked which value should be entered. New records are appended. DBFCOMP is a free tool for our customers, which can be downloaded from "http://www.hexagon.de/history/tools/dbfcomp.zip".

Recommendations for database modifications:

If you have database extensions, that are of common interest, please send us the data. Then we will update the database and send you the new dbf file.

All databases of SR1/SR1+ will be extended by an "Info" field, where not already exists.

SR1 Thread Strip Safety to Dose

An English translation of the publication about calculation of thread strip safety to Gerhard Friedrich Dose is now available at "http://www.hexagon.de/dose/dose1e.htm".


ZAR1+ Dialogue Window Strength

The new dialogue window offers "<" - Buttons to set the recommendation values.

Pricelist | Order | E-Mail | Homepage