Choosing the right rack-and-pinion design is time consuming and costly. Searching through dozens of gear reducer and motor catalogs and plugging through calculations can be tedious. Cymex (Cyber Motion Explorer) software from Alpha Gear Drives, Elk Grove Village, Ill., lets engineers size and select gear reducers and motors for rack-andpinion applications with just a few keystrokes. The software can also select parameters for ball-screw, belt-drive, and pulley-drive applications.

Cymex calculates output-bearing life, massmoment of inertia fromseveral combinedbodies, masses of combined components, transmissionratios, rigidity, backlash, mean and max speed,mean and max torque, andprofiles of distance, speed, acceleration,and torque. The Windows-based program allows the user todefine motion characteristics, special featuresof the application, aswell as the operating requirements of the gear reducer and motor.

For the rack-andpinion application, inputs include the mass to be moved, load angle, friction force, pinion reference circle diameter, width of pinion, material, and efficiency. The user defines the cycle as time/distance, distance/speed, or time/speed. They enter the maximum acceleration or maximum acceleration period, dwell time, and external force/angle if there is one. The software generates a table showing motion profile characteristics. Once calculated, different drive variations and applications can be stored and recalled for comparison without recalculating the original drive system.

From there, the software helps select a proper gear reducer and motor from its database of nearly 1,400 servomotors and 600 gear reducers. Once the optimum design has been finalized, Cymex will list geometrically equivalent motors and

automatically select the correct adapter plate and bushing. It can print out relevant data sheets, output a DXF file that can be imported into drawings, and generate orders with the correct part numbers and order codes.

Cymex requires a PC with a 486/100-MHz processor or higher, Microsoft Windows 95, Windows NT or higher, a minimum of 42-Mbytes/8-Mbytes free hard disk space, and Internet Explorer 4.0 or higher.