﻿ Getting Started Tutorials - MechDesigner > Tutorial 14: Gear-Pairs / Rack-Pinions > Rack and Pinion / Ball-Screws

# Rack and Pinion / Ball-Screws

## Rack and Pinion?

A Rack is a Linear-Gear. The Rack can drive, or be driven by, a Pinion. The Rack has a linear motion and the Pinion has a angular motion.

The preparation for the Ball-Screw is the same as for the Rack and Pinion. You do Add Rack-Pinion. Then, use the Rack-Pinion dialog-box to change the Rack-Pinion to a Ball-Screw.

### Add Rack-Pinion / Ball-Screw

 Machine Elements Toolbar : Add Rack-Pinion (Ball-Screw) Menu : Add menu > Mechanism sub-menu > Add Rack-Pinion (Ball-Screw) Rack-Pinion dialog-box : Edit the number-of-teeth on the Pinion and along the Rack, and to move the position of the rack along its axis. You can edit the Gear Module plus other gearing parameters. You can also convert the Rack-Pinion to a Ball-Screw.

## Preparation of Basic Rack and Pinion Models

#### Driving Pinion - Driven Rack

 Driving Pinion + Driven Rack. •Line in a Green Part, a rotating-Part - it will become the Driving Pinion. •Line in a Blue Part, a sliding-Part - it will become the Driven Rack. Rule : Line : radiates from the Pin-Joint. Rule : Line : in the Slide-Joint or parallel (//) to the Slide-Joint. Lines or CAD-Lines Add Rack-Pinion: command 1.Click Add menu > Mechanism sub-menu > Add Rack-Pinion / Ball-Screw - or - 1.Click Machine element toolbar > Add Rack-Pinion / Ball-Screw The Command-Manager now has two selection-boxes. You must select the two Line elements: 2.Click the Line 3.Click the Line 4.Click in the Command-Manager The Rack-Pinion is in the Assembly-Tree and Graphic-Area. Notes: The Rack is offset by the Pitch-Circle Radius of the Pinion. The Rack is on the near-side or far-side of the Pinion relative to the Slide-Joint. The Pinion may be VERY small. Use the Rack-Pinion dialog-box to edit the: •the number-of-teeth and module of Gears •move the Rack to other side of the Pinion. How to...Add a Rack and Pinion

## More Rack and Pinion Models...

#### Driving Rack - Driven Pinion

 Driving Rack > Driven Rack. •Line in a Green Part a sliding-Part, and will become the Driving Rack. •Line in a Blue Part, a rotating-Part, and will become the Driven Pinion. Note: Rule: Line is a Line in the Slide-Joint or it must be parallel (//) to the Slide-Joint. Rule: Line must radiate from the Pin-Joint. Lines or CAD-Lines Add Rack-Pinion: command 1.Click Add menu > Mechanism sub-menu > Add Rack-Pinion / Ball-Screw - or - 1.Click Machine element toolbar > Add Rack-Pinion / Ball-Screw The Command-Manager now has two selection-boxes. You must select the two Line elements: 2.Click the Line - in the Green sliding-Part. 3.Click the Line in the Blue rotating-Part. 4.Click in the Command-Manager The Rack-Pinion is in the Assembly-Tree and Graphic-Area. Notes: Use the Rack-Pinion dialog-box to edit the: •the number-of-teeth and module of Gears •move the Rack to other side of the Pinion. Add a Driving Rack with Driven-Pinion