Linkage Design Drawings

An interactive image is provided of the servo linkage. This greatly aids the design process. The intention is to make the design process a lot like the cut-and-try process used on an actual model, only a lot faster, and better too!

A drawing is provided for each of the four linkage types. Long Pushrod and Short Pushrod are essentially two-dimensional linkages in that all of the mechanism is ideally coplanar. These are represented with 2-D drawings. Perpendicular Axis Pushrod and the Rotary type are three dimensional in nature. These are represented by 3-D drawings. The 3-D effect is enhanced by the ability to view the linkage from any angle.

Each drawing features a slider bar at the lower right hand corner. This moves the servo and the linkage represented by the middle, solid lines. Moving the slider back and forth wiggles the control surface.

Two other linkages are shown. These represent the linkage at the extremes of the servo travel. This is key to setting up the linkage. Adjusting the input values moves these end-of-travel images.

The two 3-D images also have slider bars near the lower left corner. They control the altitude and azimuth of the view angle from top to bottom, around 360 degrees.

Long Pushrod

This plot shows a setup with a modest servo arm offset angle and no control horn offset. This results in slightly more down travel than up. The servo is in the neutral position as shown by the neutral position of the control surface and the middle location of the slider bar.

Short Pushrod

This shows a nearly symmetrical layout. The servo arm and control horn offsets are zero, but the servo is slightly offset upwards.

The servo is moved off center by the slider bar.

Perpendicular Axis Pushrod

This setup is approximately symmetrical, but the servo is off-center to the trailing edge down (TED) direction.

The view slider bars are set to give an approximately isometric viewpoint as indicated by the elevation and azimuth readouts just below the picture. These readouts make it easy to get to a plan view or side view.

Rotary

This drawing shows the rotary arrangement in a slightly trailing edge up setting.

Again, elevation and azimuth angle callouts let you know what the view angle is.