LifeTrac IV Loader Lift Capacity

Introduction

This is a basic calculation of LifeTrac Prototype IV loader lifting capacity. Warning: this does not include tipping load calculations. The lifting capacity of LifeTrac is significantly greater than its tipping load capacity. Tipping loads need to be calculated.

Basic Model

The LifeTrac Prototype IV loader arm concept looks like this:

Download dxf file - units of feet - File:Loaderdrawing.dxf

Basic Analysis

From the above dxf drawing, a height reach analysis is performed to determnine the loader geometry at height. This is the analysis:

Here is the DXF file: File:LTIVheight.dxf

The red triangle models the geometry between 3 points: the cylinder to frame pin - loader to frame pivot - and loader to quick attach plate pivot.

The green line is the extended cylinder. The height of the loader arm pivot is 64 inches above the ground. The angle of the extended cylinder from the vertical is 21 degeres. The angle theta between the cylinder and the loader is 8 degrees in the fully extended position, and 49 degrees in the retracted position. The angle phi off vertical of the extended loader arms is about 21 degrees.

Cylinder specification - see [1] : 2.5" diameter, 2500 psi, 36" stroke.

Force calculations indicate over 12,000 lb of lifting force at the fully retracted position, and approximately 2000 lb at full height.

Torque Balance Calculations

Downward torque at cylinder-arm attachment is (assuming all loader weight is approximately at the end of the loader arms, and assuming