Mass2 V1.1 (1989) was a commercial DOS program that included a dozen shapes and a hundreds materials density database. It performed reverse calculations and linear centers of gravity.

Mass2 V2.b (1993) was the updated commercial version that included more shapes, mass properties, a thousand material database, 3D centers of gravity and a structurals database with stress / deflection calculator. It also included a reports function and output to a standard Lotus 123-1a spreadsheet file.

Its development coincided with the widespread acceptance of Windows 3.1 and was not completed or distributed except as a beta DOS product.

Mass3j V0.b (2002) is a Javascript and Php version written for the web as an anvilfire.com tool.

Mass3j is designed to be a practical calculator for determining weights and mass properties. Over time many of the Mass2 features will be added to this on-line version.

The Mass3 logo is a "cyconex" and sphere. A cyconex is a cylinder with a cone removed from it. A cyconex of equal height and diameter has the same volume as a sphere of equal diameter.

Using Mass3j

Simply enter the dimensions of the shape you wish to know about. Cross sectional area and volume are calculated and displayed on the input form. In some cases cross section or volume will be an optional input variable. Clicking the calculate button generates a report in the this window.

Reports vary depending on the shape selected. The general reports give the weight or mass for the calculated volume in pounds and kilograms for a list of common materials. Properties reports return the engineering mass properties used to calculate deflection, stress and inertial forces. These special reports will have a shorter materials list and polar mass properties (in progress).

To print the report click on the logo button at the bottom of the report.

Input varies with the shape to be defined but is made as flexible as possible. Diameter is used rather than radius because most of us think and deal in diameters. Radius is used only for fillets or end radi if needed.

CYLINDERS have two reports, the common weight report and a mass properties report.

REGULAR POLYGONS (N-gons) are defined by the number of sides and one of four features, major inscribed circle (the circle it fits into), the minor inscribed circle (that fits into the polygon), the width of the flat OR cross sectional area. On even sided polygons the major and minor circles are equivalent to distance across corners and distance across flats. Any regular polygonal prisim can be defined from an equal lateral triangular section to a shape with thousands of facets. Shapes up to a 12 sided dodecagon are currently named in the report.

RIGHT TRIANGLES are defined by any two features, height, width, hypotenuse, angle of slope.

More shapes and reports from our Mass2 source will be added as time allows. Such as:

• Pyramids
• Cones, plain hollow, truncated
• Pipes
• Other triangles
• Reverse calculations from mass or volume known.
• Fillets and spandrels, straight and torodial.
• Open and closed tori
• Special non-geometric shapes.

Mass3j is designed to be an on-line tool. The Php reports code lives and runs on the anvilfire server. You must be on-line to use this version of Mass3j.