This document covers a simple method to decide what size and shape of 80/20 t-slot bar is required for a particular project – based on the weight the structure must support. There are infinite ways of engineering a t-slot aluminum structure, but the method outlined below is simple and straightforward – and should be easy to understand by non-engineers. Although we reference 80/20 brand t-slot extrusion data in this article, you could draw usable conclusions for other t-slot aluminum profiles if their size, weight and shapes were similar to 80/20 Inc. t-slot products.
The basic principle of choosing the right bar is understanding when a bar starts bending (commonly referred to as deflection) under a specific weight load.
There are 9 common methods for calculating deflection for t-slot aluminum bars as outlined below:
Today, we will be looking at the Two-End Supported method using Load Centered weight (circled in the chart above). While the two-end fixed test method is closest to the common vertical corner post method of design, it assumes an unbreakable connection with the vertical post. As fastener strength will play a role in any fixed design strength, we will use the two end supported method to better illustrate independent bar strength. In general, bars will bend easier...