Step 2: Measuring Arm Length

You'll start by measuring the load depth to get the minimum extent of arm length required for your cantilever rack. The load depth cannot exceed the length of the cantilever arm. The cantilever arm's capacity limit drops substantially if materials are not properly centered on the rack.

Step 3: Measure Lateral Spacing and Load Deflection

Lateral spacing is defined as the distance from the center of one cantilever upright to the center of the next upright. To calculate spacing between the uprights, one will measure the distance between the centers and consider load deflection.

What is load deflection? Load deflection is the sagging or bowing of a load; a major concern when storing long items on a cantilever rack. You'll have to check sagging or bowing level of the intended load to determine required lateral spacing between uprights which can support load weight effectively. The very distance between the uprights which causes the least load deflection represents the lateral spacing required to offer the best support. A quick and effective way to determine your lateral spacing requirements before purchasing cantilever rack is by using wood blocks placed parallel on the ground to simulate the cantilever arms. Once placed, put your load on the blocks. If you see noticable bowing or sagging, then you may need to adjust the lateral spacing of the blocks or you may need additional support by adding more equally spaced arms.

When designing a cantilever rack system, you must use as few arms as possible to store the loads. You should also be careful to keep load deflection to a minimum to prevent damage to the load.

Step 4: Calculate Height of Cantilever Upright & Height Between Levels to Determine Required Arm Quantity

To calculate required upright height, you'll start by considering ceiling height, maximum reach of lift trucks, sprinkler systems, and any other possible obstructions or limitations which limit the height of your system.

Next, you'll calculate the maximum number of levels for your system by determining the height of each level levels. To do this, you'll need to add up the clearance required between top of load and bottom of the next shelf level (the standard practice is to leave 6" of clearance, but you may need more depending on the material you're storing), the height of the arm, and the height of your intended load.

When designing a cantilever rack system, you must use as few arms as possible to store the loads. You should also be careful to keep load deflection to a minimum to prevent damage to the load.

Step 5: Determine Required Arm Capacity

The weight of each load should be evenly distributed across each arm of the cantilever rack, meaning that the required load capacity for each arm is rather easy to calculate. All you'll need to do is divide the weight of your heaviest intended load by the number of arms supporting the load as determined in step 3. To determine the required upright capacity, all you need to do is multiply the weight capacity of each arm by the total number of arms on the upright.

To get the most out of your cantilever rack system, you can place your heaviest load directly on the base without contributing towards the bay's weight limit.