The goal of this project is to fabricate a foldable aluminum step ladder made from sheet metal that can support at least 150 kg. First, the step ladder is designed and assembled in Siemens NX. The CAD model of the step ladder is shown below.

Then, a stress analysis of a step is done to make sure it can support at least 150 kg without plastic deformation of the aluminum sheet metal. Then, through iterations of design and stress analysis, modifications are made to the design until it is determined that the step will be able to support at least 150 kg. An example of a stress analysis of the step performed through Siemens NX is illustrated below.

Then, all the sheet metal parts are analyzed to make sure the bends are feasible with the bender available. Once the feasibility of the parts are verified, the tool path to cut the sheet metal on a Haas GR-510 router is created and the bend plans are made. The bend plans for all the parts are shown below.

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The parts are then cut on the router, deburred to remove sharp edges and bent according to the bend plans. Once all the parts are bent, the step ladder is assembled using rivets by following the steps illustrated below.

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Finally, the 150 kg stress test is performed to make sure that all the individual steps of the step ladder respect the requirements. The step ladder did pass the stress test and was deemed safe for use. Pictures of the finished step ladder are shown below.

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