Construction: aluminum frame, rubber pulley system

CAD / Analysis Software: SolidWorks

Testing cleaning tools manually can be tedious and repetitive, involving the same section of carpet or hard flooring cleaned over and over. This project aimed to automate the movement of a retaining sled, allowing an operator to focus on more critical tasks while the tool is tested on the sample. 

The existing method required two operators: one to push and pull the sled holding the cleaning tool at set parameters, and the other to activate any triggers, switches, or features. This automated test rig reduces the need for two operators, making the process more efficient. 

The premise of the automated test rig is a stepper motor controlled by an Arduino that pushes and pulls a pair of belts connected to the retaining sled. Once the sequence is started the sled moves slowly towards a limit switch and then moves at a set 1 ft/s speed across 3 ft.

The initial prototype used a spare testing rig for handheld cleaning tools, addressing the following challenges: 

1. Rail Misalignment: Ensuring the sled moves smoothly along the rails. 

2. Method of Linear Movement: Exploring various mechanisms, including screw drives, belt drives, chain drives, and serial positions. Belt drives were chosen for their ability to span the 6 ft length of the rig and fit within the compact design.  

The sled sits on six linear bearings over two or four 20mm x 20mm 8020 rails. After considering various options, belts were selected for their length and compatibility with the design's safety requirements. A 3D printer belt kit was used for the initial prototype, experimenting with different configurations to determine the optimal orientation (vertical or horizontal). 

Using a CAD model, the final belt drive setup was designed to address potential mounting and alignment issues. The parts were then ordered and assembled with a preassembled control board. The final design had some flaws, including bearing mounts that were not properly cut down and lack of variability in sled movement. 

Key Takeaways:

• Iterative design process

• Belt drivetrain experience

• Solidworks

At first I wanted to use a single belt to move the tool sled, this was unsuccessful and I found it required 2 belts for a smooth sliding action. This added more complications to the drive system.

This was my first time working with stretch belts and from my inexperience,  I added multiple ways to tighten the belt which were redundant and added complexity to the setup of the machine. 

My time at Sharkninja was primarily to complete and analyze results from product testing to ready the launch of a new product. As such, this testing rig project did not get as far as intended. Given more time, a control panel with knobs would have been developed; adding adjustable speeds rates and testing distances to the rig for a broader range of tests. Covering the belts and other drive components for added safety would also be on the list for further improvements.