Metal Shear Blade Replacement System
Project
Western Metals Recycling's metal shear blades are maintained or changed approximately every 2 weeks. This process is currently labor intensive and unsafe. The purpose of this project was to design and build a system or procedure to increase the speed and safety of the process, while reducing the amount of effort needed. The design requirements are as follows
- $5000 Budget Run on electrical, pneumatic, or hydraulic power
- Maintain operator safety
- Function within space constraints of shear
- Remove and replace shear blades
- Operators should not be required to lift more than 50
- Device must be able to function in temperatures from 20 F to 110 F and Any weather condition
Design Description
- This project consists of three different systems, the scissor table, crane arm/base, and the pusher puller.
- All components are built using steel to withstand the forces of blade moving and replacement
The systems of project design and their functions:
- The scissor table is moved into place in the shear throat, used to lift and lower blades to working heights safely
- The crane arm is used to move blades to and from shear mouth
- The pusher puller is used to remove the blades by placing the collet inside the blades; force is then applied to the center line of the pusher puller to remove blades
Performance Review
- Most of the tests performed on this device were done using field tests at WMR
- Test not performed in the field were done using calculations with known forces from loading conditions
- The performance of required lifting force was done by determining the maximum load required by the technician during a blade change.
| Parameter | Targets | Threshold | Actual Performance |
|---|---|---|---|
| Time to complete blade change (hours) | 3.5 | 7 | 4 |
| Manual Force required by Technician (lbf) | 50 | 100 | 60 |
| Force to tip while holding blade (lbf) | 100 | 25 | 52.27 |
| Operator distance from blade during operation (ft) | 1 | 3 | 1 – 1.5 |
| Lateral motion for blade alignment (in) | 3 | 0 | 30+ |
| Rotational motion for blade alignment (deg) | 5 | 0 | 5 |
| Static height in between phases (ft) | 3.5 | 2 | 4-1 |
| Number of steps to complete flip | 2 | 5 | 4 |
| Number of mechanical inputs to complete process | 3 | 7 | 5 |
| Number of steps to reconfigure for pulling collars | 2 | 7 | N/A |
Conclusion
This project was able to produce a working prototype of the system to WMR that met the needed requirements. These results are shown in the Performance section. The follow came as results of this project
- Working system capable of assigning with shear blade replacement
- All 3 systems working, Scissor Table, Crane Base and Arm, and the Pusher Puller
- Lessons Learned
- Clear definition of desired results allows for a clearer design path to a solution
- Understanding the customers desires for the project is critical to a good design for the customer
- Recommendations for future work
- Hydraulic device to push the top blades out without the need of an electric jackhammer
- Decreasing weight of design by building device for single blade removal instead of both blades
- Adding hydraulic cylinder to crane arm to allow for less manual effort in the blade changing process
Shane Canfield (shane.canfield@usu.edu), Nate Rowley (nate.rowley@usu.edu), Josh Fonger (joshua.fonger@usu.edu), Eric Larsen (eric.michael.larsen@usu.edu), Jared Christiansen (jared.christiansen@usu.edu)