Summary
A Copper Recycler in NE Indiana faced consistent issues with their Main Geared Drive Shaft breaking at the key slot. Toolcraft, LLC collaborated with the customer, changing the shaft’s material and refining its specifications. This resulted in a more resilient shaft, reducing operational interruptions and downtimes significantly.
Project Overview
Industry: Copper Recycling
Process: Engineering, Machining, Heat Treating, Grinding
Category: Engineering Parts
A Copper Recycler in NE Indiana encountered a recurring problem: their Main Geared Drive Shaft, a critical component in their operations, kept cracking and breaking at its key slot. This flaw not only disrupted their recycling processes but also led to frequent downtimes as the shaft required replacements.
Identifying the core issue, Toolcraft, LLC, in collaboration with the customer, reevaluated the shaft’s specifications. Originally made of 4140 Steel RC 45-50, Toolcraft recommended a switch to 4140 Pre Hard Steel (RC 28-32), opting to Induction Harden only the gear end to RC 45-50. Additionally, the engineering team made precision changes by tightening the shaft’s tolerances and introducing radius corners at the base of the key slot to further enhance its structural integrity. While Toolcraft managed the machining, heat treating, and grinding of the shaft, we strategically subcontracted the gearing portion to another specialized vendor.
Specifications
- Material: 4140 Pre Hard Steel (RC 28-32)
- Heat Treatment: Induction hardening of gear end to RC 45-50
- Dimensional tolerances: Tightened tolerances for improved fit and performance
- Key slot design: Radius corners at the base of the key slot to reduce stress concentration
Uses and Applications
- Main drive shaft in copper recycling equipment
- Power transmission in heavy-duty machinery
Capacity
- Toolcraft focused on shaft machining, heat treating, and grinding
Quality Control
- Material testing to verify properties
- Dimensional inspection before and after machining
- Hardness testing to verify heat treatment effectiveness
- Visual inspection for defects
- Key slot geometry inspection
- Balancing
- Final assembly and testing
Quality Control
Toolcraft’s comprehensive quality control procedures ensured the Brass Die scraper met stringent performance and reliability standards:
- Dimensional Inspection: Coordinate Measuring Machines (CMM) were used to verify all critical dimensions and tolerances.
- Material Testing: Metallurgical tests were conducted to confirm the material’s properties and compliance with specifications.
- Non-Destructive Testing (NDT): Techniques such as ultrasonic testing and magnetic particle inspection were employed to detect any internal or surface defects.
- Functional Testing: The assembled Brass Die scraper underwent rigorous functional tests to ensure proper operation and integration with Michelin’s manufacturing process.
- Final Inspection: A thorough final inspection was performed to validate the overall quality and readiness of the Brass Die Scraper before delivery to Michelin.
Manufacturing Process
Material procurement
Sourcing of 4140 Pre Hard Steel
Machining
Turning, milling, and grinding to achieve specified dimensions and tolerances.
Quality inspection
Hard gage checks for dimensional accuracy. Visual inspection for defects. Other relevant inspections as per specifications.
Heat treatment
Induction hardening of gear end to required hardness.
Grinding
Achieving desired surface finish and dimensional accuracy.
Inspection
Verification of dimensions, hardness, and overall quality.
Assembly
Integration of gear onto the shaft (conducted by customer).
Conclusion
The results were evident and immediate. The reengineered Main Geared Drive Shaft stopped cracking and breaking at its previous weak point, the key slot. The revamped shaft’s enhanced durability not only meant fewer interruptions to the recycler’s operations but also a marked decrease in downtime, which was previously needed for frequent replacements.