We are extremely particular in our gear inspection process. All gears and splines are inspected according to customer requirements and specifications as well as international standards.
First Piece Approval: Set-up and operator personnel at Forest City Gear are required to inspect all characteristics and document their inspected results to ensure that each inspection point is acceptable before submitting it to Quality Assurance. Quality Assurance will inspect the same characteristics to verify that all inspection points and dimensions are acceptable. When this is complete and all points of inspection are verified acceptable, the First Article Inspection form is documented as approved. In the event of a problem or any characteristic being identified as non-conforming to specification, the process must be repeated.
Throughout Production: Set-up and/or operator personnel are required to inspect all inspection points at the planned and required inspection frequency, which is documented on the traveler unless no frequency is documented. If a special frequency or requirement is not documented on the traveler, the required frequency defaults to the Forest City Gear standard sampling plan.
Last Piece Approval: The operator checks the last production piece using the same protocol for the first-piece check. After documenting all points of inspection, if acceptable, the part and documented report are submitted to Quality Assurance, which follows the same protocol as it did for the first piece. If the last piece is verified acceptable, the report is documented as such, and the process is judged complete. In the event of a nonconformance being identified, the operator must contain the lot. Following the procedure for control of non-conforming material, the production lot is inspected again to identify all non-conforming parts.
It is extremely important to have the proper inspection equipment in place to know what is happening at each step of the production process. Consistently monitoring the parameters allows us to fine-tune the production of the gear to the exact point where we can minimize noise and pinpoint accuracy for all dimensions. Here at Forest City Gear, we use a variety of inspection equipment:
- Analytical equipment to check lead, involute, pitch, and surface finish.
- Line runout equipment.
Functional roll-test equipment that uses a master gear to test radius size, tooth-to-tooth error, total composite error, and pitch line run-out is recorded and charted.
These processes can vary from 10 minutes to several hours, depending on the number of features being checked, the method of inspection used, and the size of the gear.
For the CNC gear inspection machines, we program per-part print gear data to inspect the gear teeth. For functional gear testing, we use a master gear and place it into a mesh with the part gear teeth and then roll-test it. This process is also useful for checking gear size (testing radius) and runout. We also use surface finish detection methods to evaluate microfinishing, including equipment capable of measuring to 164 magnifications.
Here at FCG, we use non-destructive testing, which means we do not destroy the parts to check for burning and cracks. For cracks, we use MPI (magnetic particle inspection) and nital etch to detect burning.
What separates us from the competition? Our 4 CNC gear inspection machines and 24 functional gear testers. We have offered outside inspection for over 45 years, and spend a great deal of time doing subcontracted inspection of gears and features that other companies do not offer for testing of gears—usually because they do not have these testing capabilities. This is also helpful for reverse-engineering. When a customer brings in a gear from a 60-year-old motor with no blueprint, we reverse engineer it to create a print so they can get a quote duplicating or even exceeding the original quality of the part.