Challenge
The application demanded internal grip with extreme accuracy while coping with an unfavorable geometry and high forces:
- I.D. ≈ 5× smaller than the O.D. , requiring very high clamping force without distortion.
- Face location + I.D. grip with ≤ 4 µm runout to both O.D. and opposing I.D.
- Grinder-ready actuation (clean, compact, reliable) compatible with OEM controls.
- Fine, repeatable grip-force control from near-zero (for delicate seating) to very high (for heavy stock removal).
Solution
We engineered a 7 in. DIAMETER internal-grip collet chuck with part seat sensing for positive face location and broad range of air-controlled clamping clamping force:
- Pull-back action : as the collet draws over a tapered mandrel, it pulls the part firmly against a fixed hard stop for perfect axial locator
- Air actuated clamp/unclamp : a simple pneumatic hookup drives the mechanism for clean integration on grinder platforms.
- Wide input pressure range : chuck operates from <5 PSI to 100 PSI , enabling precise control from essentially “0” grip to >13,000 lbf .
- Micron-class alignment : designed to maintain ≤ 4 µm runout to critical O.D. and opposing I.D. features through the grind.
Outcome
The internal-grip, pull-back design delivered stable, face & diameter located workholding that met the application’s accuracy and force demands:
- Achieved ≤ 4 µm runout to the O.D.s and opposing I.D. during finish grinding.
- High-force capability secured parts despite the small I.D.-to-O.D. ratio, with adjustable clamp force to prevent distortion.
- Pneumatic simplicity streamlined integration on the OEM grinder—no complex hydraulics required.
Purchasing Details
Ready to evaluate this internal-grip, pull-back collet chuck for your grinder? Contact our engineering team at sales@northfield.com to discuss your part drawings and receive a tailored quotation for your workholding needs.