RAY FOSTER Model F031 — High-Speed Automatic Spindle For AG03 / AG05
OEM FOSTER spindle — direct fit For current-production AG03 & AG05, plus replacement upgrade For Demco, Whip Mix, CF Price
RAY FOSTER Dental Equipment has manufactured precision dental laboratory products in Southern California since 1938. The FOSTER precision High-Speed Automatic Spindle is the original mechanism — designed For heavy-duty continuous operation, quiet and smooth running, with a clutch handle that disengages the tool, stops rotation, and opens the collet in one motion. Change tools in seconds without stopping the motor.
The F031 is the current-production FOSTER Automatic spindle For the AG03 and AG05 alloy grinders.
Key Features
- Designed For heavy-duty continuous operation
- Quiet and smooth-running precision-machined spindle
- Quick-change clutch mechanism — tool change in seconds, motor running
- Single-handle action: disengages clutch, stops rotation, opens collet
- Easy disassembly For on-site self-repair
- High-speed operation
- Direct fit: RAY FOSTER AG03 and AG05
- Replacement/upgrade fit: Demco, Whip Mix, CF Price grinders
- Manufactured in the United States since 1938
Key Selling Points
- The original FOSTER Automatic spindle — the design every other grinder brand copies
- Same-day tool changes save minutes per case across daily caseload
- Field-serviceable — technicians can disassemble and replace internal parts
- Cross-brand compatibility covers a mixed-brand bench with one spindle SKU
What Makes This Unique
Belt-driven grinders need to stop and re-tension when the operator wants to switch cutters — minutes of dead time per case. The F031 eliminates that. Pull the handle, swap the tool, release the handle, keep working. For high-volume CrCo and partial-frame finishing, it's the difference between "productive" and "profitable."
💡 Selling Tips For Sales Team
- Replacement vs. upgrade pitch. Customers replacing a worn F031 will buy on price; customers upgrading from a manual or belt-only spindle need the workflow story.
- Pair with collets. The FOSTER F106 collet set fits both F030 and F031 spindles — cross-sell.
- Don't confuse with F030. F030 is For AG04 and pre-2000 FOSTER machines (plus Whip Mix and CF Price). F031 is For AG03 and AG05 specifically.
- Made in USA. When the customer compares to import spindles, lead with this.
- Keep one on the shelf. A down grinder costs the lab more in lost cases than the spindle costs to keep on hand.
Technical Specifications
| Specification |
Value |
| Manufacturer SKU | F031 |
| Brand | RAY FOSTER |
| Type | Precision High-Speed Automatic Spindle |
| Tool-Change Mechanism | Single-handle clutch disengage with collet opening |
| Duty Rating | Heavy-duty continuous operation |
| Direct Fit | RAY FOSTER AG03, AG05 |
| Replacement/Upgrade Fit | Demco, Whip Mix, CF Price grinders |
| Compatible Collets | RAY FOSTER F106 collet set |
| Country of Manufacture | United States of America |
What's in the Box
- 1 × RAY FOSTER F031 High-Speed Automatic Spindle
- Manufacturer instructions
Manufacturer Warranty
All RAY FOSTER products carry the manufacturer's warranty against defects in materials and workmanship. For current warranty terms and service, contact RAY FOSTER directly.
Manufacturer Contact
US Dental Depot Customer Support
Downloads & Resources
Product Video
RAY FOSTER product demonstration videos are available directly from the factory. View on factory site →