Rollomatic GrindSmart 628XW
Key Specifications
grinding axes
max tool diameter
max tool length
wheel pack capacity
grinding spindle power
grinding spindle speed
Overview
The Rollomatic GrindSmart 628XW is a 6-axis CNC tool grinding machine built for the production of complex solid carbide cutting tools — end mills, drills, and specialty tools with geometries that demand full simultaneous 6-axis motion throughout the grinding cycle. Rollomatic's GrindSmart series is recognized globally as the benchmark for solid carbide tool grinding, and the 628XW is the workhorse production platform within that series.
The '28' designation refers to the maximum tool diameter capacity (28 mm), and the '6' indicates the 6 interpolated CNC axes. The XW suffix identifies the machine's extended wheel pack — the 628XW accommodates up to 10 grinding wheels on a single motorized spindle with automatic wheel changing, enabling complex multi-step grinding sequences (roughing flute, finishing flute, gash, end geometry, edge preparation) without manual wheel changes between operations. This automation of the wheel change sequence is a significant throughput driver in carbide tool production where multiple wheel specifications are required for a complete grinding cycle.
Rollomatic's grinding accuracy specification is built around edge runout: the 628XW achieves cutting edge runout of 0.001 mm (1 micron) or better in production conditions — a critical specification for end mills and drills where edge runout directly determines surface finish quality and tool life in cut. Achieving 1-micron runout across production batches requires extremely precise workholding, thermally stable machine structure, and grinding wheel geometry control, all of which Rollomatic has optimized in the GrindSmart architecture.
The machine's structural system uses a polymer concrete base for vibration damping and thermal stability, hydrostatic or precision roller guideways depending on axis, and a direct-drive motorized grinding spindle. The 6th axis (B axis) provides independent wheelhead orientation, enabling the wheel to approach the workpiece from angles that would require complete machine reconfiguration on a 5-axis platform.
Rollomatic's Virtual Grinding (VG) software is the programming environment for the 628XW. VG provides a graphical, parameter-driven approach to tool grinding programming: operators input tool geometry parameters and the software generates collision-free 6-axis programs automatically. The software includes simulation with realistic material removal visualization, and libraries for all standard and many non-standard tool types.
Pricing for the 628XW falls in the $350,000-$500,000 range. Automation options including robot loading (GrindSmart 628XW with robot cell) can add $80,000-$150,000 for complete turnkey systems.
Full Specifications
| Parameter | Value |
|---|---|
| Grinding Axes | 6-axis simultaneous (X, Y, Z linear + A, B, C rotary) |
| Max Tool Diameter | 28 mm (1.1 in) |
| Max Tool Length | Up to 300 mm (11.8 in) |
| Wheel Pack Capacity | Up to 10 wheels, automatic changing |
| Grinding Spindle Power | Up to 12 kW (16 HP) |
| Grinding Spindle Speed | Up to 12,000 RPM |
| Spindle Type | Direct-drive motorized spindle |
| Cutting Edge Runout | ≤ 0.001 mm (1 µm) in production |
| Machine Base | Polymer concrete |
| Guideways | Hydrostatic / precision roller (axis-dependent) |
| CNC Control | Rollomatic CNC with Virtual Grinding (VG) software |
| Coolant | Through-spindle and flood coolant, fine filtration |
| Workholding | Precision collet chuck, sub-micron runout |
| Automation | Robot cell compatible (optional) |
| Machine Operation | CNC |
| Grinder Type | Tool & Cutter |
| Cnc Model | Fanuc 30iMB |
| Grinding Length | 11.810"300.000mm |
| Od Min Grinding Diameter | 0.040"1.000mm |
| Od Max Grinding Diameter | 0.790"20.000mm |
| Od Max Grinding Diameter Opt | 1.000"25.400mm |
| Grinding Wheel | Grinding Wheel Diameter:6.000"150.000mm |
| Grinding Wheel Diameter | 6.000"150.000mm |
| Wheel Head | Motor:15.000hp10.000kWMotor Opt:19.000hp14.000kWRPM:12,000 |
| Motor | 15.000hp10.000kW |
| Motor Opt | 19.000hp14.000kW |
| Rpm | 12,000 |
| Longitudinal | 11.800"300.000mm |
| Cross | 7.000"180.000mm |
| Vertical | 8.600"220.000mm |
Specifications sourced from techspex.com — verified 2026-03-28
Strengths & Limitations
Strengths
- 6-axis simultaneous grinding enables complex flute, gash, and end geometry in a single clamping with no reclamping errors — critical for sub-micron runout consistency
- 10-wheel automatic pack changes eliminate manual wheel changes between operations — a complete end mill grinding cycle (rough, finish, gash, end) runs unattended
- 1-micron cutting edge runout specification is industry-leading for production carbide tool grinding — directly correlates to tool life and workpiece surface finish in cut
- Virtual Grinding software generates collision-free 6-axis programs from geometry parameters automatically — reduces programming time from days to hours for new tool types
- Polymer concrete base and direct-drive spindle combination provides the vibration damping and backlash-free motion essential for sub-micron edge quality
- Robot cell integration option enables overnight and weekend unattended production runs, maximizing machine utilization across 24-hour schedules
Limitations
- 28 mm maximum tool diameter limits the machine to small-to-medium diameter end mills and drills — shops grinding tools above 28 mm need a larger GrindSmart variant
- At $350,000-$500,000 new, plus robot automation costs, total system investment can reach $650,000 — justification requires high-volume carbide tool production
- 10-wheel packs require significant wheel inventory and wheel management discipline — maintaining and dressing wheel packs for multiple tool families is an ongoing cost
- Virtual Grinding software, while powerful, requires dedicated training — the software's full capability is not intuitive without proper instruction from Rollomatic
Best For
Frequently Asked Questions
01
On a 5-axis tool grinder, the wheelhead is typically fixed in orientation and the workpiece axes (A and C) provide all the angular positioning. The B axis on the GrindSmart 628XW is an independent wheelhead tilt axis — it allows the grinding wheel to be tilted relative to the tool axis independently of the workpiece orientation. This enables grinding wheel approach angles that are geometrically impossible on a 5-axis machine without repositioning the workpiece. In practice, the B axis provides access to undercut geometries, complex gash profiles, and relief angles that require the wheel to approach from a specific vector that the 5-axis workpiece axes alone cannot provide.
02
The GrindSmart 628XW uses a single motorized spindle with a wheel pack — an assembly of up to 10 individual grinding wheels stacked on a common arbor. The wheel pack is mounted on the spindle as a unit, and the CNC controls the Z-axis position to select which wheel face is active at any given point in the program. Switching between wheels in the pack is done by a Z-axis move — it takes less than one second and is fully programmed in the grinding cycle. There is no physical wheel changer mechanism; the 'automatic changing' is simply the Z-axis repositioning to a different wheel position within the pack.
03
Carbide grinding generates fine carbide particles that must be removed from coolant before it is recirculated — paper-band or magnetic separator filtration with fine polishing filtration (5 micron or better) is required. The 628XW uses through-spindle coolant for direct wheel-workpiece interface delivery and flood coolant for general chip washing. Oil-based coolant is preferred for carbide grinding to provide lubrication and prevent carbide corrosion. A complete coolant system sized for the 628XW (approximately 150 liters/min) adds $20,000-$50,000 to total system cost, depending on filtration specification.
04
The GrindSmart 628XW has a practical lower diameter limit of approximately 1 mm for production grinding. Below 1 mm, the workholding and wheel approach geometry become increasingly challenging, and workpiece deflection under grinding forces requires very light material removal. For micro-tools below 1 mm diameter — micro-drills for PCB drilling, micro-end mills for watchmaking — Rollomatic offers the NaNO6 platform, which is purpose-designed for micro-tool grinding with specialized workholding, wheel systems, and ultra-light cutting force management.
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