JTEKT Toyoda GP27E
Key Specifications
Max Workpiece ⌀
max workpiece length
max workpiece weight
wheel head type
grinding wheel size
work spindle speed
Overview
The JTEKT Toyoda GP27E is a CNC external cylindrical grinding machine built for precision OD grinding of shafts, pins, rolls, and cylindrical components across a range of diameters. As a conventional-wheel external grinder in Toyoda's production grinding lineup, the GP27E provides the flexibility to handle diverse workpiece geometries that the more specialized angular-wheel GT27 cannot — including pure OD grinding of long shafts, taper grinding, and traverse grinding of complex profiles.
The GP27E's work envelope accepts workpieces up to 270 mm diameter and 500 mm between centers, covering the majority of shaft grinding applications in automotive, precision component, and general manufacturing. The machine's hydrostatic work table guide provides the same stick-slip-free, frictionless motion that defines Toyoda's precision grinding platform — delivering surface finishes of Ra 0.1 µm and roundness within 0.5 µm under production conditions. The grinding wheel spindle uses precision bearings with automatic balancing, maintaining surface quality without operator intervention across long production runs.
Toyoda's GP27E uses a CNC-swiveling wheel head and table to accommodate taper grinding, allowing the machine to address both cylindrical and tapered workpiece families without fixturing changes. The TOYOPUC-Grind control integrates in-process gauging, automatic dressing compensation, and adaptive feed to maintain sizing accuracy as the wheel wears. The machine is designed for integration with robotic loading, gantry systems, and in-line measurement stations common in precision component production.
The GP27E competes with the Studer S33, Kellenberger KEL-VARIA, and Danobat GCH in the production external cylindrical grinding segment. New GP27E machines typically price between $300,000 and $500,000 depending on options, gauging, and automation configuration. Specs sourced from JTEKT Toyoda published product data.
Full Specifications
| Parameter | Value |
|---|---|
| Max Workpiece Diameter | 270 mm (10.6 in) |
| Max Workpiece Length | 500 mm (19.7 in) |
| Max Workpiece Weight | 50 kg (110 lb) between centers |
| Wheel Head Type | Conventional (perpendicular); CNC swivel optional |
| Grinding Wheel Size | ø510 x 63 mm (ø20.1 x 2.5 in) |
| Work Spindle Speed | 50–500 RPM (infinitely variable) |
| Guideway Type | Hydrostatic table guide |
| Table Traverse | 650 mm (25.6 in) |
| In Process Gauging | Optional (Marposs / Renishaw compatible) |
| CNC Control | JTEKT TOYOPUC-Grind |
| Surface Finish Capability | Ra 0.1 µm or better |
| Roundness Capability | 0.5 µm or better |
Strengths & Limitations
Strengths
- Hydrostatic table guide provides frictionless, stick-slip-free motion for consistent Ra 0.1 µm surface finish and 0.5 µm roundness under production loads
- More flexible workpiece geometry capability than angular-wheel designs — handles long shafts, tapers, and pure OD grinding without configuration limitations
- In-process gauging with adaptive feed control maintains size accuracy automatically as the grinding wheel wears, reducing scrap and operator intervention
- Toyoda's proven grinding machine heritage provides reliability in demanding multi-shift and lights-out production environments
Limitations
- Does not offer simultaneous OD and shoulder grinding capability of angular-wheel machines like the GT27, requiring sequential operations for flanged workpieces
- High acquisition cost relative to simpler conventional cylindrical grinders; payback requires adequate production volume and precision requirements
- 500mm between-centers capacity limits the machine to medium-length shafts; longer workpieces require a larger grinder in Toyoda's lineup or from competitors
Best For
Frequently Asked Questions
01
The GP27E is a conventional external cylindrical grinder with the grinding wheel perpendicular (or CNC-swiveled) to the workpiece, suited for pure OD and taper grinding across diverse geometry. The GT27 uses an angular wheel positioned at approximately 30° to the workpiece, enabling simultaneous OD and shoulder grinding in a single plunge. Choose the GP27E for flexible OD grinding of varied parts; choose the GT27 for maximum cycle time reduction on flanged and stepped workpieces requiring both OD and shoulder grinding.
02
Under proper wheel selection, dressing, and coolant conditions, the GP27E achieves Ra 0.1 µm routinely in production. Roundness of 0.5 µm is achievable with the hydrostatic table guide providing stick-slip-free motion. For applications requiring sub-0.1 µm finish or roundness better than 0.3 µm, additional process refinement and environment controls (temperature, foundation) are necessary.
03
Yes. With the CNC-swiveling wheel head option, the GP27E accommodates taper grinding by rotating the wheel head to match the taper angle. Table swivel is also available for taper grinding without wheel head movement. Both methods allow precise taper control under CNC, maintaining taper angle repeatability within seconds of arc across production runs.
04
Wheel selection depends on workpiece material. Conventional aluminum oxide and ceramic aluminum oxide wheels are standard for steel and iron workpieces. CBN (cubic boron nitride) wheels are available for high-production grinding of hardened steel where wheel life and surface finish consistency over long runs justify the higher wheel cost. Toyoda's applications team recommends specific wheel specs for new applications based on material, hardness, and finish requirements.
05
With the automatic wheel dresser on the GP27E, dressing typically takes 10 to 30 seconds depending on the dressing cycle programmed. The machine automatically compensates for wheel diameter reduction after each dress, keeping part size consistent without manual offset entry. For maximum productivity, dressing is triggered automatically based on part count, grinding time, or in-process gauge feedback — eliminating manual intervention entirely.
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