Lights Out Automation

Fully automatic centerless grinding capabilities.

Reduced Need For Labour

More cost-effective, and no human error.

Full Support Options

Complete customer support and troubleshooting.

Centerless grinding is a precise and fast way of grinding parts to size. Parts are placed on a carbide work rest that matches the profile of the part. A grinding and regulating wheel with matching profiles dressed into them feeds into the part.

The regulating wheel acts as a brake and dictates the rotation speed of the part. The stopping point of the infeed of the wheels determines the size of the part. The part is never held in a chuck or between centers, it simply is confined by the grinding, regulating wheel and work rest blade. The geometry of how the part is located when grinding can result in extremely precise roundness and size tolerances. Submicron roundness and micron tolerances can be achieved.


The Tactic 8 is a full CNC controlled precision infeed centerless grinder, with a clean sheet design using the latest technology.

Its patented overhead roller rail design uses linear motors for infeed positioning, and the Tactic 8 Centerless Grinder is designed to run as a fully automated grinding cell with built-in 100% inspection capability. The gauge data is tied back to the infeed for sizing corrections. It also uses the data to make corrections to the dress profile, automatically correcting taper and size deviations on each diameter. This allows us to run multiple parts at a time with ease. See Gauging Case Study for more information. The Tactic 8 requires minimal maintenance and full support options are available through Echo Hill Automation.

One of our biggest previous struggles when automating existing centerless grinders was that they weren’t designed for automation, so compromises in mounting and workflow were constantly made. The automation in the Tactic 8 was designed as part of the grinder not as an add on and works seamlessly as a complete work cell. A common design criterion was used in the controls and construction of the entire cell.

Tactic 8 Machine Specifications

Grinding diameter range

1 to 50 mm (0.03 to 2.0”) standard

Maximum infeed grinding length

225 mm (8.5”) standard

Floor space

900 x 2000 mm (36 x 80” plus load/unload)

Total approximate weight

6500 kgs (14,500 lbs)

Wheel Dimensions

Grinding wheel – OD, width, ID

400 x 225 x 200mm (16 x 8.5 x 8″)

Regulating wheel – OD, width, ID

250 x 200 x 150mm (10 x 8 x 6″)


Grinding wheel (constant peripheral speed)

40 m/sec (8000 SFM) (Max RPM 2000)

Regulating wheel

0 to 450 RPM


Grinding wheel spindle

15.0 kw (20HP) standard

2-axis CNC Wheel dressers

4.0 kw (6 HP)


2-axis CNC Wheel dressers

Z-axis cross roller rail driven by precision preloaded ballscrew


X axis cross roller rails driven by linear motor

CNC and Servometers


Beckhoff machine controller, Yaskawa linear and rotary motors

Grinding Wheel Spindle bearings

Precision Angular Contact

Regulating Wheel Spindle bearings

Precision Angular Contact

Lubrication and Cooling


Air purges grind and reg bearings with lubricated air

Coolant system

Coolant unit with tank, automatic paper filter and ¾ hp pump


With automated centerless grinding, parts are bulk loaded into a step feeder style hopper, which can run multiple parts at a time, and can easily change to other parts. The vision system determines the orientation of the part, and the loading head automatically orients the part before loading. Fully programmable arms move the parts through the grinder and gauging system. All parts are 100% inspected and can be placed in trays, turntable, or bulk unloaded. Automated centerless grinding will run completely unattended, and is lights-out capable.



Semi-automated centerless grinding is designed specifically for HMLV (high mix low volume) production. During semi-automated centerless grinding, parts are hand-loaded into a carousel with at least 20 minutes of production. This machine is capable of 100% inspection, and multiple parts at a time are able to be ground. The minimum of tooling at a low cost is required for each part. Semi-automated grinding involves fast changeovers, and parts can be bulk unloaded or placed back into the carousel.


The tolerances required in the manufacturing of aerospace products has become increasingly stringent within the last decade, progressing from .0001’s inch to sub micron levels (< .000040 inch).

The Tactic 8 Grinder, with the Keyence Optical Measurement System feedback has allowed us to make components well within those tolerances. It has facilitated elimination of inspection sorting of parts into classes by grinding to a specified Micron Class on demand, while holding tolerances easily within statistical process capability Cp/Pp of 1.33 – 1.67. Consequently, it has been possible to run the machine unattended, overnight, with lights out.

Alan Levesque
Grinding Engineering and Technology Development
RBC Bearings, Inc
Torrington, CT