BOOTH N-6626
IMTS 2021

TG-12×8 Thrufeed


Here at IMTS 2018, we have our Model TG-12×8 set up to thrufeed grind 8000 parts per hour. We have a vitrified CBN wheel running at 9000 surface feet per minute with multi-grit stages across the wheel face. This allows for maximum stock removal and best surface finish and tolerance results. The operator sets parts on the entrance conveyor to keep a continuous flow of parts entering the grinder. The entrance conveyor maintains a level of parts in the step feeder. The step feeder keeps the feed conveyor filled so a continuous flow of parts enters the wheels. The grinder is set up with a guide and blade assembly to support the parts through the grind. As the parts exit the guide and blade, they are moved away from the machine by way of the exit side gravity chute and collection bin. The exit conveyor can be configured to transfer or accumulate the finish ground parts.

The grinder is equipped with the Granite Bed, 4 handle sizing dial with .0001” indicator, dovetail and gib with hard chrome and Turcite coatings and over the wheel diamond dressers tracing a template to dress the vitrified CBN wheel.  All of this to make for a low cost centerless grinder.

Available in Infeed, Thrufeed, as well as Hi-Accuracy and CNC versions, this machine has a capacity of 3” (75mm) in diameter.  It offers a grinding wheel diameter of 12” (300mm) and a regulating wheel diameter of 8” (203mm), both wheels are 8” (203mm) wide.

The grinding wheel spindle design has three sets of class 7 ABEC angular contact Timken bearings inside a larger headstock with an outboard self centering bearing set for a twin grip design.  This design gives the grinding wheel spindle superior accuracy.  The regulating wheel, with its 2.25” (57mm) diameter spindle and Timken bearings allows for the most demanding applications to be ground with zero deflection.  The 8” (203mm) diameter regulating wheel allows for closer tolerance with larger diameter work.

The machine sits on our 8” (203mm) thick Starrett surface plate quality granite.  The granite bed forms a perfect platform for such a robust spindle design.  The granite known for its rigidity and thermal properties provides a superior platform to other machines on the market that have thinner cast iron beds, and makes it as strong as those who have machine platforms twice the physical size of the TG-12×8.

We added stepper motors and ball screws to our dressers for programmable traverse rates as standard equipment.  With this new platform, wheel dressers are offered as Air Sensing, Automatic dressing, over the wheel CNC as well as Rotary Diamond Disk CNC platforms.  On the TG-12×8 we upgraded our regulating wheel servo drive with 170 foot pounds of continuous torque, with a 10:1 gearbox.

Ram bed positioning has also been upgraded with a longer and wider ram bed.  With our Standard Lead Screw and Sizing Dial, Thrufeed Micro Size and with our Servo Cycle ram bed positioning options, the upper ram, utilizes Hard Chrome and Turcite for smooth, efficient and accurate movements over the dovetail and gib slideway.  This low friction ram system coupled with a Ball Screw allows for precise micron movements at a lower cost.

The main spindle motor is 10 Hp.  The Ram Bed Dovetails are Hard Chrome and Turcite coated for near frictionless movement.  The entire Ram Bed swivels with the Work Rest Holder to simplify adjustments and changeovers.  The Operator Control Screen provides digital setting of Regulating Wheel Speed, Wheel Dressing parameters as well as other standard machine controls.

Applications such as titanium bar stock, PCD diamond tools, and hard carbides are routine for this machine.  The TG-12×8 looks for larger diameter applications up to 3” in diameter that will put all this rigidity and engineering to good use.    The TG-12×8 started with a robust spindle design and worked its way out.

The TG-12×8 is available for all types of grinding and loading applications including pick and place, robotic, and bowl feeding.  In our booth at IMTS we have two systems, a TG-12×8 thrufeed grinding at high speed and a TG-12×8 Hi-Accuracy system infeed grinding a 1.5-inch diameter part 8 inches long.

Look to Royal Master Grinders for centerless grinding solutions; from standard centerless grinders to total turnkey packages.  Visit us at  See us at Booth 6626 in Chicago.