non-medical centerless grinding

Basic Machine Options

TG-12x8 Thrufeed Grinder

For over 60 years, Royal Master Grinders has been producing centerless grinders in New Jersey with our two Models, the TG-12x3 and TG-12x4. In September of 2013 we embarked on a new project, the TG-12x8. Our mission was to design a machine from scratch starting with a blank screen. Our mission statement was to build a machine that would have all of the accuracy as our current product line, with twice the wheel width, on a compact platform. Exactly one year from inception, we are proud to announce at IMTS 2014 our new product, the TG-12x8.

TG 12x8 Model Rendering

Available in Infeed, Thrufeed, as well as Hi-Accuracy and CNC versions, this machine has a diameter capacity of 3" (75mm) in diameter. It offers a grinding wheel diameter of 12” (300mm), a regulating wheel of 8" (203mm) diameter, both being 8" (203mm) wide. The advantage is clear, wider wheels allow for heavier stock removal for thrufeed grinding, multiple parts for infeed grinding, and in some infeed applications like titanium fasteners, a direct replacement for older increasingly unavailable rebuilt machines for Cam-Out applications.

When we embarked on this project the message was clear to our engineering team, no rebranding our current models, no stretching current designs and no fancy names. Just a machine that is strong, from the spindles outward. The grinding wheel spindle design has 4" (100mm) diameter bearings, with three sets of class 7 ABEC angular contact Timken bearings. It is inside a larger headstock with an outboard bearing for a twin grip design. This design gives the grinding wheel superior accuracy. The regulating wheel with its 2.25" (57mm) spindle and Timken bearings allows for the most demanding applications to be ground with zero deflection of other machines with smaller spindle designs. The 8" (203mm) diameter regulating wheel allows for CAM-out projects as for each rotation of the regulating wheel one cycle is completed.

As we grew outward from the spindle designs, the vision of the machine became clearer, it had to be placed on our Bedrock platform. The machine sits on our 8” (203mm) thick Starrett surface plate quality granite. The .0002" (5 micron) flatness specification 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-12x8.

With these newer spindles and machine bed and base, we decided that now was the time to eliminate all hydraulics for the machine. Standard on our TG-12x4 is servo driven regulating wheel spindles, but on the dressers we still have hydraulics. On the TG-12x8 we upgraded our regulating wheel servo drive with 170 foot pounds of continuous torque, with a 10:1 gearbox. We also added stepper drives for programmable traverse rates and ball screws to our dressers as standard equipment. With this new platform, dressers are offered as air sensing, automatic dressing, over the wheel CNC as well as Rotary diamond disk CNC platforms.

Ram bed positioning has also been upgraded with a longer and wider ram bed. The upper ram, utilizes hard chrome and Turcite for the most efficient and accurate movements. This friction free ram system coupled with options as the thrufeed microsize adjustment and the servo cycle systems allows for precise micron movements at a lower cost. With optional Hi-Accuracy machine controls and anti friction cross roller ways, .1 micron glass scales for ram bed positioning, sub micron tolerances are not a challenge, they are expected.

Both systems use a swivel design where the entire ram bed swivels with the work rest holder, making guide adjustments easier for faster set-ups. We also have re-conceived the work rest holder, making it easier for the operator to advance the unit after dressing, reducing set-up time, or advancement of the work rest holder after making size compensation.

Applications such as titanium bar stock, PCD diamond tools, and hard carbides are pedestrian for this machine, other companies boast these applications. The TG-12x8 looks for larger diameter applications up to 3" in diameter that will put all this rigidity and engineering to good use. Other companies talk about their intelligent machine controls to mask their basic limited machine designs. The TG-12x8 started with a robust spindle design and worked its way out.

The TG-12x8 is available for all types of loading applications including pick and place, robotic, and bowl feeding. In our booth at IMTS we will have two systems, a TG-12x8 thrufeed with microsize adjustment thrufeed grinding bar stock, and a TG-12x8 Hi-Accuracy system infeed grinding a large diameter industrial gearbox part.