Drill and Tool Grinders: 252S
The Models 250A, and 252 have a capacity of 3/32″ to 2″ diameter.
The Model 252 is the most versatile drill and tool grinder available today. The 252 can grind odd-numbered fluted tools (1, 3, 5 & 7) as well as even numbered fluted tools (2, 4, 6, 8, & 10). This is achieved with the use of a unique dual-cam workhead. The inner cam rotates at 2:1 gear ratio to grind even numbered fluted tools. The outer cam rotates at a 1:1 ratio for odd-numbered fluted tools.
The Model 252 is available in manual, semi-automatic and automatic in-feed versions.
Selected Optional Accessories
The power-driven workhead of the semi-automatic version offers a quiet, smooth rotation of the workhead. Manual effort is reduced for heavier grinding and spin grinding operations. Spark out is allowed to occur by using a minimum of manual infeed along with a reduction in workhead rotation speed. The speed is controlled by a conveniently located valve; the adjacent four-way valve allows grinding in either direction. A hand knob on the workhead is used for indexing and setup.
Automatic Infeed System
The semi-automatic versions can be equipped with the automatic infeed system. This can increase productivity by allowing the operator to do other nearby tasks while the drill is being ground. The system allows manual or semi-automatic grinding of all tool grinding, and use of the automatic infeed for standard drill points, countersinks and reamers. The grinding rate is adjustable and the counter can be preset for 1-99 cycles. An electroplated CBN wheel (standard) is used with the automatic infeed and requires no dressing. Larger, three-phase motors are standard and an ammeter is provided to monitor the grinding load.
Overhead Wheel Dresser
Timesaving option allows truing of the grinding wheel O.D. without changing the setup. (Not for use with diamond or CBN wheels)
- Sealed linear bearing with hardened guide shafts
- Downfeed with ball detent in .001″ increments
- Hardened downfeed screw with wiper seal
- High-quality diamond included for truing standard and ceramic wheels
- Air Bearing Fixture
Air Bearing Fixture on Model 250A Drill and Tool Grinder
Allows precision sharpening of endmills, reamers, shell mills and other cutters. The spindle is supported with a thin film of air providing nearly frictionless motion, resulting in a smooth, even grind. The fixture quickly mounts on the Model 132C, 250A, 252, 380 or 382S grinders, or is available with a universal base to fit most tool and cutter or surface grinders.
- Hard chrome plated and ground spindle with a 10″ stroke.
- Tools are held in 5-C or 5-ST collets or extension bushings for up to 2″ (50 mm) shanks.
- Flute finger has dovetail crossfeed and micrometer vertical adjustment.
- Rocker arm tilts fixture away for easy movement from one flute to the next.
- Direct angle settings for up to 20 degrees for the O.D., 360 degrees for rotation, and +/- 30 degrees for tilt.
- Grinds the O.D. of any number of flutes and includes 12-position index plate (others available) for end grinding.
- Unique micrometer infeed built into fixture.
- Allows fine-feeding of the tool into the wheel.
- It is graduated in .001″ (or .04 mm) of diameter.