CENTERLESS GRINDING AND LAPPING WHEELS
There is a Buffalo Abrasives Centerless Grinding Wheel for you to meet your
tight tolerance and precision grinding requirements
FEATURES:
- Manufactured in North Tonawanda, New York, USA
- Diameters through 24", thicknesses through 10" (sets through 22" thick)
- Metric sizes and special tolerances available
- High performance abrasive grain blends, through 600 grit
- Selection of phenolic, epoxy, rubber-resin and vitrified bonds
- Special formulations for exotic alloys, stainless, titanium, non-ferrous and plastics
- Standard manufacturing lead times 4-5 weeks
- Competitive pricing, quick quotations
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A centerless grinding machine consists of a
grinding wheel, a regulating wheel and an angled, adjustable work rest blade
that supports a work piece generally above the centerline of the two wheels.
The regulating wheel serves as both a driving wheel and a brake, rotating the
work piece at a constant surface speed. The purpose of grinding above center
is to improve concentricity. Any high spot in the work piece coming in contact
with the regulating wheel will push the work into the grinding wheel, creating
a low spot but not diametrically opposite.
There
are three types of centerless grinding applications: thrufeed, infeed and
endfeed. The thrufeed method is appropriate for cylindrical work pieces
of a constant diameter. The regulating wheel is dressed and angled relative to
the grinding wheel to move the work piece past the grinding wheel face
continuously. The infeed method is used for cylindrical work pieces
that have various diameter shoulders. The grinding wheel is dressed to match
the form of the work piece and the work piece does not traverse across the
grinding wheel face. The endfeed method is used for tapered work pieces
only, as the work piece traverses pass the grinding wheel face but only to a
stop.
Proper
machine set-up is a function of work piece material, work piece size, required
stock removal and required finish. Frequently trial and error is involved in
optimizing the set-up, however, general purpose thrufeed starting
recommendations are as follows:
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Regulating Wheel:
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Use a rubber regulating wheel specification of A804-R-10RX
Use a 3 degree angle of inclination and a speed of 90-100 SFPM
True with a 1-2 carat single point diamond at 1-2 inches per minute
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| Work Rest Blade: |
For work 1/2" diameter and larger use a blade angle of 20-30 degrees
Set work center above wheel centers 1/2 of work diameter (but 5/8" max)
Use maximum blade thickness to avoid chatter
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Grinding Wheel:
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Use a grinding wheel specification of KCA542-M-11B4487 or DA60-L8-V40
Dress with an impregnated diamond dressing tool at 10 inches per minute
6-8 inch wide wheels remove stock at 1 cubic inch per minute per 10 HP
Rough at 1/3-1/2 of wheel face width per work revolution, finish at 1/6-1/3
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| Coolant:
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Use 5 gallons per inch of wheel width per minute and a high velocity nozzle
Direct coolant at point of contact between work piece and grinding wheel
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TROUBLE SHOOTING
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Cause:
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Correction:
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A. Poor Finish
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Incorrect wheel grade
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Try finer and/or harder
wheel
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Dirty, incorrect or insufficient coolant
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Clean and/or replace
coolant
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Wheel dressing rate too fast
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Re-dress using a slower
feed rate
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Pick-up on work rest blade
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Regrind or replace work
rest blade
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Work rest blade angle too steep
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Replace work rest blade
with lower angle
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Work rest blade not rigid enough
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Work rest blade should be
thick as possible
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Grinding wheel out of balance
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Re-balance grinding wheel
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Improper diamond dressing tool
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Replace or re-set diamond
dressing tool
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Work piece too high above center
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Lower work piece
gradually, examine finish
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Worn bearings on grinding / regulating
wheels
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Examine and replace
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Regulating wheel speed excessive
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Lower regulating wheel
speed, examine finish
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B. Spiral Feed Lines
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Grinding wheel not relieved on exit side
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Dress 1/2" taper on exit
side of grinding wheel
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Work guides not properly set
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Re-align work guides;
clearance grinding side
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C. Chatter
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Work piece too high above center
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Lower work piece
gradually, examine finish
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Grinding wheel out of balance
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Re-balance grinding wheel
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Work rest blade angle too steep
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Replace work rest blade
with lower angle
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Work rest blade not rigid enough
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Work rest blade should be
as thick as possible
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Glazed grinding wheel
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Change diamond dressing tool or method
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Stock removal excessive
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Lower stock removal
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Harmonics
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Examine motors and machine mounting
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D. Poor Concentricity
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Work piece not high enough above center
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Raise work rest blade
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Work rest blade angle too small
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Increase angle but do not
exceed 30 degrees
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Regulating wheel not properly dressed
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Re-dress regulating wheel
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Formulas :
Stock Removal (cubic in/
min) = Mean Diameter (in) x 3.1416 x Infeed (in) x Traverse speed (in/min)
Traverse
Speed (in/min) = Regulating Wheel Angle (degrees) x Regulating Wheel Speed
(SFPM) x .21
Work Speed
(rpm) = 3.82 x Regulating Wheel Speed (SFPM) / Work Diameter (in)
Width of
Cut (in) = Traverse Speed (ipm) / Work Speed (rpm)
Width of
Cut (in) = .055 x Work Diameter (in) x Regulating Wheel Angle (degrees)
Buffalo Abrasives gives you the performance advantage.
Consistency - Our experienced professionals use proprietary formulations - utilizing the finest raw materials, accurately controlled mixtures, and unique bond systems - to produce wheels that deliver consistent performance, wheel after wheel.
Quality - Fully integrated, in-house facilities, including advanced hydraulic press technology, temperature and humidity controlled mixing and molding, and computer-controlled cure cycles, are used to produce the highest quality regulating wheels available today. Our manufacturing is supported with Statistical Process Control, TQM teams and continuous improvement programs.
Each wheel
manufactured meets strict quality standards and is tested in accordance with
ANSI B7.1 requirements.
Inquire
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