Diamond and CBN Face and Fine Grinding · century of grinding experience 3M Precision Grinding & Finishing bundles the know-how and experience of the Winterthur, Slip-Naxos and WENDT

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english

3M Precision Grinding & Finishing

Diamond and CBNFace and Fine Grinding

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A SYSTEM FOR CUSTOM-TAILORED SOLUTIONS 4

DIAMOND AND CBN FACE GRINDING WHEELS 6

DIAMOND AND CBN FINE GRINDING WHEELS 8

DRESSING TOOLS FOR DIAMOND AND CBN FINE GRINDING WHEELS 9

DRESSING TOOLS FOR DIAMOND AND CBN FACE GRINDING WHEELS 10

YOUR BENEFITS – OUR SERVICE CONCEPTS 11

Your partner with a century of grinding experience

3M Precision Grinding & Finishing bundles the know-how and experience of the Winterthur, Slip-Naxos and WENDT brands under the umbrella brand 3M. As a part of the 3M Abrasive Systems Division, 3M Precision Grinding & Finishing is your commit-ted and competentsupplier for abrasives, tools, service and support.

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A System for Custom-tailored SolutionsComplex Solutions with a System 3M Abrasive Systems offers many years of experience, references and custom-tailored solutions with a system designed for a broad di-versity of precision and surface grinding applications, machines and workpieces.

In addition to extensive pro-cess analysis, we supply you with grinding, truing and dressing tools from a single source – all matched to your production pro-cesses and custom-tailored to your requirements.

Our Service Package for Your Specific Needs

• Selection and creation of the ideal specifications and type of grinding tool

• Definition and implementation of the perfectly matching dressing strategy

• Recommendations for appropri-ate process parameters and coolant/lubricating fluids fitting to your particular application

• Process documentation (Precision Grinding LOG)

• Comprehensive customer ser-vice requirements

BondWe use the following bonds for our fine grinding wheels:

Wheel BodyFor fine finishing, we recommend wheel bodies that have been matched to the application.

Concentration (C)With multilayer bonding (R, M, V), a grain concentration is chosen such that the greatest possible tool life and required surface quality are achieved.

Innovation Close to the Customer

• Development of customer- specific solutions

• Innovative bond systems• Innovative abrasive grains• Reference tests• Quality assurance • LEAN Six Sigma

3M Diamond and CBN Grinding Wheels

Technology and Service

Grinding System

3M DressingTools

Wheel Specifications

Grit Size

Grain Type

Concen-tration

Bonding System

Core

Grit Size (FEPA)The grit size of the diamond and CBN abrasive grains used in the wheels is based on the application and the required surface quality.

Diamond

Diamond

CBN

CBN

Grain Type / Cutting MaterialDepending on the application, we use different grain types/grain qualities in diamond and CBN. The types differ in their characteristics (friable, blocky, free cut-ting, etc.).

FEPA US-Mesh Size in µm Application

181* 80 / 100 180 / 150 roughing

151* 100 / 120 150 / 125 roughing

126 120 / 140 125 / 106 roughing

107 140 / 170 106 / 90 roughing

91 170 / 200 90 / 75 roughing

76 200 / 230 75 / 63 finishing

64 230 / 270 63 / 53 finishing

54 270 / 325 53 / 45 finishing

46 325 / 400 45 / 38 finishing

Micro-grains (for fine grinding)

M 40600** 40 / 30 lap grinding

700** 36 / 22 lap grinding

M 25800** 30 / 20 lap grinding

1100** 22 / 12 lap grinding

M 16 1200** 20 / 10 lap grinding

M 10 1800** 12 / 6 lap grinding

M 6.3 3000** 8 / 4 lap grinding

* for face grinding** approximate equivalent mesh size

Resin bond, multilayer

Vitrified bond, multilayer

Metal bond, multilayer

AL

Aluminum

ST

Steel

C Carat/cm3

25 1,1

50 2,2

75 3,3

100 4,4

150 6,6

175 7,7

Diamond / CBN

C 100 C 150Secondary grain

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Face grinding in through-feed processes with diamond and CBN grains has firmly established itself in the market. Grinding wheels with porous bonding systems have gained acceptance due to their technological advantages such as high stock removal, continual heat dissipation and reduced wear. New bonding systems now make it possible to achieve significant improvements in service life as well as greatly reduced machining times.

Benefits of Face Grinding:

• Reduced cutting forces• Increased removal rates• Highest part quality• Ideally profiled dressed wheels

work in the self-dressing range of the machine

• Increased precision• Easy repairs simply by replacing

individual abrasive segments• Reduced machine downtime

More detailed information avail-able on request.

• Junker • Diskus• Linear Abrasive• Viotto

Workpiece Examples

Application Examples

Grinding Wheel Examples

Typical Face Grinding Machines

Diamond and CBN Face Grinding Wheels for Roughing and Finishing

Face Grinding of a Connection Rod

Vitrified Bond / CBN D = 340 mm

Resin Bond / CBN D = 457 mm

Vitrified Bond / CBN D = 500 mm

Resin Bond / Diamond D = 457 mm

Face Grinding of TC Blades

CBN Wheel Dressing

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Wheel cores made of cast mate-rial, steel and aluminum with CBN or diamond grains guarantee first-rate grinding results for all small and large surface area parts. Re-gardless of whether steel or alumi-num, hard metal, ceramic or plas-tic: our range includes the fitting solution for every application.

Advantages of Fine Grinding Compared to Conventional Grinding and Lapping Processes:

• Reduced cutting forces • Increased removal rates • Reproducible sharpening with

dressing rings and stones • Reduced tool wear • Increased precision • Easy repairs simply by replacing

individual abrasive segments/pellets

• Reduced disposal costs (no lapping sludge)

• Reduced machine downtime

Product Benefits:

• Flexible layouts tailored specifi-cally to the workpieces

• Optionally available with edge protection or filling

• Trained wear-resistant bonding with the appropriate dressing technology

• Customer-specific, high-preci-sion coolant drainage systems

• Layouts adapted to the load for uniform wheel wear make it possible to achieve high-preci-sion parts

More detailed information avail-able on request.

• Peter Wolters • Melchiorre• Stähli• Lapmaster• AM Technology

Workpiece Examples

Application Examples

Fine Grinding Wheels – Various Layouts

Typical Fine Grinding Machines

Diamond and CBN Fine Grinding Wheels for Roughing and Finishing

Machining of Roller Bearing Rings

Segmented

Machining of Sealing Disks

Hexagonal “L”

Machining of Circular Blades

Hexagonal “M”

Machining of Steel Rings

Coordinate “S”

Cost-effective fine grinding with reproducible grinding and dressing processes requires the right dress-ing tools.We supply sharpening stones and rings matched to the specifications of the particular precision grinding wheel.

• Stones are inserted loosely • Various grain types and bonds

available• Easy dressing

• Rings are inserted loosely into the carrier ring

• Rings are suitable for maintain-ing the flatness and sharpness of the grinding wheel

• Optimized to grinding wheel width

More detailed information on dressing technology available on request.

• Two-layer versions available to adapt to different upper and lower wheel specifications

• Different colors of the layers ensure that the rings are inserted correctly

Sharpening Stones

Sharpening Ring Benefits

Sharpening Rings

Dressing Tools for Diamond and CBN Fine Grinding Wheels

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Your Benefits

• Our multifaceted experience with customer- specific applications worldwide

• Customer-specific solutions with highest quality tools

• Worldwide technical support

Our Service Concept

• Close cooperation with machine manufacturers (OEM)

• Continual further development of existing tool concepts with corresponding dressing and truing technologies

• Application-focused customer training • Worldwide availability of service and application

specialists

3M offers various types of Dressers for Face Grinding Wheels.

Please find further information in catalogue “3M™ Diamond Dressing Rollers” or contact us.You can find contact information on the back of this brochure.

Dressing Tools for Diamond and CBN Face Grinding Wheels

Your Benefits – Our Service Concepts

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The ability to influence process-relevant factors such as the operating conditions, configuration of the axes, speed

ratio, direction of rotation, infeed, and rollout when profiling with diamond profile dressing rollers offers numerous

opportunities for optimization of the results.When profiling with form dressing rollers, it is also possible to specifically influence the topography on the grinding

wheel and optimize the results by matching the individual factors such as the working conditions, infeed per overflow,

speed ratio, direction of rotation, feed rate, etc.

fdr = 0.72 µmf

dr = 0.18 µm

Up-cut dressing

Number of dwell revolutions

Down-cut dressing

0 80

160 240

320

12

10

8

6

4

2

0

Effe

ctiv

e ro

ug

hn

ess

R ts [µ

m]

ad = 0.7 µm

ad = 0.5 µm

Recommended working area

qd =

VR

VS

Up-cut dressing

Down-cut dressing

Speed ratio qd

Effe

ctiv

e ro

ug

hn

ess

R ts [µ

m]

1.0 0.75 0.5 0.25 0 -0.25 -0.5 -0.75 -1.0

15

10

5

0

Direction of rotationDown-cut and up-cut dressing refers to the relative direction of ro ta-tion of the diamond dressing roller with respect to the grinding wheel. They have correspondingly diffe-rent effective roughnesses (Dia-gram 1). Since down-cut dress ing is associated with high effective rough nesses, it is used for high

Influencing factors that can be coordinated:performance profiling of rough grinding wheels and fine grinding of critical profiles that have a tendency to burn when grinding. By changing the speed ratio, it is possible to have a greater influence on the effective roughness than with up-cut dressing. Up-cut dressing, which is associated with a lower effective roughness, is used for fine grinding

wheels used to grind non-critical profiles that do not tend to burn during grinding.

3M™ Diamond profile and form dressing rollers

Diagram 1

3M™ Diamond profile dressing rollersDiagram 2

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apd = 1–2 (bd +fad) Width of cutapd Width of cut

in mm

aed Dressing infeed

in µm

bd Effective width of the dressing tool in mm

fad Dressing infeed per revolution in mm/U

vfad Axial feed rate

in mm/min

vr Dressing roller circumferential speed in m/s

vsd Grinding wheel circumferential speed in m/s

rp Profile radius of the form roller in mm

+ Down-cut- Up-cut

Ud =––apd

fad qd = ±––vr

vsd

Dressing overlap ratio Dressing speed ratio

bd = 8·rp·aed

with √

Vr

Vr

Vsd

Vfad

rp

aed

apd

fadbd

Form roller

Grinding wheel

Terms and Formulas

Speed ratio (qd)The greatest influence on the effective roughness is obtained by

changing the speed ratio qd, which is the quotient of the

circumferential speed of the dressing roller VR to the circum-

ferential speed of the grinding wheel VS (Diagram 1: Down-cut

and up-cut dressing at different feed increments). Speed ratios

of 1 or almost 1 are not permitted since they indicate that the

diamond dressing roller is either dwelling on the grinding wheel

or that the dressing roller is prematurely worn or damaged.Axial feed rate (v)Another working parameter required when using diamond form

dressing rollers is a feed movement with velocities in the axial or

tangential direction. As the feed rate increases (in down-cut

dressing more than in up-cut dressing), the effective roughness

increases. Since the feed rate depends on the combination of

the application and working conditions, we can only specify

100–300 mm/min as a standard value for rough grinding and

30–100 mm/min for finishing grinding.Dwell revolutions (na)The effective roughness is also influenced by the number of

dwell revolutions (na). As the number of revolutions increases

(for down-cut dressing more than for up-cut dressing), the

effective roughness decreases (Diagram 2). At about 150 dwell

revolutions for down-cut dressing and 50 dwell revolutions for

up-cut dressing, it becomes impossible to minimize the values

any further. While the number of dwell revolutions needs to be

kept low in cases where there is a tendency of grinding burn,

they should be increased when the surface roughness values of

the workpiece are high. (All values were determined in fixed

systems with specific machine and equipment stiffness values,

but are still useful in a general sense.)Infeed (ad)Our parameter for the infeed is the radial feed increment a

d (μm)

of the diamond dressing roller per revolution of the grinding

wheel. As the infeed increases (for down-cut dressing more

than for up-cut dressing), the effective roughness increases

(Diagram 1). The recommended feed increments are between

0.25 – 0.5 μm per revolution of the grinding wheel. The total

infeed selected should always be as small as necessary to

restore the grinding wheel profile (generally < 0.03 mm). When

continuous dressing (CD), the tool is fed continuously at a rate

of up to 0.2 μm per revolution of the grinding wheel. When profiling with diamond form dressing rollers, the feed

increment depends mainly on the type of form dressing roller,

the desired grinding wheel profile, the cutting conditions, and

whether you are rough grinding or finishing grinding. Due to

the numerous combinations of the application and working

conditions, we can only specify 0.1–0.5 mm as a standard value

for rough grinding and 0.005–0.05 mm for finishing grinding.

Operating conditionsWe know how to do it

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3M Precision Grinding & Finishing

3M™ Diamond Dressing Rollers

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Wendt GmbH 3M Abrasives Fritz-Wendt-Str. 140670 MeerbuschGermanyTel.: +49 2159 671-0