KNECHT S 20 User manual

Status 07.2022 Version 3.0 | Translation
Operating Instructions
Universal Wet-Sharpening Machine
S 20 | S 20 B

3
Universal Wet-Sharpening Machine S 20 | S 20 B
Manufacturer
KNECHT Maschinenbau GmbH
Witschwender Straße 26
88368 Bergatreute
Germany
Phone [phone]
Fax [phone]
[email protected]
www.knecht.eu
Documents for machine operator
Operating Instructions
Date of issue of the operating instructions
July 28, 2022
Copyright
These operating instructions as well as the operating documents remain the copyright property of KNECHT
Maschinenbau GmbH. They are supplied only to customers and operators of our products and belong to
the machine.
Without our express permission, these documents may neither be duplicated nor made accessible to third
parties, in particular competitor companies.
Operating Instructions

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1. Important notes 8
1.1 Preface to the operating instructions 8
1.2 Warnings and symbols in the operating instructions 8
1.3 Warning signs and their meaning 9
1.3.1 Warning and mandatory signs on/in the grinding machine 9
1.3.2 General mandatory signs 9
1.4 Rating plate and machine serial number 10
1.5 Figure and position numbers in the operating instructions 10
2. Safety 11
2.1 Basic safety instructions 11
2.1.1 Observe notes in the operating instructions 11
2.1.2 Obligation on the part of the operator 11
2.1.3 Obligation on the part of the personnel 11
2.1.4 Hazards involved in handling the grinding machine 11
2.1.5 Malfunctions 12
2.2 Intended use 12
2.3 Warranty and liability 13
2.4 Safety regulations 13
2.4.1 Organizational measures 13
2.4.2 Protective equipment 13
2.4.3 Informal safety measures 14
2.4.4 Selection and qualification of personnel 14
2.4.5 Machine control system 14
2.4.6 Safety measures in normal operation 14
2.4.7 Hazards due to electrical power sources 14
2.4.8 Particular hazard areas 15
2.4.9 Servicing (maintenance, repair) and fault rectification 15
2.4.10 Structural alterations to the grinding machine 15
2.4.11 Cleaning the grinding machine 15
2.4.12 Lubricants/oils and greases 16
2.4.13 Relocation of the grinding machine 16
3. Description 17
3.1 Intended use 17
3.2 Technical specifications 17
3.2.1 General 17
3.2.2 S 20 (version with grinding wheel) 18
3.2.3 S 20 B (version without grinding wheel) 19
3.3 Functional description 20
3.4 Description of the assemblies 21
3.4.1 Tool cabinet 22
Table of Contents

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3.4.2 Coolant dosing wet-grinding belt 22
3.4.3 Control panel 22
3.4.4 Grinding unit (S 20) 23
3.4.5 Grinding and polishing unit for wet-grinding belt and finned brushes 23
3.4.6 Dressing tool HV 201 (S 20) 23
3.4.7 Coolant unit 24
3.4.8 Circular knife grinding attachment HV 25-1 for circular knives 80 – 250 mm (optional, S 20) 24
3.4.9 Circular knife grinding attachment HV 25-2 for circular knives 250 – 470 mm (optional, S 20) 24
3.5 Functional description of units 25
4. Transport 27
4.1 Transport aids 27
4.2 Transport damage 27
4.3 Transport to another installation site 27
5. Installation 28
5.1 Selection of qualified personnel 28
5.2 Installation site 28
5.3 Supply connections 28
5.4 Settings 28
5.5 Initial start-up of the grinding machine 29
6. Commissioning 30
7. Operation 32
7.1 General grinding fundamentals 32
7.2 Grinding sickle-shaped cutter knives on the grinding wheel
(convex cutting edge) S 20 33
7.2.1 Positioning the mounting head 33
7.2.2 Inserting the function disc 35
7.2.3 Mounting the grinding plate SP 107 36
7.2.4 Clamping the sickle-shaped cutter knife 38
7.2.5 Positioning the sickle-shaped cutter knife on the grinding wheel 40
7.2.6 Setting the grinding angle 40
7.2.7 Grinding the sickle-shaped cutter knife (convex cutting edge) 41
7.3 Grinding sickle-shaped cutter knives on the wet-grinding belt
(convex cutting edge) (S 20 | S 20 B) 43
7.3.1 Setting the grinding radius 43
7.3.2 Locking the carriage in place 45
7.3.3 Inserting the function disc 45
7.3.4 Setting the grinding angle 46
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7.3.5 Mounting the grinding plate SP 107 46
7.3.6 Adjusting the swivel range of the grinding plate 47
7.3.7 Clamping the sickle-shaped cutter knife 47
7.3.8 Basic function of the locking mechanism of the grinding and polishing unit 49
7.3.9 Bringing the grinding and polishing unit into the adjustment position 50
7.3.10 Grinding the sickle-shaped cutter knife 51
7.3.11 Polishing and deburring the sickle-shaped cutter knife 53
7.4 Grinding linear cutter knives on the grinding wheel
(convex cutting edge) (S 20) 59
7.4.1 Positioning the mounting head 59
7.4.2 Inserting the function disc 61
7.4.3 Mounting the grinding plate SP 107 61
7.4.4 Clamping the linear cutter knife 62
7.4.5 Positioning the linear cutter knife on the grinding wheel 64
7.4.6 Aligning the linear cutter knife on the grinding wheel 65
7.4.7 Setting the grinding angle 66
7.4.8 Grinding the linear cutter knife (convex cutting edge) 67
7.5 Grinding linear cutter knives on the wet-grinding belt
(convex cutting edge) (S 20 | S 20 B) 69
7.5.1 Setting the grinding radius 69
7.5.2 Releasing the carriage 71
7.5.3 Insert the function disc 71
7.5.4 Setting the grinding angle 72
7.5.5 Mounting the grinding plate SP 107 72
7.5.6 Clamping the linear cutter knife 73
7.5.7 Basic function of the locking mechanism of the grinding and polishing unit 74
7.5.8 Bringing the grinding and polishing unit into the adjustment position 75
7.5.9 Aligning the linear cutter knife on the wet-grinding belt 76
7.5.10 Grinding the linear cutter knife 77
7.5.11 Polishing and deburring the linear cutter knife 79
7.6 Grinding hand knives on the wet-grinding belt (S 20 | S 20 B) 84
7.7 Dressing the grinding wheel (S 20) 86
7.8 Adjusting the grinding wheel guard (S 20) 88
7.9 Changing the grinding wheel (S 20) 89
7.10 Changing the wet-grinding belt 90
7.11 Adjusting the belt movement 92
7.12 Changing the finned brushes 93
7.13 Circular knife grinding attachment HV 25-1 (optional S 20) 95
7.14 Circular knife grinding attachment HV 25-2 (optional S 20) 96
8. Care and maintenance 97
8.1 Cleaning 97
8.1.1 Lubricant table 97
8.2 Maintenance plan (one-shift operation) 97
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9. Disassembly and disposal 98
9.1 Disassembly 98
9.2 Disposal 98
10. Service, spare parts and accessories 99
10.1 Postal address 99
10.2 Service 99
10.3 Spare parts 99
10.4 Accessories 100
10.4.1 Abrasives used, etc. 100
11. Appendix 101
11.1 EU Declaration of Conformity 101
Table of Contents

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1.1 Preface to the operating instructions
These operating instructions are intended to make it easy to learn how to use the Universal
Wet-Sharpening Machine, hereafter referred to as the grinding machine, and to properly utilize
its features.
These operating instructions contain important notes on how to operate the grinding machine
safely, properly, and efficiently. Observing these instructions helps to avoid hazards, reduce repair
costs and downtimes, and to increase the reliability and service life of the grinding machine.
The operating instructions must always be stored in the location that the grinding machine is
used.
The operating instructions must be read and applied by every person tasked with working with
the grinding machine, e.g.:
• transport, installation, commissioning
• operation, including error rectification during operation, as well as
• servicing (maintenance, repair).
Recognized technical standards for safe and professional work must be observed in addition to
these operating instructions and the binding accident prevention regulations applicable in the
country of use and at the place of use.
1.2 Warnings and symbols in the operating instructions
The operating instructions use the following symbols/designations that must be followed:
The hazard triangle with the signal word “CAUTION” serves as a work
safety notice for all work for which there is a risk of personal injury or
death.
In these cases, work should be done with special attention and care.
ATTENTION
“ATTENTION” is written in places where special attention must be paid to
prevent damage or destruction of the grinding machine or its surroundings.
NOTE “NOTICE” refers to user tips and especially useful informations.
1. Important notes
CAUTION

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1.3 Warning signs and their meaning
1.3.1 Warning and mandatory signs on/in the grinding machine
The following warnings and mandatory signs have been affixed on/in the grinding machine:
CAUTION! DANGEROUS ELECTRICAL VOLTAGE
(warning sign on switch housing)
The grinding machine carries life-threatening voltage when it is
connected to the current supply.
Current-carrying device parts may only be opened by authorized
personnel.
The grinding machine must be separated from the mains supply
before carrying out servicing, maintenance and repair work on it.
CAUTION! RISK OF INJURY FROM ABRASIVE PARTICLES
(mandatory sign on machine front)
Grinding, polishing, deburring and dressing gives rise to grinding
particles which can enter the eyes.
Wearing eye protection is mandatory when carrying out such
work.
1.3.2 General mandatory signs
The following general mandatory signs must be followed:
CAUTION! RISK OF INJURY FROM KNIFE
Working with the grinding machine involves grinding knives that
could cause serious cut injuries due to their sharpness.
Protective gloves must be worn when clamping and releasing
knives.
Caution when transporting blades. Use the protective equipment
provided by the knife manufacturer. Protective gloves and safety
shoes must be worn.
1. Important notes

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1.4 Rating plate and machine serial number
The rating plate (1-1/1) is located on the rear
panel of the machine.
The machine serial number can be found on the
rating plate and on the right side wall underneath
the wet-grinding belt.
1.5 Figure and position numbers in the operating instructions
If the text makes a reference to a machine component depicted in a figure, the figure and posi-
tion number will be given in parentheses.
Example: (6-2/1) means figure number 6-2, position 1.
Check the direction of rotation of the finned brushes.
The direction arrow (6-2/1) indicates the direction of
rotation of the wet-grinding belt and finned brushes.
If the finned brushes are rotating in the right direction,
then the direction of rotation of the grinding wheel and
of the wet-grinding belt is also correct.
If the finned brushes are rotating in the wrong direction,
have the phase reversed by a qualified electrician.
1. Important notes
Figure 1-1 Rating plate
Figure 1-2 Machine serial number
Figure 6-2 Checking the direction of rotation
1
1
1

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2.1 Basic safety instructions
2.1.1 Observe notes in the operating instructions
The basic prerequisite for the safe handling and uninterrupted operation of this grinding machine
is knowledge of the basic safety instructions and regulations.
• These operating instructions contain important notes on how to operate the grinding machine
safely.
• All persons carrying out work on the grinding machine must follow these operating instructions,
in particular the safety notices.
• In addition, the rules and regulations regarding accident prevention at the place of use are to be
observed.
2.1.2 Obligation on the part of the operator
The operator is obliged to allow only those persons to work on the grinding machine, who
• are familiar with the occupational safety and accident prevention regulations and have received
instruction in handling the grinding machine,
• have read and understood the operating instructions, in particular the section entitled “Safety”
and the warning notes, and have provided signed confirmation of this.
The safety-awareness of the personnel at work will be monitored at regular intervals.
2.1.3 Obligation on the part of the personnel
All personnel working on the grinding machine shall be obliged, before starting work, to
• observe basic occupational safety and accident prevention regulations,
• read the operating instructions, particularly the section entitled “Safety” and the warning notes,
and provide signed confirmation that they have understood them.
2.1.4 Hazards involved in handling the grinding machine
The grinding machine has been built to the latest technological standards and the recognized
rules of technical safety. In spite of this, its use poses inherent risks which could result in bodily
harm or even death of the user or third persons, or damage to the grinding machine or other
property.
2. Safety

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The grinding machine may be used only:
• for its intended purpose
• in faultless condition with regard to safety-related aspects.
Malfunctions that may impair safety are to be eliminated immediately.
2.1.5 Malfunctions
If safety-relevant malfunctions occur with the grinding machine, or if the processing behavior
indicates that such malfunctions may have occurred, the grinding machine must be stopped
immediately and until such time as the malfunction has been found and eliminated.
Allow only authorized trained personnel to eliminate the malfunctions.
2.2 Intended use
The grinding machine can be used universally for all standard cutter knives, as well as circular
knives, hand knives, and other cutting tools.
Except for hand knives (e.g. cutting knives), all cutting tools must be clamped on the correspond-
ing grinding plates.
First, check whether the grinding plate matches the knife to be ground. The knife can only be
ground if this is the case.
Any other use is considered to be improper. KNECHT Maschinenbau GmbH is not liable for any
damage arising from this. The user alone bears this risk.
Use as intended includes the observance of all the notes in the operating instructions.
ATTENTION The grinding machine is being used im-
properly if, for example:
• cutting tools that cannot be guided by hand
are ground without a grinding plate.
• fixtures are not properly attached.
• knives are sharpened/polished in the op-
posite direction of the cutting edge on the
wet-grinding belt or the finned brushes.
2. Safety

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2.3 Warranty and liability
Warranty and liability claims in case of personal injury or property damage are excluded if such
damage is attributable to one or more of the following causes:
• improper use of the grinding machine,
• improper transport, commissioning, operation, and maintenance of the grinding machine,
• operating the grinding machine with defective safety devices, or using improperly attached or
malfunctioning safety and protective equipment,
• failure to observe the instructions with regard to transportation, commissioning, operation,
maintenance and repair of the grinding machine,
• unauthorized structural alterations to the grinding machine,
• unauthorized modification, e.g. of the drive conditions (output and speed),
• failure to monitor machine parts that are subject to wear, and
• use of unapproved replacement and wear parts.
Use only original replacement and wear parts. If externally purchased parts are used, it is not
guaranteed that they have been designed and manufactured to meet the requirements in terms
of stress and safety.
2.4 Safety regulations
2.4.1 Organizational measures
Inspect all available safety devices regularly.
Observe prescribed intervals for recurring maintenance work or as specified in the operating
instructions!
2.4.2 Protective equipment
Before every commissioning of the grinding machine, ensure that all protective equipment is
properly mounted and in functional condition.
Protective equipment may be removed only after the grinding machine has stopped and has
been secured against accidental restart.
When attaching spare parts, the protective equipment must be attached by the operator as
stipulated.
2. Safety

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2.4.3 Informal safety measures
The operating instructions must be permanently available at the place of use of the grinding
machine. In addition to the operating instructions, the generally applicable as well as locally
relevant accident prevention regulations must also be made available and observed.
All safety alert symbols and hazard warnings on the grinding machine must be complete and
clearly legible.
2.4.4 Selection and qualification of personnel
Only trained and instructed personnel may work on the grinding machine. Observe the legally
permitted minimum age!
The responsibilities of personnel with respect to commissioning, operation, maintenance, and
repair must be clearly specified.
Personnel still undergoing training or instruction may only work on the grinding machine under
the permanent supervision of an experienced person!
2.4.5 Machine control system
Only trained and instructed personnel are permitted to switch on and operate the machine.
2.4.6 Safety measures in normal operation
Do not operate the machine in any unsafe manner. Only operate the grinding machine if all
the safety devices are installed and fully functional.
At least once per shift (or per day), check the grinding machine for externally visible damage
and proper functioning of the safety devices.
Immediately report any changes present (including those of the operating behavior) to the
responsible office or person. If necessary, immediately shut down the grinding machine and
secure it against restart.
Before you switch on the grinding machine, ensure that no one can be injured by the start-up
of the machine.
In the event of a malfunction, immediately stop the grinding machine and secure it against
restart. Rectify malfunctions immediately.
2.4.7 Hazards due to electrical power sources
Work on electrical systems or operating materials may only be performed by a qualified
electrician, in accordance with electrical regulations.
Defects, such as damaged cables, cable connections, etc. must be immediately rectified by
an authorized specialist.
2. Safety

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The yellow power supply cable is electrically live even when the main
switch is turned off.
CAUTION
2.4.8 Particular hazard areas
Hazard in the area of the grinding wheel, wet-grinding belt and finned brushes: objects, e.g.
clothing, fingers and hair, can be pinched and drawn in. Wear suitable personal protective
equipment.
2.4.9 Servicing (maintenance, repair) and fault rectification
Maintenance work is to be carried out on schedule by trained personnel. Inform operating
personnel before beginning repair work. Designate a supervisor responsible for this.
For all service work, the grinding machine is to be disconnected from the current supply and
secured against accidental restart.
Remove power plug. Secure repair area as necessary.
After completing maintenance work and rectifying any faults, install all safety devices and verify
that they are fully functional.
2.4.10 Structural alterations to the grinding machine
Alterations to or retrofits or rebuilds of the grinding machine are not allowed without the
permission of the manufacturer. This also applies for installation and configuration of the safety
devices.
Any conversion work requires the written permission from KNECHT Maschinenbau GmbH.
Immediately replace machine parts that are not in perfect condition.
Use only original replacement and wear parts. If externally purchased parts are used, it is not
guaranteed that they have been designed and manufactured to meet the requirements in terms
of stress and safety.
2.4.11 Cleaning the grinding machine
Properly handle any cleaning agents and materials used and dispose of them in an environmentally
friendly manner.
Dispose of the wear parts and replacement parts in a safe and environmentally-friendly manner.
2. Safety

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2. Safety
2.4.12 Lubricants/oils and greases
When using oils and greases, follow the safety regulations applicable to the product. Comply with
the special regulations for the food areas.
2.4.13 Relocation of the grinding machine
Disconnect the grinding machine from any external power supply, even in the event of a minor
change of location. Before restarting the grinding machine, connect it properly to the power
supply.
For loading work, use only lifting equipment and load-bearing devices with sufficient lifting
capacity. Appoint a qualified instructor for the lifting operation.
No persons other than those designated for this work may be present in the loading and installa-
tion area.
Only lift the grinding machine properly with lifting gear as specified in the operating instructions.
Only use a suitable transport vehicle with sufficient load-bearing capacity. Secure the load reliably.
Use suitable attachment points. When restarting the machine, proceed only in accordance with
the operating instructions.

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3. Description
3.1 Intended use
The S 20 | S 20 B Universal Wet-Sharpening Machine is meant for grinding, deburring and polish-
ing all commonly used cutter knives as well as circular knives, hand knives and other cutting tools.
3.2 Technical specifications
3.2.1 General
Power supply* ������������������������������������������������������������� 3x 400 V
Mains frequency* �������������������������������������������������������������� 50 Hz
Output* ������������������������������������������������������������������� 1,17 kW
Power consumption* �������������������������������������������������������� 1,61 kW
Back-up fuse ������������������������������������������������������������������� 16 A
Measured A-weighted emission sound pressure level ����������������������������� 78 dB (A)
at workplace LpA**
Grinding device wet-grinding wheel
Traverse (maximum cutting edge length) ����������������������������������������� 320 mm
Maximum grinding radius ����������������������������������������������������� 450 mm
Minimum grinding radius ������������������������������������������������������ 80 mm
Possible cutter knife sizes ���������������������������������������������������� 45 – 500 l
Grinding device wet-grinding belt
Traverse (maximum cutting edge length) ����������������������������������������� 300 mm
Maximum grinding radius ����������������������������������������������������� 430 mm
Minimum grinding radius ������������������������������������������������������ 80 mm
Possible cutter knife sizes ���������������������������������������������������� 45 – 500 l
*) This information may change depending on the electrical current supply.
**) Two-digit sound emission value according to EN ISO 4871 (measurement uncertainty KpA. 3 dB (A)).
Emission sound pressure level according to EN ISO 11201.
A K24 cutter knife from KNECHT Maschinenbau GmbH was ground.

1400 mm
1300 mm
1400 mm
1700 mm
1400 mm
1300 mm
1400 mm
1700 mm
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3. Description
Figure 3-1 S 20 dimensions in mm and centers of gravity (CoG) of the machine
3.2.2 S 20 (version with grinding wheel)
Energy consumption* ��������������������������������������������������������� 2,79 A
Height ������������������������������������������������������������ approx. 1400 mm
Width ������������������������������������������������������������� approx. 1300 mm
Depth ������������������������������������������������������������� approx. 1700 mm
Space requirement (W x D) �������������������������������������������� 1300 x 2000 mm
Weight ��������������������������������������������������������������� approx. 180 kg
Diameter finned brushes ��������������������������������������������������� d. 200 mm
Speed of wet-grinding belt/finned brushes ������������������������������������ 1700 1/min
Diameter grinding wheel ��������������������������������������������������� d. 200 mm
Speed of grinding wheel ���������������������������������������������������� 420 1/min
*) This information may change depending on the electrical current supply.
CoGCoG

1300 mm
1050 mm
1300 mm
1700 mm
1300 mm
1050 mm
1300 mm
1700 mm
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3. Description
3.2.3 S 20 B (version without grinding wheel)
Energy consumption* ��������������������������������������������������������� 2,70 A
Height ������������������������������������������������������������ approx. 1300 mm
Width ������������������������������������������������������������� approx. 1050 mm
Depth ������������������������������������������������������������� approx. 1700 mm
Space requirement (W x D) �������������������������������������������� 1300 x 2000 mm
Weight ��������������������������������������������������������������� approx. 160 kg
Diameter finned brushes ��������������������������������������������������� d. 200 mm
Speed of wet-grinding belt/finned brushes ������������������������������������ 1700 1/min
*) This information may change depending on the electrical current supply.
Figure 3-2 S 20 B dimensions in mm and centers of gravity (CoG) of the machine
CoGCoG

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3.3 Functional description
The Universal Wet-Sharpening Machine can be used to grind, deburr and polish linear, sickle-
shaped and circular knives.
All knives other than hand knives must be clamped onto grinding plates for grinding, deburring
and polishing.
The grinding angle on the grinding wheel can be steplessly adjusted. The grinding angle on the
wet-grinding belt is adjusted with different spacer discs.
3. Description

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3. Description
3.4 Description of the assemblies
1 Grinding unit for wet-grinding wheel (S 20)
2 Grinding arm (S 20)
3 Wet-grinding wheel (S 20)
4 Finned brushes
5 Wet-grinding belt
6 Control panel
7 Carriage
8 Grinding and polishing unit for wet-grinding belt and finned brushes
9 Dressing tool HV 201 for grinding wheel (S 20)
10 Machine feet
Figure 3-3 General view of sharpening machine S 20
4
4
8
6
10
3
7
5
9
12 2