MEFE CAT 139100 User manual

MEFE—Mitchell Engineering Food Equipment Pty Ltd
23 Storie Street Clontarf QLD 4019 Australia
www.mefe.com.au
AUG 23 Page 1
[phone]
[email protected]
Instruction Manual
Revision 2
Power Knife Sharpener
100mm CMB Coated Wheel
CAT 139100

MEFE—Mitchell Engineering Food Equipment Pty Ltd
23 Storie Street Clontarf QLD 4019 Australia
www.mefe.com.au
AUG 23 Page 2
[phone]
[email protected]
1. MACHINE OVERVIEW
This manual refers to the Model CAT 139 100 Knife Sharpener Machine, with belt drive technology. A view of the machine and
its component terminology can be seen below
This machine is supplied with spiral abrasive wheels which are suitable for sharpening (and re-sharpening in service environ-
ments) a wide range of hand held designs (whether a handle is ed or not). This is in the main a dry operaon.
The standard wheels supplied on the machine have a small front radius, which is a big help to the operator when blades have a
concave shape or a small radius at the choil, e.g. a boner. These will also sharpen the vast majority of straight or convex forms
blades. Straight form wheels are recommended in applicaons where it is required to sharpen the blade right up into the choil,
e.g pocket and pen knifes. If many short blades are sharpened then disproporonate wear on the abrasive coang may occur
at the front of the wheels. In such cases we can supply wheels with a centre hub adaptor, which allows the wheels to be re-
versed.
All personnel should read this document before installing or using the machine.
Figure 1.1

MEFE—Mitchell Engineering Food Equipment Pty Ltd
23 Storie Street Clontarf QLD 4019 Australia
www.mefe.com.au
AUG 23 Page 3
[phone]
[email protected]
1.1 Service Contacts
Mitchells Engineering Food Equipment (MEFE)
23 Storie St
Contalrf 4019
Queensland Australia
Telephone: [phone]
Email: [email protected]
Web: www.mefe.com.au
Figure 1.2

MEFE—Mitchell Engineering Food Equipment Pty Ltd
23 Storie Street Clontarf QLD 4019 Australia
www.mefe.com.au
AUG 23 Page 4
[phone]
[email protected]
1.2 Equipment
The following schedule of parts is supplied as standard:
QTY Descripon
1Sharpening Machine (fully stainless cover and ying lead)
1 pair Spiral Interlocking Abrasive Wheels 100mm dia (4 ins)
130mm A/F Box Spanner with “T” Bar
18mm AF Open Ended Spanner
1Safety Glasses
1Instrucon Manual
1.3 Specicaon
Height 200mm
Width 360mm
Length 350mm
IP Rang 54 Overall
Weight 20kg
UK & Europe USA
MOTOR
Voltage 220/240V AC 1ph 50Hz 110V AC 1ph 50Hz 110V AC 1ph 60Hz
I100 / S I100 / F I100 / F
Power 0.25 Kw 0.25 Kw0.18 Kw 0.24 Kw
RPM 1370 2850 2790 3420
Current 1.6 A 2. A 4 A 4.7 A
Wheel spindle Speed 1340 2870 2790 3420
WHEEL SURFACE SPEED
30 1324 sfpm 2836 sfpm 2776 sfpm 3404 sfpm
40 1362 sfpm 2916 sfpm 2854 sfpm 3499 sfpm
50 1413 sfpm 3026 sfpm 2962 sfpm 3631 sfpm
60 1481 sfpm 3172 sfpm 3105 sfpm 3806 sfpm
Note: The wheel spindle speed is correct for the type of wheels ed to this machine and should not be altered except in con-
sultaon with MEFE
Wheels
 Nominally 4” dia 1 1/2” wide spirally interlocking, see secon 3.3
 1/2” Pitch
 CBN Coated—125 and 76 grit standard

MEFE—Mitchell Engineering Food Equipment Pty Ltd
23 Storie Street Clontarf QLD 4019 Australia
www.mefe.com.au
AUG 23 Page 5
[phone]
[email protected]
1.4 Installaon
Check and idenfy the equipment supplied against
the schedule above and inspect for any defects
occurring in transit before preparing the machine
for use.
Site the machine on a rm level bench convenient
for connecon and electrical supply and extracon
equipment.
The machine should be set at a height such that is
relavely tall person meets the arrangement
shown in Fig 1.3. Adjust the posion for shorter
operators use of a board / Plinth in order to
achieve an elbow heigh slightly above the wheel
level.
If the grinding wheels are not ed, inspect them
for any damage. Fit the wheels following the pro-
cedure in Secon 4.4. Correct rotaon is facilitat-
ed by the capacitor start motor. On start up there
should be no ringing noise including wheel inter-
ference.
Connecng To A Power Supply
This machine should be connected to a suitable single phase electrical supply of the
rang according to the factory site specied by the customer.
When supplied to Australia the electrical lead has a moulded standard 3 pin 13 A Plug
for single phase (220/240 V 50Hz) operaon and a 5 amp fuse.
Wiring Convenon
Live - Brown
Neutral - Blue
Earth - Green/Yellow
The starter on the machine provides both no-volt release and overcurrent circuit pro-
tecon funcons by thermal magnec sensing. It is recommended that the machine be
connected to the supply via fused outlet with a means of isolaon.
The circuit breaker can be tested and adjusted by gaining access to the front of the
device. Remove the two screws in front of the starter enclosure and put aside being
careful not to strain the wires to the indicator lamp.
NB Isolate the machine from supply before accessing any electrical connecons.
Fig 1.3

MEFE—Mitchell Engineering Food Equipment Pty Ltd
23 Storie Street Clontarf QLD 4019 Australia
www.mefe.com.au
AUG 23 Page 6
[phone]
[email protected]
1.5 Dust Extracon
There is very lile wheel wear (i.e. loss) using the CBN abrasive wheels. However, the main by-product of sharpening will be
parcles of steel dust produced by grinding. This can be removed locally from the machine using a suitable extracon system.
The wheel guard of this machine has been ed with an extracon outlet ready to be connected to a suitable system. The out-
let (32 mm) should be covered when not in use, using the cap provided, (see Fig 1.1).
In some circumstances, it may be useful to have an addional dust extracon point over the top of the grinding area, as shown
in Fig 1.5. This can be designed un the shape of a hood, which does not obstruct the operators’ vision or access to the knife
blade. The poron of blade over the back of the wheels may actually enter this hood.
2. SAFETY
As in any grinding machine, there is an element of risk to the user of either trapping or physical abrasion to parts of the body.
However, the design of the MEFE machine incorporates several features to reduce the chance of accidental injury,
 All mechanical moving parts are fully enclosed in solid guarding.
 Only the minimal “V” shaped aperture in the wheel cover is available for applicaon of the component to wheel and is
of a size small enough to prevent the inseron of a nger
 The risk of grinding wheel bursng (as with convenonal wheels) is negligible due to the solid steel construcon of the
wheels.
 The surface speed of the abrasive wheels is considerably less than that for convenonal wheels.
 The interlocking principle of the wheels and their upwards direcon of rotaon presents a posive locaon and makes it
easier for the operator to present the component to the wheels than in any other similar o-hand grinding operaon.
Fig 1.5
Use the machine without all the guards in place
Start the machine with the grinding wheel loose or badly adjusted for clearance
Start the machine with anything obstrucng the wheels
Apply anything other than knife blades to the wheels, this could invalidate our guarantee
Grind anything with a hardness less than 50Rc, this could invalidate our guarantee
Wear safety glasses or a face shield at all mes whilst using the machine
Isolate the machine from the electrical supply while ng wheels, carrying out roune maintenance or any
other acvity where moving parts of the machine are exposed
Employ dust controls and/or protecve measures appropriate to the materials being ground
Give appropriate training to operators in the use of the machine and the techniques of grinding components.
MEFE can provide training and/or video instrucons by agreement.

MEFE—Mitchell Engineering Food Equipment Pty Ltd
23 Storie Street Clontarf QLD 4019 Australia
www.mefe.com.au
AUG 23 Page 7
[phone]
[email protected]
3. OPERATING THE MACHINE
Run the machine only when the wheels are secured and set up correctly, (refer to secon 4). Ensure that all the guards are
ed securely.
Start and stop the machine using the buons on the starter enclosure at the front of the machine. Allow a few seconds on
start up for the wheels to get to speed and proceed only if the wheels are in good order and running sasfactorily.
3.1 Principle of Sharpening
The design and arrangement of the interlocking wheels on the machine means that there is a xed angle in the “valley” at the
intersecon of the wheels. This angle is determined by the diameter and the centres of the wheels, (see Secon 3.3). When
the wheels are rotang in the normal direcon, an abrasive surface is “generated” capable of grinding simultaneously on both
sides, an included angle on a knife blade, which is made to pass through the intersecon point.
The knife should be held by its handle in the operator’s hand and oered into the intersecon of the wheels, applying light
downwards pressure making the edge of the blade contact in the very boom of the “v”
Fig 3.1
Fig 3.2
A)
B)

MEFE—Mitchell Engineering Food Equipment Pty Ltd
23 Storie Street Clontarf QLD 4019 Australia
www.mefe.com.au
AUG 23 Page 8
[phone]
[email protected]
Whilst maintaining the atude of the blade vercal (Fig 3.1) and parallel (Fig 3.2B) to the intersecon of the wheels, the blade
should be traversed in a moon, which maintains the prole of the edge in contact with the wheels and the line of the “V”
form normal to the curvature of the blade (as in Fig 3.2A).
Depending upon the blade edge thickness, a combinaon of several passes through the wheels with regulaon of the applied
pressure is required to ensure that a sharp edge is produced, Ensure that sharpening has fully taken place with the sides of the
blade coming to a sharp point. This can be achieved by looking vercally on to the blade edge, under a bright light. If the blade
is not completely sharpened, a shiny reecon will be seen.
The component should be kept constantly moving in
the forward and backward moon to ensure an even
grind over the length of the blade edge and reduce the
risk of overheang. Blades should be rst applied to
and removed from the wheels in the middle of the
width available (Fig 3.2A)
3.2 Useful Hints
3.2.1. Do not hold the component with too rigid a
grip. Adopt a comfortable and relaxed atude at the
wrist and ngers which will allow the blade to self align
itself in the intersecon of the wheels. Using the fore-
nger on the back of the blade helps to control the
pressure.
3.2.2 Avoid excessive use or over pressure on the
front of the wheels where the spiral form runout is
rising as this causes chaer and damage to the wheels.
3.2.3 Avoid passing the blade over the front and back edges of the wheels at an incorrect atude as this causes indentaons
in the ground edge and damage to the wheels.
3.2.4 Avoid starng to sharpen by placing the blade point rst down in to the wheels or withdrawing the blade point over the
front edge as both these will cause the blade to receive a kick.
Fig 3.3
Fig 3.4 Fig 3.5

MEFE—Mitchell Engineering Food Equipment Pty Ltd
23 Storie Street Clontarf QLD 4019 Australia
www.mefe.com.au
AUG 23 Page 9
[phone]
[email protected]
3.2.5 Special non-standard wheels can be manufactured to
cater for blades which may have a concave shape on the
cung edge. Contact MEFE for further details.
3.2.6 Where it is parcularly important to sharpen the
blade right up to a point very close to the handle, then it is
very useful to t a stop either to contact the point of the
blade or the front of the handle whichever is the most suita-
ble. This will give the operator condence to enter the blade with the handle as close up to the front of the wheel as possible.
3.2.7 As no two knife designs have the
same blade edge prole, the blade moons
for each paern through the wheels should
be designed to opmise the number of
passes required (thus shorten the process
me) and also ulisaon of the abrasive
surface of the wheels.
3.2.8 Although CBN has a high thermal
stability, a coolant / lubricant should be used wherever praccal. It has a good dry performance when used for sharpening op-
eraons by hand however the use of a lubricant will increase wheel life by as much as 50% over a dry operaon provided that
the recommended coolant is used.
Inferior wheel life results from using water based coolants and therefore these should not be used.
The use of straight sulphurated mineral oils is recommended, however, problems of oil mist which requires the use of air lter-
ing systems arises when copious amounts are used.
When sharpening knives, a much simpler technique can be used without these problems occurring. Simpler technique can be
used without these problems occurring. Simply wipe the edge of the knife to be sharpened over the surface of a felt pad stand-
ing in a dish of oil. A small amount of oil will be transferred locally to the blade without and undue excess.
3.3 Selecng the Grind Angle
The model CAT 139 100 Knife Sharpening Machine has xe wheel centres and therefore has no angle adjustment feature. How-
ever, it is possible to select a grinding angle from one of four standard opons by ng wheels of dierent diameters.
• It is, therefore, necessary for the user to carry In stock pairs of wheels that suit the angles to be ground
• It is impraccal for the machine to sharpen below 25 included angle.
• Change the wheels as described in Secon 4.3 & 4.4
Fig 3.6
Fig 3.7
Fig 3.8
Knife Type Wheel Dia (mm) Grinding Angle (inclusive)
Table blades 107.24
103.70
60°
54°
Kitchen / Professional Knives 95.86 30°
Professional / Special Knives 94.83 25°°

MEFE—Mitchell Engineering Food Equipment Pty Ltd
23 Storie Street Clontarf QLD 4019 Australia
www.mefe.com.au
AUG 23 Page 10
[phone]
[email protected]
4. ABRASIVE WHEELS
The Grinding wheels ed into this machine are of special design. The are made of steel and supplied in matching pairs with
one each le and right handed threaded form—termed “spiral”.
The standard wheels range from 94.8—107 mm diameter with a thin uniform electroplated coang of CBN abrasive on the
periphery of the form. Standard abrasives are CBN 126 and 76 grit although other grades are available on request.
Due to this special construcon, no reducon in wheel diameter in the convenonal sense. Is experienced in the grinding pro-
cess. This means than any form of compensaon for wheel wear or methods of maintaining a consistent grind angle are not
required. In addion, CBN used at the designed speeds produces a relavely cool grind in most cases and be used dry.
CBN has been found to be parcularly suitable for applicaons such as knife sharpening where a small depth of cut per pass is
required. It is a very cool cung abrasive, and as such does not normally overheat martensic stainless steels used for knives
even when used in the dry condion, except in cases where heavy metal removal is required or excessive pressure used. Such
excessive pressure may reduce wheel life and also eect the corrosion resistance of the stainless steel blade and may under
certain circumstances lead to cracking.
4.1 Care of Wheels
The spiral wheng wheel should be handled carefully at all mes, both on and o the machine. Extra care should be taken not
to damage either the CBN coang or the bores and boss faces.
If damage has occurred due to chaering, usually on he lead in of the spiral form, this can be reced by removing the wheels
from the machine and smoothing in the damage with an engineer’s le to produce a burr free leading angle again.
If the wheels are incorrectly interlocked damage will occur to the edges of the abrasive coang and to the grooves in the
wheels. A disncve ringing noise will
signify this problem. To correct this the
clearance of the wheels must be re-set
as described in Secon 4.4.
In extreme cases of incorrect interlock
serious damage may occur if an
aempt to use the machine is made.
Damage resulng in unnecessary loss
of wheel life will be caused if grinding
is connued when the coang be-
comes excessively worn, in whole or
part, resulng in the steel surface of
the wheel being exposed.
4.2 Abrasive Recoang
With increased use the single layer abrasive becomes worn and loses its bite without loss of wheel size.
Normally, wheels can be chemically stripped of the electroplate and any CBN recovered, and if the form has not been dam-
aged, then recoated. This process can be repeated a number of mes, but if however, the form is damaged, then it will need to
be re-machined to the original prole before replang. Depending on the applicaon, obviously there will be a limit to the
number of mes this can be done before a new wheel is required. (see also Secon 3.3).
Fig 4.1