ROTA MASTER RM3000 User manual

1
ROTA MASTER • RM3000
© Bernhard and Company Limited
ROTA MASTER • RM3000
Please read this manual carefully before using the Rota Master.
This manual should be kept in a safe place so that it can be used for future reference.
ROTA MASTER
RM3000 Automatic Rotary Blade Grinder
User’s Guide &
Instruction Manual

2
ROTA MASTER • RM3000
© Bernhard and Company Limited
ROTA MASTER
Contents
BERNHARD AND COMPANY LTD
Bilton Road • Rugby • England • CV22 7DT
Tel [phone] • Fax [phone]
Email: [e-mail]
USA Toll Free 1-888 GRIND IT ( 1-888 474 6348)
RM3000 Automatic Rotary Blade Grinder
You are now the owner/operator of a Bernhard’s Rota Master (RM3000) which,
if cared for and operated correctly, will give you years of good service.
This manual will enable you to obtain the best results from your RM3000 so please
read it thoroughly before using your machine.
If you have any service or operational problems contact your distributor,
or phone our
Technical Helpline (USA only) – 1-888 474 6348
or
Bernhard and Company Ltd, England – ([phone]
or email
[email protected]
use the technical support feedback form on our web site
www.expressdual.com or www.bernhard.co.uk
Overview 3
Safety 4
Installation 5
Setting Up 7
Grinding the Blade 13
Blade Balancing 16
Cleaning 17
Part Numbers and Reference Diagrams 18
Wiring Diagram 24
RM3000_2004/03

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ROTA MASTER • RM3000
© Bernhard and Company Limited
Adjusts mist coolant ow rate
Index stop
Adjusts
motor height
and angle
Spark/debris
scoop
‘Quick’ nut
Index stop
Traverse
stop
Locating
cone
Blade
balancer
Spark/debris scoop
mount point
Spark/debris
scoop mount
point
Grind (clockwise)
Left side of stone
Grind (anti-clockwise)
Right side of stone
Task light
(on/off)
Vacuum
(on/off)
Emergency
stop
Auto traverse
(on/off)
Fuses
Anti-rotate
stop
Adjusts blade angle to stone

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ROTA MASTER • RM3000
© Bernhard and Company Limited
1.1 This machine is primarily designed for safe and accurate grinding of rotary mower blades.
It should not be used for any other purpose.
1.2 This machine should be installed, operated and maintained by only competent personnel.
1.3 Before carrying out any work on the machine, other than actual grinding, isolate the
electrical power supply
1.4 Always operate the machine with the guards in place. Always wear adequate eye, ear
and breathing protection.
1.5 Only use grinding wheels recommended for this type of grinding unit, rated at the speed
specied on the grinder identication plate.
1.6 Never leave rags or tools on the machine, or allow combustible materials to accumulate
around the machine.
1.7 Always ensure that the unit to be ground is securely mounted on the machine with no
loose components.
1.8 Always ensure that all electrical connections are sound, with cables safely routed.
1.9 Stay alert. Wear suitable clothing. Never operate the machine when tired or under the
inuence of alcohol or drugs.
1. Safety

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ROTA MASTER • RM3000
© Bernhard and Company Limited
2. Installation
End cap is swapped to
opposite end if grinding on
right hand side of stone
2.3 Connect to a 230-240v 50 Hz mains power supply, OR,
In the USA, to a 220v 60 Hz mains supply with a 30A breaker.
NOTE: (Pre. Oct. 2001 Rotamaster)
USA/ Canada units are connected to 110-120v mains supply.
Motor, vacuum and control gear are 220v.Power is stepped up from 110v to 220v by
the transformer tted into the base of the machine cabinet.
Fig: 2.2
2.1 Having removed the Rota-Master from its packing, the unit should be positioned in a well
lit area, with good ventilation, on a at and solid oor. If required the unit can be bolted
to the oor for added stability.
2.2 Check that the vacuum unit in the cabinet base is turned on (secondary switch on the
vac’ unit) and that the hose is connected to the spark debris collector on the appropriate
side of the grinding head.

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ROTA MASTER • RM3000
© Bernhard and Company Limited
2. Installation (Continued)
Air
regulator
Fig: 2.4
Air supply
connector
Cross (in-feed) of carriage
2.5 Fill the coolant reservoir with
clean water (or water with
a  capful of rust inhibitor
added).
Fig: 2.5 Interior of cabinet:
Coolant and vacuum unit
2.4 Connect to the workshop air supply, set regulator (on right hand side control panel) to
85 – 90 psi (~ 6 bar)

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ROTA MASTER • RM3000
© Bernhard and Company Limited
3. Setting Up
Clockwise Counter-clockwise
3.2.3 Place the blade support over the spigots on the appropriate side of the carriage (so that
the front of the blade should be around ” (6mm) clear of the front of the grind stone when
the carriage is fully out)
Fig: 3.2.2
Fig: 3.2.3
Spigot
3.1 Blade Preparation
3.1.1 Clean the blade. Remove dirt, debris and surface rust from the cutting area of the blade.
Typically use a stiff wire brush.
3.1.2 Carefully examine the blade for cracks. If any cracks are observed SCRAP THE BLADE
– DO NOT ATTEMPT TO SHARPEN IT as cracks can lead to breakages, ying debris
and potential injury.
3.1.3 Check the blade for straightness. If a blade is bent DO NOT SHARPEN IT. DO NOT
STRAIGHTEN A BENT BLADE so that it may be sharpened. This could unduly stress the
blade and lead to breakage at some point in the future.
3.2 Blade Mounting
3.2.1 Switch on the task light.
3.2.2 Determine the cutting direction of the blade (clockwise or counter-clockwise)
A clockwise rotating blade should be sharpened on the left-hand side of the grinding stone.
A counter-clockwise rotating blade should be sharpened on the right-hand side of the
grinding stone.
ROTATION ROTATION
BLADE BLADE

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ROTA MASTER • RM3000
© Bernhard and Company Limited
Spark/debris scoop
Locking knobs
3.2.4 If not yet done, mount the spark/debris scoop on the side of the grind stone guard where
blade grinding is to take place.
The spark/debris scoop is symmetrical and the end bung and vacuum hose are a push t.
These may be removed, the scoop retted to the alternative mounting point, and then the
bung and hose retted.
3. Setting Up (Continued)
Alternate spark/debris mount
Spark/debris
scoop
Mounting for
Spark/debris
scoop

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ROTA MASTER • RM3000
© Bernhard and Company Limited
3.2.5 Place the front of the blade on the front pillow block, as close to the tip as practical (this
may be determined by the shape of the blade – an overhang can be tolerated).
NOTE: Always grind the worst end (most worn/damaged) of the blade rst.
Slide the upper member of the blade support so that the tapered cone will locate in the
mounting hole of the blade:
Alternatively, place the blade over the threaded pin rst, then locate the blade by
positioning the cone from ABOVE the blade:
3. Setting Up (Continued)

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ROTA MASTER • RM3000
© Bernhard and Company Limited
3.2.6 The “quick” nut looks as though it has been badly made! Slide it over the central cone pin’
thread. When it rests on top of the blade tighten, as a normal nut, lightly.
CROSS SECTION:
Thread is removed on one side at ‘A’ and ‘B’.
Tilt nut as shown, slide over thread until it rests on
top of blade.
Tighten as a normal nut.
“QUICK NUT”
3.2.7 Position the assembly clamp
over the support assembly, as
close to the cone axis as
possible (better still around it
as shown).
3.2.8 Position the side/anti-rotate
stop over the clamp as shown
(with the large diameter
“emery” friction washer
between) and tighten the lobed
knob to lock the assembly in
position.
3.2.9 Fully tighten the “quick” nut to
lock the blade in position.
NOTE If the blade is located with the cone beneath, the “quick nut” should be tightened with
it’s at face upwards.
If located with the cone from above, lock in place with the at face of the “quick” nut
downwards.
3. Setting Up (Continued)

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ROTA MASTER • RM3000
© Bernhard and Company Limited
3.2.10 Loosen the locking knob and rotate pivoting top tray (complete with support and blade
assembly), to approximately align the edge to be ground with the carriage axis and lightly
tighten the locking knob.
3. Setting Up (Continued)
Pivot tray
locking lever
Carriage travel axis
Rotate tray so that the blade edge*
aligns with carriage axis
(*Stone edge)
Grindstone

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ROTA MASTER • RM3000
© Bernhard and Company Limited
3.2.11 Slide the carriage in and
wind it across with the feed
handwheel on the right hand
side of the machine, until the
blade edge is close to the
grind stone.
Loosen locking knob on the left hand side of the grinding head and adjust the height of the
grind stone so that it contacts the blade at the angle to be ground.
Locking knob Height/angle adjust:
clockwise raises grindstone,
counter-clockwise lowers grind stone
3. Setting Up (Continued)
3.2.12 Move the carriage in to the
desired depth of cut (length
of blade cutting edge), slide
depth stop in until it pushes the
traverse reverse valve contact
home, and lock it in position
with the wing knob.
Traverse reversing valve
Depth stop
Locking wing knob

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ROTA MASTER • RM3000
© Bernhard and Company Limited
4.1 Ensure that the blade is positioned correctly, clear of the grind stone and that the support
assembly is securely clamped in place. Ensure that the debris/spark catcher is correctly
positioned (just clearing the blade as low as possible to ensure any mist coolant drips into
the pivoting tray).
4.2 Move the feed carriage to it’s fully out position.
4.3 Switch on the vacuum unit.
4.4 Press the relevant start button to select the correct direction of grind stone rotation for the
blade (the grind stone should rotate upwards against the blade cutting edge.
Left hand button = clockwise
stone rotation, clockwise
rotating blade, blade ground on
left hand side of grind stone.
Right hand button = counter-
clockwise stone rotation,
counter-clockwise rotating
blade, blade ground on right
hand side of grind stone.
4.5 Push the carriage in manually and with the feed hand wheel on the right of the machine,
bring the blade across to contact the grind stone.
4.6 Manually move the traverse in and out, whilst (if necessary) pivoting the top tray (complete
with mounted blade) to set even stone contact along the length of the edge to be ground.
4.7 Fully tighten the locking knob on the pivoting top tray.
4.8 Pull traverse control knob
at the front right hand side
of the machine to engage
automatic traverse of blade
past grind stone. The mist
coolant starts automatically.
4. Grinding the Blade

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ROTA MASTER • RM3000
© Bernhard and Company Limited
4.9 Position the infeed stop close
to the side of the carriage (on
the side in which in-feed is to
occur). Estimate the amount of
infeed travel required to nish
sharpen the edge and set the
gap between stop and carriage
the same.
4. Grinding the Blade (Continued)
4.10 Apply a light cut to the blade.
4.11 Engage the automatic infeed
using the lever on the control
panel to the right of the
machine.
Down = feed to the right
(grinding a blade to the
left of the stone).
Up = feed to the left
(grinding a blade to the
right of the stone).
4.12 When the carriage reaches the stop, the infeed will cease and the carriage will continue to
traverse in and out past the grind stone until stopped by the operator.
4.13 Push in control knob to disengage auto traverse and mist coolant, stop the traverse with
the carriage in the out position.
Move the control lever to the central position to disengage the infeed.
Back the blade away from the stone.
4.14 Switch off the grind stone motor and the vacuum.
4.15 Undo the “quick” nut, reverse the blade on the support and re-secure.

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ROTA MASTER • RM3000
© Bernhard and Company Limited
4.16 Place the magnetically
retained “hot guard” over
the edge just completed.
4. Grinding the Blade (Continued)
4.17 Grind the opposite end of the blade as before, until the infeed stop is reached.
4.18 Both ends should now be ground the same, post grind’ balancing should be minimised.
Flow Controls:
These may be used to adjust the speed of movement of the carriage. These do not
generally require adjustment from the factory settings
Flow controls

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ROTA MASTER • RM3000
© Bernhard and Company Limited
(The balancer can be bolted to the left hand side of the unit as shown, tapped holes are
provided in the chassis, or to some other suitable rigid location in the workshop)
5.1 Position the blade centre over
the cone of the balancer and
slide the magnetic holder to the
back of the blade to support it
(Blade MUST be clean).
5.2 Rotate the blade to a horizontal
attitude, then carefully release
it. If one end of the blade drops,
indicating that end is heavier, the
blade is out of balance.
5.3 Replace the blade on the machine and remove more material from the cutting edge at
the heavy end. Re-check on the balancer (and re-grind as necessary) until balance is
achieved.
5. Blade Balancing

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ROTA MASTER • RM3000
© Bernhard and Company Limited
DO NOT SWITCH ON THE GRIND STONE MOTOR WHEN THE GRINDER HOOD IS
TILTED BACK (OPEN).
6.1 Loosen the two securing knobs and tilt back the hub.
6.2 Remove the vacuum hose from the transfer pipe on top of the grinding head. Attach the
cleaning pipe/nozzle.
6.3 Switch on the vacuum and use the hose to clean up any debris not collected during
grinding.
6.4 Switch of the vacuum and re-connect the hose to the transfer pipe as before.
6.5 Close the hood and secure with the locking knobs.
NOTE: Regularly remove the vacuum unit from the base cabinet and empty it, replacing the lter
as necessary, since efciency drops dramatically with clogged lters.
The surface of the lter can be blown clean with a compressed air gun many times before
replacement is necessary, provided that cleaning occurs on a regular basis (Ensure that
safety spectacles/goggles are worn when blowing off a lter).
6. Cleaning

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ROTA MASTER • RM3000
© Bernhard and Company Limited
7. Parts List
Ref # Name of Part Qty. Part #
ROTAMASTER BASE ______________________________________________________
1 Rotormaster Cabinet ................................................................1 A6381
2 Door..........................................................................................1 A6358
3 Vacuum.....................................................................................1 A6027
4 Vacuum Hose 2.2m..................................................................1 A6782
5 Vacuum Extension ...................................................................1 A6796
6 Vacuum Bag .............................................................................2 A6797
7 Cabinet Aperture Trim 800mm.................................................1 A4207
8 Door Magnet.............................................................................2 A6704
9 Auto Transformer......................................................................1 A8033
18
7
ROTAMASTER BASE
34 5 6
9
2

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ROTA MASTER • RM3000
© Bernhard and Company Limited
7. Parts List (Continued)
Ref # Name of Part Qty. Part #
ROTAMASTER CHASSIS __________________________________________________
1 Rotor Chassis........................................................................................... 1 A4100
2 M12 x 80mm dia Lobed Knob .................................................................. 1 A6140
3 M6 x 40mm dia Lobed Knob.................................................................... 2 A6141
4 Lateral Traverse Stop Rod ....................................................................... 1 A9131
5 Push on Fix Washer ................................................................................. 1 A5425
6 Lateral Traverse Stop............................................................................... 2 A4206
7 Wing Knob M6 x 15.................................................................................. 2 A6129
8 Motor Height Adjuster Pivot ..................................................................... 1 A4205
9 Carriage Upper ....................................................................................... 1 A6354
10 Hood ......................................................................................................... 1 A6355
11 Handle ...................................................................................................... 1 A6108
12 Carriage Lower......................................................................................... 1 A4201
13 Pneumatic Cylinder 25 x 250................................................................... 1 A6777
14 Elbow 1/8”BSP – 8mm............................................................................. 1 A6780
15 Bearing 628zz .......................................................................................... 7 A7723
16 5/2 Direction Valve Tappet / Tappet ........................................................ 1 A6865
17 Makrolon Spark Guard............................................................................. 1 A6781
18 M5 x 10 Button Head Screw .................................................................... 5 A5129
19 Electrical Panel ........................................................................................ 1 A6361
20 M5 x 10 Button Head Screw .................................................................... 3 A5129
21 Index Ratchet Gear .................................................................................. 2 A4328
22 Traverse Feedscrew................................................................................. 1 A9192
23 Pneumatic Cover Panel ........................................................................... 1 A6434
24 M10 Lobe Knob ........................................................................................ 1 A6139
25 Height Adjuster Guide.............................................................................. 1 A4204
26 Captive Nut............................................................................................... 1 A9130
27 Reversing Bracket .................................................................................... 1 A4273
28 Button Head Socket Screw M5 x 10 ....................................................... 2 A5129
29 Nut M5 ...................................................................................................... 2 A5512
30 Stroke Stop............................................................................................... 1 A4274
31 Stop Collar ............................................................................................... 1 A9163
32 Rubber Buffer........................................................................................... 2 A6180
33 Mounting Bar Upper................................................................................. 1 A4209
34 Mounting Bar Lower ................................................................................. 1 A4332
35 Blade Mounting Bar Clamp...................................................................... 1 A4208
36 Front Support Block (early version)......................................................... 1 A4211
37 Grub Screw M4 x 6 .................................................................................. 1 A4213
38 Back Rest ................................................................................................. 1 A4212
39 Quick Nut.................................................................................................. 1 A4214
40 Centre Cone ............................................................................................. 1 A9133
41 Centre Cone Spring ................................................................................. 1 A6792
42 Diamond Dresser ..................................................................................... 1 A6737
43 Wing Knob M6 x 15................................................................................. 1 A6142
44 Cap Head Socket Screw M6 x 40............................................................ 1 A5154
45 Cap Head Socket Screw M6 x 12............................................................ 1 A5171
46 Washer M6 ............................................................................................... 1 A5320
47 Handwheel 100 dia .................................................................................. 1 A6138
48 Spring ....................................................................................................... 1 A6912
49 Pawl.......................................................................................................... 2 A4331
50 M10 Feed Nut........................................................................................... 1 A9130
51 Cap Head Socket Screw M6 x 20 ............................................................ 1 A5150
52 M10 Locknut ............................................................................................. 2 A5503
53 M10 Double Coil Spring Washer.............................................................. 1 A5309
54 M10 Washer ............................................................................................. 1 A5310
55 3/2 Lever Roller Valve.............................................................................. 1 A6872
56 Microswitch Cam...................................................................................... 1 A9234
57 Grub Screw M4 x 6 .................................................................................. 1 A5190
58 Blade Alignment Clamp ........................................................................... 1 A4339
59 Friction Washer ........................................................................................ 1 A6904
60 Pivoting Top Plate .................................................................................... 1 A6443
61 Kip Lever M6 (female).............................................................................. 1 A6124
62 Spring ....................................................................................................... 2 A6792
63 R Clip........................................................................................................ 1 A6728
64 Side Stop Plate ........................................................................................ 1 A4390
65 Grub Screw M4 x 6 .................................................................................. 1 A5190
66 Locking Nut M8 ........................................................................................ 1 A6179
67 Knob M8 x 45 ........................................................................................... 1 A6192
68 Hex Half Nut M8 ....................................................................................... 1 A5229
69 Side Stop Disc ......................................................................................... 1 A9278
70 Front Support Block (latest m/cs) ............................................................ 1 A4336
71 Pad (latest m/cs) ...................................................................................... 1 A4373
72 C’s’k Screw M6 x 12................................................................................. 1 A5237
73 Pan Head Screw M3 x 20 ........................................................................ 2 A5430
74 Diamond Dresser Mounting Block........................................................... 1 A4333
75 Fluorescent Lamp (not shown) ................................................................ 1 A8799

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ROTA MASTER • RM3000
© Bernhard and Company Limited
7. Parts List (Continued)
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