MasterCraft MTHC16EHR-3450 Guide

READ & FOLLOW ALL INSTRUCTIONS,
WARNINGS & CAUTION
BEFORE USING THIS FLOOR MACHINE
This floor machine will afford you many years of
trouble free operating satisfaction if it is given
proper care. All parts have passed rigid quality
control standards before being assembled to pro-
duce the finished product. Prior to packaging,
units are again inspected for assurance of flawless
operation.
This floor machine was protectively packed to
prevent damage in shipment. We recommend
that upon delivery, remove the unit from its car-
ton and carefully inspect it for any possible dam-
age in transit. A warranty card is affixed to the han-
dle. It is your responsibility to fill it out and send it
to our office to register your purchase and start
your warranty. Failure to send us this card in one
week upon receipt of the machine may void the
warranty.
If damage is discovered, immediately notify the
transportation company that delivered your floor
machine. As a shipper, we are unable to act upon
any claim for concealed damage. You must origi-
nate any claim within 5 days of delivery.
These instructions are for your protection and
information. PLEASE READ CAREFULLY!
Failure to follow these precautions could result in
injury or discomfort.
Treat this floor machine as you would any other
high grade precision made product. Throwing,
dropping, unreasonable bumping across thresh-
olds and other misuse may result in a damaged
unit and invalidate the warranty.
PLEASE READ
CAREFULLY
BEFORE
OPERATING
PAGE 1
SAVE THESE INSTRUCTIONS
PN 493538 Rev B - MTHC16EHR-3450 Floor Machine - Printed in USA 12/18/07
MTHC16EHR-3450
MULTI-PURPOSE
FLOOR MACHINE
SAFETY, OPERATION &
MAINTENANCE
MANUAL
W/PARTS LIST
TThhiissuunniittiissiinntteennddeeddffoorrccoommmmeerrcciiaalluussee..
Parts and Service Center
777 South Street
Newburgh NY 12550-0606
TTeell::845.565.6623
FFaaxx::845.565.8894

GROUNDING
INSTRUCTIONS
Improper connection of the equipment-grounding conductor can result in a risk of electrical shock. Check with a qualified electrician
or service person if you are in doubt as to whether the outlet is properly grounded. DO NOT modify the plug provided with the
machine. If it will not fit the outlet, have a proper outlet installed by a qualified electrician.
NOTE: In Canada, the use of a temporary adaptor is not permitted by the Canadian Electrical Code.
WARNING
IMPORTANT
SAFETY
INSTRUCTIONS To reduce the risk of fire, electric shock or injury;
Read all instructions before using this floor machine.
WARNING:
Improper use of the grounding plug can result in a risk of electrical shock.
DANGER:
1) DO NOT leave the floor machine plugged
in when not in use. Unplug from the outlet
when not in use and/or before servicing.
2) Electric shock could occur if exposed to
rain. Store indoors.
3) This is NOT a toy. Close attention is nec-
essary when used around or near children.
4) Use only as described in this manual. Use
only manufacturer's recommended attach-
ments.
5) DO NOT pull or carry by cord, use power
cord as a handle, close a door on cord, or
pull cord around sharp edges or corners. DO
NOT run machine over cord. Keep cord
away from heated surfaces.
6) DO NOT use with damaged cord plug. If
the floor machine is not working as it should
because it has been dropped, damaged, left
outdoors, or dropped into water, contact the
manufacturer or authorized service center.
7) DO NOT use an extension cord.
8) DO NOT handle the plug or operate with
wet hands.
9) DO NOT put any object into the motor
openings.
10) DO NOT unplug by pulling on cord. To
unplug, grasp plug, not the power cord.
11) Keep hair, loose clothing, fingers and all
parts of body away from moving parts.
12) DO NOT use an optional vacuum with-
out manufacturer’s filters in place.
13) DO NOT operate where anesthetics
and oxygen are used.
14) DO NOT use around flammable or
combustible liquids such as gasoline or use
in areas where they may be present.
1155))Replace damaged or worn parts imme-
diately with genuine manufacturer’s equip-
ment parts to maintain safety and protect
your limited warranty.
16) Floor sanding can result in an
explosive mixture of fine dust and air.
Use a floor sanding machine only in a
well ventilated area.
17) DO NOT to leave sawdust in the
filter bag when sander is not in use,
this is a fire hazard.
This floor machine must be connect-
ed to a properly grounded outlet only.
(See grounding method below.)
This unit must be grounded. If it should malfunction
or breakdown, grounding provides a path of least
resistance for electrical current to reduce the risk of
electric shock. This machine is equipped with a
cord having an equipment-grounded plug. The plug
must be inserted into an appropriate outlet that is
properly installed
and grounded in accordance with all local codes
and ordinances
If repair or replacement of the cord or plug is neces-
sary, DO NOT connect the grounding wire to either
flat blade terminal. The wire with insulation having
an outer surface that is green with or without yellow
stripes is the grounding wire.
This floor sander is for use on a nominal 120 volt
circuit, and has a grounding plug that looks like the
plug illustrated in (Fig A). A temporary adaptor that
looks like the adaptor illustrated in (Fig B & C) may
be used to connect the plug to a 2-pole receptacle
as shown in (Fig A) if a properly grounded outlet is
not available.
The temporary adaptor should be used only until a
properly grounded outlet (Fig A) can be installed by
a qualified electrician. The green color rigid ear, lug,
or like extending from the adaptor must be connect-
ed to a permanent ground such as a properly
grounded outlet box cover. Whenever the adaptor is
used, it must be held in place by the metal screw
(Fig C).
GROUNDING METHODS
PAGE 2

DO NOT attempt to operate this machine if it is not fully assembled.
When servicing or replacing an accessories turn OFF the machine
and disconnect from power source.
To start operating, tilt machine back on transport wheels, turn ON
machine and carefully lower machine onto the working surface.
1) Clear the floor of any materials or objects.
2) Select and install the accessory set
required for the job. (See above for installa-
tion instructions.)
3) Move handle from the upright “storage”
position to the angled “operating” position
and lock in place with the quick release pin.
4) Place your hands on the handle grips tilt
sander back on the transport wheels.
5) Engage the safety trigger and trigger lock
beneath the right handle grip.
6) When the machine is running, carefully
lower it onto the working surface and
release the trigger lock.
7) To stop the machine release the safety
trigger and it will automatically turn OFF.
8) Move the machine side-to-side while
maintaining a steady, consistent pace with
the machine.
9) When not in use a set of attachments
MUST be left on the sander to protect the
heads.
Note: If the machine unexpectedly shuts
down due to a circuit overload, before
restarting the wait 30 seconds, then press
the reset button .
When installing or changing the accessories, turn OFF the sander
and disconnect the power cord from the electrical outlet.
Before Installation or Changing of
Attachments:
1) Unplug the sander from the wall outlet.
2) Ensure handle is in the storage position
(straight up) and locked in place with the
quick release pin.
3) Tilt machine back by bracing it with your
foot until the handle is laying on the floor and
the three heads are fully exposed.
NNoottee::It is recommended that a towel or pad is
placed under the machine to protect the floor.
Changing and Installation the
Attachments
1) Position the first attachment head at 12
o’clock.
2) Using both hands, reach beneath the bot-
tom side of the attachment and pull up
towards yourself to free it from the sander.
3) Select the attachment required for the
job, and line up the holes on the attachment
with the four metal pins protruding from
each of the three heads.
4) Push the attachments on by hand and if
necessary, carefully tap it into place with a
rubber mallet.
5) Repeat steps 1 thru 4 with the remaining
2 attachments.
6) Carefully raise the handle, supporting the
axle with your foot to control the head of the
machine as it is placed on the floor.
7) Since the attachments are different
heights you may need to adjust the dust
skirt to make sure it is level with the attach-
ments. This will ensure clean and virtually
dust-free operation.
9) To adjust skirt, align the skirt with the cen-
ter of the machine and wrap it around.
10) Move the handle back to the operating
position and lock in place with the quick
release pin.
When installing or removing attachments, always wear protective gloves and start at the 12
o’clock position.
ATTACHMENTS
INSTALLATION &
CHANGING
CAUTION:
PAGE 3
CAUTION:
FLOOR
MACHINE
OPERATION
INSTRUCTION

MTHC16EHR-3450
16” HANDLE/BASE
ASSEMBLY DRAWING &
PARTS LIST
SWITCH BOX
ASSEMBLY
_________________________________
Ref Part Description Qty Part
No No
_________________________________
1 Rubber Handle Grip 2 490180
2 Strain Relief Assembly 1 425427
3 30 Ft Power Cord w/Plug 1 491160
4 Handle Assembly 1 495840
5 Quick Release Pin w/Cable 1 456896
6 Wire Retainer 1 479152
7 Bronze Bushing 2 491055
8 .37-16 X
1
/ 2 ” Shoulder Bolt 2 491063
9 Motor Cord w/Female Plug 1 490210
10 Wheel Base Assembly 1 493716
11 6” X 2” Wheel 2 490903
12 Palnut 2 490881
13 20 AMP Circuit Breaker 1 217166
14 Trigger Lock 1 390119
15 Plastic Trigger Kit 1 386839
_________________________________
_________________________________
Ref Part Description Qty Part
No No
_________________________________
16 Trigger 1 385654
17 Small Trigger Spring 1 376671
18 Large Trigger Spring 1 383147
19 80-32 X
5
/ 8 ” Screw 1 374075
20 Roll Pin 2 383139
21 .10-24 X .63 Shoulder Screw 1 495875
22 #6 Int Tooth Lockwasher 2 355224
23 6-32 X.87 Screw 2 335576
24 Micro Switch 1 469637
25 Leaf Spring 1 335584
26 Micro Switch 1 495867
27 Vinyl Cap 1 459933
28 Mounting Bracket 1 495824
29 .25-20 X
1
/ 2 ” Screw 1 413291
30 Switch Box Plate 1 493481
_________________________________
PAGE 4

MTHC16EHR-3450
16” OUTER BOWL
DRAWING &
PARTS LIST
_______________________________
Ref Part Description Qty Part
No No
_______________________________
11
1
/ 2 HP Motor, 3450 RPM’s 1 491608
2 Rivet 2 374768
3 Spacer 1 490873
4 Recess Plug 1 490865
5 20# Weight 1 491691
6 Nyloc Nut 3 380784
7 Weight Knob 3 491632
8 Bowl Handle 2 492051
9 16” Outer Bowl Assembly 1 474827
10 Velcro Strip 1 491659
11 Rubber Dust Skirt 1 491640
12
1
/ 2 -20 X
5
/ 8 ” Screw 4 457310
13
1
/ 4 -20 X .75” Screw 3 342831
14 .37 Washer 4 327433
15 1
3
/ 4 ” External Snap Ring 1 491292
16 Felt Gasket 1 450073
17 .37-16 X 1” Bolt 4 368830
_______________________________
PAGE 5

PAGE 6
___________________________________
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NNooNNoo
___________________________________
12
7
/ 8 Internal Snap Ring 1 490598
2 Bearing (6009-2RS) 2 490563
3 Large Bearing Spacer 1 490571
4 Outer Pulley Shaft 3 490547
5 16” Inner Bowl 1 490407
6 Center Cog Pulley 1 494836
7 Shaft Spacer 3 490555
81
1
/ 2 Internal Snap Ring 3 490466
9 Ball Bearing w/Seals 6 464910
10 Small Bearing Spacer 3 490474
11 Flange 1 490989
12 Low Profile Bolt 1 490997
13 3” ID x 6” OD Ring 3 222828
14 #10-32 x .5 Phillips Screw 9 377201
___________________________________
___________________________________
RReeffPPaarrttDDeessccrriippttiioonnQQttyyPPaarrtt
NNooNNoo
___________________________________
15 Accessory Pins 12 490458
16 .62-11 Nylock Nut 3 490628
17 Washer 3 490636
18 Felt Gasket 3 491373
19 Aluminum Ring 3 490652
20 Pop Rivet 12 456918
21 .25-20 x .5 Phillips Screw 9 331740
22 #14, .43”OD Lockwasher 9 491012
23 Aluminum Cover Plate 1 490644
24 Belt (210-L050) 3 494089
25 48 High Tooth Pulley 1 490512
26 48 Middle Tooth Pulley 1 490490
27 48 Low Tooth Pulley 1 490415
___________________________________
MTHC16EHR-3450
16” INNER BOWL
DRAWING &
PARTS LIST

MACHINE
MAINTENANCE
1) Unplug the machine.
2) After each use, wipe off machine with a
clean cloth.
3) Empty the vacuum you are using in
accordance with specific manufacturer’s
safety & operation instructions.
3) Check for loose parts and fasteners.
4) Check the power cord for any breaks in
the wire. Breaks will most likely occur near
the plug or switch. Repair or replace any
breaks immediately.
1) Unplug the
motor power
cord from the
handle.
2) Pull the speed pin from the handle and
remove the handle. Carefully set aside the
handle.
3) Turn sander chassis upside down on a
table resting on the motor cover.
4) Remove pads/attachments (see page 3
for instructions.)
5) Remove the 9 Flat head screws and
beveled washers from cover plate.
6) Remove the cover plate from inner bowl.
7) Vacuum up the dust and debris from inner
bowl.
8) Remove the old belt or belts by pulling
upwards and and roll off using a screwdriver
while turning the pulley.
9) Roll new belt or belts back on the pulley.
10) Reassemble the machine reversing the
above steps.
BELT CHANGING INSTRUCTIONS
VACUUM
OPERATING
INSTRUCTIONS
IF THIS FLOOR MACHINE IS USED FOR SANDING,
DO NOT LEAVE SAWDUST IN THE FILTER BAG WHEN THE
MACHINE IS NOT IN USE. THIS IS A FIRE HAZARD.
This machine can be used with a variety of
vacuums to pick up wood and concrete
dust.
Operation of the vacuum cleaner must be in
accordance with the specific manufacturer’s
safety & operation instructions.
Recommend separate dedicated power
source for machine and vacuum.
The vacuum hose must be attached to the
1
1
/ 2 ” hose barb on the outer bowl of the
floor machine.
During operation, periodically check the
vacuum. When the cloth or paper filter bag
is
3
/ 4 full or dust is forming around the bot-
tom of the machine, it MUST be emptied.
GENERAL SAFETY
PRECAUTIONS
This machine is designed for surfacing concrete and sanding wood floors.
All operators and maintenance personnel should read and
understand the safety procedures with this floor machine.
1) All personnel in the immediate work area
must wear safety glasses with side shields
whenever the machine is in operation.
Protective clothing is also recommended.
Long sleeve shirts and safety shoes should
be worn. Avoid wearing loose clothing.
2) DO NOT attempt to service or replace
attachments while the machine is running or
connected to a power source.
3) DO NOT operate this machine in the rain
or in areas where liquids could enter the
electrical components of the machine.
4) Keep the power cord away from the
revolving heads to avoid damage.
5) Check the main power supply to assure
that you are connecting the equipment to a
proper dedicated service.
WARNING:
CAUTION:
PAGE 7

PN 493538 Rev B - MTHC16E-3450 Floor Machine - Printed in USA 12/18/07
We guarantee to the original purchaser this floor
machine against defects in material and work-
manship for a period of 1 year from the date of
delivery. Please note the following conditions per-
taining to this warranty.
1) This warranty does not apply to any repair aris-
ing by reason of misuse, neglect, or abuse, or to
proprietary parts.
2) Applies only to the original owner and is not
transferable.
3) Machine will not have been dismantled or
tampered with in any way.
4) Covered components proven defective will be
repaired or replaced at no charge. Covered
components include motors, bearings, belts and
switches.
5) This Warranty is in lieu of and excludes every
condition or warranty not herein expressly set out
and all liability for any form of consequential loss
or damage is hereby expressly excluded.
6) This Warranty is limited to repair or replace-
ment of covered components and reasonable
labor expenses.
PROBLEM: Motor will not run.
POSSIBLE CAUSE POSSIBLE SOLUTION
1) Defective switch. 1) Check switch, replace if defective.
2) Defective power cord or wiring. 2) Check and replace if defective.
3) Defective motor. 3) Have motor checked by an authorized service center.
4) Blown fuse or tripped circuit 4) Replace fuse or reset circuit breaker. If this does
breaker at the wall panel. not correct the problem, have the sander checked by
an authorized service center.
5) Power cord not plugged in 5) Plug in power cord properly or replace power cord
properly or damaged. if damaged.
PROBLEM: Machine bogs down and runs slow.
POSSIBLE CAUSE POSSIBLE SOLUTION
1) Defective capacitor or switch. 1) Have machine checked by an authorized
service center.
2) Circuit may be overloaded with 2) Plug floor machine into a dedicated power outlet. If the
more than one appliance. problem still exists there could be a short. Have the
floor machine checked by an authorized service center.
3) Low line voltage in building. 3) If wiring is old in the building have voltage
checked by the power company.
PROBLEM: Motor runs, driver will not rotate.
POSSIBLE CAUSE POSSIBLE SOLUTION
1) Belt is broken. 1) Replace belt.
PROBLEM: Noisy machine or vibration.
CAUSE POSSIBLE SOLUTION
1) Defective motor. 1) Contact the manufacturer or authorized service center.
2) Attachment is not level or 2) Level attachment and make sure all fasteners
securely attached. are secure.
TROUBLE
SHOOTING
GUIDE
PAGE 8
WARRANTY
INFORMATION