Central Machinery 91977 User manual

3/8” Reversible Air Drill3/8” Reversible Air Drill
3/8” Reversible Air Drill3/8” Reversible Air Drill
3/8” Reversible Air Drill
ASSEMBLY AND OPERATING INSTRUCTIONS
3491 Mission Oaks Blvd., Camarillo, CA 93011
Visit ourWeb site at http://www.harborfreight.com
Copyright © 2004 by Harbor Freight Tools®. All rights reserved. No portion of this
manual or any artwork contained herein may be reproduced in any shape or form
without the express written consent of Harbor FreightTools.
Fortechnicalquestions,pleasecall1-800-444-3353
91977
®

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Specifications
Save This Manual
You will need the manual for the safety warnings and precautions, assembly
instructions, operating and maintenance procedures, parts list and diagram. Keep
your invoice with this manual. Write the invoice number on the inside of the front
cover. Keep the manual and invoice in a safe and dry place for future reference.
Safety Warnings and Precautions
WARNING: When using tool, basic safety precautions should always be fol-
lowed to reduce the risk of personal injury and damage to equipment.
Read all instructions before using this tool!
1. Keep work area clean. Cluttered areas invite injuries.
2. Observe work area conditions. Do not use machines or power tools in
damp or wet locations. Don’t expose to rain. Keep work area well lit. Do not
use electrically powered tools in the presence of flammable gases or liquids.
3. Keep children away. Children must never be allowed in the work area. Do
not let them handle machines, tools, or extension cords.
4. Store idle equipment. When not in use, tools must be stored in a dry
location to inhibit rust. Always lock up tools and keep out of reach of children.
5. Use the right tool for the job.Do not attempt to force a small tool or
attachment to do the work of a larger industrial tool.There are certain
applications for which this tool was designed.It will do the job better
and more safely at the rate for which it was intended.Do not modify this
tool and do not use this tool for a purpose for which it was not intended.
6. Dress properly. Do not wear loose clothing or jewelry as they can be caught
in moving parts. Protective, electrically non-conductive clothes and non-skid
footwear are recommended when working. Wear restrictive hair covering to
contain long hair.
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SKU91977 Page 3
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7. Use eye and ear protection. Always wear ANSI approved impact safety
goggles.Wear a full face shield if you are producing metal filings or wood
chips.Wearan ANSI approveddust mask orrespirator when workingaround
metal, wood, and chemical dusts and mists.
8. Do not overreach. Keep proper footing and balance at all times. Do not
reachoveror across running machines.
9. Maintain tools with care. Keep tools maintained and clean for better and
saferperformance.Followinstructions for lubricating andchanging
accessories.Inspect tool cords periodically and, if damaged, have them
repaired by an authorized technician.The handles must be kept clean, dry,
and free from oil and grease at all times.
10. Disconnect air power.Disconnect tool from air supply when not in use.
11. Remove adjusting keys and wrenches. Check that keys and adjusting
wrenchesareremovedfromthe tool or machineworksurfacebefore
connecting air supply.
12. Avoid unintentional starting. Be sure the trigger is in the Off position when
not in use and before connecting it. Do not carry any tool with your finger on
the trigger, whether it is connected to the air supply or not.
13. Stay alert. Watch what you are doing, use common sense.Do not operate
any tool when you are tired.
14. Take caution as some woods contain preservatives such as copper
chromium arsenate (CCA) which can be toxic.When drilling these materials
extra care should be taken to avoid inhalation and minimize skin contact.
15. Check for damaged parts. Before using any tool, any part that appears
damaged should be carefully checked to determine that it will operate
properly and perform its intended function.Check for alignment and binding
of moving parts;any broken parts or mounting fixtures; and any other
condition that may affect proper operation.Any part that is damaged should
be properly repaired or replaced by a qualified technician.Do not use the tool
if any switch does not turn On and Off properly.
16. Replacement parts and accessories. When servicing, use only identical
replacement parts.Use of any other parts will void the warranty.Only use
accessories intended for use with this tool.Approved accessories are
availablefromHarbor FreightTools.
17. Do not operate tool if under the influence of alcohol or drugs. Read
warning labels on prescriptions to determine if your judgment or reflexes are
impaired while taking drugs. If there is any doubt, do not operate the tool.

SKU91977 Page 4
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18. Maintenance. For your safety, service and maintenance should be performed
regularlyby aqualified technician.
19. Always secure the workpiece with a vise, or other appropriate means. Never
holdthe workpiece byhand when drilling.
Warning:Thewarnings,cautions,andinstructions discussed in this instruction
manual cannot cover all possible conditions and situations that may occur. It
must be understood by the operator that common sense and caution are fac-
tors which cannot be built into this product, but must be supplied by the opera-
tor.
Unpacking
When unpacking, check to make sure the following parts are included.
Air Drill with 3/8” Chuck
Chuck Key
If any parts are missing or broken, please call Harbor FreightTools at the number
onthe coverof this manual.
Operation
1. Install a standard 1/4” Air Connector (not included) to the Air Inlet (28). First
wrapthe threaded portion of the1/4” airconnector withpipe thread seal tape
before threading it into the Air Inlet (28).Tighten securely.
2. Attach a standard quick connector (not included) to your 3/8” i.d. air pressure
source hose.Then attach the air hose to the Air Drill.
NOTE: If you are not using an automatic in-line oiler, add a few drops of pneumatic
oil to the Air Inlet (28) before attaching the air hose. Add a few more drops of oil
aftereveryhourof continual use.
WARNING: Some dust created by power sanding,sawing,grinding,
drilling, and other construction activities, contain chemicals known [to
the State of California] to cause cancer, birth defects or other reproduc-
tive harm. Some examples of these chemicals are:
* Lead from lead-based paints
* Crystalline silica from bricks and cement or other masonry products
* Arsenic and chromium from chemically treated lumber
(California Health & Safety Code 25249.5, et seq. )

SKU91977 Page 5
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2. Set the air pressure regulator at 90 psi.
WARNING: Donot exceedthe recommended pressureof 90psi.Damage to your
tool, and possible personal injury may result.
3. Check the air line and its connections for air leaks. Make note of these, and
repairthem before using this tool.
NOTE: Turnoffyour air compressorand disconnect theairpressure hose before
changing bits or making any adjustments to this tool.Severe injury or property
damagemayotherwise result.
WARNING:Thistoolgeneratesconsiderabletorquewhenin use.Alwaysholdthe
tool with both hands when using, and brace yourself to resist the torque which will
bedelivered to thework piece.
4. Select the appropriate size drill bit (not included) for your needs. The Chuck
may be opened and closed using the Chuck Key (see photo). Turn the Chuck
Key counterclockwise to open, and clockwise to close the Chuck.
5. Insert the base of the drill bit into
the Chuck (16). With the bit in
place, tighten the Chuck with the
Chuck Key until the bit is
securelyheld.
6. Movethe Direction Switch(30) to
the LEFT to drill clockwise, move
the Direction Switch (30) to the
RIGHTtodrill counterclockwise.
NOTE: In most cases, drill bits
aredesigned tobore intothe work
material turning clockwise, and to
reverseoutof the work material
byturning counterclockwise.
AirDrill

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7. Place the point of the drill bit at the spot you wish to drill. When it is safe to do
so, squeeze the Trigger (24). The Drill will begin to operate, and the drill bit will
begin to drill into the work material. Drill until you have reached the desired
depth.Release the Trigger(24) tocease operation ofthe drill.
WARNING:Thisdrilloperatesat non-variablespeed.Thatmeans oncetheTrigger
is squeezed it will begin to operate at full speed. When the trigger is released it will
stop operating. Be prepared for the drill to operate at full speed immediately
when the trigger is squeezed.
8. In most cases, you will be able to simply retract the drill bit from the hole. If
the bit can not be easily pulled out of the hole, move the Direction Switch (30)
tothe RIGHT toreverse direction ofthe drill. Squeezethe Trigger(24) to
operate the drill, and pull the bit out of the hole as it rotates counterclockwise.
NOTE:To extend the life of your tool, wait for the drill to stop rotating before moving
the Direction Switch to reverse direction. Operating the Direction Switch while
the drill is still turning may cause damage to the tool.
9. When you are done, disconnect the Drill from the air supply, and store it
properly.
Maintenance
1. After each use, wipe the tool with a clean cloth to remove any dirt, oil or other
contaminants.
2. If an automatic oiler is not being used, always add a few drops of pneumatic
oil(availablefrom HarborFreightTools) to the airline beforeeachuse.
3. After each use, drain any collected water from the air compressor tank, air
lines and filter.Before each use recheck these to be sure they are dry.
Accumulatedmoisture cancause rustingand corrosionof your compressed
airequipment.

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Parts List
NOTE: Some parts are listed and shown for illustration purposes only and are not
available individually as replacement parts.
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SKU91977 Page 8
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PLEASE READTHE FOLLOWING CAREFULLY
THE MANUFACTURER AND/OR DISTRIBUTOR HAS PROVIDED THE PARTS DIAGRAM
IN THIS MANUAL AS A REFERENCE TOOL ONLY. NEITHER THE MANUFACTURER
NOR DISTRIBUTOR MAKES ANY REPRESENTATION OR WARRANTY OF ANY KIND TO
THE BUYER THAT HE OR SHE IS QUALIFIED TO MAKE ANY REPAIRS TO THE
PRODUCT OR THAT HE OR SHE IS QUALIFIED TO REPLACE ANY PARTS OF THE
PRODUCT. IN FACT, THE MANUFACTURER AND/OR DISTRIBUTOR EXPRESSLY
STATESTHATALLREPAIRSANDPARTSREPLACEMENTSSHOULDBEUNDERTAKEN BY
CERTIFIEDANDLICENSEDTECHNICIANSANDNOTBYTHEBUYER.THEBUYERAS-
SUMESALLRISKANDLIABILITYARISINGOUTOFHISORHERREPAIRSTOTHEORIGI-
NALPRODUCTORREPLACEMENTPARTSTHERETO,ORARISINGOUTOFHISORHER
INSTALLATIONOFREPLACEMENTPARTSTHERETO.
Assembly Drawing