Bosch GCM12SD - User Manual

The operation of any power tool can result in foreign objects being thrown into the eyes, which can result in se- vere eye damage. Always wear safety goggles that comply with ANSI Z87.1 (shown on pack age) be- fore commencing power tool operation. 6 SAVE THESE INSTRUCTIONS Additional Safety Rules GF...

7 Double Insulated Tools Double insulation is a design concept used in electric power tools which eliminates the need for the three wire grounded power cord and grounded power supply system. It is a recog- nized and approved system by Underwriter’s Laboratories, CSA and Federal OSHA authorities. IMP...

8 Symbols Important: Some of the following symbols may be used on your tool. Please study them and learn their meaning. Proper interpretation of these symbols will allow you to operate the tool better and safer. Symbol Designation / Explanation V Volts (voltage) A Amperes (current) Hz Hertz (frequen...

21 20 19 22 18 17 16 14 13 12 ! 15 11 9 8 6 29 7 5 4 10 9 8 23 24 25 27 26 28 1 2 3 30 31 10 Getting To Know Your Miter Saw 2610051827 GCM12SD 08-18.qxp_GCM12SD 9/19/18 2:51 PM Page 10

12 Getting To Know Your Table Saw 32. Depth Stop Screw – Turn the knob end to adjust the blade depth for cutting grooves. 33. Depth Stop Plate – Plate can be swung out to limit the depth of the blade travel. 34. Pivot Post – Provides support for the saw head, dust collection system and other functio...

13 Unpacking And Checking Contents Unpacking the Miter Saw – When removing this tool from packaging materials, reach down to the two side carry-handle locations and slowly lift until it clears the package. To avoid severe pinching, never lift or move this saw by gripping any component of the mech- a...

14 Tools Needed For Assembly Combination Square 6/4mm Hex Key (supplied) #2 Phillips Screwdriver NOTE: A 6mm and a 4mm hex key can be substituted for the supplied 6/4mm hex key. no gap or overlap 2. Flip square (shown in dotted position) 3. Check edge of flipped square against the drawn line. There ...

Assembly 15 To avoid possible injury, disconnect plug from power source before performing any assem- bly, adjustments or repairs. Attaching the Miter Lock Knob – Locate the miter lock knob from among the loose parts. 1. Look under the turntable’s front arm above the lock lever and locate the 10mm ho...

16 Assembly To avoid possible injury, disconnect plug from power source before performing any assem- bly, adjustments or repairs. Moving Guard Assembly 1. Position the saw in the UP position and at 0° bevel. If in the DOWN position, press down slightly on the saw head assembly and pull out the head ...

To avoid possible injury, disconnect plug from power source before performing any assem- bly, adjustments or repairs. The dust collection system used on this tool is unique because it is not attached to the upper guard. This placement provides superior dust collection for the majority of cuts. When ...

20 Adjustments To avoid possible injury, disconnect plug from power source before performing any assem- bly, adjustments or repairs. Head Assembly Lock Pin The head assembly lock pin (item 43 - page 12) is located on the right side of the pivot post (item 34 -page 12). It is used to hold the saw’s h...

21 Adjustments Using the Mechanism Lock Lever To avoid possible injury, disconnect plug from power source before performing any assem- bly, adjustments or repairs. Mechanism Lock Lever The lock lever (item 27 - page 11) is located on the rear left side of the mechanism. When engaged, it locks the sy...

22 Adjustments Depth of Cut Adjustment To avoid possible injury, disconnect plug from power source before performing any assem- bly, adjustments or repairs. When a new blade is installed, it may be neces- sary to check the clearance of the blade to the turntable structure. The depth stop plate is a ...

23 Adjustments Miter Detent System – Adjustment Procedure To avoid possible injury, disconnect plug from power source before performing any assem- bly, adjustments or repairs. Calibrating Miter Detent System 1. Engage the miter detent at the 0° position. Loosen the miter lock knob 1/2 turn. 2. Look ...

Kerf Insert Adjustment The kerf inserts should be adjusted close to the blade, but without touching the blade, to avoid tear-out on the bottom of the workpiece.1. Hold the saw head assembly down and push in the head assembly lock pin (item 43 – page 12) to keep the saw in the DOWN position. 2. Loose...

25 Adjustments 0° Bevel Stop – Adjustment Procedure To avoid possible injury, disconnect plug from power source before performing any assem- bly, adjustment or repair. Adjusting 0° Bevel Stop (Blade 90° to Table) 1. Pull up the bevel lock lever to loosen.2. Loosen bolt heads “A” and “B” using a 10mm...

26 45° Bevel Stop – Adjustment Procedure To avoid possible injury, disconnect plug from power source before performing any assem- bly, adjustment or repair. Checking 45° Bevel Stop Setting 1. Hold the saw head assembly down and push in the head assembly lock pin (item 43 – page 12) to keep the saw i...

27 45° Bevel Stop – Adjustment Procedure To avoid possible injury, disconnect plug from power source before performing any assem- bly, adjustment or repair. Adjusting 45° Bevel Stop (Saw Blade 45° to Table) 1. Pull up the bevel lock lever to unlock. Move the left sliding fence fully to the left. 2. ...

28 Adjusting Bevel Lock Tension Checking Bevel Lock Tension 1. Pull up the bevel lock lever to release tension. If it feels too hard to pull up, an adjustment may be required. 2. Check the tilt resistance. Grab main handle and slowly tilt the saw to the left. While tilt- ing, some resistance should ...

29 Adjusting Front Stabilizing Bolt The front stabilizing bolt is located on the bottom of the saw’s base near the 0° miter detent slot (Figure 27). It provides additional support when making slide cuts.The stabilizing bolt has been factory set. If it is loose or needs adjustment, follow these steps...

30 Transporting and Mounting To avoid injury, follow all statements identified below by the BULLET ( • ) symbol. • Never lift this saw by grasping the base ex- tensions when they are in the extended po- sition. • Unplug electric cord and wind up. Use the hook and loop strap to hold the wrapped cord ...

31 Transporting and Mounting Mounting Applications Be certain the miter saw is mounted or placed on a level, firm work surface before using. A level and firm work surface reduces the risk of themiter saw becoming unstable. Workbench Permanent Attachment 1. Each of the four mounting holes should be b...

Use sliding base extensions, sliding fence, and ad- ditional workpiece supports (see page 34) to properly support the workpiece and hold or clamp it outside of the “No Hands Zone”.Workpiece can be held against table and fence by hand only outside of the “No Hands Zone”.• Hold workpiece firmly agains...

34 Preparing for Saw Operations Workpiece Support Clamps Using the Workpiece Clamp – This clamp eas- ily secures a workpiece to the table or base, see fig. 33. 1. Insert the clamp’s knurled bar down into a clamp post hole; there are two post holes lo- cated in the base behind the fence. The knurled ...

35 Preparing for Saw Operations Workpiece Support Long Workpiece Support Long workpieces have a tendency to tip over un- less clamped down and properly supported from underneath. Do not use another per- son as a substitute for a table extension or as additional support. Un- stable support for the wo...

36 Making an Auxiliary Fence Certain types of molding need a fence face ex- tension because of the size and position of the workpiece. Holes are provided in the fence to attach an auxiliary fence. The auxiliary fence is used with the saw in the 0° bevel position only.1. Place a piece of wood against...

37 Saw Operations Switch Activation For safety, the switch lever is designed to pre- vent accidental starts. To operate safety switch, slide the switch “Lock-OFF” release button with either thumb to disengage the lock, then pull the power switch trigger and release the switch “Lock-OFF” release butt...

39 Chop Cuts Saw Operations What’s a Chop Cut? • A “chop cut” is a cross-cut made when the saw is held to the rearmost position and is operated like a conventional (non-sliding) miter saw. Using the chop cut method low- ers the cross-cutting capacity; however, many users prefer using this method be-...

40 Saw Operations Slide Cuts What’s a Slide Cut? • A “slide cut” is made with the head assem- bly unlocked and able to move away from the fence. This movement is supported and precisely controlled by the axial glide sys- tem. The maximum cross-cutting capacity is utilized by using this method. • A s...

41 Saw Operations Miter Cuts What’s a Miter Cut? • A “miter cut” is a cross-cut made with the blade perpendicular to the horizontal table.The blade is not tilted and the bevel point-ers are both on the 0° lines. • Miter cuts can be made at any angle across a workpiece within this saw’s range, from52...

42 Saw Operations 12 12 12/12 RO OF AN GL E = 45 ° (S LO PE ) RA FT ER RISE RUN 12 RUN 6 6/12 ROO F AN GLE = 26 .56° ( SLO PE) RISE RAFT ER Pitch angle information – The top section of the miter scale shows angle settings required to cut roof rafters to the “Pitch Angle” system. 2/2, 4/12, 6/12, etc...

43 Saw Operations Miter cutting 6-3/4" base boards – This saw can miter cut 6-3/4" tall base boards vertically positioned against the fence at any angle from 0° to 52°. All angled cuts must be made with the base board placed on the left side of the table. For certain cuts, the base board wil...

44 Saw Operations “33.9” positions are for cutting 38° “spring angle” crown molding flat on table Note: Saw has a 33.9 detent feature to automatically hold it at this bevel angle setting “30” positions are for cutting 45° “spring angle” crown molding flat on table Watch While Tilting to Right BEVEL ...

45 Saw Operations Bevel Cuts Bevel Range Selector Knob Right Side of Table Bevel range selector knob – This saw has a front control on the right side of the table arm. This is called the bevel range selector knob (item 41 – page 12). It is linked to stops and locking mech- anisms in the rear which c...

48 Saw Operations Compound Cuts Before sawing, always check that there is no in- terference between moving and stationary parts of the saw. Do not operate the saw in the following range of miter and bevel combi- nations: Left Bevel 45° to 47° PLUS Right Miter 40° to 42°. These miter and bevel com- b...

50 Saw Operations Cutting Base Molding • Base molding can be cut vertical against fence or flat on the table. The maximum size that can be vertical on the fence is 6-3/4", flat on table is 13-1/2". • Follow the table for helpful hints on cutting base molding for corners that have 90° angles....

51 Saw Operations Crown Molding Angled to Table and Fence The preferred method for cutting crown mold- ing with this saw is with the molding lying flat on the table.The advantage to cutting molding angled against fence is that no bevel setting is re- quired. Only the miter angle is adjusted.The maxi...

53 Miter and Bevel Settings for Standard Crown Molding Cuts (With Molding Flat on Table) Assumptions: Molding is milled consistently. Corner is exactly 90°. Molding Spring Angle 38º Molding Spring Angle 45º Note: Always place top edge against fence Miter (Table) Setting Bevel (Tilt) Setting Miter (T...

54 Saw Operations Crown Molding Auxiliary Fence When making a com- pound cut on a molding lying flat on the table, narrow cut-off pieces (2" or less in width) may be propelled at high speed over the fence and beyond the back of the tool (see Fig. 59). Use auxiliary fence as instructed and shown ...

55 10-19/32" 3-1/16" 7-15/32" 8" OVERALL LENGTH = 26-1/16" 3-1/16" OVERALL HEIGHT = 1-1/2" Drill 4 Holes = 5/16" Diameter 5/16" New Auxiliary Fence (assembled to Miter Saw) Stationary Fence Saw Base Top of Base and Table Note: The Stationary Fence is permanently a...

56 Saw Operations Special Cuts Cutting bowed material and round material are only two examples of special cuts. Use clamping position that does not interfere with operation. Before switching on, lower head assembly to make sure clamp clears guard and head assembly. Be aware of the path of the saw bl...

57 Maintenance and Lubrication Service Preventive maintenance performed by unauthorized personnel may result in misplacing of internal wires and components which could cause serious hazard. We recommend that all tool service be performed by a Bosch Factory Service Center or Authorized Bosch Service ...

58 Maintenance and Lubrication Cleaning / Inspecting Drive Belt: 1. Unplug the saw.2. Remove the two belt cover screws using a #2 Phillips screwdriver. 3. Clean area with a brush or compressed air.4. Inspect the belt. If dried out, cracked or ex- cessively loose, it may require service and/or replac...

59 Troubleshooting PROBLEM CAUSE CORRECTIVE ACTION Brake does not stop blade in about 5 seconds. 1. Brushes not seated or lightly sticking or worn. 2. Motor overheated from use of dull blade/too heavy of a blade, not recommended accessory or rapid on/off cycling. 3. Blade bolt loose.4. Other. - Insp...

60 Troubleshooting PROBLEM CAUSE CORRECTIVE ACTION Head assembly does not bevel to desired position. 1. Bevel detent pin is en- gaged and locks bevel angle at 33.9°. 2. Bevel range selector knob setting limits movement. - Pull out 33.9° bevel detent pin, then rotate pin 1/4 turn to keep out. - Chang...

61 Troubleshooting Troubleshooting Guide - General PROBLEM CAUSE CORRECTIVE ACTION Tool vibrates or shakes. 1. Saw blade not round. 2. Saw blade damaged. 3. Saw blade loose. 4. Other - Replace blade. - Replace blade. - Check that blade is prop- erly seated on the inner washer. See Removing and Insta...