Makita BHP454, BHP444 instruction manual Maintenance, Optional Accessories

grip and switch handle during operations. Failure to do so may result in the loss of control of the tool and potentially severe injury.

First, slide the action mode change lever so that it points to the marking. The adjusting ring can be aligned in any torque levels for this operation. Be sure to use a tungsten- carbide tipped bit. Position the bit at the desired location for the hole, then pull the switch trigger. Do not force the tool. Light pressure gives best results. Keep the tool in position and prevent it from slipping away from the hole. Do not apply more pressure when the hole becomes clogged with chips or particles. Instead, run the tool at an idle, then remove the bit partially from the hole. By repeating this several times, the hole will be cleaned out and normal drilling may be resumed.

Blow-out bulb (optional accessory) (Fig. 15)

After drilling the hole, use the blow-out bulb to clean the dust out of the hole.

Screwdriving operation

First, slide the action mode change lever so that it points to the marking. Adjust the adjusting ring to the proper torque level for your work. Then proceed as follows.

Place the point of the driver bit in the screw head and apply pressure to the tool. Start the tool slowly and then increase the speed gradually. Release the switch trigger as soon as the clutch cuts in.

NOTE:

•Make sure that the driver bit is inserted straight in the screw head, or the screw and/or bit may be damaged.

•When driving wood screws, predrill pilot holes to make driving easier and to prevent splitting of the workpiece. See the chart.

Nominal diameter of wood	Recommended size of pilot
screw (mm)	hole (mm)
3.1	2.0 - 2.2
3.5	2.2 - 2.5
3.8	2.5 - 2.8
4.5	2.9 - 3.2
4.8	3.1 - 3.4
5.1	3.3 - 3.6
5.5	3.6 - 3.9
5.8	4.0 - 4.2
6.1	4.2 - 4.4

NOTE:

•If the tool is operated continuously until the battery cartridge has discharged, allow the tool to rest for 15 minutes before proceeding with a fresh battery.

Drilling operation

CAUTION:

•Pressing excessively on the tool will not speed up the drilling. In fact, this excessive pressure will only serve to damage the tip of your bit, decrease the tool performance and shorten the service life of the tool.

•There is a tremendous force exerted on the tool/bit at the time of hole break through. Hold the tool firmly and

exert care when the bit begins to break through the workpiece.

•A stuck bit can be removed simply by setting the reversing switch to reverse rotation in order to back out. However, the tool may back out abruptly if you do not hold it firmly.

•Always secure small workpieces in a vise or similar hold-down device.

•If the tool is operated continuously until the battery cartridge has discharged, allow the tool to rest for

15 minutes before proceeding with a fresh battery. First, slide the action mode change lever so that it points to the marking. The adjusting ring can be aligned in any torque levels for this operation. Then proceed as follows.

Drilling in wood

When drilling in wood, the best results are obtained with wood drills equipped with a guide screw. The guide screw makes drilling easier by pulling the bit into the workpiece.

Drilling in metal

To prevent the bit from slipping when starting a hole, make an indentation with a center-punch and hammer at the point to be drilled. Place the point of the bit in the indentation and start drilling. Use a cutting lubricant when drilling metals. The exceptions are iron and brass which should be drilled dry.

MAINTENANCE

CAUTION:

•Always be sure that the tool is switched off and the battery cartridge is removed before attempting to perform inspection or maintenance.

•Never use gasoline, benzine, thinner, alcohol or the like. Discoloration, deformation or cracks may result.

Replacing carbon brushes (Fig. 16)

Replace when they wear down to the limit mark. Keep the carbon brushes clean and free to slip in the holders. Both carbon brushes should be replaced at the same time. Use only identical carbon brushes.

Use a screwdriver to remove two screws then remove the rear cover. (Fig. 17)

Raise the arm part of the spring and then place it in the recessed part of the housing with a slotted bit screwdriver of slender shaft or the like. (Fig. 18)

Use pliers to remove the carbon brush caps of the carbon brushes. Take out the worn carbon brushes, insert the new ones and replace the carbon brush caps in reverse.

(Fig. 19)

Make sure that the carbon brush caps have fit into the holes in brush holders securely. (Fig. 20)

Reinstall the rear cover and tighten two screws securely. To maintain product SAFETY and RELIABILITY, repairs, any other maintenance or adjustment should be performed by Makita Authorized Service Centers, always using Makita replacement parts.

OPTIONAL ACCESSORIES

CAUTION:

•These accessories or attachments are recommended for use with your Makita tool specified in this manual. The use of any other accessories or attachments might

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