Makita BHP446 Instruction Manual

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Contents

8OPERATIONCAUTION:• Always insert the battery cartridge all the way untilit locks in place. If you can see the red part on theupper side of the button, it is not locked completely.Insert it fully until the red part cannot be seen. If not,it may accidentally fall out of the tool, causing injuryto you or someone around you.Hold the tool firmly with one hand on the grip and theother hand on the bottom of the battery cartridge tocontrol the twisting action.Hammer drilling operationCAUTION:• There is a tremendous and sudden twisting forceexerted on the tool/bit at the time of holebreak-through, when the hole becomes cloggedwith chips and particles, or when strikingreinforcing rods embedded in the concrete.First, turn the action mode changing ring so that thearrow on the tool body points to the marking. Theadjusting ring can be aligned in any torque levels for thisoperation.Be sure to use a tungsten-carbide tipped bit.Position the bit at the desired location for the hole, thenpull the switch trigger. Do not force the tool. Lightpressure gives best results. Keep the tool in position andprevent it from slipping away from the hole.Do not apply more pressure when the hole becomesclogged with chips or particles. Instead, run the tool atan idle, then remove the bit partially from the hole. Byrepeating this several times, the hole will be cleaned outand normal drilling may be resumed.Blow-out bulb (optional accessory)Fig.12After drilling the hole, use the blow-out bulb to clean thedust out of the hole.Screwdriving operationFig.13First, turn the action mode changing ring so that thearrow on the tool body points to the marking. Adjustthe 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 andapply pressure to the tool. Start the tool slowly and thenincrease the speed gradually. Release the switch triggeras soon as the clutch cuts in.CAUTION:• Make sure that the driver bit is inserted straight inthe screw head, or the screw and/or bit may bedamaged.NOTE:• When driving wood screws, predrill pilot holes tomake driving easier and to prevent splitting of theworkpiece. See the chart.Nominal diameter of wood screw(mm)Recommended size of pilot hole(mm)3.1 2.0 - 2.23.5 2.2 - 2.53.8 2.5 - 2.84.5 2.9 - 3.24.8 3.1 - 3.45.1 3.3 - 3.65.5 3.7 - 3.95.8 4.0 - 4.26.1 4.2 - 4.4006421Drilling operationFirst, turn the adjusting ring so that the pointer points tothe marking. Then proceed as follows.CAUTION:• Pressing excessively on the tool will not speed upthe drilling. In fact, this excessive pressure will onlyserve to damage the tip of your bit, decrease thetool performance and shorten the service life of thetool.• There is a tremendous force exerted on the tool/bitat the time of hole break through. Hold the toolfirmly and exert care when the bit begins to breakthrough the workpiece.• A stuck bit can be removed simply by setting thereversing switch to reverse rotation in order to backout. However, the tool may back out abruptly if youdo not hold it firmly.• Always secure small workpieces in a vise or with asimilar hold-down device.• If the tool is operated continuously until the batterycartridge has discharged, allow the tool to rest for15 minutes before proceeding with a fresh battery.Drilling in woodWhen drilling in wood, the best results are obtained withwood drills equipped with a guide screw. The guidescrew makes drilling easier by pulling the bit into theworkpiece.Drilling in metalTo prevent the bit from slipping when starting to make ahole, make an indentation with a center-punch andhammer at the point to be drilled. Place the point of thebit in the indentation and start drilling.Use a cutting lubricant when drilling metals. Theexceptions are iron and brass which should be drilleddry.