Jet J-7040 Operating Instructions And Parts Manual

Also see for J-7020: Operating instructions and parts manual

8Raising/Lowering the SawHead1. Lift the saw head using the handle on the far left sideof the saw head.2. To lower the saw head, press the green pushbuttonon the right side of the control panel.3. To adjust the feed rate, adjust the feed rate controlvalve knob on the top of the saw head (see figure3).4. To lower the saw head with power off, pull and turnthe red knob (manual override) on the electro-mag-netic valve (see figure 4).Controlling the Cut:Hydraulic Feed ControlThe weight of the saw arm provides all the forceneeded to move the saw blade through the workpiece.In fact, if the full weight of the arm is allowed to makethe cut, rapid blade wear and poor cutting accuracywill result. A hydraulic feed control is provided thatgives the operator a means to control the speed andefficiency of cutting.The hydraulic cylinder is attached between the sawbase and the saw head. The hydraulic cylinder resistsmovement of the saw head in the downward direction.However, the hydraulic cylinder offers no resistancewhen the saw head is raised upward.The amount of downward force can be controlled byusing the feed rate control valve. When the valve isopened slightly, the saw head will move downward. Thefurther the valve is opened, the faster the saw head willmove downward.The feed control is adjusted by the operator until thesaw is operating efficiently. This is usually determinedby observing the chip formation. (See Evaluating BladeEfficiency for more information on cutting efficiency.)Figure 3: ControlsSaw HeadLift HandleControl Box Blade TensioningHand WheelVise ClampingHand WheelBlade GuideSupportsDrive MotorBladeSaw HeadFeed RateControlSpeedControlSawHeadBeltCoverEvaluating Cutting EfficiencyIs the blade cutting efficiently? The best way to de-termine this is to observe the chips formed by the cut-ting blade.If the chip formation is powdery, then the feed rateis much too light, or the blade is dull.If the chips formed are curled, but colored — thatis, either blue or straw-colored from heat generatedduring the cut — then the feed rate is too high.If the chips are slightly curled and are not coloredby heat — the blade is sufficiently sharp and is cuttingat its most efficient rate.Blade SelectionThe cut-off saw is provided with a saw blade that isadequate for a variety of cut-off jobs on a variety ofcommon materials. A 4/6 vari tooth bi-metal blade(5674011) and a 6/10 vari tooth bi-metal blade(5674021) are available from JET .See Setting Blade Speed for the speeds recom-mended for various materials. These selections, whileappropriate for many shop cutting needs, do not en-compass the wide variety of blades of special configu-ration (tooth pitch and set) and special alloys for cut-ting unusual or exotic materials.A coarse blade could be used for a solid steel barbut a finer tooth blade would be used on a thin-walltube. In general, the blade choice is determined bythe thickness of the material; the thinner the material,the finer the tooth pitch.Figure 4: Lowering head with power offElectro-MagneticValveRedReleaseButton