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Safety Issues When Using Machine Tools

Machine tools located at Machine Shop are divided into two groups: manual (conventional) and CNCs. The manual machine tools are not covered fully with a protective case. CNC Machine tools on the other hand, are fully covered but can go up to very high spindle speeds and feed rates. Therefore, when using both types of machine tools, people should be very careful and be defensive when taking actions.

It is essential that people / students / machine operators receive quality and working instructions before attempting to use any CNC equipment. 

The detailed cautions when using these meachine tolls are given below:

Drilling Machine Tool

  • Drilling must be operated at the correct speed according to the diameter of drill bit and material.
  • Sample must be clamped or attached to the drill table and controlled several times.
  • Use a correctly drill for the material being drilled. Machine shop personnel can help select the correct drill type.
  • Appropriate cutting fluid must be chosen for the material. Ask the machine shop personnel about the appropriate fluid for the material you are machining.
  • Chips must be removed by brush, not by hand.
  • Ease up on drilling pressure as the drill starts to break through the bottom of the material
  • Don't use a worn or cracked drill. Inspect the drill before using.
  • Material must be supported with backing board or on parallel when drilling through material.
  • Always clean drill shank and/or drill sleeve, and, spindle hole before mounting.
  • The drill must be loosen when the power is off.
  • The drill spindle must be lowered close to the table when releasing the drill chuck or taper shank drill to reduce the chance of damage should when they fall onto the table.
  • Always clean the machine in off mode.
  • If the drill binds in a hole, stop the machine and turn the spindle backwards by hand to release the bit.
  • When drilling a deep hole, withdraw the drill bit frequently to clear chips and lubricate the bit.
  • Always remove the drill chuck key or, the drill drift from the spindle immediately after using it.
  • Let the spindle stop of its own accord after turning the power off. Never try to stop the spindle with your hand.
  • Plexiglass and other brittle plastics can be difficult to drill. Ask the machine shop LS for advice on drill and coolant selection when drilling these materials.
  • Wear protective safety glasses when drilling.

Milling Machine Tools

  • Workpiece must be clamped securely in a vise and the vise clamped tightly to the table, or workpiece must be clamped securely to the table.
  • Make sure cutter is rotating in the proper direction before cutting material.
  • Appropriate cutting fluid must be chosen for the material. Ask the machine shop LS about the appropriate fluid for the material you are milling.
  • Milling must be operated in correct speed according to diameter of milling bit and material.
  • Do not approach movable parts of the milling machine during operation.
  • Do not touch the tool or tool holder when rotating. Otherwise, user might be hauled by the rotating machine, which may result in serious injuries or accidents.
  • Sharp and good condition cutters must be used.
  • Don't place anything on the milling machine table such as wrenches, hammers, or tools.
  • Feeding speed and weight must be determined.
  • Remove the collet tightening wrench immediately after using it.
  • Use the milling machine spindle brake to stop the spindle after the power has been turned off.
  • Before cleaning the mill remove cutting tools from the spindle to avoid cutting yourself.
  • Wear protective safety glasses when the milling machine tool is running.

Lathe (Turning Machine Tool)

  • Make sure that the chuck, drive plate, or, faceplate is securely tightened onto the lathe spindle.
  • Machine must be off, when removing/installing the chuck, drive plate, or faceplate.
  • Move the tool bit a safe distance from the collet or chuck when inserting or removing work.
  • Machine must be operated in proper cutting speed according to diameter of milling bit and material.
  • In setting up the tool holder place it to the left side of the compound slide to prevent the compound slide from running into the chuck or spindle attachments.
  • Always clamp the toolbit as short as possible in the toolholder to prevent it from breaking or chattering.
  • Always make sure that the toolbit is sharp and has the proper clearance. Ask for assistance making adjustments.
  • If any filing is done on work revolving in the lathe, file left handed to prevent slipping into the chuck. Never use a file without a handle.
  • If work is turned between centers, make sure that proper adjustment is made between centers and that the tailstock is locked in place.
  • If work is being turned between centers and expands due to heat generated from cutting, read just centers to avoid excessive friction.
  • Do not grasp or touch chips or turnings with your fingers, but get rid of them using a blunt instrument. It is safer to turn off the lathe before clearing chips then to leave it running.
  • Set the toolbit on the centerline of your work to prevent work from climbing over tool or cutting above center and dragging.
  • Don't cut work completely through when turning between centers.
  • Remove chuck key from chuck immediately after using.
  • Turn chuck or faceplate through by hand before turning on the power to be sure there is no binding or clearance problem.
  • Stop the machine before taking measurements.
  • Before cleaning the lathe remove tools from the tool post and tailstock.

Band Saw

  • The upper guide and guard should be set as close to the workpiece as possible.
  • In case of band breaking, the power must be shut off the power and stand clear until the machine has stopped.
  • The blade must be examined before installing to see if it is cracked, cracked blade must not be installed.
  • Proper pitch blades must be used for the thickness of the material to be cut. There should be at least 2 teeth in the material when cutting aluminum and three teeth when cutting steel. Check the speed table for the material that you are cutting. Do not run the band saw too fast or the blade will wear out quickly.
  • If the saw stalls in a cut, the power must be off and the blade must be reversed by hand to free it.
  • Wear protective safety glasses when the saw is running. 

Grinding Machine Tool

  • Special training is required before using the surface grinder CNC machine tool.
  • Abrasive wheel machinery shall not be operated without the appropriate guards in place.
  • Never use a wheel that has been dropped or received a heavy blow, even though there may be no apparent damage. Such wheels may be weakened or unbalanced enough to fly apart on startup.
  • Do not grind on side of wheel unless wheel is specifically designed for such use.
  • Any cracked, broken or otherwise defective wheels must be reported to LS/LSS immediately.
  • The new wheels must be mounted and balanced by the supervisor.
  • Hold work securely while grinding, use the tool rest to support the work when off-hand grinding on bench or pedestal grinders.
  • When grinding Aluminum extra precautions must be taken as the Aluminum dust is explosive. A proper grind and cutting parameters should be selected.
  • If a magnetic chuck is being used, on the surface grinder, make sure it is holding the work securely before starting to grind.