====== Session 2 ======

===== Bench Work =====

  - Layout of sample block. Dyekem & Scribing lines-square, protractor, divider, punch.
  - Hack saw: various pitch blades available, teeth on blade face away from handle, starter teeth at one end of blade.
  - Files: must have handle on tang, hard (do not use to pry, use file card to clean, cut on forward stroke, many shapes and sizes, needle files to large rasps.

===== Vertical Band Saw & Horizontal Cutoff Saw Rules =====

  - Use proper speed for material being cut.  Shift to low speed for SS & steel and shift to high speed for aluminum, wood, copper, and  brass.
  - If blade breaks or the work piece gets very hot or you have to push hard the blade is probably dull.  Come to main shop to get blade replaced.
  - The upper blade guide should be no more than 1/4" above your work piece.
  - Use a wood stick to push part and keep fingers away from blade. Use a vice to clamp small parts and prevent round stock from spinning.
  - Never use a rag to wipe off chips when machine is running.
  - Make sure at least 2 teeth of blade are engaged in work. Do not cut thin sheet with a coarse blade.

===== Measurement =====

  - Micrometers-accuracy to .0005" (.0001" with vernier), come in 1" increments.
  - Vernier & dial calipers-accuracy to .001" at best, used for measuring inside and outside dimensions as well as depth.


===== Drill Press =====

==== Safety Rules ====

  - Always wear safety glasses.
  - Use a vise or clamp your work piece to prevent it from spinning if the drill grabs.  Never use your hands to hold your work piece.
  - Make sure the drill is tight and aligned in the chuck jaws.  Remove the chuck key before turning on the drill.  Never leave the key in the drill chuck.
  - Set the drill press for proper speed for the size drill being used and material being drilled.
  - Use a sheet metal drill or Rotex punch if material is less than 1/8”.
  - Always peck drill (periodically retract the bit when drilling thicker stock) to prevent long chips from building up on the drill.
  - Use special ground drill bits for brass, copper, and acrylic to prevent the bit from digging into part.
  - Use a brush or compressed air to remove chips.  Do not use a rag when the machine is running.
  - Let the spindle coast to a stop on its own after turning off. Never grab the chuck with your hand. Wait until spindle has stopped before making any adjustments. 
  - Do not use too much pressure when drilling.  Check to see if bit is dull.  Use a smaller drill first if a large hole is to be drilled.
  - Clean drill bits and return to proper place in rack.  Wipe off drill press table and vise when done.


==== Video: Operations Performed on Drill Press ====
 
  - Center drilling
  - Drilling-drill sizes (number, letter, fractional, metric), size of drill marked on shank, checking drill for sharpness
  - Reaming
  - Counter-boring (for socket head cap screws)
  - Counter sinking (for flat head screws)
  - Clamping: Use vise or clamp to table
  - Cutting fluids
  - Speeds

==== Bench layout and drill press exercise ====

  - Use band saw to cut stock.
  - File off burrs.
  - Layout holes and center punch.
  - Drill, counter bore, ream, and tap holes.
  - Deburr top and bottom of part.

===== Pedestal Grinder Safety Rules =====

  - Make sure safety shield is in place.
  - Tool rest must be close to wheel without touching (no more than 1/8” gap).
  - Grind only steel. No aluminum, brass, copper, or SS as they will load up the wheel.  
  - Redress wheel if grooves are worn into wheel.
  - Grind only on the face of the wheel, not the sides.
  - Use water pot to keep parts cool.

===== Threads =====

  - Taps - tap wrench, tapping block
  - Dies - die stock
  - Tap drill chart
  - Determining the size of a thread
    * Measure OD
    * T.P.I. (use thread pitch gauge) 

===== Handouts =====


Drill charts, aluminum stock for drilling, spare micrometers and digital & dial calipers.