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student_shop:class2

Session 2

Bench Work

  1. Layout of sample block. Dyekem & Scribing lines-square, protractor, divider, punch.
  2. Hack saw: various pitch blades available, teeth on blade face away from handle, starter teeth at one end of blade.
  3. 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

  1. 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.
  2. 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.
  3. The upper blade guide should be no more than 1/4“ above your work piece.
  4. 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.
  5. Never use a rag to wipe off chips when machine is running.
  6. Make sure at least 2 teeth of blade are engaged in work. Do not cut thin sheet with a coarse blade.

Measurement

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

Drill Press

Safety Rules

  1. Always wear safety glasses.
  2. 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.
  3. 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.
  4. Set the drill press for proper speed for the size drill being used and material being drilled.
  5. Use a sheet metal drill or Rotex punch if material is less than 1/8”.
  6. Always peck drill (periodically retract the bit when drilling thicker stock) to prevent long chips from building up on the drill.
  7. Use special ground drill bits for brass, copper, and acrylic to prevent the bit from digging into part.
  8. Use a brush or compressed air to remove chips. Do not use a rag when the machine is running.
  9. 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.
  10. 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.
  11. 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

  1. Center drilling
  2. Drilling-drill sizes (number, letter, fractional, metric), size of drill marked on shank, checking drill for sharpness
  3. Reaming
  4. Counter-boring (for socket head cap screws)
  5. Counter sinking (for flat head screws)
  6. Clamping: Use vise or clamp to table
  7. Cutting fluids
  8. Speeds

Bench layout and drill press exercise

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

Pedestal Grinder Safety Rules

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

Threads

  1. Taps - tap wrench, tapping block
  2. Dies - die stock
  3. Tap drill chart
  4. 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.

student_shop/class2.txt · Last modified: 2011/06/06 15:53 by allan