Introduction to Design & Technology

1. Introduction to Design & Technology Final Review

2. Oxy-Acetylene Terms • Fusion -- Heating two pieces of metal to their melting point and allowing them to flow together. • Base Metal -- Metal to be welded • Penetration -- Distance at which fusion ceases • Inner Cone -- Inner white part of Neutral flame • Tack Weld --Short weld to temporarily hold metal in place • Backfire –Momentary burning back of flame into the tip. Flame goes out with a loud pop. • Flashback – Flame burns back inside the torch body.

3. Arc Terms • Arc-flow of current across a small gap. • Crater--depression at the end of the weld • Penetration--depth of weld into the base metal • Welding--joining of two or more metal by fusion • Spatter – Deposit of small spots or particles of metal on the base metal. • String Bead – Weld bead made with very little rod manipulation. • Pad – Series of overlapping String Beads

4. Arc Safety • Keep floor dry to prevent electrical shock. • Make sure ventilation is turned on. • Always wear the proper P.P.E. • Never look at an Arc without the proper welding shaded lens. • Make sure machine is properly set up before starting the welding process. • Always place the Electrode Holder on its hook and never set it on the work bench. • Never engage yourself in any activity that would endanger the well being of yourself, other students, the teacher and the shop.

5. Oxy-Acetylene Safety • Never adjust Acetylene above 15 psig. • Stand of to one side when opening the Regulator. Never directly in front. • For a Flashback, turn off Oxygen torch valve first then Acetylene torch valve. • Keep cylinders upright and firmly anchored. • Keep valves closed on empty cylinders. • Make sure Adjusting Screw is released or turned out before opening valve.

6. THE FIRE TRIANGLE HEAT OXYGEN FUEL

7. Classes of Fires • Class A – Combustible Materials • Class B – Flammable Liquids • Class C – Electrical • Class D – Combustible Metals

8. 7018 E = Electrode 70 = 70,000 lbs. per square inch (Tensile Strength) 1 = All Positions (Position) 8 = Low Hydrogen, DCEP, AC, Medium Penetration (Special Characteristics)

9. Methods to Strike an Arc

10. Arc Length

11. Table Saw • Stock must be this long to safely rip on the Table Saw: • 12” • How high should the blade be adjusted above the stock: • 1/8” to 1/4” • When ripping a board that is narrower then ______inches, you must use a __________ __________: - 6 & Push Stick • When ripping, when is the stock released. After it passes: - The back of the Blade Insert or Throat Plate. • How much should the stock be oversized when ripping: - 1/8” • Should the good face of the stock be facing up or down when using the Table Saw: - Up • Stand to the ________ side of the blade when ripping narrow stock: - Left

12. Planer • Amount of material removed with each pass: • 1/16” • Length the board must be to safely run through the planer: • 12” • Must use this when plaining stock thinner then 1/2”: • Auxiliary Bed • Have the face of the stock you want surfaced facing: • Up • The Concave (cup) surface of the stock should be facing: • Down

13. Jointer • Amount of material removed with each pass: - 1/16” • Length the material must be to safely joint: - 12” • Is the stock feed with or against the grain: - With • When edge jointing, is the “Crown” facing up or down: - Up

14. Miter Saw • Size of saw determined by: - Diameter of blade • Must keep fingers and hands from the saw blade this distance: - 6” • The process to line up the cut is called a: - Dry Run • Have the good face of the stock facing: - Up

15. Miscellaneous • Rule of thumb for the depth of a Dado or Rabbet cut if not shown on a set of plans: - 1/2 the thickness of the stock • A slot or trench that is cut with or parallel to the grain: - A Groove • A slot or trench that is cut against or perpendicular the grain: - Dado • When staining, how long should the stain soak into the wood. - Ten Minutes

16. When changing a Saw Blade or Router Cutter loosen the nut with the rotation. • When gluing up stock together • Make sure growth rings are alternating • Put glue on both parts • Do not smear glue into the face grain • Tighten clamp until glue beads up. • Do not over tighten clamps.

17. On sandpaper the higher the number the finer the grit. • Before making any type of cut, make sure: • Stock is securely held down • Blade or Cutter is clear of stock • Proper P.P.E.

18. Board Foot N x T x W x L” or N x T x W x L’ 144 12 Example: 4 – ¾” x 4-1/2” x 15-1/4” 4 x 1 x 4.5 x 15.25 = 274.5 274.5 / 144 = 1.90 Bdft.

19. The End