Term
| What is the work piece charge and cutting tool charge on a ECM machine |
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Definition
| Workpiece is a positive charge and Electrode is negative. |
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Term
| What creates the conductive environment in an ECM |
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Definition
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Term
| What is some advantages of using an ECM? |
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Definition
| No spark or tool wear, very fast (Compared to EDM), easier than machining difficult materials, No heat affecting (Thin sections, better finish, no distortion) |
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Term
| What is the overcut on an ECM? |
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Definition
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Term
| How does the ECM process work? |
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Definition
| Pressurized electrolytic fluid and low voltage high amperage DC charge melts required metal away. |
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Term
| What materials can be used as an electrode in ECM machines? What is used to prevent overcutting? |
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Definition
| Graphite, Copper, brass, stainless. Electrode is insulated to prevent overcutting (.002/.003 gap) |
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Term
| What charge is the grinding wheel in a ECG? |
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Definition
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Term
| The current and flow electrolytic fluid between the wheel and work controls what? |
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Definition
| Controls rate of removal and finish |
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Term
| The process in an ECG removes __% of material and abrasive wipes __% often complete in one pass. |
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Definition
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Term
| The positive charge in an ECG is the? |
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Definition
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Term
| Reversing the polarity in an ECG will cause what? |
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Definition
| Will scrub the abrasive wheel |
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Term
| Why would you choose to use an ECG? |
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Definition
| Good finish, no burrs, fast, hard material ground fast, no burning, warping, stress |
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Term
| To use an ECG the work material must be? |
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Definition
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Term
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Definition
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Term
| The cutting tool/electrode is ______ in an EDM? |
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Definition
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Term
| Dielectric fluid qualities? |
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Definition
| Non conductive, insulator. also can be a fire hazard and skin irritant. |
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Term
| Die sink electrode materials and some qualities of each? |
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Definition
| Graphite: Rigid, wear can be an issue Copper: Good conductor, bends, not easy to machine Tungsten carbide: Very rigid, brittle, expensive |
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Term
| What are the guides on a wire EDM made out of ? |
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Definition
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Term
| What determines cutting conditions of EDM machines? What affects finish and speed? |
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Definition
Current and voltage.
-More voltage: Faster, Poor finish
-Less voltage: slower, tool wear, better finish |
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Term
| What is used in laser (light)? |
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Definition
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Term
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Definition
| Solid, gas, liquid, and semi-conductor(C02, YAG, Ruby, Excimer-exciplex laser(Dimer)) |
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Term
| Light in lasers travel through tubes containing? |
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Definition
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Term
| Where and how do cut start in lasers? |
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Definition
| Cut is started with pulses in waste material and then traces outline. |
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Term
| What is used to blow molten material away from cut? |
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Definition
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Term
| What types of assist gases are there? |
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Definition
| Oxygen, Nitrogen (Stainless and aluminum), Argon (Titanium), Air (Economical) |
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Term
| What causes a better finish on a laser? |
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Definition
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Term
| What would the focal length be for a 7.5" piece of material be compared to a 1.0" thick material. |
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Definition
| A longer focal length and wider (.007-.01) |
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Term
| Systems used (laser) and the differences? |
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Definition
Fixed beam: Cutting head is stationary, table moves, bigger footprint, stable cutting head.
Moving beam: Work is stationary, cutting head moves, vibration and cutting head, focal point, and movement will affect cutting head. |
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Term
| Medium power laser can cut? |
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Definition
| 1" mild steel, 5/8" stainless, 3/8" aluminum, 1/8" copper. |
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Term
| Advantages of powder metallurgy? |
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Definition
| Red hardness inserts, porosity, magnetism, flexibility, hard surface |
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Term
| Process of powder metalizing? |
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Definition
| Mixing exact material in right order, compacting, drying (pre-sinter or sweating), sinter(Heat and pressure in protected environment) |
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Term
| Types of thermal spraying? |
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Definition
| Wire, powder, plasma spraying |
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Term
| Physical bond of thermal spraying, mechanical bond? |
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Definition
Physical: Melting into parent material
Mechanical: Undercut parent material |
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Term
| Prep needed for wire spraying? |
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Definition
| Clean, rough surface (Square thread like), ends beveled, anti splatter on ends, pre-heat |
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Term
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Definition
| Pre-heat, powder in hopper is sprayed on, reheated after to fuse to substrate |
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Term
| Plasma spraying is suitable for spraying? |
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Definition
| zirconia, tungsten, alumina, tantalum, carbide, carbide, copper. |
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Term
| Inert gas protects environment, raises temps to ____ to _____ to melt additive (6500 to 11000) (In reference to plasma spraying) |
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Definition
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Term
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Definition
| Drilling long (Deep) small diameter holes (300x diam) |
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Term
| How many cutting edges on gun drills? |
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Definition
| One cutting edge with 2 bearing supports |
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Term
| What is needed to trepan? |
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Definition
| Starting groove or guide bushing |
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Term
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Definition
| Fast MMR and leaves you with core of material |
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Term
| What is used to cut in water jet cutting (AWC) |
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Definition
| Garnet is used to cut the material. |
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Term
| How thick of mild steel can AWC cut? Stainless? |
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Definition
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Term
| Why would you want to use portable machining equipment? |
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Definition
| Can take machine to worksite. |
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