3560739
Description
Flashcards by Vincent Bergeron, updated more than 1 year ago
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Created by Vincent Bergeron
over 8 years ago
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| Question | Answer |
| Which variable is the most important when determining a spindle speed? | The diameter of the drill |
| Cutting speed refers to: | The rate at which the cutting edge of a tool moves through the metal measures in feet per minute |
| How fast should a 1/2" drill turn when drilling machine steel if the cutting speed (CS) is 90? | rpm=(cs x 4)/drill dia (90 x 4)/0.5=720 rpm |
| Do small drills require a higher feed per revolution than larger ones? | Small holes require lower feed per revolution than large drills but turn at a higher rpm |
| Which abbreviate is used to express the feed rate on a drill press? | ipr (inch per revolution) |
| A drill press spindle has a #2 Morse taper. A twist drill with #3 Morse taper shank must be mounted in the spindle. How would you secure the drill in the spindle? | with a drill socket |
| To remove a tapered shank twist from the drill press spindle, use a ? | drill drift |
| Drill chucks may be mounted in the drill press spindle or a tapered shank by means of a ? | either a taper or a thread |
| V-blocks are used mostly on the drill press for: | holding round material |
| To clamp a workpiece correctly with a straight clamp: | you must bolt as close to the workpiece as possible |
| When using a sensitive drill press, what should you do as the drill breaks through the workpiece? | ease up on the cutting pressure so the drill doesn't grab the part. |
| If a drill wanders off centre, the best method to draw it back to centre is to use a : | diamond point chisel |
| The recommended drill size to ream a 3/8" hole on a drill press is: | 23/64" 1/64" smaller than the reamer |
| The included point angle of a countersunk hole for most flathead screws is: | 82 degrees |
| Which type of machine tap will push the chip out ahead of the tap: | spiral point tap |
| The lip relief (clearance) angle on a drill should be: | between 8 to 12 degrees |
| A general purpose drill bit for drilling most metals has an included point angle of: | 118 degrees |
| Carbide drills may be operated at a cutting speed how many times faster than high speed steel drills? | 3 x faster |
| A drill which is ground with lips of unequal length, will drill a hole which is: | an oversize hole will be drilled because cutting will only be done on one of the cutting edges. |
| Define drilling | the operation of producing a hole using a tool called a twist drill |
| Define boring | the operation of truing and enlarging a hole by means of a single point cutting tool, usually held in a boring bar |
| Define reaming | the operation of sizing and producing a smooth round hole from a previously drilled or bored hole with the use of a cutting tool having several cutting edges |
| What is the difference between spot-facing and counterboring? | spot facing - smoothing and squaring the surface around a hole to provide a a seat for the head of a cap screw or nut. counterboring - enlarging the top of a previously drilled hole to a given depth to provide a square shoulder for a bot or capscrew. |
| State two methods by which the size of a drill press may be determined. | - the distance from the center of the spindle to the column of the machine - the diameter of the largest circular piece that can be drilled in the center |
| Compare a sensitive drill press with an upright drilling machine. | sensitive drill press - only one hand feed machanism so the operator can "feel" how the drill is cutting. Generally light, high speed machines. upright drilling machine - larger and heavier. gearbox to provide greater variety of speeds. - 3 methods to advance splindle, hand lever, handwheel and automatically. - table may be raised or lowered - coolant reservoir on some models |
| Describe and state the purpose of the following parts of a sensitive drill press: base | provides stability for the machine, and rigid mounting for the column |
| Describe and state the purpose of the following parts of a sensitive drill press: column | - table is mounted to column and can be adjusted to any point between the base and the head - drill press head is mounted to top of column |
| Describe and state the purpose of the following parts of a sensitive drill press: Drilling head | contains the mechanisms used to revolve the cutting tool and advance it to the workpiece |
| Describe and state the purpose of the following parts of a sensitive drill press: Table | used to support the workpiece |
| Describe and state the purpose of the following parts of a sensitive drill press: Depth stop | can be set to control the depth that the cutting tool enters the workpiece |
| What are the advantages of a radial drilling machine? | - larger and heavier work can be machined - drilling head can be easily raised or lowered - drilling head can be easily moved to any location - more power - head can be swiveled on universal models |
| Compare the construction of a radial drilling machine to that of a standard upright drill press, | larger and heavier |
| What is the purpose of a drill chuck? | to hold the straight shank cutting tool |
| Name four types of drill chucks. | key type keyless type precision keyless jacobs impact keyless |
| What is the purpose of a drill sleeve? | used to adapt the cutting tool shank to the machine spindle |
| What is the purpose of a drill socket? | used to adapt the drill when the hole in the machine spindle is too small for the taper shank of the drill |
| How is a tapered-shank drill removed from a drill press spindle? | with a drill drift |
| Name three types of drill vises and state the purpose of each. | drill vise - used to hold round, rectangular, square or odd shaped pieces for any drilling operation angle vise - allows drilling holes at an angle contour vise - special movable jaws that automatically adjust to odd shaped work pieces |
| What is the purpose of V-blocks? | to support round parts for drilling |
| What is the purpose of step blocks? | used to provide support for the outer end of the strap clamps |
| Describe an angle plate and state its purpose. | 90 degree plate used to fasten work for drilling |
| What is the advantage of a drill jig? | eliminate the need for laying out hole locations |
| Why is it important that work be clamped properly for any machining operation? | so the part does not come loose |
| Define the body of a twist drill. | portion of drill between the point and the shank |
| Define the web of a twist drill. | Thin partition in the center of the drill that extends the full length of the flutes |
| Define the point of a twist drill. | The tip of the drill, consists of the chisel edge, cutting edge, heel and body clearance |
| State the purpose of the following parts: Tang | On the end of a tapered shank to prevent the drill from slipping while it is cutting and allows the drill to be removed without the shank being damaged |
| State the purpose of the following parts: Flutes | They form the cutting edges, admit cutting fluid and allow the chips to escape from the hole |
| State the purpose of the following parts: Margin | it is the narrow raised section on the body of the drill. its purpose is to provide a full size to the dill body and cutting edges |
| State the purpose of the following parts: Body clearance | it is the undercut portion of the body between the margin and the flutes. it is made smaller to reduce friction between the drill and the hole. |
| What is the purpose of the following drill points and what degree is it ground to: conventional | 118 degrees general purpose drilling |
| What is the purpose of the following drill points and what degree is it ground to: long angle | 60 to 90 degrees used for drilling non ferrous materials |
| What is the purpose of the following drill points and what degree is it ground to: flat angle | 135 to 150 degrees used to drill hard and tough material |
| Why is it necessary to thin the web of a drill? | to reduce pressure and heat while drilling |
| List four systems of drill sizes and give the range of each. | Fractional drill sizes Number drill sizes Letter drill sizes Millimeter (metric) drill sizes |
| State the purpose of the high-helix drill | for drilling deep holes in aluminum, copper, die cast material and other material where the chips have a tendancy to jam in a hole |
| State the purpose of the Core drill | has three or four flutes. used to enlarge cored, drilled or punched holes. |
| State the purpose of the Oil hole drill? | has one or two oil holes to force oil to the cutting edge cooling the drill and forcing chips out |
| State the purpose of the Straight-fluted drill | for drilling soft materials like brass copper or plastic. straight flutes prevent the drill from drawing itself into the material while cutting |
| State the purpose of the gun drill. | used for producing holes as deep as 20ft |
| State the purpose of the hard-steel drill | used for drilling hardened steel |
| What problems generally result from the use excessive speed and excessive feed? | excessive speed = wear at corners of drill excessive feed = breakdown of chisel point and cutting edges/lips |
| Discuss excessive lip clearance and insufficient lip clearance. | excessive clearance = lack of support behind cutting edge insufficient clearance = causes drill to rub behind the cutting edge |
| What is the effect of drills with unequal angles on the cutting lips? | one cutting edge works harder than the other causing bellmouth holes and poor tool life |
| What is the effect of drills with cutting lips unequal length? | produces oversize holes |
| What are the characteristics of a properly ground drill? | both cutting lips should be same length both cutting lips should be same angle lips free from wear or nicks no sign of wear on the margin |
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