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SMT 302 Final
final
90
Other
Undergraduate 3
04/25/2014

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Cards

Term
What is the disadvantage of the straight line rip saw technique?
Definition
High labor, low yield, low flexibility
Term
What is the disadvantage of the fixed gang rip saw technique
Definition
Low flexibility, long setup times
Term
Does higher grade lumber or lower grade lumber cost more to process
Definition
Lower grade costs more to process- knots, uneven grain, size etc.
Term
When considering whether to rip first or crosscut first, list factors that affect layout decision
Definition
capital, labor skill, length, width, straightness, defects, number of parts, volume of parts etc
Term
Sawteeth that are like chisels are used for what type of sawing
Definition
Rip
Term
Define or sketch conventional sawing
Definition
operates against direction of stock feed, less HP, poorer finish quality, less vibration.
Term
What is a disadvantage of climb sawing?
Definition
faster tool wear, more power requirement
Term
Define rough mill
Definition
1st step in secondary wood product manufacture
Term
How does lumber quality (as input material) affect yield of finished parts?
Definition
The higher the lumber quality, the higher the yield (generally)
Term
Define or sketch ways to obtain side clearance on a saw body
Definition
LOOKUP
Term
In sawing how does depth of cut affect horsepower?
Definition
Increase in depth of cut increases power consumption, increased horsepower
Term
What is the pitch of a saw
Definition
the distance between teeth, the "bite"
Term
Consider two blades, different sizes with same amount of teeth, how does pitch compare
Definition
Bigger saw has larger pitch
Term
Define kerf
Definition
width of cut
Term
When vibrating a saw and sprinkling sand on the blade to determine mode shape what is essential to completely evaluate blade
Definition
Measure frequencies and record, and compare to a standard (balanced control blade)
Term
What is noise?
Definition
Unwanted sound, usually from work
Term
List two sources of vibration
Definition
Mechanical- loose nut cause metal on metal vibration. Aerodynamic- propulsion of air causes sound
Term
List results discussed in class of a saw not having sufficient side clearance
Definition
Burn kerf wall, overheat. Temp or perm loss of balance- catastrophic failure
Term
Define or sketch strobe saw
Definition
carbide blades along body of blade to prevent binding and overheating. Good for knotty/low grade,
Term
optimum degree for rake angle
Definition
20-40 degrees
Term
Define peripheral cutting. Give an example
Definition
Rotary gang. Most common, rotary cutting knives on cutterhead, intermittent contact with material, workpiece passes by or through cutterhead
Term
What does saw tensioning mean to do?
Definition
Intentional use of favorable residual stresses created through plastic deformation by hammering rolling or concentrated heat applicaton.
Term
What is main disadvantages of polycrystalline diamond?
Definition
Money, brittle
Term
What is the advantage of helical moulter or planer head?
Definition
Less noise, better surface, better tool wear.
Term
HSK advantage
Definition
precision tooling,quick tool holder change
Term
List two of the four tool wear mechanisms
Definition
Abrasion, oxidation, electrochemical,
Term
Define incremental programming on a CNC router.
Definition
Moving from the last point rather than based on a a total coordinate system
Term
What is nesting
Definition
Using a program to fit multiple pieces onto a sheet to be cut
Term
What is the purpose of the down shear design of a router bit?
Definition
Downshear holds down the work piece, less top chipping
Term
Name 2 types of router bits
Definition
downshear, upshear, hogging bit, compression bit
Term
What is the advantage of tungsten carbide tool material over high speed stell
Definition
It is harder although more brittle, more corrosion, chemical resistant
Term
What is the purpose of the first two heads of a moulder
Definition
Set reference planes
Term
List types of tool holding techniques discussed for routers
Definition
Hydraulic, collet
Term
What does CAM mean
Definition
Computer Assisted Machining
Term
What is the result of an unbalance tool on surface quality
Definition
Decreases surface quality
Term
What is the disadvantage of an open coated abrasive
Definition
Less material buildup due to less grit
Term
What is the single most important characteristics in a wide belt sander that controls the rate of cut and finish?
Definition
wheel density
Term
List the three types of moulder clamping systems
Definition
conventional, hydro, HSK
Term
What is the amount of abrasive coverage for open coat abrasive
Definition
35-70%
Term
What are the advantages of a continuous press system
Definition
Mix chip particles and resins, heat and compress in progress, faster, more uniform product, less cold spot issues
Term
What is the most common operator error for a wide belt sander.
Definition
improperly utilizing the entire width of the feed bed
Term
List three of the types of wood composites listed in class
Definition
PB, MDF, HB, OSB
Term
In general what is the overall disadvantage of wood composites as a class of material
Definition
Lower dimensional stability, heavy
Term
What is a caul in the production of particleboard
Definition
Cookie sheet
Term
Characteristics that affect conversion process
Definition
grade, length, species, width, mc
Term
List 3 possible sorts in a log yard
Definition
grade, length, species, width
Term
why are sprinklers used in a log yard
Definition
to help species susceptible to blue staining, prevent rapid drying/cracking
Term
List disadvantages of using water storage
Definition
marine borers, sinkers, water pollution
Term
what is the definition of a board foot
Definition
144 cubic inches 1x12x12
Term
list different board foot log rules discussed in class
Definition
doyle, scribner, international
Term
which board foot log rule is the most accurate
Definition
international
Term
What is the main disadvantage of the newton scaling method
Definition
slow, measure 3 points
Term
what are tree sections called when they are 8 feet or greater in length
Definition
logs
Term
Why is desirable to debark a log before further processing
Definition
Prolongs life of cutting equipment, reduces debris in sawmill
Term
List debarkers discussed in class
Definition
mechanical ring debarker, drum debarker
Term
List 2 disadvantages of mechanical ring debarker
Definition
rought cut, can pull knots
Term
When is a drum debarker typically used
Definition
pulpwood
Term
list the 4 types of bucking systems
Definition
endwise, sidewise, bunch bucking, slashing
Term
what is the primary advantage of the endwise bucking system
Definition
maximum recovery
Term
what is the definition of a headrig
Definition
lumber is taken to for primary processing
Term
List some cutting systems for primary breakdown
Definition
scragg, single band, multiple band, chipper headrig
Term
what is the main advantage of a conventional headrig
Definition
can turn log or cut for grade
Term
What is advanage of a band mill over a circular headrig
Definition
saw kerf, size of logs that can be cut
Term
what is the main difference between a pony and a resaw
Definition
Pony has a carriage
Term
what is the primary purpose of the edger
Definition
removes wavy edges
Term
list types of edges
Definition
reman edgers, band mill edgers
Term
what is a combination edger
Definition
machine that will handle selectiove on one side and fixed battery on the other side
Term
Define trimming operation
Definition
practice of crosscutting lumber to square the ends or remove defects to raise the grade
Term
list types of trimmers
Definition
line shaft drop trimmer, multiple drop
Term
what is advantage of line drop shaft trimmer over similar trimmers
Definition
no motor, less heat buildup
Term
what is the difference between edging and trimming operations
Definition
edging rips to width. trimming crosscuts to length
Term
list four types of sorts when sorting lumber
Definition
grade, species, length, width
Term
list methods of sorting lumber
Definition
green chain, chain tray
Term
disadvantage of a drop sorter,
Definition
drops the wood, damage
Term
disadvantage of chain tray sorter
Definition
Space
Term
what is the definition of green chain
Definition
manual sorting
Term
list unstacker
Definition
crib unstacker, breakdown hoist
Term
what is disadvantage of crib unstacker
Definition
high capital cost
Term
what is disadvantage of abrasive planer
Definition
cost
Term
what happens if there are too many knives per fee speed?
Definition
too many knives in a cutterhead at too slow speed can cause hammer marks, dull more quicker and burning can occur
Term
What does S4S mean
Definition
surface four sides
Term
Grading of dimension lumber is based on....
Definition
worst side
Term
Define what is meant by a "board"
Definition
less than 2" thick- 1" or more in width
Term
how does feed speed affect chip size
Definition
Faster feed speed, thicker the chip
Term
advantage of breakdown hoist
Definition
lower capital cost
Term
disadvantage of breakdown hoist
Definition
requires fork truck and driver
Term
Planing rule of thumb
Definition
1 blade for every 50 feet of feed speed required
Term
too many knives per feed
Definition
small chips, raised grain, damages knives
Term
too few knives/speed
Definition
make large shavings, poor surface
Term
how does feed speed affect chip size
Definition
Faster feed speed, thicker the chip
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