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ENGG1000 BIOMED > Materials > Flashcards

Flashcards in Materials Deck (16):
1

what should you consider prior to selecting a given material for your project?

-strength: how strong does it have to be

-workability: do i have the tools and skills to make use of the material

-expense: can i afford the material

2

what are two types of wood?

hardwood, softwood and plywood

3

what are the properties of hardwood?

-strong
-can be difficult to work with
-more likely to split when nailing or screwing if not careful
-used for decking usually

4

what are the properties of softwood?

-not as strong
-easier to work with, more forgiving
-can be light and soft
can be used for a range off applications

5

what are the properties of plywood?

-sheet material, made up of layers of thin sheets of wood(piles) which alternate in sheet direction
-strong in all directions
-resistant to splitting
-good for curved components
-easy to saw but hard to shape with hand tools

6

in what direciton must the grain be?

in the direction of load

7

what are the properties of acrylic?

-shatter-resistant alt to glass
-transparent, half as heavy as glass
-difficult to work witih by hand, must use a lazer cutter etc

8

what are some other names to acrylic?

perspex, plexiglass, polyglass, lucite

9

what are the properties of aluminium?

-easy to work with
-if thin, can be cut with tin snips
-can make it stronger by folding layers upon layers, highly malleable

10

how do you convert electrical energy into mechanicall energy?

connecting a shaft coupler to a dc motor

11

what can i use to mount a motor to the chassis?

mounting bracket

12

how do i convert rotational motion to linear motion?

connecting a lead screw

13

what are some common types of fasteners?

screws
bolts
nuts
glues
solder
pop rivets
welding
duct tape

14

what are the three types of screws and what distinguishes them from one another?

wood to wood:
wide spaced thread with a threadless shank

sheet metal to wood:
consists of a threaded and threadless shaft combination with wings near the bottom of the nail. wings prevent the threads from engaging with wood. wings break in contact with metal allowing threads to become engaged with metal. must be drilled into wood first then metal

metal to metal:
threads are closer together and the whole shaft is threaded

15

what are pop rivets good for?

very good for sheet metal, not very good for plastic

16

what are the three types of glue and what distinguishes the three?

white glue: joining wood to wood, relatively tight fit

many epoxy-type adhesives: mix and apply

superglue: may not be useful