ME105 MECHANICAL ENGINEERING GRAPHICS


ME105
MECHANICAL ENGINEERING GRAPHICS
FALL
2016
Tommy Smith
Milestone
#
3
Due date: Sec001
9
/
2
9/2016
M
ILESTONE
3:
B
LOCKS
This project milestone will require students to practice the following SolidWorks skills
:
Extrudes (boss and cut), Shell,
Sketch Relations, Convert Entities, Linear Feature
Patterns, Equations, and Global Variables.
`
Students must create a 6×2
black
block similar to LEGO part number
3
79521
(see last page of
your LEGO kit documentation). The block must be created according to
the following, and in
this order
.
Save your
original SolidWorks part file
to your project folder on the W drive, called
“skinnybrick
.
The file type should be SLDPRT (*.prt; *.sldprt).
1.
Create global variables “Length” and “Width” and set Length=6 and Widt
h=2.
2.
Create the base extrude feature, based on a sketch where the length and width are defined
using an equation referencing the two global variables already defined in Step #1 and
multiplying by 8mm to calculate the total width and length of the block.
Place your sketch
on the “top” plane for this base feature and be sure to extrude “up”. Extrude the sketch to
3.2mm.
3.
Create one circular knob feature, with diameter of 5mm and height of 1.8 mm. Locate the
center of the boss 4mm each direction from the co
rner of the base feature.
ME105
MECHANICAL ENGINEERING GRAPHICS
FALL
2016
Tommy Smith
4.
Create a linear feature pattern in two dimensions, using the edges of the base feature to
define the direction. Set the spacing to 8mm and set the number of instances in each
direction by using equations to reference the two global variables already define
d in Step
#1
5.
On the bottom of the base feature, use the shell command to create a shell feature with a
thickness value of 1.5 mm.
6.
Adjust the depth of the hollow under the LEGO by doing another extrude cut that is 0.1 mm
deep. This makes the depth 1.8 m
m instead of 1.7mm (so the LEGO blocks would fit
together properly)
.
7.
Create a sketch on the underside (same face you just adjusted in step 6). Use “convert
entities” to bring the four circular edges of the bosses into your sketch. Select the four
circles
in your sketch and make them construction geometry (dashed lines). Now create an
annulus (circle inside a circle, concentric) such that the outside circle is tangent to the
dashed circles (only need three tangencies to define) and the inside circle has a
diameter of
5mm.
8.
Notice that you don’t have enough of the annulus bosses on the underside. Fix this by
creating another linear feature pattern in two directions, using an equation to link it to the
“Length” and “Width”. Hint: Remember that you need to use
an “n
1” approach…there are
always one less ring underneath in each direction compared to the number of knobs on top.
9.
Try redefining “Length” and “Width” to be other values. Note that your patterns work well so
long as there is more than one new instance
of the feature. For instance, if you set Length=2
and Width=2 you will get an error because the pattern for the ring underneath no longer has
any new instances. The solution to this problem is to “suppress” the pattern when it is not
being used (“suppress
” is available when you right
click a feature in the tree).
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