FreeCAD Lesson 10 - Heart-shaped Ashtray Video Lecture | Mastering FreeCad: Tutorial for Beginners - Design Softwares

hello and welcome to another video
tutorial about free CAD in this video
tutorial we are going to model this
heart-shaped ashtray like it is shown
here on the screen and since we will use
the part design workbench to do that we
will have a closer look at the sketcher
and the solver we will also have a
closer look at the sketcher workbench
and some of its commands the version of
free CAD I'm using here is with 0.15
stable release on a Windows 7 64 bit
system now when beginning with 3d CID
modeling a lot of people like to ask as
a first question do I really need to
have a fully constraint sketch in order
to be able to pet a pocket with sketch
or to revolve it the simple answer is no
you don't need to have a fully
constraint sketch to do this let's look
at an example
we will create a new document we will
set up a sketch on the XY plane we will
use a polyline tool and we will create a
contour and we will make sure that it is
closed
I'll even insert
two small circles here and that's it I
closed the sketch we have an under
constrained sketch with 18 degrees of
freedom so I close the sketch and I
padded let's set for length to 20
millimeter that's okay and as you can
see free cat did paddler sketch we
didn't have any constraints except for
the obvious ones the polyline tool with
Auto constraining setting preferences
includes having coincident constraints
on these points
so the only thing validated by free cut
before doing a pet or pocket or revolve
operation is is the contour closed or
not if the contour is not closed you
will receive an error message saying
failed to validate broken face so why do
we need constraining then well there are
two obvious reasons for that the first
reason is that most parts do have a
technical background that means that for
example a bolt should fit in a hole and
therefore the diameter of the bolt
should be a little bit less than the
diameter of a hole that would be nice in
order for a bolt to fulfill its
technical function and to make sure that
this is the case we need constraining
the other obvious reason is but even in
our modern times with computers spread
it everywhere the best way to
communicate in technical things is to
have a good technical drawing showing
all necessary views or necessary
dimension all necessary information
and on this technical drawing if you are
apply dimensions to the edges and you
want to tell somebody this edge has to
be 20 millimeters long well you need to
model it in 3d with a constrained set to
20 millimeters length so the real answer
to a question is if we need a fully
constrained sketch we do not necessarily
need a fully constrained sketch but in
most cases if you design a part you will
end up with a more or less fully
constrained sketch what's the story
about this catcher and the solver now
well
the solver is running constantly in the
background and taking into account all
manually and automatically set
constraints in the sketch and the solver
is trying constantly to find a valid
solution and of course the solver is
reporting back constantly its findings
if everything is okay or if we have a
problem
but unfortunately the solver is not able
to tell us what specific constraints we
need to be able to fully constrain the
sketch he only can tell us how many
constraints we need to be able to solve
for sketch let's look at an example
let's open a new document and create a
new sketch on V XY plane and for
demonstration purposes we will use a
simple line in the sketch our line has a
start point and an end point and the
solver is reporting back under
constraint sketch with four degrees of
freedom let's think a little bit one
obvious possibility to constrain the
sketch would be to have a vertical
dimension and a horizontal dimension as
constraint applied to a start point and
the end point of a line
which is called absolute dimensioning
absolute meaning in regard to the origin
so now we have a fully constrained
sketch we gave an X and the y coordinate
to a start point and the end point of
the line another idea would be to have
for example
horizontal and vertical constraints set
up from a start point when we will set
up an absolute length for the line and
we will set up an angular constraint and
here we go we are again fully
constrained but we used different
constraints when in the first case of
course there is a third way of
constraining the line let's use a second
line from the origin to the start point
let's define this line as construction
element
and now let's use polar dimension in
giving a direction and the length for
both lines so we apply absolute length
to both lines and we apply an angular
constraint here and reply apply an angle
constraint here and we are again fully
constrained using completely different
constraints when in the other two cases
and there are even more possibilities so
as you can see all the cases here had in
common but we had to use four
constraints to fully constrain the
sketch but since we were able to use
different constraints in every case the
solver was only able to tell us well we
need four constraints to fully constrain
the sketch the solver was not able to
tell us what specific constraints we
should use that's up to us to decide
please take into account but also
construction geometry has to be fully
constrained in order to be reported by
the solver as fully constrained
so when using sketches in your 3d model
it is a good idea not to use one single
complicated sketch but to use several
less complicated sketches instead also
if very is a possibility try to make use
of symmetry or try to use patterns when
designing a part in 3d now when
constraining a sketch there is no real
golden rule to be followed but in my
opinion a good workflow would be to
first look for the pop vyas coincidences
in the sketch and constrain them the
next thing would be to look for obvious
vertical or horizontal lines and make
sure that we saw constrained when you
will perhaps look for tangency for
equality and symmetry and then you can
begin with setting up horizontal and
vertical dimensions with rady constraint
and angle constraints
and if you have setup all obvious of
these constraints you may be able to
have a look at the solver and see if
some constraints will remain to be set
and then you have to hunt down all of
the constraints if you want to have a
fully constraint sketch now as I have
said before free cut will validate the
contour if it is closed or not before it
executes a pet or pocket or revolution
operation so if we use our demonstration
object once again and apply to this face
a sketch which is not closed so the
contour is here again
and we try to apply a pet operation in
this case free cat will give us no
preview of the operation and if you
click on ok free cat will issue your
warning saying felt failed to validate
broken face this is because the contour
is not closed in this case so we can now
switch to it sketchup workbench to
validate the sketch and this is what we
will do so we will switch to a sketch of
workbench we will select our sketch and
we will select from the top menu here
sketch validate sketch so now you have
access to some tools allowing you to
search for missing coincidences by
setting up a search tolerance you can
search for invalid constraints for
reversed external geometry and you can
do constraint orientation locking
remember that when you are in edit mode
with your sketch you else also have a
list of elements used in the sketch here
you can click on one of the elements
they are highlighted in the 3d view here
so you can search for overlapping lines
maybe you have a sketch where you have a
line on top of another line and that
would lead to also a not closed contour
and free cat would refuse to do a 3d
operation with a wet sketch
the next point is but for example let's
delete the sketch then just insert the
circling and do
a pet operation
and maybe you just have realized that
you map the sketch to the wrong face so
now you need to remap the sketch to
another face you can do this by using
this icon here of your proprietary
sketcher workbench but since this sketch
is already in use by this pet here
it cannot be remapped let's select
another face from a sketch to be mapped
let's select remap a sketch icon and
select a sketch 0:01 to be remapped and
we get a cyclic dependency error so now
we have to delete this pet operation so
with only the sketch remains and now we
have to select the new face from the
sketch to be mapped to again we have to
as I said click on the icon here or
select from a sketcher workbench sketch
map sketch to face
we select the sketch 0:01 click on ok
and now the sketch is mapped to this new
face here
so
the next point is that
ah let's talk about visibility of space
object here and talk about visibility of
sketch here okay so the next point is
that varies something special with pet
operation and the revolution operation
in the part design workbench
you can either map the sketch to be used
for these operations to a face and when
padding freecad will also automatically
fuse the pet to the base solid and when
you choose to map the face of a sketch
not to one of the faces of the solids
but to one of three main planes you will
get an independence solid so at the
moment if we will have a look at the
dependency graph we will have one object
so maybe you don't want to fuse with or
you want the pet completely reorient it
so this is also doable if you select a
pet zero zero one in this case and
select from the top menu sketch no sorry
we have to select the sketch zero zero
one not for pet since we iearn sketchup
workbench and we have to select now
sketch reorient sketch and we get a
warning but the sketch with a support
face cannot be reoriented do you want to
detach it from a support if we click on
yes we can now choose a new plane which
was kept the sketch should be mapped to
or if we click on cancel we just created
two independent solids because this pet
is now not no more fused with base solid
it is detached from the base solid let's
have a look at the dependency graph we
have now two objects this is a trick you
can use to model in 3d space normally
you would choose one of the main planes
to your pet operations and then do
placement to orient your pet in 3d space
but you can also select an existing face
to your pet operation and then detach a
pet from base solid
like I have shown here with a sketchy
workbench reorient sketch command so now
that's enough for today with theory
let's start with finally modeling we
heart-shaped ashtray
so let's discard all changes create a
new document switch to part design
workbench and let's go so a basis of the
heart should be a triangle consisting of
construction lines so the first thing I
am going to do is I'm setting up a
sketch on the XY plane I choose the
polyline tool and I will create a
triangle here making sure that this line
is horizontal I will apply equality to
these two lines I will apply an angular
constraint of 60 degrees and I will
apply a horizontal dimensional
constraint of 55 millimeters
to this line here now I will select all
these three lines and toggle
construction mode so we have now erected
the basis of our heart the next thing is
I'm going to basically draw some lines
namely four of them my heart should at
least the outer contour of a heart is
formed out of four straight lines and
four arcs so now I am drawing the arcs
I'm making sure that the mid point of
the arc is set on the y-axis and I'm
trying to catch this point and this
point okay we repeat the operation here
with a mid point set now well for mid
point set here on the corner of this
triangle you will catch this point and
now it didn't catch so we will just set
up a coincidence constraint here
as we will try to make this
a little bit nicer here okay so the next
thing is to set up an arc here with a
midpoint on the y-axis okay and we will
set up one last arc here
okay everything looks nice so now we
will start to set up a tangent row
constraints so here you want to have
tangency
let's try to set up a tendency here okay
miss worked maybe good some of the next
thing is we set up a tag and see here
set up and cancel constraint here and
here
and here so everything's set up here the
next thing is but these two lines should
be parallel and these two lines should
be parallel as well okay so now we can
set up because of a symmetry of heart
equality between these two radius
elements and we can try to set up
equality between these two radius
elements okay so now we have to apply a
dimensional constraint of 25 millimeters
to this radius and we will select the
lower radius here and apply a
dimensional constraint of 3 millimeters
and here we go we have fully constraint
sketch we close the sketch we Pat it to
a length of 20 millimeters saying okay
and we just did our first successful
operation now let's apply a trick we
just learned by selecting a basic sketch
since we want to now create this in a
pocket
we will now select edit duplicate
selection to duplicate this sketch here
but we sketch is at the moment mapped to
the XY plane we want to map it to this
face because when we will do a pocket
operation so we choose this top face
here we choose the remap sketch icon and
we want to have sketch 0:01 remapped we
click on OK and we will change this
radius constraint to be 13 millimeters
and we are set up with a pocket sketch
of course we could also try to create a
edges link to external geometry and then
draw some sort of offset in the sketch
and use that for our pocket operation
okay we close with sketch and we do a
pocket operation we choose a depth of 15
millimeters we click on okay and if we
choose isometric view and fit all our
heart will look like this so let's try
this operation again basically so we
will select the sketch we will choose
edit duplicate selection and we will
remap the sketch to this top face here
my sketch 0:02
okay
and we will change with rages constraint
to be 22 millimeters
so now
we will draw once again
our heart
and
we will draw our
four lines here when we will choose an
arc
to be the midpoint of for arc on the
y-axis and let's catch up these points
so catch this midpoint here this point
here and this point here let's select
the y-axis here
and catch these two points and set up
the last arc
set up a midpoint and catch these points
here okay
so let
huh
now we are set up
with tangential constraint here and here
and let's use
these lines are now set up for tangency
here once again
and let's set up one last time at
angandjen constraint okay now we did set
up as far as I remember parallel
constraint with these two lines and
parallel constraint with these two lines
we did set up an equality with these two
lines and with these two lines equality
and we apply here a radius constraint of
16 millimeters and we will apply once
more here radius constraint of 3
millimeters
and so we are set up
to do our next operation so let's make
sure that the sketch 0 0 zu 2 is
selected and apply a pet operation with
a length of 4 millimeter to get a shape
like this the next thing is we will
select this face and we will also select
this face here this face here and this
face here we are all select it now and
then we will apply a filler of one
millimeter to all these faces then we
will select the inner face and apply a
radius of 3 millimeter to get also a
fill out here
so now let's create these pockets needed
for the cigarette by using two times a
pocket operation and we have our two
times we will see what trick we can use
bare so let's select this face here and
create a sketch
we will
use external geometry we will use the
polyline tool to create a line here the
vertical line here we will use the
polyline tool again and start from the
same point here creating our sont align
a line slope the little bit here and a
vertical line here when we will create
an arc catching up with end point here
and this end point here so now we will
set up a tangential constraint here and
we will set up a tangential constraint
here we will set up equality here
we will set a horizontal dimensional
constraint of 8 millimeters here we will
set up a vertical dimensional constraint
of 2 millimeters here we will set up an
angular constraint of 45 degrees here
and we will also set up this angle
constraint here to be 45 millimeters at
45 degrees so all we have to do now is
to set up a horizontal I mention a
constraint in regard to the origin of
this point of 10 millimeters
and when we have to set up a horizontal
dimensional constraint and our vertical
one between these two points of eight
millimeters and we are fully constrained
we will do a pocket operation not only
of five millimeters
let's see two first oh what looks good
let's click on okay and we just did our
first pocket
so for the next pocket operation we will
try to reuse we sketch so we select the
sketch 0:03
we click on edit duplicate selection the
selected object have a dependency to
unselected objects do you want to
duplicate well this is the external
geometry link so I don't want to
duplicate them and now I want a sketch
here to be remapped to this face so I'm
set I'm selecting with face here I'm
selecting remap sketch to face I'm
selecting now sketch 0:04 click on OK
I will delete
this external geometry here and this 10
millimeter constraint here I will select
all geometry and pull it to the left
hand side okay
so now again we will use external
geometry we will use with edge here we
will select this point here and with
external geometry line here and we will
fix a point on the object now we will
apply once more the 45-degree angle our
constraint
and we will apply here also 45 degrees
now if we select this point and the
origin and apply our horizontal
dimensional constraint of 10 millimeters
once again we have set up everything we
will apply the pocket operation to first
we click on OK and here we have both
pockets
okay so now we want to do these two
pockets here and well it seems like we a
little bit in trouble because the pocket
operation does need a sketch mapped to a
plane our face and here we don't have a
planar face where we can map a sketch to
so we will use a little trick maybe you
remember the lesson - with a little ball
and where we also have a problem that we
wanted to cut off the edges of our cube
and since we couldn't use my pocket
operation since we didn't have a planar
face to attach per a sketch to we used
metric that we did a pad operation
starting in the middle of 3d space and
then we used the boolean cut operation
to cut the pad from the base solid this
trick we will use here again
okay so let's toggle the visibility
of this pocket model here let's
change back to party sign workbench
insert a sketch on the Y Z and weld the
XZ plane and we will create is pocket
like this
I'm creating some sort of upper head on
this pocket to make sure that I get some
overlapping of the bodies if I would
just have reused of a sketch once more
for the pocket I wouldn't have got
overlapping and that would have resulted
in an invalid sketch so now I'm going to
set the tangential constraint here and
the tangential constraint here I'm going
to select equality here
and
if we set up symmetry here
we will select
and overall angle of 90 degrees
we will select
here a horizontal vertical dimensional
constraint of two millimeters here we
will apply two millimeters once more
here we did constrain to eight
millimeters
and here we constrained
eight meter meters again
and here we will set equality
and we will set these two points to be
at a vertical distance of 24 millimeters
we will apply okay we will close the
sketch we will toggle the visibility
once more and we will apply to the
sketch a placement and we will apply an
incremental change we will apply a
rotation around the z axis of minus 30
degrees remember that we set in the
basic sketch in this triangle an angle
of 60 degrees between these two legs of
the heart so we click on OK we do a pet
operation we click on reverse direction
and
let's end up with 90 millimeters okay
and then as you can see we now have some
overlapping here
we will select the pocket and the pad we
will change back to part workbench and
we will do our boolean cut operation and
here we are with a pocket done and now
we just have to create the last pocket
here so the last pocket is a no-brainer
we have to just reuse the sketch from
this pad here so I select it and I click
on edit duplicate selection I will apply
a placement
an incremental one rotation around z
access of 60 degrees
I will talk about visibility yes we did
we were at minus 30 degrees so now we
can see the better we have minus 30
degrees and so I turned 60 degrees in
this direction I will change to park
design workbench and I will do my pet
operation I will click on reversed I
will set up 90 millimeters again I will
select this cut solid I will also select
the pet I will change to part workbench
to my boolean cut and here we are
we have completed our heart-shaped
astray model well with that operation we
reached the end of today's lesson I hope
I did show some interesting things and
that you learned something and well have
fun we freq it and maybe see you in a
video bye