FreeCAD Lesson 09 - Outer Threads Video Lecture | Mastering FreeCad: Tutorial for Beginners - Design Softwares

hello and welcome to another video
tutorial about free ket in this video
tutorial we are going to talk about out
of threads we are going to look at a
several screws and how to model them for
an example and we are going to have a
look at the workflow of groov tool in
part design workbench and we are going
to have a look at the workflow of linear
pattern tool in the part design
workbench perversion of freaking time
using here is with 0.15 stable release
on a Windows 7 64 bit system as already
explained in the tutorial bout the inner
frets when it comes to modeling screws
and frets in 3d as far as mechanical
engineering is concerned we often use an
abstract representation of a screw like
for instance here I like here because on
first look you can see it is a screw in
this case it is a hexagon head and well
you can use of course your measurement
tools within 3d to get an idea about the
size and the length of the screw and of
course you have like with the inner
frets more means to model a thread in 3d
as for example you could use a
concentric groove and the linear pattern
in this case but you don't have to
design some sort of tooth profile along
here and of course if you can try to
model a real threat as far as you can go
with in 3d means by using a swept
profile along the hallux and then do a
boolean cut on the solids to get your
Fred when it comes to modeling a screw
in 3d for example you can do it like
this in this model I have used in a part
design workbench to operations every
revolution from the basic profile and a
pocket operation for getting this
hexagon slot so if I have a look at the
sketch of a revolution you can see here
the basic profile getting revolve at 360
degrees to get a shape like this and
then I just drew my hexagon sketch here
on this plane and set I wanted to use
the pocket operation and that's it
the same idea was applied at modeling
risk screw as you can see here i also
used revolution and pocket from part
design workbench to obtain a shape like
this so in this case this was the
profile to be rotated at an angle of 360
degrees and then I choose this face here
and applied a hexagon and the circle
sketch on this like you can see here
with this Mexican and business with
circle when I applied a pocket operation
to get rid of let's say the outer
material here to obtain the final shape
like this
of course at least some of the shapes
can also be obtained by using the part
module workbench within free DC ad
there is no golden rule how to model an
object and you will quite often find
yourself looking at the model you
already obtained and deciding well maybe
it's best to delete the model you
already have and start all over again
using a different design approach so now
I'm going to show you how to obtain a
hexagon socket screw by using the pod
module workbench so first of all I'm
going to close all most windows and I'm
going to start a new document so first
I'm going to switch to a part module
workbench I'm going to insert a cylinder
I will highlight the cylinder in the
preview here and I will apply with a
dataview a radius of 3 millimeter and 8
of let's say 40 millimeters I will now
insert a second cylinder giving it a
radius of 5 millimeters and 8 of 6
millimeters
switching to X symmetric you say fit all
I am now going to highlight the second
cylinder here and I'm going to apply a
placement to it I will change the Z
value to 40 millimeters to get the head
here I say okay
and now I will highlight I would like
these two cylinders here and I will
apply a fusion to make a union of the
two shapes
now for which hexagon socket I'm going
to select this upper face here I will
switch to the sketch erect bench and
apply a sketch to his face here I will
create a regular polygon I will select
the center point here and a point here I
will now select this point and the
vertical axis here and I will say I want
to use the constraint fix the point onto
an object okay I will apply the same
here and now I will select these two
points and with access and apply
symmetry which could be one possibility
or I can say I want to make this point
and this point coincident this will
result in the same situation so now we
have only one degree of freedom left so
if I select these two points and apply a
horizontal dimension of 5 millimeters we
have a fully constrained sketch and
that's it we are done with the sketch it
is not absolutely necessary to every
time fully constrain a sketch but it is
good advice to do this because if you
leave an under constraint sketch that
might lead to errors and
misinterpretation in the future
so we will close the sketch we will
switch back to my part module workbench
we will do an extrusion as you can see
here we want to extrude along the
negative z axis so either we could apply
here a minus 3 4 minus 3 millimeter or
we could apply a value here in length
which is the same result we will create
a solid and we do not want to be conical
or something like that in in some way we
don't want to apply a taper so we say ok
and now if we highlight fusion and
extrude and we apply a boolean cut we
have our socket here now we can apply a
radius if we like or to say fill it of
in this case well we choose one tenth of
the diameter of the bolt of a screw so
in our case we choose a diameter of six
millimeter so we will apply a fill out
here of zero comma six millimeter I say
okay follow the supplied and now I will
apply a chamfer here
and a problem all let's save a
restriction with four chamfer operation
in part design and part modulus that at
least at the moment raised only at gem
for operation with 45 degrees possible
so if you need another angle and when we
try to model realistic we are facing
very striction that a metric Fred uses
an angle of 60 degrees it is not
possible to apply a chamfer of 30
degrees with this operation here so in
this case I apply a chamber of let's say
0 comma 5 it's just not particular
representation and I'm done here so this
is another way of doing with shape here
for this square for school and as you
can see here I use quite a lot of
operations within part design as you
could see I only use two operations
which was a little bit faster and it's
more parametric if I want to use another
length in this case I have to change the
length or just to be exactly eighth of
this cylinder here
and then I have to apply an error Z
value to the head here to get a correct
shape again with in part design I would
just have to change a value in
revolution sketch and that's it that's
one of the big advantages of using part
design over part module
now for the version with a concentric
groove and with linear pattern I will
start in part design workbench with a
new document first I will apply a sketch
to a wise that plane I will use the
polyline tool to roughly outline the
basic rotational shape of the screw so I
will sketch here rough outline of a head
head back to the origin and that's it
now as often precut assigned here to
constraints conflicting each other so I
have to delete one of the constraints
and the solver as you can see issue is
now no warning everything is OK so first
thing we will do is to create a full it
will click on the icon we will click on
a point here and a point here and free
cut automatically creates a fill it here
with tangential constraints and
everything else needed I will do right
click to end this operation the next
thing is to constrain the whole sketch
so first of all sins in a metric thread
we have an angle of overall 60 degrees
here we will need an angle of 30 degrees
here or in other words an angle of 150
degrees here so I apply here an angle
constraint of 150 degrees
I will also apply a radius constraint
here of 0 comma 6 millimeters
I will apply a vertical dimension
constraint here and the values 2 comma 3
8 5 millimeters I did look in re
instructions for the metric threads
before creating this tutorial so I
looked all the values of all dimensions
to be able to create real dimensions
like this one here so now we apply to
these two points a vertical dimension
constraint of 3 millimeters since we
since we want to do in this case a
thread of 6 millimeters I will also
apply 8 to the head of the screw of 6
millimeters
I will drag my line a little bit
downwards to be able to apply a radius
of 5 millimeters to the head and now I
will apply a vertical and horizontal
length constraint of 40 millimeters for
the bolt or to save a shaft length here
and everything is constrained I will
close my sketch apply a revolution I
will switch to horizontal sketch axis
and the basic shape is done now we will
apply this hexagon socket we will select
the face here we will apply a sketch to
the faith we will
a change to polygon sketch a tool we
will apply a hexagon here and then we
will select this point here and this
axis here and we will fix a point on the
axis we will repeat this operation here
and we will apply a symmetry constraint
to these two points and this axis here
so we choose symmetry and we are left
with one degree of freedom
of course with a basic size of a hexagon
so I will choose five millimeters for
this dimension here I will close some
sketch I will apply a pocket operation
and the length should be free
millimeters so overall I'm done now with
a basic shape of the screw and will now
continue with a groove
unfortunately the groove tool needs a
flat face for its basic sketch and since
we have a revolved feature here we don't
have a flat face to apply a first basic
sketch to so we will do a trick and a
trick is met with select front face here
we will apply a sketch to a front face
here we will select
a rectangle here we will apply equality
constraint to these twos I sides we will
also apply a dimensional constraint of
let's say five millimeters we will close
the sketch and we will Pat the sketch to
five millimeters as you can see we just
did an additional operation providing us
a flat face for a basic sketch we need
for the groove so the next operation is
to select with front face office cube
here or with this in fact a pad and we
apply a sketch and we will apply with a
polyline tool a triangle here we will
apply a horizontal constraint to this
line here
we will apply equality to these two
lines and now we will apply once more a
vertical constraint a vertical dimension
constraint of two comma three eight five
millimeters to this point here we will
apply also a vertical dimension
constraint of three millimeters here
and when we I closed the sketch for one
moment and I talked with a visibility of
a pet to have a better view of a sketch
and to be able to work a little bit
better the next thing is we will apply
an ink constraint here of 60 degrees and
now we need to position the sketch in y
direction as you can see the sketches
under is under constraint if I click on
a line here I can drag around this catch
so the next thing is that we should
apply some construction geometry so I'm
applying these two lines here I will
mark these two lines and apply
construction mode to these two lines and
I will apply equality constraint here to
this line as well and when I will select
this point here this X's here and I will
put a point or I will fix my point to
this axis here I will close the sketch
and if I toggle the visibility you will
see this is the first groove and I will
apply my groove operation to a
horizontal sketch axis I will click on
ok and we just made a correct groove we
will need this cube also to define an
axis for our linear pattern which I will
now define so I will make sure that the
groove is selected here I will apply a
linear pattern feature and I will apply
to an overall length of 23 millimeters
as you can see transformation succeeded
freaka did already two occurrences on a
length of 23 millimeters but I will have
a 23 our currencies and let's how free
cut does here with operation I will
click on OK and that's it
so all we have to do now is cut away
with ku cube we just insert it as a
helping feature and when we are done so
I will select in this case with face I
will apply a sketch to a face I will
create an edge link to external geometry
so I will select this edge here I will
create an rectangle selecting a starting
point this point here because then I can
fix this point on this point
I'm sorry this possible wrong constraint
coincidence is needed and when the next
operation will be to set equality to
East Alliance and Vasquez is fully
constrained we closed our sketch we do a
pocket operation we say through all we
click on OK
and the screw is done as you can see
visually it really looks a little bit
like a fret so this is a commonly used
trick if you want to do rendering with
high quality and good-looking pictures
of your part you'd normally don't use
hallux frets because that would mean a
lot of CPU usage and a lot of
calculation power and so a lot of time
to calculate a good-looking picture in
most cases a concentric groove with a
linear pattern or something like that
will be sufficient enough for these
cases so now we will start with the
hallux fret and therefore I will just
delete most features and I will also
delete those remaining two sketches and
I just realized I will also have to
delete the pet okay so this is our
starting shape as you may remember we
started with our revolution and when we
did our pocket operation to obtain this
hexagon socket here
so now we will start with inserting the
hallux and was we profile and everything
like that
okay so now we switch back to a pop
module workbench we insert our hallux so
we choose here Alex the pitch is one
millimeter the eight should be 26
millimeters radius should be three
millimeters angle is zero degrees
coordinate system is right-handed that's
okay but the location we will change a
little bit the position is okay and the
direction should not be the z direction
the direction should be a y direction as
you can see looking at the triode here
this is a y direction okay so we choose
create and we just see that Alex is
inserted correctly which is close
and then our next thing is to create a
sketch to be swept so with triangle so
the next thing is to go back to the
sketch of workbench of a part design
workbench and we will create a new
sketch on the Y Z plane and then we will
create our triangle here and first thing
we will do is create an equality
constraint and applying it to these two
lines we will then apply an angular
constraint of 60 degrees to these lines
we will also apply a vertical
dimensional constraint in regard to the
origin of 3 comma 1 millimeter and we
will apply another vertical dimensional
constraint of 2 comma 3 8 5 millimeters
to this base point of the triangle here
you close the sketch and we are done so
the next thing is when I click an empty
space to make sure everything is d
selected we switch back to a part module
workbench we choose a utility to sweep
and we will do a double click on the
sketch 0 0 tool as you can see it is now
here highlighted we click an empty space
to deselect everything again and to get
to a sweep path
we will do a double click on this Alex
here if we do a double click we will
select the complete Alex if we only
click once we will select only the first
turn of the helix so we click on done we
want to create a solid not a shell
object and we want the threaded option
to be true this is to make sure with the
beginning face and the end face of the
sweep operation are coplanar so I click
on OK as you can see here the HELOCs
sweep was done correctly and now I apply
a boolean cut on these two shapes
and here we go we toggle the visibility
of basic sketch and we also toggle the
visibility of Alex and as you can see
here we are basically done but one thing
remains as you can see here we end up in
the middle of a material with our sweep
and cut operation so the main question
is is there something we can do to
improve this situation and yes basically
you have two options here
the first option would be to do a sketch
on this face and apply a pocket
operation to get a straight ending here
the second option would be to insert
another hallux this time with an angle
applied so that you will get a swept and
cut helix which will leave the material
at some point but as you will see
freecad basically can do hallux
operation but its main geometric core is
very weak on such operations we will
have to cheat to do at least before 0.15
stable release on Windows 7 64 bit to
achieve the correct result with these
operations if you will try a pocket
operation here free cut will issue a
narrow and will refuse to do the
operation so we do cheat we do a sketch
and we do not pocket it we will pet it
and then apply a boolean operation
which will result in a nearly correct
correct shape in the end and when
inserted the second helix if you will
apply the correct dimension in this case
the correct dimension of this base point
here in regard to the origin which was s
you may remember two comma three eight
five millimeters with Daleks operation
when when applying the boolean cut will
fail as well let's Bible why we will
apply a little cheat bear as well by
changing the value to two comma three
eight six millimeters and then the
boolean operation will succeed so now
I'm going to show you all these two
operations so for first idea we will
unhide this shape here we will switch
back to the part design workbench we
will create a new sketch with time on
the Y Z plane we will sketch out our
basic triangle making sure that this
line is horizontal we will apply
equality to these two lines and we will
also apply an angular constraint of 60
degrees to VC lines we will choose base
point of a triangle applying a vertical
dimensional constraint of two comma
three eight five millimeters we will
apply a vertical dimensional constraint
to these two points a free comma one
millimeter
and we will also apply a horizontal by
mention a constraint of 26 millimeters
to the base point of a triangle in
regard to the origin we will close the
sketch we will apply our pad operation
leaving the length to 10 millimeter
choosing symmetric to plane okay and
when we will toggle the visibility of a
basic shape here once more and then we
will apply our boolean cut twist to
shape so I will switch to the pod module
workbench apply my boolean cut and
that's it so as you can see these lines
remained because we did a pet operation
symmetric to plane this is the cheat
that did the trick
because if we would have padded only in
one direction in this case in the
x-direction we would have ended up with
an arrow just like if we would try to do
the pocket operation so as you can see
sometimes we have to cheat because free
cut is quite weak on helix based
operations you may succeed with older or
newer freaking versions it is sometimes
the question may be of a little bit luck
and maybe sometimes you just have cases
with with a relationship between your
geometry constraints when is good and
sometimes you will have situations where
it is a bad relationship between your
constraints leaving basic or being
unable to perform requested operation so
sometimes as you can see you have to use
some small dirty tricks to cheat a
little bit in freecad to achieve the
result you want to have so let's have a
look now at a second a possibility by
inserting another helix so I will delete
a cut operation and I will delete a pet
operation and I will leave the sketch
here in place and then I will insert the
hallux and do my sweep and my boolean
cut okay so let's insert another helix
we will leave the pitch at one
millimeter v8 we will leave at two
millimeters will change from radius to
be three millimeters we will change the
angle to be 20 degrees and we will
change the location and direction in 3d
space as you may remember we ended up of
26 millimeters in y direction so we
choose for y value to be 26 millimeters
and the direction to be Y as well so we
click on create close and as you can see
here the Alex operation was done
successfully we click in empty space to
make sure everything is deselected we
click on the utility to sweep we double
click on the sketch 0:03
to make it a sweep profile we click in
the empty space again to make sure
everything is deselected we click on
sweep path we make a double click on the
hallux to select the whole Alex we click
are done we want to create a solid and
we want
a fragment option to be true we click on
OK and this is how a sweep operation is
done and then we will perform a boolean
cut on these two shapes as you can see
here free cut will not perform this
operation successfully so as I told you
before we will go back and try a little
cheat changing this value to be 2 comma
3 8 6 millimeters we click on OK we will
later over will wait a little bit for
free care to perform the operation and
as you can see here our cheat did for
trick and the hallux operation is done
successfully as you can see here this is
how the end of a Fed does look like now
speaking of mechanical engineering not
in case of screws but mostly in cases
where you will cut the fret yourself to
mechanical parts where is also the
option to have a groove at the end of
the thread a groove with an inner
diameter of less than V inner diameter
or fret so that the tool used to machine
were friend will end up in empty space
at the end or for Fred so with this we
reach the end of a video I hope you
enjoyed watching it I hope also that I
could show a lot of your things and well
I have fun with free kit and maybe see
you in another video bye