hey robot fans this is the first video
in my chopper build chopper is the
disgruntled yet lovable astromech droid
from the Star Wars rebels series in this
first video we're going to look at some
potential functionality design the frame
and start taking a look at the head
mechanism so let's get started okay here
we are I downloaded this model from
deviantART it was posted by someone
named met let's fleet yards the models
free it comes with all the textures
included I had to download a couple
other models to mix and match the parts
to get all the pieces that I wanted but
my ultimate goal was to create a
functional 3d model that I could play
around with see all the parts get a
sense of scale and test out some
functionality for the final droid so I
set up this control panel here it has
quite a few functions split into a maybe
category because I'm not sure if I'm
going to be able to do them but if we
start going through we have the head
spin
this one's pretty obvious there's also a
head bob or head nod i've noticed by
watching the show that when he's talking
chopper tends to Bob's his head quite a
bit if you think about him talking to
anyone it's always whoa boom not sure
how easy it's going to be to implement
on the droid but I think if we could
it'll be a really cool feature for
puppeteering a simple swivel controller
can make the conversation get a lot more
animated with minimal work on the
control side another function that I
like is the periscope periscope up
periscope down while it's up it could
spin maybe even put a little camera in
there I'm not sure about the privacy
issues involved with that but the option
is there the main function of chopper
that sets them apart from pretty much
every other droid are his head arms so
we have the doors open and closed and
then the arms come out I want these arms
to be as fully articulated as possible
if I can get every joint to move that
would be the ultimate goal so we have
the shoulder here elbow full arm
rotation from the shoulder and if we can
get this pincer to work the little claws
at the end I think that would be amazing
maybe if we use a little mini servo and
a piece of string I don't know this is
definitely one of the maybes I'm going
to test it out before I build the final
arm see what we could do but if I can
get
to work I think that would be amazing
left arm has the same functionality no
need to go into that there is another
arm on the body which also opens swings
out and opens and closes this one closes
and opens more like a vise then like a
pair of scissors or a pincer but I don't
know if that makes it easier or harder
but I'd like to get that working as well
and I definitely want this to be a 2 3 2
droid so when we shifted the 3 leg mode
choppers little caster wheel comes out
which is super cool yeah if we can get
all these functions to work I think that
would be awesome there's some I can
sacrifice like the little pincers but
let's work towards that goal so I guess
the next step is going to be building
the frame for the body and thinking
about how it's going to connect to the
shoulders and the head and taking into
account all of this functionality so
here's some of the hardware I want to
use for this build I have two bearings
that I want to use for the shoulders I
think these will be enough for the
design that I have in mind but just in
case they're not I have two left over
120 mil bearings from my bb-8 build that
I could use I don't think I'm going to
need them but it's nice to have the
option one lazy susans that I'm
definitely going to use is this big guy
for my head rotation I know it's pretty
commonplace in the r2 Club to use the
450 millimeter bearing but this is
actually 392 millimeter I'd like to have
the extra room on either side because I
want to do that headbob and head nod
functionality which is going to require
a little extra room I'm going to keep
these dimensions in mind and probably
build some 3d models of these when I'm
designing my frame so let's take a look
at that so here's the design cheat sheet
I was using while I was building the
frame there's no official dimensions
that exist for chopper yet every
builders kind of doing their own thing
at this point so I took a look at
everything and kind of round it off the
dimensions two numbers that were pretty
easy to work with if you look off to the
right here I have a top-down view of how
I'm going to divide up the body the
front assembly is going to consist of
the body arm and everything above and
below it
I want to try to keep this whole thing
as one giant removable chunk so I can
access the inside for maintenance just
off of that I'm going to have the to
shoulder assemblies those are going to
be very rigid and permanently installed
and on the back I have the hex panel the
bumper-sticker panel and the grille
panel which will also be removable for
maintenance
I'm going to use this little pie chart
here to keep the proportions in mind as
I'm placing the interior posts and rings
which is what I did here here's my first
general massing of how the frame is
going to be constructed I have my top
and bottom rings I also did 10 posts
going around leaving a gap for the front
assembly the top and bottom rings are
ribs are actually going to be exterior
pieces so they're going to be seen on
the final droid which means I had to
inset the posts and these interior rings
six millimeters to allow for my skins
right now these rings are going 360
which is a little bit overkill so in the
next step I'm going to refine them down
to what's necessary I also had to start
thinking about how I was going to attach
the head the shoulders the skins and the
skirt to the final frame so in this next
step I cut down all the rings to what
was necessary I added in this brace to
the bottom of the posts I removed a lot
of mass from the base piece because it
was just going to be a lot of
unnecessary printing I built the skirt
and placed that where it needs to be so
when I start making mounting holes it'll
be right there ready to go I made a 3d
model of the lazy susan and put that
into place I really have to start
thinking about how this is going to
attach to this top rim keeping in mind
that I need the center ring of the lazy
susan to rotate and I need the whole
thing to bob or nod like I wanted to for
the shoulders I just basically kept a
hole here for that bearing that I want
to use I think I could fit everything
inside of this space the only thing
that's really left to address is how the
skins are going to attach and the way I
did that was to place holes everywhere
basically I put holes in all the posts
all the Rings into this bottom brace
here and all throughout the base so this
should allow me to mount all the skins
it'll keep extra mounting places for all
the motors that are coming and anything
else that I'm not thinking of I also
thought of a way to do the head
mechanism I'm going to talk about that
in a minute
at this point my frame is pretty much
done I'm ready to start printing I just
have to split them off into printer
compatible parts
so I did that here I took each piece and
broke them up into many many sub pieces
I plan on printing this in ABS and abs
tends to contract as it cools which
leads to a lot of work äj--
so I'd rather have 60 parts that I have
to glue together than have 20 parts that
warp crazy and don't fit together
anymore so in the end this frame is
actually going to be about 58 pieces and
if you put them all back together it
looks like this here you can see all the
pieces in different colors come back
together at this point though it's ready
to print so I can start printing this
right away
these exterior pieces like this top cap
and the bottom base here I'm going to
print in silver abs just to make the
painting that much easier and everything
else is going to be printed in white the
last thing that we need to talk about is
the head mechanism so I have this as
part of this top ring piece which is
split into three layers and in addition
to those three layers I have these two
chunks separated out these have recesses
for hardware one is a bolt and one is a
sleeve bearing which you can see here
this is a 12 millimeter bolt I
downloaded this model from mcmaster-carr
that's one of the huge advantages of
using McMaster for all your hardware is
that you could download CAD models of
their parts and use them in your builds
which is super convenient because
there's no guesswork really when you
have the model right in front of you the
way that this is going to work is the
sleeve bearing is going to push in from
the back and that's going to support the
bolt which is going to go in from the
front and fit into its own recess and
then on top of all of that this 22
millimeter bearing is going to go and
spin freely and this is what's going to
attach to the lazy susan bearing to
allow everything to nod and Bob so let's
take a look at that in real life with
the 3d printed parts
so here's my 3d printed part and the
hardware anytime I'm building a 3d
printed part that has a recess for
hardware I always make the recess a
little bit bigger about 0.25 millimeters
parts that fit together really well in
CAD never fit together in real life you
always have to sand them down so I left
a recess for all of these parts and
since the ABS contracted a little bit it
still fits really snugly so if I put the
sleeve bearing in the back it just takes
a push fit and one more here on the
corner and that's in there really well
same thing with the bolt I could take
the bolt line it up with the recess push
down on the table and that's installed
there really well I'm not going anywhere
I could find glue if I need to but I
don't think I'm going to this 22
millimeter bearing will then fit on to
the bolt and that spins freely so I
already did the other side of this now
the next step will be to assemble the
full top ring and then we can test this
mechanism on the lazy susan bearing to
make sure we can get our nod here's the
rest of the 3d printed parts for the top
ring these will be solvent welded
together back-to-back I also printed out
two brackets which will hold the bearing
against the 12 millimeter bolt and screw
into the lazy susan so that we can test
the rotation all right here we are I
have the top ring fully assembled and I
have the lazy susan installed with those
two brackets
I had to drill holes on either side of
the lazy susan to install the screws
overall I think the test was pretty
successful we have the rotation that we
want and the lazy students not crashing
into the top ring which i think is all
we could have hoped for out of this test
right now it's sitting a little bit
above the top ring but there's going to
be a cap piece that goes on top which
will make everything sit flush with the
top of the body then the rotation of the
head will come from the interior ring
and I'm going to design another
mechanism to control the front to back
rotation of the nod all right we have a
free spinning head mechanism I think
that's going to be it for this video
next time I'll continue with the head
getting the rotation and the nod setup
on tracks in order to do that I'm going
to have to build the rest of the frame
so there's a bit of work to be done in
between
but hopefully next time we could set up
some motors and get this thing rolling
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description and I'll see you next time
Oh
you