This week we start working with computer aid design tools, I will
give you a review of several of them and later you will find my first
sketch in 2D and 3D of the robot.
Auto CAD 360
The first thing I think about drawing was autocad, I know it is a old
and very famous vectory program and it is my first parade in this
revision; I look for a recent and simple version and fond
Autocad 360. It is a 2D tool for drawing from your laptop, desktop and mobile phone.
It
is look very friendly, the best part of it is that look like very easy
and very powerfull to work, my golden rule to review software is that
if I need to spend more thatn 15 minutes try to figurate how work with
it, then I leave it.
In this case I open and example and start
to play with it the House 3D example, in a great change from the old
days with a hundrends manus and tool bars.. Just a few options
very easy to understand, so I started a design.

The
plot was easy to do, but there is a lot of features I dont find (at
least easily), and just is 2D with some features of 3D, actually I need
something to create a object in 3D and then the software made the
blueprints. For a architect I guest it is great, but for my is not
enougn, because I not only need drawing, I need something to help me to
design the objetc and then do the blueprints for me.

My very simple drawing you can find
here.
This
software is front AutoDesk too, look far more what I like, something
which help me to made the object and the software do the blueprints for
me. The first time to opened start a tutorial, which I will follow
now...

The tutorial is clear, but always is better find a
video tutorial, which some google I found a 4 parts tutorial in this
link, it is a great tutorial, only an hour to view, after a while playing with the tools I get
this. 
Well, now I´m ready to made my 3D robot design, it
is the first version wich I will improve in the coming weeks.
First I need some way to measure my first sketch, so
put my first design into a grip to stimate the size of every parts,
each square is around 50 mm aprox, so with this I can start to see the
size of every part, the critical part is that the head should have
around 20cm high, if the head is smallers could be difficult to
acomoodate the Intel NUC or Raspberry plus the other mechanics, in
addition, a 20cm head is simmilar in size to a child.
.
The next steps are diagram in the program the
differents parts, I divide the job in five: wheels, Motor house,
Chassis, loose wheel, and Head. Starting for the more easy, this is the
wheel, very easy, just a toroide plus a cilinder: 175mm hight and 22 mm
wide.

Next, I start working in the motor house, the
diameter is a little smaller than the wheels with 125 mm diameter and
250mm wide

Now is time to work in the chassis, from the drawing
look like 400 mm high from the floor, so leaving 25mm clearance from
the floor, we get 375 mm high, same wide as motor house 250 mm. The
chassis is just a semi sphere plus a trunk cone.

Then,
is time to the head, I experimented with different options, spheres,
cubes, rounded cilinders and rounded cubes, many options to try
to identify the best options, it take a while, a little more tedious to
explore the options:
After a while we finaly have a head more or less funtional, maybe I
will improve it in the future, but as first draft look great for me
Here a close up of the final version

Now assembling all together

After several hours of emprovements, the file of the project is
here.