Full Scale Mouse Droid From Star Wars

I love star wars and have always loved building things from the film franchise. I have my own Stormtrooper armour, after visiting a star wars day at our local science center i decided i wanted to make a Droid from the film.

R2D2 was my first choice but i lack the space for a full size R2 in our house so i decided on the fun little mouse droid that you see chewbacca shout at and frighten away.

so this is how i went about building my little mouse droid.

Tools.

-laser cutter

- files and sand paper

- ruler/straight edge

- knife and cutting tools

Materials.

- acrylic plastic

- foamcore / foam board

-eva foam

- glues

-plastic solvent

- hot glue

-PVA /wood glue

- Black spray paint

- Miliput filler

- plastic tube

-plastic rod

- Donor Rc car and rc system

- new Rc wheels.

i did a little google search and found some images of the mouse droid from screen grabs of the films and i also found the mouse droid builders yahoo group. https://groups.yahoo.com/neo/groups/Mouse_Droid_Bu...

The droid builders groups on yahoo are a great place to find out info on the droids, they are a fantastic font of knowledge and information and photos and builds.

The top greebles are from some sort power strip type thing. a lot of the original little details from the star wars films were things they found lying around. these strips were also used on the landspeeder and other detailing parts.

there are ways of finding the original things used or buying reproductions and casts etc but i wanted to make my own (easier and cheaper) i started by making the the U channel which holds all the detailed tubes and other things.

I did this by looking at research images and the plans (see making the plans section) to get the dimensions and drew up the bottom and sides in illustrator. I marked out where i thought the tubes and rods were going to go. when i had cut out the parts i glued the two sides to the base (these are repeated as the two top greebles are the same in detail they just reverse angle and direction of tilt)

There where three different size tubes and rods per u channel, on each there were :

8 x 7mm rods at 25mm long

6 x 8mm rods at 35mm long

6 x 15mm tube at 20mm long

I made little star shaped inserts to go inside the tubes to make them look more like the research photos i found.

Then i just glued all the rods and tubes in the places marked on the bottom plate.(see the last picture)

The angle of the tilt on the greebles is around 45 degrees. the front rack tilts with the taller of the sides of the U channel to the back (low part of the tilt) and the rear rack tilts with the shorter side of the U to the rear (low part of the tilt) and they go onto a thick block of perspex, i used a small block with a 45 degrees tilt on the top edge.

The side panels on the original are made from a circuit board or large bread board style board with chip mounts and computer chips inserted into some of the chip holders.

You can go down the route of buying the bread board and all the chips and chip mounts but i

A) didnt know where to get them, or

B) wanted to get started as fast as i could, so i decided to make them using a laser cutter.

I started by getting the research images of the side panels and drawing up some plans of the board and the chip holders and chips for each side.

I cut the large panels and while cutting i engraved the chip holder places on so i would know where to put the chip holders. i cut all the chip holders. i cut two holes and rastered the middle of the holder to make it lower than the edges of the holder. Once cut i glued them all onto the marked places.

while i was gluing the holders on the base plate i cut the chips out, then i followed my plans and the source images to work out where to glue the top chips onto the chip holders.

Either side of the side panels are a heat-sync type bar, so i made these by cutting one bar thats just a little longer than the height of the side panel and about 20mm wide, and three thin strips that are the same length but only 4mm tall (all these out of 2mm plastic) and glued the thin strips at 5mm intervals.

I got some plans from the yahoo mouse builders group: https://groups.yahoo.com/neo/groups/Mouse_Droid_Bu...

and drew up some of my own using theirs as a standard base. the plans i got from the site were in inches and i like to work in millimeters.

These plans were then printed full size. i used both a large format printer and an A3 printer and tiled it and taped it together.

These printed plans will be used to build the foam board shells.

Using the full size printouts i cut out the rectangle that forms the the body join. I made the top of the top shell and used scrap to work out angles and placements (i forgot to take photos of this part, sorry) once i had made the top half of the shell i started on the bottom half, this was made exactly the same way as the top half.

looking at the reference images it shows that the bottom (and top) edge of each shell is thick with a shadow gap inbetween, to do this i used 10mm EVA mats (the type people make armour from) cutting 1inch wide strips at the length of the long side of the mouse droid shell. then i cut a 45 degree angle on the ends, make sure you cut the same side not so you can make a square frame.

I glued one long side (using hot glue) on first then worked round the shell to make the thick edge to the shell. i repeated it for both the top and bottom shell. on the front of the top shell i used a 3inch wide strip instead of 1inch, this will help when securing the two shells together.

To create the shadow gap i marked half an inch into each edge of the frame and repeated the technique but inset the foam strips to the half inch line. and on the back of the bottom shell i used another 3inch wide strip for securing the shells.

Using the remote controlled car i have had for a long time i will make the little droid move.

I measured the rc car i already had and realised that the wheel base of the car i had was far too small.

The wheel base i had was around 230mm and i needed it to be 310mm so i needed to extend the middle of the original chassis out by around 80mm so i measured up the existing one and marked out all the holes for the mounting points for the servos and all the electronics etc.using the existing bolts and nuts i screwed the front and back assemblies to the new chassis extension. This will house all the electronics that will make my mouse move.

Extending the track of the wheels was an interesting obstacle.

The front wheels (steering wheels) are pretty straight forward, i cut some spacers out of 3mm acrylic to extend the axle, steering rack wheel mount section of the
RC car, the only thing i had to buy in for this process is a new pair or threaded push rods, to enable the steering to continue to work.

One issue i encountered with the new front wheels and tyres is that when attached to the axle where the old tyres were the inside of the rims and tyre rubs onto the push rod mounting point. to remedy this i made a small 2mm spacer to go inside the rim between the axle mount point and the rim. (see picture 3 and 4)

For the rear wheels i had to be a bit more creative with the spacing to get a larger track size as the drive axle cannon be extended so i created a new hub that goes where the old wheel went with 6 holes in and then created a set of spacer rings with corresponding holes. Then a new hub for the new wheel with a new axle for the new wheel. six bolts holding the new hubs together with the spacer rings in between beaning i could make the track narrower or wider to match the shell.

the bots on the inside of the new wheel extension can be cut off to the correct length as to not interfere with the running of the wheels.

i know these methods are not the best as they will change the performance of the RC car but the droid will not be a racer anymore it will just be a little crawler. also changing the size of the wheels means the gearing is not the correct ratio anymore so the motor will have to work harder, i plan to get a crawler high torque motor to make it a better runner.

Trim plans of the bottom of the shell with the wheels and taped them to the bottom of the shell.

place the chassis with the wheels attached to double check that all the parts fall in the correct place.

once you know its all correct its time to cut the wheel wells out. The rear wells are pretty easy just use the plans for the side and bottom (make sure you cut it back into the center towards the chassis far enough to accommodate the rear wheels and hubs.

the front wheels are a little different, i started with the side arch to get the look from the plans. once i had done that i put the RC chassis back on top of the plans and drew around the front wheel as i turned it to make sure that the turning wheels would not clash with the bottom shell. (see picture 6) i cut one side and used the part i cut out as a template for the other side.

The chassis needs to be dropped through the bottom of the shell as well as the wheels. i placed the chassis with the front wheels attached and the rear wheels removed but the hubs still on so i could see where the hubs and axles meet the chassis so they would fit through the chassis hole.

With the chassis in the bottom frame i drew around it giving clearance of the motor and the heat-sync as to not cause fire risks.

To mount the shells on to the RC chassis i used the existing body shell mounts for the original RC car.i propped the shell up ate the correct height, i used RC batteries and foam (what ever i had to hand) once i had the shell at the correct height i cut some strips out of the foam board to go across the body over where the body shell mounts sit in the chassis, i then cut/drilled/poked a hole in the foam board for the post to go through. i layered the foam board to give it some strength. I repeated it for the front and back.

to hold the two shells together i used two magnets and two washers.

on the top shell i cut a little hole and glued the magnet into the foam at the front and back. and on the bottom shell i glued the washer to the foam using hot glue. this will keep the shell together while the droid is running.

i used some styrene tube and rods that fit into each other to create some locating pegs. i just cut a grove in the bottom shell foam (shadow gap foam) and glued the tube in place. then i glued the rod in the top shell in a place they will slide into the tube to keep it in place.

The last image is just a little mock up of how the droid will look, this is before treating and painting.

Preparing the droid for paint.

i filled all the seams and joins of the shells with a milliput filler. once the milliput set/drys i sanded down all the rough edges to be ready for paint.

Once all the sanding is done its time to coat the foam.

I mixed PVA glue and water and painted several coats onto the shells of the droid. this will help when i paint the droid with spray paint, the reason for this is that the paint will soak into the EVA foam and the paper on the outside of the foamboard. the pav will seal the EVA and foamboard which means the paint will take much better.

I painted the side panels, top greebles, the chassis extension and ,after masking the foam tyres so only the hubs were exposed, i sprayed them all with a white plastic primer and then painted them a satin black.

I spray painted both shells with the same paint as the top and side parts. I then sanded down the edges and rough patches again and then gave it another coat of paint.

Using a two part epoxy glue i started by gluing the top greebles onto the top shell.

i glued these an equal distance from the front and sides for the front one and the same for the back one (but the back and sides.)

in the first photo the top greebles are glued on they then give a guide as where to glue the side parts on, the side parts are just leaning to get an idea of what the spacing will look like.

The large side panel sits between the top parts, the edges match up with the inner sides of the top greebles. gluing one side at a time by leaning the top shell at an angle so that one side is flat and using the epoxy glue. i stuck the main panel and then the two little heat sync type parts either side of it. After waiting for all the glue to dry on one side to fully dry i turned the shell over and repeated the gluing process on the other side.

now all the parts have been glued on and dried you have a finished Droid. charge up your batteries and get your droid patrolling the halls of your death star (watch out for wookies though)

Conclusions and future ideas: I think it would be great to add a little remote controlled sound board into the to shell so i can make the droid squeak as it drives around. i would also like to make the shells the same way the originals were made, using plywood and a vacuum former, but due to costs and space i cant have a vacformer.