I have changed my approach to the Dalek ears and got some translucent filament so I could put a LED at the bottom and light.
Below are images of the ear the first being a prototype of the ear, in this design I added a tube with an opening at the bottom and an extension.
The intention was that would fit into the dome this was my first attempt and I used regular white filament.
Got back from Chicago Tardis a couple of days ago. I had a great time. I took Mini-Me and he trundled up and down the hallway again like last year.
Most people were happy to see him and took the opportunity to get their sonic screwdrivers out. (Ha like that really has an effect on Daleks).
Last year it was obvious that he moved rather slowly and while he was cute and everything, he was also very s-l-o-w.
This year I chose to “update” his motor control by changing the gear ratio on the VEX chassis that I made for last year. I changed it from being high torque to more speed. I learned an important lesson. High torque works better on carpet especially when you want to turn.
If I were to make an upgrade to the VEX chassis for next year, I would add floating wheels for the front. I did not realize that having four fixed wheels does not mix well with low torque. I did not realize that it was more of a fluke that he could turn on a dime last year and due to the higher torque.
There were many amazing costumes and though I did not have a camera with me at all times, I managed to get a few pictures.
I have been so busy this year at nights and weekends – sometimes work…(Boo) … sometimes…. Linux (yeah!)…. Sometimes vacations (yeahhhhh!!!).
But Vickie has been able to steal some time from her schedule to design herself a little Cyber-coolness.
K-9, the robotic companion to the Fourth Doctor, was my first project and I learned a lot from making him. Since the BBC had long ago released plans for K-9, I thought that this would be an easy project to do. I was SO wrong. It was much harder to do than I imagined. I found the plans that the BBC released. Sadly several dimensions were missing.
10 Things I would do differently next time
Use a better amplifier.
Add a method of sensing people to start interaction.
Use servos to control the radar (ears), gun (nose) and wagging tail.
Build the whole body from lighter materials.
Change the head (in the plans issued by the BBC, the dimensions for the head are incorrect).
Use an ISD2560 IC for the speech or similar IC.
Remote control drive.
Make the electronics accessible via a panel on the side of the body.
Use PCBs instead of using stripboard for the electronic circuits.
Make the electronics more modular.
I did not initially make a list of features that make it recognizable as a character. But if I had it would be like this.
After playing around with some battery operated drill motors I felt that they were too long to fit inside K-9’s body side by side
I instead used 2 electric window up/down motors from a car.
The H-bridge worked fine however the weight of the body and the wheels being slightly misaligned made the wheels rub on the frame. When I powered it up the first 3 or 4 times K-9 shot across the floor proudly.
As they rubbed it got worse until the fuses started blowing. I gave up trying to fix this because it because I had made the motors very inaccessible. Lifting the body made its just too difficult to access the motors each time.
I did not really consider things being accessible
For the ‘computer’ that sits on K-9’s back I purchased a large calculator that was the correct dimension and modified it to look somewhat authentic.
The lights that flash are LED’s controlled by a Pic16F84A programmed with JAL.
Basically it is the ‘Knight Rider style’ sample program that comes with JAL but with some slight modifications and some fancy wiring.
The head was assembled last,
The TV K-9 has a gun that comes out just below his nose. I had the gun moving back and forth but no way to actually fit it in the head, plus the motor driver IC was getting hot, so I glued it in place and it is non movable.
K-9’s ears are two radar dishes that oscillate back and forth. I purchased some surplus stepper motors which would fit side by side inside the head. I then created a circuit to make them oscillate back and forth. Once powered up, the circuit worked marvellously, almost totally silent, and the ears rotated back and forth very smoothly. I noticed current consumption of the stepper motors was quite high.
Here are the ears moving
I had someone do the K-9 voice and modified the files with Audacity, which then I burned to a CD. I had a CD player that was controlled by a Pic16F84A IC for Play, Stop, FF, etc.
Here is where timing became an issue (and thus the down side of using this method).
As the CD does not provide feedback on what is happening, you cannot tell if it is playing or not or even which track is playing. I so everything had to restart from a reference point for each track, each track was exactly the same length and every thing was based on timing and then, when finished playing, back to that reference point.
Overall this is not the best way to control speech or music.
The body and head were based on the plans that the BBC released.
A piece of plywood approx 29″ x 18″ is the base everything sits on.
Then I made a frame that was the size of the body and the skin sides were cut from hardboard and glued to the frame
Building the body of the dog took a lot of sanding and filling.
The body was painted with car spray paint.
The neck piece was made from dryer hose painted black.
The eyes were red stained glass paint on some perspex.
Some tartan material folded and glued became the collar.
I had K-9 engraved on a dog tag.
Pipe insulation painted black made the edge stripping along the bottom.
Ears are pieces of screen door attached to thick gauge wire.
Stepper motors turn the ears from side to side.
For the tail of the dog a portable VHF radio antenna.
The bellows (tail) were molded using cardboard and air drying clay.