This project went through many adaptations and in the end, it did not turn out as a blue box, but more like a weathered garden statue. The hydrostone did not turn out completely white, but grime on the urethane molds made little swirls, further enhancing the marbleized look. It is not bigger on the inside, but the wiring and battery did fit nicely within the internal cavity. A switch turns it on and off. Although this endeavour did not turn out exactly as planned, I learned many things about thinking in 3D and many more about construction and molding objects in 3D.

So what makes this model a “TARDIS” not just a model of a British police box that looks like a light-up garden statue? Honestly, nothing but my intent. I set out to make a model of the TARDIS and that is what it will be called.

The process I used to create this model:

Previous Posts:

1. I designed the TARDIS in Google Sketchup. > See Previous Post: TARDIS: 3D Modeling

2. I used the Modela to mill out the front, individual sides and roof of the model in machinable wax. > See Previous Post: TARDIS: Moldmaking

3. I used the block of machinable wax to create urethane molds of each of the pieces. > See Previous Post: TARDIS: Moldmaking

Laser-Cut The Casting Container:

• I designed and laser cut an adjustable press-fit box to place the individual urethane molds in order to cast the TARDIS in hydrostone. (I also custom-cut shims to key in the urethane mold edges.)

Putting Together the Casting Container / Aligning the Mold:

• When casting, I did my best to align the sides and roof together at the appropriate angles and hoped for the best. An additional laser-cut box with an empty pen casing was inserted into the larger mold when pouring the hydrostone in order to create a cavity for the wires to run form the LED on the top through the cast down into the base where the wiring, battery and other components are housed. The inside box then became part of the cast.

Removing the Casting Container:

• When taking apart the mold, I found that some of the fine details of the windows and the moldings became stuck in the urethane mold or broke off easily. I may not have mixed the hydrostone long enough, or there may have been an issue with the proportions I used. Further experimentation is this matter is needed to determine the source of the problem. This breaking away of the fine detail gave the statuette a weathered appearance, like a tombstone left out in the elements.

Adding the Electrical Components:

• In addition - I wanted to have a LED light on the top to simulate the police box light, so when cutting the outside casting box, I cut a congruent interior box (see number 4. pictures above.) This small inside box allows for an open area for the wiring from the LED through the top of the hole in the stone to the battery. The wiring consists of:
• 1 ultra bright white 10 mm LED
• 1 330 ohm resistor
• 1 small switch
• 1 battery connector and a 9V battery
• A few lengths of wire

I dedicate this project to David Tennant for his the excellent portrayal of the 10th Doctor, which has just come to an end. ;-)

Image © BBC

Anna Kaziunas France
[http://www.kaziunas.com]

halfdrill-blender.stl

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Starting with the cad.py created .rml files (for details on the 3D modeling process see my TARDIS: 3D Modeling post), I carved several molds out a block of machinable wax using the Modela milling machine.

Wax Molds

There were a few mishaps creating these molds. The z-max setting was not high enough on the side mold (you can see where the Modela bit drug through the wax and made lines that were not part of the design.). I learned that it pays to set the z-max close to the max of 1 so that it will clear the edges of the design. However, because this particular design took so long to mill out , 7 hours or so, I opted not to redo it if the damage was minor. Instead, I attempted to repair the damaged areas with wax.

After I made the wax molds, I made casts of each side and the roof using urethane rubber. The door was cast once, but the side needed to be cast 3 times to create the 3D object.

I did not allow for space at the top of the wax molds, so to ensure that the rubber would have enough room to capture the top of the design, I laser-cut some tempered masonite frames in to increase the vertical space for the rubber to fill. These frames also make it a little easier to get the rubber out of the mold. (Credit for the frame idea goes to Elliot Smith - he used this technique on his Moon Crater mold and cast).

Creating and Gluing the Frames

Mixing Urethane / Creating the Molds

At Fab Academy Providence, we used a smooth-on 2 part urethane mold mix. Just mix equal parts of each container (A and B) and mix slowly in a figure eight pattern to minimize the bubbles.

What I learned about this material:

• Mix very thoroughly. Take your time (at least 10 - 15 minutes if you can stand it). The end result will be sticky if the parts are not mixed together well - My first two molds were sticky. (suggested by Neil Gershenfeld)

• Add heat. Heat both accelerates the process and creates a less sticky end product. I used a desk lamp positioned in close proximity to the freshly poured mold. (suggested by Neil Gershenfeld)
• Be careful not to leave the heat on longer than 15 minutes or so and let the wax and rubber cool before removing the rubber mold from the wax.
• I learned the heat lesson the hard way when my mold melted from excessive heat. (see photos below)

Beware of Melting Molds

All The Molds (Good and Bad)

Next Steps:

• Create a box and system for keying in the sides of the police box so it can be cast.
• Get LED, resistor and battery to wire up the light on the top.
• Cast in hydrastone

Anna Kaziunas France
[http://www.kaziunas.com]

When reading through instructables.com, I found a great pattern for a polygon construction kit. I thought I would use it for my first laser cutter / computer controlled cutting project at Fab Academy. The instructable I reviewed is for a plastic lamp shade, but I decided to use playing cards instead and make a construction kit minus the lamp. (Also, the cards are too opaque for a lamp and I didn’t want to take a chance with heat in such a small space.) In the end, I created a sculpture construction kit.

Laser Cutting the Cards:

Putting Together The Construction Kit:

This construction kit shape can be put together to form a variety of shapes.

My Final Construction:

Anna Kaziunas France
[http://www.kaziunas.com]

Our assignment this time around was to design a circuit board, mill it, and program it in Assembly language. Each student had to become acquainted with the following work flow:

• Designing the board
  
• Machining
  
• Stuffing components
  
• Programming
  

Makeda Stephenson in the Providence Fab Lab

In a Fab Lab, circuit boards are either milled from copper-clad PCB stock or cut on a vinyl cutter from copper tape with conductive adhesive. We try to avoid the etching process in order to limit the used chemistry we have to deal with. Whether etching or cutting, the first step is to choose one of the options for creating a tool path to send to the machine:

1. Draw the circuit as a black and white PNG image and bring it into cad.py for tracing.

2. Draw the circuit using Eagle, a free PCB drafting tool, and export Gerber files, a standard format for PCBs. Gerber files can be converted into PNGs using gerbv or the online tool from circuitpeople.com. Bring the PNGs into cad.py for tracing.

3. Draw the circuit in Eagle and use Eagle's CAM processor to generate mill and drill files that can be sent directly to the machine. This process was described by Marc Boon in a workshop at the Amsterdam Fab Lab in 2008.
   

My year project will be a diorama of a mechanical dance party on a base, and the ceiling above the dance floor will be a functioning record player. The moving figures and the record player will all work on the same motor. I'll be casting these boomboxes in different materials to position around the diorama.

This article was written for the MAKE Magazine blog.

Since October of 2009, a handful of small groups of students have been taking part in an educational experiment called the Fab Academy. The Fab Academy is a distance learning collaborative that's built on the infrastructure of the Fab Lab network. Labs in Spain, Iceland, Kenya, Amsterdam, India, and Rhode Island participate in Wednesday morning lectures by videoconference. The curriculum is concentrated into two week topics with a project due at the end of each and a more ambitious annual project due at the end of the year. This series of articles for the Make: Online will follow each of the two week sessions in the curriculum and highlight the work, tools, and techniques being developed in the pilot year of the Fab Academy.

All the endmills are now in this cigar box, which lives near the Modela. Grab the SVG file for the insert here.

Attempting to cast one out of urethane plastic with a layer of soap scum failed, as I hadn't mixed the plastic enough and weird white blobs of goo got stuck in the mold. I'm currently making another mold from the wax original after having stuck the bit that came off back on.

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I've been in L.A. for about a week now and I'm really eager to get back to the lab. I have so many ideas about how to incorporate every lesson thus far into my big project, especially making molds to cast multiples of tiny body parts for the characters I've been sculpting. I'll also be molding some 3-D rendered forms. Complicated and interactive automata dioramas!

I hand- sculpted the heads above in Cernit. I flameworked the glass eyes, and the "hair" on the right is made of trochus shells.