Introduction: Building a Drinkbot: the Elixirator

About: I like to tinker and experiment with electronics, robotics, programming, and photography. Along with my latest interest in Steampunk.
The Elixirator is a Steampunk cocktail mixing machine. Up to 10 different drinks from four ingredients can be selected and dispensed. Four bottles are used to hold the spirits and mixers for the drinks.  The contents of the bottles are pressurized with an aquarium pump and released into the glass with solenoid valves.  The valves and functions of the drinkbot are controlled with a single 40X2 Picaxe MCU. The Elixirator won a bronze metal at the 2012 Robogames.

The project uses stained wood, brass and found objects to give it a look straight out of a Jules Verne novel.  The story is, "I Doc Hadacoff, a time traveler, have been trapped in the 19th century to sell elixirs to make a living.  My machine uses Tritium to power a plasma generator to add curative properties to my elixirs".

This instructable is not intended to be a step-by-step instructions to build a particular drinkbot, but more of a step-by-step discussion on how I built mine. All this with the hopes that one can collect enough information to build there own.

Step 1: The Steampunk Elements

To start building a drinkbot, you need to decide what theme to use.  I wanted to construct mine out of wood, brass and some modern elements to give it a Steampunk look.  I'm trying to make the illusion of a machine using extraordinary materials, yet still using 19th century concepts such a steam-power and electricity. Let me start by showing the details of the machine. Making the machine dispense drinks is actually the easy part.

I used 1/2 inch hardwood panels from Home Depot for the project.  To give the wood real beauty, I stained the wood with water-based stain (rosewood color) and finished with water-based semigloss polyurethane finish. Two coats of finish is just enough. Lightly sand between coats. Water based finishes are very easy to clean up after.  The finish dries in just a few hours with the added plus of low odor and no strong fumes.

Step 2: Box Design

Before I built the box, I had to decide how big it needed to be. Decide how many bottles you will need for the spirits and mixers. Think about how you will transport your machine.  Will the proposed dimensions fit the trunk of your car?  Will you be able to lift it out?

In my design, I made it possible to remove the side panels easily.  This aids in the stowing of the Elixirator in the car's trunk. Front and top doors were added for easy bottle refilling.  A back door was added for access to the electronics.  These are all important details that have to be thought of before construction.  Don't be in a hurry to start cutting wood.  I spent a few months just thinking how I was going to build it.  After it was clear in my head, the building part went pretty smoothly.

With my design, I'm able to unpack and setup the Elixirator at an event in less than an hour. With the removable sides, the theme can be changed. Dimensions of the Elixirator's main body is:  12 inches wide by 13 inches deep and 28 inches high. The width of the additional side panels is about 6 inches for each panel.

Step 3: The Picaxe Controller

I used the Picaxe 40X2 MCE to control the drinkbot.  Programming is done in the easy-to-understand language of Basic.  Programming software is free and uses the PC's serial port to program the Picaxe.

Picaxe is a product of Revolution Education Ltd and is based in the UK.

The schematic of the system and program can be downloaded at my Elixirator webpage.  The PC board is a special adaption to a controller I had designed for a different project. The board was made using ExpressPCB. You can build the controller on perf-board and hand-wire the connections.

The program first scans the control buttons, waiting for a button to be pressed.  By pressing the selection button, the drink number is advanced by one. This drink number is retained.

If the start button is pressed, the drink formula for each drink opens and times the flow through each solenoid valve and the drink is dispensed.

Step 4: Left Side Panel

On the left side of the box is a detachable panel that contains the glowing crystals (Video) and flame generator. Brass parts from a discarded ceiling lamp was used to form the parts. Plastic crystals purchased from a crafts store were placed in a large glass tube. Several color-changing leds were hidden with the crystals to give the illusion of glowing radioactive reactions. The leds are wired in parallel to 4 AA size batteries hidden in the brass bowl-like container at the bottom of the panel. This container was also salvaged from the same brass ceiling lamp.

Step 5: Hide the Wires

I hid the wiring by drilling holes and running the wires on the back of the panel. I gouged out some of the wood on the back of the panel so wires can lay flush.  Then, placed tape over the wires to keep them in place. Drilling 4 mounting holes on the panel corners for the mounting bolts makes the panels removable.  I used #10 screws and placed threaded nut inserts on the main box to receive the screw.

Step 6: Fake Flame Generator

The fake flame generator is a small box attached to the side panel.  A fan is placed inside to blow an air stream past a piece of white fabric at the top. Red super-bright leds project red light on the fabric as it flaps in the breeze.  All this makes the illusion of a flame. To add to the illusion, yellow flicker leds are added inside the box and cast flickering light on a screen. Power to the box is supplied to a socket mounted on the box and passes power to a plug.  This arraignment makes the panel detachable.

Step 7: Fake Flame Leds and Fan

Two super-bright red "Piranha" leds are used to project red light on the fabric flame.  A light-weight fabric like silk is best. Not having silk, I used some light-weight polyester fabric. A single 12 volt DC fan makes the air stream.

Step 8: Attach the Flame

The fabric flame is attached to a horizontal wire with staples. The effect produced is very realistic (video).

Step 9: Right Side Panel

This panel is to give the illusion of a boiler.  These parts also came from the same brass ceiling lamp. The lamp was completely disassembled and re-assembled to make the boiler.

Step 10: Boiler Lighting

Color-fading RGB leds are used to give the illusion of a glowing radioactive reaction in the boiler chamber. A non-functioning pressure gauge is also added to the top of the chamber. Power for the leds are from a hidden battery case inside a bowl shaped container below the boiler. Wires travel behind the panel and are hidden from view.

Step 11: Colorful Effects

With the leds and flames running in a darkened room, the effects are simply amazing.

Step 12: Neon Flames Illuminate the Drink

A pair of neon flicker flames are placed inside the box where the drink is served.  I saved the candelabra sockets from that lamp I salvaged and used them for the neon lamps.

I use a 9 ounce clear plastic cup for the drink.  Each drink is about 3 ounces of mixer (cranberry-pomegranate) and 1-1/2 ounces of spirits. I used Vodka, Tequila and Southern Comfort for the spirits. Later I substituted Grand Marnier for the Southern Comfort. If you build a drinkbot, you can come up with your own drink combinations and mixes by changing the program.

Step 13: The Lamp That Supplied Many Parts

I bought this lamp at a thrift store for 8 bucks. The next step will show it all in pieces.

Step 14: Salvage Pieces and Parts

Go to your local thrift store, find a lamp and go ahead and take it apart.  Save all the pieces and start thinking how you can used them for your drinkbot.

Step 15: The System

Now for the drink serving part.  I used four apple cider bottles for the contents of the spirits and mixers. #2 stoppers with 2 holes are used to connect air and fluid lines. Each bottle gets pressurized through a manifold connected to the aquarium air pump.  Nothing fancy, I got the pump at Walmart for 6 bucks.  You only need a few pounds pressure. Use food-grade tubing. I used 1/4 inch Tygon 06408-47 from Cole Parmer. I was able to get it on sale for 5 bucks for 50 feet at a surplus electronics store.  What a deal, I bought 2 boxes. The hose attaches to the solenoid valves with 1/8 inch plastic barbs with 1/8-27 NPT male threads.

Mounted inside are also the solenoid valves.  These operate on 12 volts and are normally closed when power is not applied. After a drink is selected, the operator presses the start button.  The air pump starts and pressurizes the bottles. Then the Picaxe opens a valve for a timed amount to release contents into the glass.  Each drink is a sequence of timed operations of the valves. A complete drink takes about 20 seconds to dispense. I measured an accuracy of about 3% in the consistency of each drink. When filling the bottles, don't fill to the very top. Fill to about were the curve starts. This keeps the surface area consistent. Flow is a function of surface area and pressure.

I got the solenoid valves from McMaster and Carr. Part number 7877K313.

Step 16: Drink Funnel

The drink ingredients mix at the exit funnel right before they reach the cup. I got the glass funnel from Home Science Tools. Right above the funnel is a white led that illuminates the mixture as it enters the cup.

Step 17: Tritium Meter

At a salvage sale many years ago, I came across a tritium meter.  I saved it all these years for something really special.  The meter is used as a progress meter during the dispensing of the drink.  The Picaxe 40X2 has a DAC that can supply a voltage to the meter.  To drive the meter, an op amp is added to supply more drive current. The meter looks nice with the stained and finished wood. A built-in lamp illuminates the dial.

Step 18: Nixie Tube Readout

To give the project that extra Steampunk look, I used a Nixie tube for the drink selection readout.  Nixie tubes were popular during the 60's as readouts to voltmeters, frequency counters and other electronic equipment.  They lost there popularity after the led was invented. The led was able to run on low power, whereas the Nixie tube requires 170 volts to operate. To run the Nixie tube display on the Elixirator, a power supply and decoder circuit was made. Each time the selection button is pressed, the drink number advances by one count from 0 to 9. Thus, ten drinks can be selected.

Step 19: Controls

Three buttons control the Elixirator. These are Select Drink, Start and Emergency Stop. Just in case dispensing needs to be stopped in a hurry, an emergency stop is needed. The buttons light up when pressed.

I also placed a lock-out switch that needs a key to operate the controls.  You may need to lock-down the machine when not attended at an event. I usually have an attendant with me at all times during events.

Step 20: Plasma Sphere

I added a plasma sphere (video) to give it that Si-Fi look. I got mine from American Science and Surplus for less that $18 dollars. I even bought an extra one when it was on sale. The sphere is mounted on a small wooden bracket placed behind a 3 inch hole bored in the front door of the box.  I placed a sheet of glass between the sphere and the hole to protect it from people touching the globe. These things always attract people to touch and leave finger prints. The glass was from a picture frame purchased from a thrift store and attached to the wood with caulking.

Step 21: Name Plate

I made a name plate with "Elixirator" in bold etched letters.  The plate is made out of copper and the lettering was transferred from a sheet of overhead transparency material. Using a laser printer, toner is printed on the material as a negative and resist.  Then using an iron, the toner is bonded on a sheet of clean copper.  A few hours in ferric chloride etchant, the plate is ready to be cleaned and drilled for mounting. Deep black lettering was made by dipping in a weak solution of Liver of Sulfur.  Then the surface was buffed and polished.  I left the surface un-coated so a patina will develop over time.

My Picasa webpage has more photos of the process.

Ferric chloride etchant and Liver of Sulfur can be purchased at Blick's Art Supply.

More details on etching objects are at Jake Von Slatt's Steampunk Workshop

Step 22: Stoppers

Stoppers for the bottles are #2 rubber stoppers with two holes for the glass tubing.  I was able to find the stoppers at a local home brew shop, but they did not have holes.  I ended up drilling my own holes.  Take the handle off a cork boring tool (they are made of brass tubing) that has a diameter slightly less than the glass tubing. Sharpen the edge using a file along the edge.  Chuck the tubing in a drill press and start boring through the stopper with the stopper upside down.  You will need to stop periodically and clear out the rubber pieces in the tubing with a smaller drill bit. Use the bit to force out the pieces.  Lubricate as you drill with water.  After awhile, you will eventually punch through.

I used 5 mm glass tubing cut to 2 inch pieces for the tubes.  You can get the cork borer at American Science and Surplus and the glass tubing at Home Science Tools.

To cut the tubing, draw a file across the tubing and make a scratch. It does not need to go all the way around. Then simply snap the tubing with your fingers.  It should break cleanly. Use goggles to protect the eyes and a towel around the tubing.  The end can be held over a gas flame on your stove or a propane touch to smooth the edge of the cut. The tubing melts easily.

Lubricate the tubing with soap and water and slip it into the stopper as shown in the photo.  You will need to make enough for four stoppers.

Step 23: Display a Menu

So the partaker of the Elixir can make a selection, I displayed a menu of the drinks along side the Elixirator. Drinks were served with ice in the cup. Never serve a drink warm, its just not right.

Number 3 was one drink that had no alcohol. Just straight cranberry/pomegranate. This allowed those who didn't want any alcohol to still use the machine.

Step 24: Show Off Your Drinkbot

To complete the Steampunk look, I dressed up for the part as a 19th century snake oil salesman. Complete with a hand-made costume my wife painstakingly made. You can get Steampunk outfits ready-made at various establishments on the Internet. My favorite is Gentleman's Emporium, that's were I got my hat.

Every year Drinkbot Makers show off their creations at an event called Barbots. Every machine will be different and each will have their own theme or style to show. Always a fun event. This event is put on by the wonderful and hard-working people at Robogames.

Another excellent event is Roboxotica.

So if you like making things and desire to make something that is truly individual and unique, then consider building a Drinkbot. Cheers!