Introduction: Candle Making Machine (Arduino)
After holidays, there are tons of burned out candles. Reuse them to make new candles, is a time-consuming job and you're limited to candle forms. Using forms to make candles is not the only way, dipping is another (old, traditional) way to make candles, but doing this by hand, is a boring work. That technique inspired me to make an automatic Arduino powered candle machine. The candle wax is melted by a... candle (tea light). Let's start!
Step 1: Materials
Here is a list of the materials needed for the machine.
Machine
- tea lights (local store)
- wooden (wine) box (app. 32 x 27.5 x 8.5 cm / 12.5 x 10.9 x 3.3 inch)
- some lumber
- screws and bolts:
6 wood screws, length: 20 mm (20 inch, 8 inch)
4 bolts with nuts, ø M8, length: 180 mm (3.1 inch, 7 inch)
Electronics
- Arduino
- passive buzzer (optional)
- servo
- some electric wires
- breadboard (or soldering iron)
Candles
- burned out candles (or candle wax)
- spool candle wicks
Step 2: Build the Stove
My first idea was to use an electric heat element, but that was dangerous to use and i like to keep it simple. During dinner, i saw a tea light dish warmer and i got an idea. I could use a tealight to melt the wax! In that way, wax is used to melt wax.
The stove consists of 4 bolts and nuts. If the wood of the box is too thin you can add a wooden plank inside, see picture.
- Measure the diameter of the biggest can (= D).
- Place the marks on your box or wooden plank (see picture).
- Fix the plank into the box (with wood glue)
- Drill the holes
- Place the bolts into the holes and assemble it with the nuts
For extra stability, a 'plate' (perforated bottom of the biggest can) is added. Cut the the biggest can at 5 cm / 2 inch from the top and perforate it (with a big nail, drill,...). Place it on the 4 bolts.
Step 3: Supports
Make the construction using wood glue. For the instructions/dimensions, see pictures.
TIP: for the hole in the horizontal plank, use a chamfer tool. Make the edge of the hole smooth for guiding the rope.
Step 4: The Servo and Lever
The servo
Take a plank (length: min 5 cm / 2 inch) and drill two holes in the front for the servo. Take another plank (the length doesn't matters) and drill two holes in the side for the servo. Attach the planks to the servo with four screws. Glue and screw the servo to the machine (see picture).
The arm
Saw a drop looking arm. Fix a clothes peg on the arm. Make sure the clothes peg is above the hole, add a wooden block, if needed. Use thumb tacks to attach the servo.
Step 5: Circuit
The circuit is easy. You can solder it, or use a breadboard (like i did). See the first picture.I used rubber bands to attach the wires to the plank. Drill a hole in wooden box and place the circuit (Arduino) under the box. Drill another hole for the usb / power cable. (Fritzing file: see file attached)
Optional: the buzzer
This is used to warn you when the candle is ready (after a preset amount of cycles) .
Attachments
Step 6: Setting Up the Software
Upload the sketch to your Arduino. Disconnect the Arduino. Place the (empty) can on the stove and make sure the arm hit the plank when the servo is at 0 degree. Attach a candle wick to the (servo) arm, make sure it just does not touch the bottom of the can. Power on the Arduino. Check the movement before working with the hot wax: the wick must go up and down. In the upper position the end of the wick comes outside of the can. If not you can adjust by changing parameters in the Arduino sketch. See picture.
Attachments
Step 7: First Candle
The first candle, is the hardest one.
Lower the can using the four screws (make sure the tea light has enough oxygen) to get more heat from the candle. This makes the wax melt more easily. Place a tea light under the stove, fill the can with candle wax. Once it is liquid, higher the plate to lower the temperature of the wax. After the first dip, make sure the wick is straight (if necessary you can stretch it once by hand).
Common problems:
The candle does not thicken. Try one of these:
- Higher the build plate (if possible) to decrease wax temperature.
- Increase the movement speed to avoid melting of the solidified wax on the wick
- Adjust interval time between two cycles
The candle shape is thinner at the bottom.
- Stir the wax to make its temperature more uniform. Position the candle out of the center of the can.
- Increase the movement speed to avoid melting of the solidified wax on the wick

Runner Up in the
Arduino Contest 2016

Participated in the
Epilog Contest 8

Participated in the
First Time Authors Contest 2016
18 Comments
5 years ago
Much cooler than Shrek's way of making candles.
5 years ago
Hi,
my friend that looks brilliant!!!
Congrats!!!
Can I ask you how I can make the circuit? It will be my first time.
From where can I buy the placket e.t.c and which one should I buy?
Also, how I will load the software once I will set it up?
Thank you very much in advanced!
Cheers,
Athanasios
Reply 5 years ago
Hi Athanasios,
great that you are interested in this project and Arduino.
it's maybe a good idea to start with some simple breadboard projects to get familiar with Arduino. You can find thousand tutorials online (example).
There is no all in one packet for this project, so you have to order the parts separately. Digikey, amazon, ebay, ... are popular sites to order electronic parts.
If you have questions/problems with the Arduino, send me a message and I will answer as soon as I can.
Regards Floris
Reply 5 years ago
Hey Floris,
Thank you very much for your quick reply.
I would ask you one more thing.
Could you list exactly the items that I will need for this project, in order to search the parts?
I'm beginner on this and I would like specific directions to understand the nature of this project and know exactly what I will need in order to search it and buy it.
Thank you very much for all your help!
Regards,
Athanasios
Reply 5 years ago
Hi,
Here is the
list:
Arduino: ‘Arduino
Uno’ (Arduino Uno is the best board to get started)
Servo: ‘standard
servo’ (e.g. S3003)
Buzzer: ‘Arduino
passive buzzer’ (I used a ‘KY-006’)
Jumper
wires: ‘Jumper wires’ (you could use solid core wires (22AWG), but jumper
wires makes life easier -_-)
Breadboard:
‘Full sized breadboard’ (take a full sized one, you can reuse it for other
projects)
Wood: local
store
If you have
more questions/problems, don't hesitate to contact me!
Regards,
Floris
5 years ago
which servo have you used?
It's a nice job!
Reply 5 years ago
Sorry for late reply!
I used a 'modelcraft rs2'
5 years ago
Brilliant, simple, fun... You nailed it!
5 years ago
Cool! voted for you.
Reply 5 years ago
Thanks!!
5 years ago
Make it Drill press powered!
5 years ago
That's genius!
I love clever uses for technology to do old world crafts!
5 years ago
A very beautiful inspiring machine. Great!
5 years ago
Great way to make the most of what you have!
5 years ago
What kind of servo did u use?
Reply 5 years ago
A 'modelcraft rs2'
5 years ago
This is so cool, I will to to make a custom logo candle. Thanks!
5 years ago
This is fun! You could do a lot with it since they're homemade :)