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24 May 2010
Author: Giorgos Lazaridis
Instant Cold Coffee Machine

Worklog - The challenges (May 24 2010)

The worm gears are NOT the best solution for the coffee/sugar supply...

There are some major challenges that i need to deal with. First of all, the coffee/sugar supply. I need to find a way to supply the proper amount of coffee and sugar, depending on the size of the glass and the type of coffee (sweet, medium, black, strong. light etc) that someone wants. The coffee/sugar tanks must be closed, so that the air and moisture will not come in contact with the contents. Although the use of a worm gear seems to be the best solution,it did not comply with one of my requirements: The coffee just in front of the worm gear is always in contact with the air and moisture! So i had to figure out a way to close the front side of the worm gear whet it does not rotate. That would require an extra mechanism and would increase complicity.

Another challenge was the raising/lowering mechanism. It sounds easy to make one, and actually it is, unless you try to make it! By the time i began designing and making this mechanism, i came across multiple problems that i could not even imagine. The main challenge was to keep the whole mechanism compact and light with fast response to start/stop actions. But the factor "price" was the basic challenge. I could use prismatic linear guides or cylindrical bearing-rods, but that would cost over 100 euros!

Another problem to solve, is the glass base. The glass must be fixed on a base during the shaking time, otherwise it will fall. Also, either the shaker or the glass needs to move during that time, so that all the contents inside are shaked.

A major challenge is also the cleaning of the shaker. If the shaker is not cleaned immediately after use, then the remaining coffee sticks on the metal. And finally, i had to solve the "cold water" factor and the ice cubes factor. I do have something in mind about the cold water. As for the ice cubes... I am not quite sure...

Finally, the straws! The frappe requires a straw, and although i could just have the straws near by to pick up one, that was not enough for me. The most difficult thing is to separate one straw from the others. If for example you put 20 straws in a funnel-like construction and you start vibrating it, then there will be a time that 2 or more straws will try to go inside the funnel and they will stuck. I have to deal with this also.

Worklog - The rough design of the robot (May 27 2010)

The following steps have to be taken:

  • Add a few water
  • Add coffee
  • Add sugar (if any)
  • Mix
  • Clean/fill
  • Add straw
  • Serve
  • I began designing the machine in through-feed style. This means that i would put the glass on one side and get the coffee from the other. But i found a more compact solution. The glass will not move linear, but polar. This is the rough design of the machine:

    As always, click on the images to enlarge them. The steps are as follows:

    The glass is entered and fixed on the base (base is not visible here) It turns 90o and goes under the coffee where the coffee is poured It turns another 90o, goes under the sugar and the sugar is poured Turns another 90o and goes under the mixer
    The mixer is slowly lowered while it rotates at low speed. Gradually goes to full speed When the coffee is mixed, the mixer is raised half way. At that point it rotates 1'' at full speed. The filling procedure is started while the mixer is washed When the coffee is filled with water, it goes to the starting position. Above the start position there is the straw tang with the mechanism to put the straw in the coffee. The procedure is completed with a straw insertion!

    So, there are 5 groups. The sugar group, the coffee group, the mixer along with the water supply group, the straw group and the rotating table. Within the next pages, i will present each group separately, how i made it and the several difficulties i faced.



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  • At 3 July 2015, 6:23:11 user Alex wrote:   [reply @ Alex]
    • Still watching this space every other month only to find the project still not being updated. Hoping to see some progress soon. :)

  • At 28 March 2014, 3:28:25 user Nikos wrote:   [reply @ Nikos]
    • re si, nomizo the "redux" version should have an optional milk stage too for those of us who prefer it a bit easier to drink :)

      subscribed on YT, keep up the good work!

  • At 18 January 2014, 7:31:43 user Giorgos Lazaridis wrote:   [reply @ Giorgos Lazaridis]
    • @Alex In Greece during the Ancient times there was this saying: "Oyden monimoteron ek toy prosorinoy" which means that "nothing is more permanent than the temporary".
      But now that you said that again, i think i should restart this project, shouldn't I? Hopefully within this year.

  • At 17 January 2014, 19:59:52 user Alex wrote:   [reply @ Alex]
    • Dude what happened with this project, there hasn't been any updates for quite some time now. Looking forward to see the end result :)

  • At 13 November 2013, 17:56:48 user Robert wrote:   [reply @ Robert]
    • This is a great invention! I especially like the straw delivery, it is perfect. how wonderfully useless! you are a genious!

  • At 16 September 2013, 15:38:37 user praveen wrote:   [reply @ praveen]
    • excellent job......

  • At 14 June 2013, 17:45:35 user Amir wrote:   [reply @ Amir]
    • Hi ,

      Great work . From where did you buy the worm gear extruder ? Can you give me a website for that .

      Many thanks

  • At 29 March 2012, 21:03:02 user alex wrote:   [reply @ alex]
    • Hi you have a nice coffee Instant Cold Coffee Machine but you wanted to use a fridge for cold water but no water cooler that you use waron also in coffee automaaten is where you can get I know old water out of if not the name but it can look for you we have that built-in devices greetings alex
      mail alex.heijkens@kpnmail.nl

  • At 6 March 2012, 10:25:13 user Giorgos Lazaridis wrote:   [reply @ Giorgos Lazaridis]
    • @steve salvaged from an old photo copier. it was used to push the toner

  • At 5 March 2012, 13:56:29 user steve wrote:   [reply @ steve]
    • Where did you found the worm gear for the sugar and coffee supply?And awesome project.Good Job

  • At 9 January 2012, 9:40:16 user qwerty wrote:   [reply @ qwerty]
    • Tromeri i frapediera sou.bravo sou

  • At 24 August 2011, 11:38:08 user a.mira@vmcogulf.com wrote:   [reply @ a.mira@vmcogulf.com]
    • niccccccce i like this machine :) did you manufacuter it ???

  • At 26 July 2011, 17:53:16 user Sergio wrote:   [reply @ Sergio]
    • Excelent Job! Very good videos an explanations.


      Segio from Argentina

  • At 24 May 2011, 15:00:24 user Kammenos wrote:   [reply @ Kammenos]
    • @Fung no of course not. i will have different programs for different sizes. there are 4 sizes of cups (in respect to the volume)

  • At 24 May 2011, 14:24:55 user Fung wrote:   [reply @ Fung]
    • Do the cups which being used are restricted to the same size and same volume? (ie other cups are not allowed?)

  • At 14 May 2011, 19:27:58 user Ivan wrote:   [reply @ Ivan]
    • Great work.....

  • At 27 April 2011, 4:54:19 user Kammenos wrote:   [reply @ Kammenos]
    • @Dimitris it was part of an old photo copier, used to push the toner.

  • At 26 April 2011, 20:23:01 user Dimitris wrote:   [reply @ Dimitris]
    • Congratulations man!
      Awesome machine!
      Can you tell me, where did you find the 'worm' thing
      for the dispenser mechanisms?

  • At 27 March 2011, 6:16:30 user Kammenos wrote:   [reply @ Kammenos]
    • Hello George. Regarding the elements, these are hardware wiring to indicate wire connections between the modules. The orange boxes indicate wires coming from the output module (Digital Output Module - DOM), and the green indicate wires going to the Digital Input Modules. Notice that for example, from module "Rotary table", 4 wires comes out, then 2 of them arrive from the DOM and 2 goes to the CPU.
      As far as the diode is concerned, this is only for polarity protection. It is the same as the D2. But you are right, It is not necessary and i may not put it after all.

  • At 27 March 2011, 5:57:10 user George Hadley wrote:   [reply @ George Hadley]
    • I think your architecture diagram (first figure) is slightly confusing, because it seems to include elements of code (the elements above the CPU) with hardware elements. Ideally, you would have a system-level block diagram detailing your hardware and a separate functional block diagram to describe your code. If I'm misreading your architecture diagram, feel free to ignore this.

      Secondly, looking at your reset circuitry, I see you have a 1N4148 diode between your microcontroller pin and your ICSP header (pin 1). I'm fairly certain this diode is not necessary, so you may want to double check that.


  • At 25 March 2011, 11:45:30 user Fung wrote:   [reply @ Fung]
    • Why does PIC16F1937 have 2 Vdd's and 2 Vss's?

  • At 12 March 2011, 16:40:13 user de.das.dude wrote:   [reply @ de.das.dude]
    • you are sooooo awesome!!!

      there are no words to describe your awesomeness!

      i hope i can be as awesome as you!

  • At 25 May 2010, 1:53:39 user Tom Hargrave wrote:   [reply @ Tom Hargrave]
    • Frappé has become very popular here in the States. The difference is we use fresh coffee grounds to make coffee then we chill the hot coffee. But we tend to make more fresh coffee here while Europeans tend to make more instant coffee.

      To serve we pour some in a glass and add chipped ice.

      We also tend to add flavors to our frappé in the States. We can't leave a good thing alone - we have to tinker with it to make it more sellable.

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