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24 May 2010
Author: Giorgos Lazaridis
Instant Cold Coffee Machine

Worklog - The straw separation mechanism: A revolver is not only a gun (June 6 2010)

This group is by far the most complicated in this machine. The most difficult part is to manage to separate just one straw. I tried several models with different shapes-configurations. Apparently, straws have a very bad habit:they stuck! If a funnel is to be used, there will be a time that two or more straws will try to go through the funnel and they will stuck. I tried cylindrical funnels and flat funneled surfaces. They all had this problem.

So i completely changed my orientation to the solution. I tried a revolver mechanism. The straws will be inside a tube. At the bottom of the tube, a 4 positions revolver will be rotating. Each position of the revolver will be able to fit only one straw. Under the revolver, there is a cover with a single hole. When a position of the revolver that has a straw inside lyes over this hole, then the straw will fall from this hole.

First i cut out the plates of the revolver from a 10mm plexi-glass With the conical drill i drilled the revolver holes I cut 4 pieces of aluminum tubes That is the revolver assemble

To fix the revolver on the motor...

First i did some M3 threads vertically on the motor shaft A screw perpendicular on the shaft will secure the revolver. With the dremel i engraved the shape of the screw on the bottom plate. Finally, on the tops side, i cut an aluminum piece with 3 holes. The middle hole will be used to screw it on the motors shaft, while the other 2 holes will screw this piece on the revolver piece

A commutator out of garbage

Now i need to have a vibrator on te revolver to help the straws go down the pipe. The problem is that the vibrator must be fixed on the revolver - which rotates! So i must make a commutator for the power supply of the vibartor:

From an old cassette recorder/player i removed a small limit contact on which i soldered only i wire on both pins I grooved a pocket for the contacts to fit in at the bottom side of the bottom revolver piece. I glued them with hot glue Now when the piece is inserted onto the motor, the two contacts will touch the shaft of the motor. This is the first pole of the commutator

The other pole:

From a tin can i cut a round (approximately round) ring I soldered a wire on this ring And then i glued it on the base of the revolver - the statro

Now to pass the current to the rotor. First from the ring to the rotor:

I made a hole with 2 diameters. The big diameter is a little bit larger than a metal ball that i will use, while the other fits a wire I passed through the first vibrator wire through this hole and soldered a washer at the end This is the metal ball with a tension spring. The ball comes from a vandalized ball bearing and the spring from a (same situation) power relay The washer is at the bottom, the spring follows and then comes the ball. The ball now is always pushed against the ring on the stator

The other wire for the vibrator come from the shaft itself. The wire is connected on the screw that is fixed on the shaft, to hold the revolver on the motor. The vibrator is just a motor with an eccentric weight:

Then, i fixed the vibrator on the top piece of the revolver. I also put a thin cover of white plexi-glass with smaller holes for the straws. This is the finally assembly of the revolver:

Puting it all together

The revolver must be inserted into the tube where all the straws are. So, i did 4 holes on the tube and the revolver base (stator). The motor of the revolver is fixed on the base. With 4 screws, i screwed the revolver base on the tube:

I did 4 holes on the tube and the revolver base With 44 screws, i screwed the revolver on the tube This is how it looks like from the top side of the tube The overall assy



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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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