Unfortunately, the first revolver did not work. The idea was good, the implementation suffered. The lack of precision caused the whole thing to collapse after some tests. So i had to re-make the revolver with better materials and better precision. Regarding the materials, the only change i made was a smaller in diameter revolver chamber aluminum tube. This would cause the straws to be more vertical when they go down the chamber. As far as the precision is concerned, i managed a 0.2mm precision! How? Well, the answer is a CNC machine. I went to a customer of mine named Polidorou. He owns a high end CNC for wood processing. Here are some photos from the whole process:

This is the machine (half of it)	Ant the CAD/CAM software. Here i program the pieces	These are the pieces ready with astonishing precision!	The owner of the machine. Thanks Christara!

I then cut the new (and smaller in diameter aluminum tubes) with a saw again in the company of Mr. Polidorou. The assemble of the revolver looks perfect now! The whole construction is rigid and the tubes are firmly placed in position.

I decided NOT to make a commutator as before. I will test the vibrator fixed on the housing. This way, the revolver will be simpler. Mechanics loves simplicity because it works. The vibrator is strong enough, and hopefully it will shake the whole group. Then, i did 2 holes on the revolver plates and i used 2 long screws to fix it all together. I have oder blind nuts for the top side because now it looks awful. On the bottom side, i routed pockets for the nuts so they do not go over the plane of this side. I cut narrow self-stick air-block tapes and sticked them at the perimeter of the two revolver pieces. These pieces are about 4mm smaller in diameter from the straw tank diameter which they are supposed to fit in. The air-stop will act as a bush-bearing... or something. Also, the scary noise from the vibrator will be eliminated.

I made 2 holes on each revolver plate for the screws to go thorugh	Two pockets will "hide" the nuts inside the bottom piece of the revolver	The aero-stop will act as a bush-bearing and as a noise shield

The sensors are basically mounted on the base of the revolver. This is the 3^rd piece with the single hole. First of all, the straw sensor. This sensor checks if there is a straw on the chamber ready to be sent to the coffee glass. I routed 2 pockets one opposite the other, at the perimeter of the straw hole. One pocket is for the LED, and the other for the photo resistor. The circuit that i used for the sensor is the Light / Dark Activated Relay, the third circuit (with the 741). Of course i do not use the relay! The transistor output is sent directly to the PIC. First i tried an SMD blue LED. Ridiculously, it did not work! The blue light penetrated the straws! Unbelievable. I changed then the LED with a normal red 3mm (i had no SMD red LED). It works perfectly.

I did 2 pockets at the perimeter of the hole	At first, i used a blue SMD LED. Ridiculously, the blue light penetrated the straws unaffected!	I changed it with a red 3mm LED	With hot glue, i glued the LED opposite the large photoresistor. Whenever a straw goes through the hole, the beam is cut!

Next, the alignment sensor. For this sensor, i drilled one 2mm hole at the base, near the edge (perimeter), not too close though. I also made a pocket for the small photo-resistor. Then, i made 4 2mm holes at the bottom piece of the revolver in a way that, when one chamber is aligned with the base hole, one 2mm hole of the bottom piece will be aligned with the base hole! The, i drilled the tube that the revolver goes inside and i planted an LED inside. When the holes are aligned, the LED light will go though the 2mm holes directly on the surface of the photo-resistor and voila! I used the same Light / Dark Activated Relay circuit for this sensor as well.

This is the hole with the pocket for the small photo-resistor	And these are the holes on the bottom revolver piece. I also sticked an opaque black film to cut parasitic light rays	The holes are aligned!	I drilled the tube that the revolver goes in and planted the light-transmitter LED from the sensor pair.

The revolver and the sensors are now completed. I used the same technique as before to fix the motor on the revolver, but i spent more time and i did a professional job. It was just about time for the.... stinger!!!!

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