I'm building a machine to make drinks and I would like to be able to put a straw into the cup. To achieve this, I need to build some kind of mechanism, that will be able to feed me with one straw on demand.

What I was thinking about is some V-shaped box where all the straws will be stored, with a hole at the bottom, but there will be a gear blocking the hole, so the straws will not fall out of the box. However, the gear will have a cut in it and will be rotating. So each turn, one straw will fall into this cut. Something like this:

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Will it work? Or is there any better way of achieving this? Thanks.

  • $\begingroup$ If the straw will be fed to you or the operator of the machine, you're better off just buying a standard straw dispenser. Is your intention for the machine to place the straw in the drink without human intervention? $\endgroup$
    – J. Ari
    Aug 4, 2017 at 18:36
  • $\begingroup$ @J.Ari Yes, I wanted to put the straw into the cup without any human interaction. But you've just helped me much more. Googling straw feeder didn't find anything usefull, but when you mentioned straw dispenser, it finded what I want. I don't want to buy a dispenser, I wanted to build it myself, but googling straw dispenser led me to some working mechanisms, so now I know what to do. Thanks! $\endgroup$ Aug 4, 2017 at 18:54
  • $\begingroup$ Ok, happy building! Maybe answer your own question here so the thread will be complete? $\endgroup$
    – J. Ari
    Aug 4, 2017 at 19:15
  • 1
    $\begingroup$ You just need one drum at the bottom of the tapered feeder. The drum needs a groove slightly larger than a single straw. The drum fits in a cylinder with a slot at the bottom. $\endgroup$
    – Eric S
    Aug 4, 2017 at 20:21
  • $\begingroup$ Seems like it would be better to narrow the feeder so there is only a single straw available to pick up at the bottom. Of course then use a single wheel, as others have already pointed out. $\endgroup$ Oct 6, 2017 at 12:45

1 Answer 1


Mechanisms like this can work, although I think in this case you would be better with one roller mounted directly under the hopper. As it is the two cutouts don't line up untill the 3 and 9 o'clock positions so there is nothing to s top both notches trying to grab a straw each and ending up with both trying to occupy the same space.

You should also be prepared for a lot of fine adjustment in prototyping to get it to work properly. I've worked on a few mechanisms like this and they tend to be a bit of a nightmare to get right.

You also need to ask yourself whether you really need an automatic straw dispenser. Presumably at some point a human being will pick up the drink in their hands and is it really a benefit to save them the effort of picking up a straw from a manual dispenser?


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