Re: Automatic Pellet Dispenser

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"Marc_F_Hult" <MFHult@xxxxxxxxxxxxxxxxxxxxx> wrote in message
news:9sstt2h968j7lesi5id6qjj7fgkg8j3eag@xxxxxxxxxx
> On 23 Feb 2007 05:45:56 -0800, "Dave Harper" <dharper@xxxxxxxxxxxxxxxx>
wrote
> in message  <1172238355.967425.64000@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>:
>
> >For what it's worth, I had pretty much the same reaction as "jack ak"
> >when I read the initial post.  Having read the details in the followup
> >post it's obvious that it's an entirely different situation.  I love
> >dogs and am impressed with your rescue efforts; I don't think I could
> >do it myself - I'd find it too depressing.
> >
> >That said, perhaps you could provide some more details.  It's been a
> >number of years since I last had a dog and I'm not familiar with
> >kibbles.  Therefore:
> >
> >1) Could you describe kibbles?  Approximate size, weight, shape, etc.
> >Anything that might be relevant information to consider when
> >constructing a dispenser.
> >
> >2) Are you thinking in terms of a single unit that would dispense to
> >all crates or something you would replicate on a crate by crate basis?
> >
> >3) Do you have any problems preloading the dispenser with individual
> >kibbles or are you looking for something with a hopper type
> >arrangement where you just pour in a bag of kibbles and somehow the
> >kibbles settle out into individual treats before being dispensed?
> >
>
> Same questions here. (My wife designed and built such a feeder when
working
> in a neuroanatomy lab almost 40 years ago. She quickly learn that some one
> else beat her by a few decades ...  Have you looked for a commercial
version
> or searched for existing designs?)

Yes, but the major company supplying the one-at-a-time units appears to be
in flux.  More importantly, research has indicated that motor and solenoid
noise will
probably be more disruptive to the other dogs than reinforcing to the target
dog, at least in the mode I was intending to use.  That's going to restrict
what I am able to do.  It has me thinking my first step should just be to
analyze their reaction to momentary activation of a high-torque motor before
I sink lots of time and effort into building the actual device.  That would
be pretty easy to test.

> If the pellets are all lined up vertically nice-like, all you need is a
hole
> (slightly larger than the diameter of one pellet) drilled  through a
traveler
> slightly thicker than one pellet and to cause the traveler to  slide from
> side to side. A solenoid can be used to pull the traveler forward  so that
a
> pellet can enter the hole (but not pass through). When the solenoid is
> released, the traveler moves back to its original position owing to a
spring
> (or second solenoid) and the pellets drops out through a hole in the rack
> holding the traveler.
>
>                         O
>                         O
> At Rest:   ____________|O|___
>            | |---------------
>            | |_______________
>
>                         O
> Loading::  ____________|O|____
>            ------------|O|----
>            | |_______________
>
>                        O
> Delivering:___________|O|____
>            | |----------------
>            |O|_______________
>
>                       O
> Delivered !__________|O|___
>            | |-------------
>            | |_____________
>             O
>
>
> Similar thing can be done with a rotary motion using a stopcock like
device
> in which the hole for the pellet only goes half-way through the stop cock.
> You can move with either a rotary solenoid or a stepping motor (doesn't
need
> to reverse).

See my note to BF about the revolving pistol cylinder design, which I think
you're describing above.  Feed hopper feeds rotating cylinder with round
cylindrical compartments around the edge, inserting a pellet into each
empty one that passes under it.  There's a hole on the bottom plate that
the cylinder rotates upon that lets a pellet drop when a full cylinder hole
is rotated into position above it.   Wouldn't require a stepper motor, per
se, just a motor with enough torque to advance the cylinder to drop a pellet
or two after a momentary activation.

All this got me to thinking.  California used to use pellet dropping as the
ultimate sanction of *bad* behavior, as in the cyanide pellets used in the
gas chamber.

--
Bobby G.