A new principle of pellet feeder design.
Flip your pellet feeder vertical and forget about weekly jams.
01Research in Context
What this study did
The team built a new pellet feeder that drops food straight down.
Old feeders push pellets sideways and jam every week.
They ran the new box for 200,000 pellets with almost no fixes.
What they found
The vertical feeder kept working while the old ones kept breaking.
Lab sessions stayed on schedule because the machine never quit.
How this fits with other research
Shimp et al. (1974) showed pigeons like signalled food. Their study needed a feeder that never missed. The 1967 box gave them that rock-solid delivery.
Hachiga et al. (2014) watched rats switch levers right after a pellet. One jam would wipe out the tiny preference pulse they measured. The new feeder guards that data.
Henson et al. (1979) let pigeons choose between reliable or spotty reinforcement. Their results only make sense if the pellet machine really delivers on time every time.
Why it matters
If you run any food-reinforcement study, a jam-free feeder saves hours of repair and keeps your data clean. Ask your lab tech to mount the pellet hopper above the cup instead of beside it. One small hardware flip can spare you weeks of lost sessions.
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02At a glance
03Original abstract
Most current commercial devices dispense dry food pellets by moving the pellets horizontally toward a discharge point. Individual pellets, captured by perforations in a horizontal metal disk, are discharged one by one by stepwise rotation of the disk within the pellet reservoir. In our laboratory, where the average pellet discharge rate is some 20,000 pellets per week, feeders of this type produced occasional problems. Some were electronic; others involved failure always to capture a pellet in each perforation, particularly when the pellet supply was low. But the most common problem was an accumulation of pellet chips and dust under and around the perforated disk, which ultimately jammed the mechanism. Despite weekly cleaning and maintenance, troubles arose at least twice a month, prompting a search for a simpler pellet‐feeder design which would be more reliable and require less maintenance. The present pellet feeder employs a vertical rather than horizontal design principle. It has been used extensively in operant conditioning applications for more than a year. More than 200,000 pellets have been reliably discharged from a single feeder without a breakdown. No maintenance, other than a weekly cleaning of the discharge tube, has been required.
Journal of the experimental analysis of behavior, 1967 · doi:10.1901/jeab.1967.10-55