Fed3 free feeding
33 views
Skip to first unread message
Bugra Gungul
Oct 12, 2025, 10:35:16 AMOct 12
to FEDforum
My name is Buğra Güngül, a Ph.D. student at the University of Virginia. I’m using FED3 in a fiber photometry experiment to drop one pellet each time my mouse finishes eating — triggered manually by a TTL pulse.
To let the pellet fall directly into the cage, I removed the food well, but now the IR detector often misses the drop, causing the motor to spin too long and release multiple pellets. When I tried disabling the detector, the wheel sometimes over-rotated and dropped 2–3 pellets per trigger.
Do you have suggestions for:
A firmware or code change that would let me trigger a fixed motor rotation per TTL pulse, or a mechanical modification (e.g., flag or beam-break design) that ensures reliable detection without the food well?
My goal is one consistent one pellet per TTL trigger without mouse interaction.
To let the pellet fall directly into the cage, I removed the food well, but now the IR detector often misses the drop, causing the motor to spin too long and release multiple pellets. When I tried disabling the detector, the wheel sometimes over-rotated and dropped 2–3 pellets per trigger.
Do you have suggestions for:
A firmware or code change that would let me trigger a fixed motor rotation per TTL pulse, or a mechanical modification (e.g., flag or beam-break design) that ensures reliable detection without the food well?
My goal is one consistent one pellet per TTL trigger without mouse interaction.
Bugra
Lex
Oct 12, 2025, 12:00:49 PMOct 12
to Bugra Gungul, FEDforum
Hi Buğra,
I created a modified nosepiece exactly for this use case! See post about it here with a short video of how it works. I'm attaching the STL file to this response too. Please post back if this works for you! -Lex
--
You received this message because you are subscribed to the Google Groups "FEDforum" group.
To unsubscribe from this group and stop receiving emails from it, send an email to fedforum+u...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/fedforum/3d091592-224e-4335-b8fe-94a90174f73bn%40googlegroups.com.
Bugra Gungul
Oct 13, 2025, 5:06:33 PMOct 13
to FEDforum
Hi Lex,
I printed the nosepiece you shared and now it works!! Thanks a lot. Meanwhile, I need to do non-food object control for my recordings. I was thinking to get plastic balls or sth that could fit into fed3 holes. But do you have any suggestion for non-food object that could work with FED3? Thanks!
Bugra
Lex
Oct 13, 2025, 5:15:59 PMOct 13
to Bugra Gungul, FEDforum
Glad it worked!
We have used 3mm beads as a non food object, they dispense great!
Something like this: https://a.co/d/cecr9uY
Best, -Lex
To view this discussion visit https://groups.google.com/d/msgid/fedforum/a2183487-d11d-42fe-97c5-4ad33286bb43n%40googlegroups.com.
Reply all
Reply to author
Forward
0 new messages