I made a robot to give my pet rabbit pellet food in an enrichment ball on a timed schedule. I managed to put this together in just a couple days.

I presented this project at the Feb 2022 Sector67 Monthly Meeting. The presentation is mainly me showing the resources on this blog post, so there is substantial content overlap.

I planed it out in Adobe Illustrator

I exported SVGs from Adobe Illustrator and made them 3D in OpenScad before 3D printing them at Sector67. I also laser cut the 2 wooden disks at Sector67. I think the warped wooden disks are the weakest part of this robot, and thinner, flatter, metal disks would be a nice improvement. Although, it does work pretty well in it's current confirmation.

Parts List

• Food dispensing balls for rabbits
• Arduino Computer
• Stepper Motor (Nema 17 4.0V 1.2A 1.8° Bipolar)
• Motor Shield
• Real Time Clock - PCF8523 with Breakout Board - STEMMA QT (I kind of wish I got the more accurate one, this one looses ~15 secs a day, which really adds up.)
• LCD screen with buttons
• Shaft to disk connectors
• 10mm diameter, 200mm shaft
• Ball Bearing with 10mm inside diameter
• 12V 2A Power Supply Adapter
• Barrel connector (because the motor power supply is wired in)
• Shield stacking headers
• Aluminum Flex Shaft Coupler - 5mm to 10mm
• Nema17 motor mounting bracket
• 4-pin to Male Headers Cable - 150mm Long (for plugging into Real Time Clock)
• Coin battery for real time clock
• USB Power Supply cable
• PVC Pipe
• Pipe mounting straps
• Spare lumber to hold it upright

Program

I put this program together using various tutorials and a lot of copy and pasting.

Thank you to Becka L, Chris M, and Brian V for their help!