I love the concept of the Farmbot and I am excited to become part of the community. I had a thought recently of other configurations for Farmbot. The major one that came to mind is a circular or rotary Farmbot. I see these all the time in actual farms. I propose that a circular Farmbot would consist of following features:
- Able to rotate through an angle up to 360 degrees. I would not recommend totally continuous rotation as that would require rotary unions for water, vacuum, and electrical. 360 degrees of rotation would be easily achieved with a little bit of extra slack in the cables and would not require a cable carrier for the center post.
- Leveled circular garden bed. This would likely be the trickiest part of the circular configuration. Curved bed forms could be used to get a nicely curved edge. Or a large section of corrugated pipe say 10 feet in diameter. (Ideas and suggestions would be appreciated on this one)
- The theta (rotation) drive would be mounted on the drive wheel and would not require a timing belt, pulley and tensioner.
- Theta feedback could easily be provided from the center pivot. There are these really nice magnetic encoders that use a ring magnet and give an extremely high accuracy for $15 and the magnet is $2.70. Here are the links: http://ams.com/eng/Support/Demoboards/Magnetic-Position-Sensors/Linear-Position/AS5311-Adapterboard http://ams.com/eng/Products/Magnetic-Position-Sensors/Magnets/AS5000-MR10-128
- Magnetic encoders could also be used on the r and z axis which would cut at least $100 off the cost. Also magnetic encoders are better at environmental extremes and are not effected by dust or moisture.
I will work up some CAD and an updated bill of materials to show the proposed difference.
Any thoughts or suggestions are welcomed. I will keep everyone posted if/when I make progress.