Harvesting lettuce


#1

Has anyone done any work on a harvesting head for UTM? I’m just starting to think about it, interested in other’s thoughts.

I’m only interested in lettuce as it’s my main crop, and hard on the back.

Initial thinking:

  • Use an Aluminum mulch to retain water, stop weeds, and make the harvested product clean

  • Use a noose of thin cheese wire to loop down over a lettuce head, tighten to cut

  • Keep the noose spread with four or five springy arms

  • Collect the product in a stretchy mesh bag that fits over and contains the springy arms.


#2

Actually two 25cm long blades connected with two linear activators might be easier.

The thing opens up leaving a 25cm x 25cm square, it’s dropped over the plant, two acutators close bringing the blades together.

Lettuce falls on blades, the head is moved to harvesting crate, opens blades, lettuce falls out.

Repeat


#3

I started thinking about this a bit more & did a really crappy model (My first)

  • Red bits are 20x20 extrusion
  • Black bits are ‘carriages’ that slide over the extrusion
  • Blue bit is just a hinge
  • Orange bits are linear actuators
  • Grey bits are aluminium plates, to which you attach a sharp blade on the leading edge.

You drop it over your lettuce, close the actuator, the lettuce is cut and falls onto the plate. You move the assembly over your harvesting crate and use the other actuator to tip it in.

The link to the crappy model is here


Extend Farmbot to “infinite” length & “multi-bed”
#4

Now with added edge bits to stop the lettuce falling on the floor


#5

Hey @sam_uk

How did you plan to move the blades? Use high power servos or even a stepper motor with a short leadscrew?
In general it would be enough to move one blade against the other one.

Your ideas are really nice, I will follow your further development and am looking forward how it will work :slight_smile:


#6

The initial thought was a Linear actuator

But a leadscrew based thing might work too