FarmBot Genesis V3 exhibits the following changes from Genesis V2:

• Updated bracket design to minimize the number screws needed, making assembly easier and faster and decreasing the number of parts
• Simplified cross-slide design combining 3 plates into one
• Cable routing holes and extra hardware for a trolley style system to carry the cables across long distances
• Universal tool mount simplification and manufacturability improvements
• Universal tool mount configuration is vertically switched to bring the tool more in-line with the z-axis leadscrew for better force distribution
• Fixed issue with gantry belts running into screws be rearranging components
• Added simpler endstop integration onto plates, no longer uses extra plates to hit the buttons, just screws and teenuts

Tracks

The tracks brackets of Genesis V3 are slightly smaller than those of V2. The are generally the same design though.

Issues and Proposed Solutions:

• Using 4 screws to attach each track piece to each bracket is unnecessary and increases assembly time significantly. Using 2 screws will simplify the process and the reduce the number of parts while still being adequately strong enough for the application.
• The mounting holes for the bracket to the vertical post are spaced apart by 40mm rather than 20mm. This means they cannot be mounted to 20x40mm extrusions. Spacing these holes closer together will allow a single type of extrusion to be used throughout the design. Also, currently there are 4 screws attaching the bracket to the vertical column. This is unnecessary so the plate will effectively be cut in half in V4 and only two screws used.

Gantry

The Track/Gantry plates are slightly modified from V2 to re-position the endstops so that they can be clicked by screws and teenuts rather than small plates.

Issues and Proposed Solutions:

• It is difficult to adjust the width of the gantry once the main beam is cut. One must either re-cut the main extrusion to be shorter, or have limited ability to extend the gantry width before the brackets no longer attach to the extrusion. Positioning the main beam such that it is not obstructed in length by any brackets would solve this.
• The wire and trolley cable management system across the gantry will not work because the wires will get caught on taller plants. A cable carrier system will be cleaner and work better.

Cross-Slide

The Genesis V2 cross-slide was composed of three plates sandwiching all of the other components together. This was difficult to assemble and added little strength to the cross-slide. The V3 cross-slide has been simplified to a single plate with all components attached to it, making assembly much easier. There have also been extra slots added for cables to be cleanly routed through the plate and avoid all moving components.

Issues and Proposed Solutions

• There may be an issue with where the cables exit the cross-slide with the switch over to the cable carrier system from the wire and trolley system. This has yet to be determined in V4

Z-Axis

The Z-axis motor mount has remained the same since V2.

Issues and Proposed Solutions

• It's pretty ugly and bulky and I can't figure out a way to make it better without a custom bent bracket. Likely a custom bracket or 3D printed part will be in V4.

Universal Tool Mount

The V3 Universal Tool mount has been vertically flipped so that the solenoid locker is on the right side and the tool is inserted on the left side. This allows for the tool to be more aligned with the z-axis leadscrew so that there is minimized induced torque from the tool's weight. The tool mount has also been optimized for printing with a 3D printer. It no longer has any overhanging edges, and no support materials is required. Lastly, the electrical contact screws have been decreased in size to 3mm to allow for more clearance between themselves.

Issues and Proposed Solutions

• The extra gusset on the back side is unnecessary. It adds to printing time and is difficult to get the screws to align with tee nuts once the main bracket is attached to the extrusion. This extra gusset will be removed in V4.
• The slot for the solenoid locker to go through the plastic needs significantly more clearance to avoid friction. This slot will be increased in size in V4.
• All screw holes need to be enlarged slightly to allow screws to easily pass through even with the slight manufacturing variations that are expected with the 3D printing process.
• There may be significant difficulty inserting and removing tools and locking them in place due to friction forces, rough 3D printed surfaces, and tolerances. A more simple concept may be perform better.

Electronics

• The power supply used in Genesis V1 through V3 is very large in size. A smaller form factor supply might suit the project better.
• Electronics enclosures or housings need to be added to weatherproof everything.

Cable Management

The trolley and wire system is a good concept, but it is best suited to larger scale installations. It should not be used along the gantry though in any circumstances as the cables will get in the way of the plants when hanging. For smaller systems such as FarmBot Genesis, a cable carrier system will be more attractive and function better for both along the gantry and the tracks. This will likely add cost, but would likely increase reliability.

Files can be downloaded here.