Gantry
Documentation and assembly instructions for the FarmBot Genesis gantry
Component List
To prepare for assembly, gather all the components from the table below and lay them out in a logical manner. To complete the assembly in the next pages, you will also need the following tools:
- 3mm allen (hex) wrench
- 8mm wrench
2 hours
This is the estimated time it will take to assemble the Gantry.
Qty. | Component |
---|---|
1 | Gantry Main Beam (20 x 60 x 1500mm aluminum extrusion) |
2 | Gantry Columns (20 x 60 x 650mm aluminum extrusion) |
2 | Gantry Wheel Plates |
2 | Gantry Corner Plates |
1 | Gantry Motor Mount Plate |
4 | Belt Clip Plates |
4 | M3 x 10mm Screws |
4 | M3 x 5mm Setscrew |
48 | M5 x 10mm Screws |
4 | M5 x 16mm Screws |
18 | M5 x 30mm Screws |
10 | M5 x 6mm Spacers |
8 | M5 x 6mm Eccentric Spacers |
22 | M5 Washers |
48 | M5 Tee Nuts |
22 | M5 Locknuts |
1 | Horizontal Motor Housing |
6 | Cable Carrier Supports |
18 | Complete V-Wheels (one polycarbonate wheel, two 16 x 5 x 5mm rubber sealed ball bearings, and one 10 x 5 x 1mm shim) |
1 | NEMA 17 Stepper Motor and Rotary Encoder with 500mm length cables |
2 | 20 tooth GT2 Pulleys |
1 | 1.6m GT2 Timing Belt |
Change Log
- Gantry corner plates are slightly taller to bring back enough clearance for the cross-slide to be removed from the gantry main beam without removing the main beam from the columns
- The horizontal motor housing has been completely re-designed to better protect the end of the motor and the rotary encoder from rain
- Introduction of the belt clip that allows the gantry belts to be easily secured to the extrusions without damaging the belts
- Increased the thickness and length of the gussets on the drag chain mounts and driveshaft supports
- Increased the tolerance of the driveshaft bearing plate bearing hole, and the eccentric spacer holes on the gantry main plates
- Incorporated a bearing into the driveshaft supports
- Added more wheels to the gantry plates to increase rigidity
- Began tumble polishing all plates to remove burrs and manufacturing marks and improve the overall aesthetic of the plates
- Switched from low-profile M5 socket head screws to M5 button-head style screws. The new screws still have 3mm hex drives, but have a lower profile (2.75mm instead of 3.5mm) that provides better clearance between lower gantry v-wheel screws and track plates. They also have larger diameter heads (9.5mm from 8.5mm) that distribute loads more evenly and provide more secure connections, especially for the plastic components.
- Added cable clips near the electronics box to better manage cables and tubing
Room for Improvement
- The driveshaft is difficult to install and the flex coupling connection to the motor is barely adequate. The driveshaft design also introduces many additional components (bearings, motor mount plate, flex coupling, driveshaft, driveshaft supports). All of those could be replaced with a second x-axis motor. This would also better prepare the Genesis concept to scale to longer lengths (more cable carrier to pull) and a wider gantry (more weight to move).
- The corner plates and motor mount/bearing plates could be a single bent plate that would significantly improve the connection between the gantry columns and the main beam. It would also ease assembly.
- The cable clip could be a bent metal component.
- Explore a bent plate version of the cable carrier supports.