Design in Progress
We need to move away from being dependent on Vention products, this will be a clean sheet design:
They are not compatible with other similar parts and are often discontinued.
Limited choices are causing sub-optimal design decisions.
Existing gantry is limited in width, the optimal solution is a gantry that is the width of the entire plot, thus eliminating the need for turning / complex navigation systems.
We have decided to use the Farm-ng Amiga robot as the base power unit for BB 3.0
Key | Summary | Description | Allowable Limits | Status |
|---|---|---|---|---|
Axis of Movement | Shall provide 3 integrated axis of movement X, Y, Z. | True | Draft | |
Tool Head | Shall provide standard electrical & mechanical interface for mounting a toolhead (such as a camera or actuator). | Draft | ||
Tool Head Positioning Range | Shall be capable of positioning the tool head anywhere in an operating envelope defined by X, Y, Z dimensions offset by minimum or maximum height from the operating surface. | True | Draft | |
Tool Head Position Accuracy | Shall be capable of positioning the toolhead in the operating envelope to this degree of accuracy. | 1cm > PA | Draft | |
Tool Head Mass | Shall be capable of supporting a tool head of at least this mass in all operating areas. | 50kg < M | Draft | |
Assembly | Shall not require significant specialized labor to assemble onsite. | True | Draft | |
Gantry Width Configurability | Gantry width shall be field configurable to a specified range without major design changes. | True | Draft | |
Min Configurable Gantry Width | Gantry shall be configurable and fully functional / structurally sound to at least this width. | W_max >=6m | Draft | |
Max Configurable Gantry Width | Gantry shall be configurable and fully functional / structurally sound to as little as this width. | W_min <=2m | Draft | |
The concept design is for a 20ft wide gantry, but it can be configured in many widths, definitely smaller and possibly larger with further engineering verification.
Cost Estimation
Component | Cost estimate | Link / info | Notes |
|---|---|---|---|
Amiga Robot Base Unit | $13k | ||
F34 Square Truss 3m straight segment (9.8ft) | 2 x $ 506 = $1012 | Global Truss Straight Square Segment for F34 Square Truss (bhphotovideo.com) | Lots of other distributors for compatible truss (Keyword F34) |
F34 Truss 6-Way Junction Block | 2 x $392 = $784 | Global Truss Universal Junction Block (Silver) ST-UJB-12 B&H (bhphotovideo.com) | |
F34 Square Truss 2m straight segment (6.6ft) | 2 x $392 = $784 | Global Truss Straight Square Segment for F34 Square Truss (bhphotovideo.com) | (Configure this to alter gantry width) |
3M Horizontal linear rail guide | 2 x $852 = $1704 | IVTAAQ Bolt-On Integrated Linear Guide - Double Width (pbclinear.com) | (Configure this to alter gantry width) |
3M Horizontal linear rail carriage | $412 | IVTAAQ Bolt-On Integrated Linear Guide - Double Width (pbclinear.com) | |
2M Vertical linear rail guide and carriage | $760 | IVTAAG Integrated Linear Guides - Integrated Aluminum Extrusion (pbclinear.com) | (Configure this to alter gantry height) |
Horizontal Travel Servo Motor | $350 | TBD Exact Part | |
Vertical Travel Servo Motor | $550 | TBD Exact Part | |
Equipment Box | $200 | TBD Exact Part | |
Linear guide mounting bracket | 26 x $20 = $520 | Laser cut Aluminum/steel plate (send-cut-send) | Design Not Finalized |
Truss Base Mounting Plate | 4 x $117 = $468 | Laser cut Aluminum/steel plate (send-cut-send) | Design Not Finalized |
Horizontal Drag Chain | TBD | ||
Vertical Drag Chain | TBD | ||
Current Total Estimate (will go up): | $7,544 + $13k = $20,544 |
Motion Components
Horizontal linear motion will be done with timing belts. As this is the most cost-effective way to make a repeatable weather resistant setup.
Vertical Motion will be accomplished with a stainless-steel lead screw. These are surprisingly affordable and offer the corrosion resistance and load capability we need.
Component | Cost estimate | Link / info | Notes |
|---|---|---|---|
304 Stainless Steel Precision Acme Lead Screw | $154 | ||
Plastic Externally Threaded Precision Acme Nut | $42 | Plastic Externally Threaded Precision Acme Nut, Right Hand, 3/4"-6 Thread Size | McMaster-Carr | |
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