Genesis V0.5 exhibits the following changes from Genesis V4
- The Tracks cable carrier is repositioned and now supported with teenuts and long M5 screws, just like on the Gantry
- The Z-axis motor mounting bracket has been made thicker and the holes for the M5 screws enlarged to 6mm to prevent cracking
- The magnetic Universal Tool Mount (UTM) system integrates connections for water, air, and liquid amendments. This allows the syringe pump for liquid amendments, the water valve, and the vacuum pump for the seed injector all to be placed on the gantry column near the electronics. This keeps the z-axis light weight and smaller in size
- A 3D printed Seed Injector Tool was introduced, incorporating a debris catching chamber
- The syringe pump Liquid Amendment Tool was built for the first time
- The water valve and Watering Tool were built for the first time
- Rotary encoders were 3D modeled into the system
Contents
- 1 Tracks
- 2 Gantry
- 3 Cross-Slide
- 4 Z-Axis
- 5 Universal Tool Mount
- 6 Electronics
- 7 Seed Injector
- 8 Nutrient Dispenser
- 9 Manufacturing Files
- 10 3D CAD Files
Tracks
Tracks Change Log- Repositioned the cable carrier alongside the track extrusion rather than below it. This eliminates the custom bent brackets in V4 with long screws and tee nuts
- The track joining plates had to be modified to have a lower profile so that they only cover half of the track extrusions. This allows the cable carrier to rest flush against the extrusions and prevent snagging on top of the plates.
Part Name | Description | Quantity | Source | Cost/Unit | Total Cost |
---|---|---|---|---|---|
Vertical Posts | Can be aluminum extrusions, wood posts, or other supporting infrastructure | 6 | - | - | - |
Track Joining Plates | 3mm thick aluminum plates to join Track Extrusions to Vertical Posts | 6 | Self Manufactured | ~$1 | ~$6 |
Fasteners | For attaching the Track Joining Plates to the Vertical Posts. Could be wood screws, machine screws with tee nuts, etc. | 12 | Various Sources | ~$0.10 | ~$1.20 |
M5x8mm Screws | M5 machine screws, 8mm length, 0.8 thread pitch, low-profile 3mm hex heads | 8 | OpenBuilds | $4.50/25 pieces | $4.50 |
Tee Nuts | For attaching M5 screws to OpenBuilds aluminum extrusions | 8 | OpenBuilds | $4.95/25 pieces | $4.95 |
Track Extrusions | 20x40mm, 1.5m length V-Slot Aluminum Extrusions | 4 | OpenBuilds | $19.50 | $78.00 |
- Setup the Posts
- Depending on where you are installing your FarmBot will change what material and how you might setup your Track Posts. You might use 2x4s of wood, or aluminum extrusions, or existing infrastructure. The posts might attach to a wooden raised bed, or be set in the ground or in small foundations. The choice is up to you how you set this up.
- Install short (100-500mm) vertical posts for one of the tracks. Attach or secure the posts however you like, though it is critical to ensure that the posts will not significantly move once installed. Space the posts 1500mm apart, center to center unless you are using shorter track lengths, in which case space the posts that far apart. Ensure the posts are aligned properly and the same height. You may want to use a level to ensure this.
- If you are setting up multiple track sections (more than 1500mm in total length), it is best to install the end posts first and tie a guide string in between these two posts to ensure your tracks are installed in a straight line.
- Depending on the width of your FarmBot, space the second Track's posts the appropriate distance away from the first Track's. It is critical that the distance between the two sets is consistent, if it is not, there will be unnecessary forces placed on the Gantry and Tracks.
- Attach the Track Plates
- The track plates should be screwed onto the inside of the posts using the appropriate fasteners: 8mm M5 screws and tee nuts if the posts are aluminum extrusions, standard wood screws if attaching onto wood posts. The top of the posts should NOT be flush with the top of the plates. Rather, the top of the posts should come up to cover only half of the plates.
- None
Gantry
Gantry Change Log- A syringe pump and leadscrew-stepper motor have been added to the Gantry column as part of the Liquid Amendment Tool
- A servo valve has been added to the Gantry column to control the Watering Nozzle Tool
- The corner brackets are now smaller to save on material and to keep the spacing of all bracket M5 holes to 20mm
Part Name | Description | Quantity | Source | Cost/Unit | Total Cost |
---|---|---|---|---|---|
Vertical Columns | 500mm long 20x40mm V-Slot aluminum extrusions | 2 | OpenBuilds | $6.50 | $13.00 |
Gantry Plates | 3mm thick aluminum or acrylic plates to attach the Track wheels to the Vertical Columns | 2 | Self Manufactured with a Laser Cutter, CNC Router, or WaterJet Cutter | ~$5.00 | ~$10.00 |
Solid V Wheel Kits | Each assembly includes one 25mm M5 screw, one locknut, two bearings, one precision shim, and one solid delrin v-wheel. | 8 | OpenBuids | $3.95 | $31.60 |
1/4 inch Eccentric Spacers | For adjusting the distance between the V-wheels | 2 | OpenBuilds | $2.00 | $4.00 |
Main Beam | 1.5m long 20x40mm V-Slot aluminum extrusion for spanning the width between the tracks | 1 | OpenBuilds | $19.50 | $19.50 |
Gantry Corner Brackets | 3mm thick aluminum plates to attach the vertical columns to the main beam | 2 | Self Manufactured with a Laser Cutter, CNC Router, or WaterJet Cutter | ~$5.00 | ~$10.00 |
Gantry Motor Mount | 3mm thick aluminum plate to attach the gantry motor to the vertical column | 1 | Self Manufactured with a Laser Cutter, CNC Router, or WaterJet Cutter | ~$5.00 | ~$5.00 |
NEMA 17 Stepper Motor | Dual, 5mm shafts with integrated rotary encoder on back side. Used for moving the gantry along the tracks | 1 | Unknown | ~$30.00 | ~$30.00 |
8mm M3 Screws | For attaching the stepper motor to the mounting plate | 4 | Pack of 25 from OpenBuilds | $2.00 | $2.00 |
5mm to 5mm Flex Coupling | For attaching the stepper motor to the drive shaft | 1 | Adafruit | $4.95 | $4.95 |
5mm staineless steel rod | 1.5m in length | 1 | unknown | ~$20 | ~$20 |
Drive Shaft Bearing Plate | 3mm thick aluminum plate to hold the drive shaft's bearing | 1 | Self Manufactured with a Laser Cutter, CNC Router, or WaterJet Cutter | ~$5.00 | ~$5.00 |
Drive Shaft Bearing | 16mm OD, 5mm ID, 5mm thickness | 1 | OpenBuilds | $1.00 | $1.00 |
Drive Shaft Lock Collars | 5mm ID, they capture the drive shaft bearing in place | 2 | OpenBuilds | $0.90 | $1.80 |
Motor Housing | 3D printed | 1 | Self manufactured or ordered from Shapeways | ~15.00 | $15.00 |
Total Cost | All components of the Gantry | - | Various | - | ~$172.85 |
Gather and lay out all of the parts. You will need: 2 Gantry Plates, 8 solid V-wheel kits, and 2 eccentric spacers. It is best to lay out the gantry plates as a mirror image of each other and attach all of the wheel kits facing towards you to ensure you end up with both a left facing and a right facing assembly!
Attach the three solid V-wheel assemblies with normal spacers onto each plate. The order of parts is: Screw head, Plate, Spacer, Wheel Assembly, Lock-nut. Use a 3mm allen wrench and a 8mm crescent wrench to tighten the assemblies. Use a moderate amount of torque.
Attach the single solid V-wheel assembly with the eccentric spacer onto each plate. The eccentric spacer fits into the largest hole on the plate. You should now have two Gantry plates with 4 V-wheel assemblies on each.
Attach the Gantry Plate Assemblies to the Gantry Columns using 4 8mm M5 screws and tee nuts for each assembly. Make sure that the column is attached to the same side of the Gantry Plate as the V-wheel assemblies. It is easiest to partially screw together all of the screws and tee nuts, slide in the extrusion, and then tighten all of the screws at once.
Assemble the Gantry Main BeamAttach the two corner brackets at either end using 2 8mm M5 screws and tee nuts for each bracket. Make sure both of the brackets are in the same orientation and on the same side of the extrusion.
Lightly screw together 5 sets of 25mm M5 screws and tee nuts and slide them onto the Gantry Main Beam. Evenly distribute them across the beam and then tighten them into place.
Attach the Column Assemblies to the Main Beam AssemblyUsing two 8mm M5 screws on each side. Make sure that the V-wheels are facing outward and both of the plates are attached to same side of the Main Beam, and facing in the same direction.
Attach Gantry to TracksFeed and Secure BeltsGantry Issues and Proposed Solutions- None
Cross-Slide
Cross-Slide Change Log- None
Z-Axis
Z-Axis Change Log- The Z-axis motor mounting bracket has been made thicker and the holes for the M5 screws enlarged to 6mm to prevent cracking
- All ideas for mounting tools to the z-axis extrusion have been nixed in order to keep weight down and the bulkiness of the z-axis to a minimum. Tools are now being consolidated to work with the Universal Tool Mount in combination with component mounted on the Gantry column.
Partially screw 2 8mm M5 screws and tee nuts into the motor mounting bracket. Route the Stepper Motor's cable through the bracket and attach the motor to the bracket with 4 8mm M3 screws.
Z-Axis Issues and Proposed Solutions- None
Universal Tool Mount
The Universal Tool Mount (UTM) allows FarmBot Genesis to automatically switch tool is on the z-axis depending on the operation needing to be completed. The UTM is ncessary because it is not feasible to have all tools mounted on the z-axis at one time for several reasons:
- This would be very heavy and create more stresses on all components, as well as necessitate a larger z-axis motor.
- Most tools need to be the "lowest" thing on the z-axis in order to work. Having multiple tools competing for the lowest position (ex: a temperature probe and a seed injector) would not be ideal and may not work at all. The use of individual tool raising and lowering mechanisms, or a turret style mechanism would be complex, heavy, bulky, and limited in the number of tools it could support.
- The Z-Axis's size must be kept to a minimum in order for it to have minimal impact on the plants, especially when there is not very much space between them.
The UTM is a single 3D printed component that mounts to the Z-Axis aluminum extrusion using two M5 screws and tee nuts. It features 3 strong neodymium ring magnets to magnetically hold tools in place via washers or other magnets placed in the same configuration on the Tool. The magnets double as the keying system to ensure that tools are properly oriented in the UTM. The magnets also function as the passage ways for water, liquid amendments (eg: fertilizer), and vacuum or compressed air to pass through from the UTM (and the rest of FarmBot) to the Tool. In addition, the UTM has 4 spring loaded screws that make electrical connections with Tools. Two are for power (GND and +5V), and two are for data (0 to +5V).
Universal Tool Mount Change LogThere are many changes from the V4 UTM design including the following. For a video overview of the design, click here.
- Switched from the single central magnet design from V4 to a three magnet design in order to keep the tools from easily being torqued out from the mount, and to increase the holding power.
- The ring magnets are now glued in place instead of held in with screws in order to keep the hole free.
- The ring magnets are now the passageways for air, water, and liquid amendments (eg: fertilizer) to pass through from the UTM to the Tool.
- The outer diameter of the UTM has increased slightly to accommodate the increased number of pass-through components.
- Center screw is now spring loaded too.
- Mounting flange is now 8mm thick instead of 5 for extra strength.
There are two versions of the Universal Tool Mount this time around. Both are functionally the same, one is simply optimized for the Fused Deposition Modeling (FDM) 3D printing process while the other is optimized for Stereolithography or Selective Laser Sintering (SLS). The major change is that the FDM version is much bulkier so that no support material is needed. This means that the part takes a long time to print, but it requires very little to no manual cleanup once done printing.
The SLS version is significantly smaller in volume, allowing to be printed with less material, thereby saving on time and cost. However, these printers are generally more expensive and not as widely available to the public as FDM printers are such as RepRaps.
Therefore both versions have great merit and will are made available for download. Make sure to select the correct model before printing depending on the process you choose or have access to!
A note about Tools, Power, and DataTim Evers and Rory Aronson had a lengthy discussion in email regarding how to handle communication between the tools and the Arduino/RAMPS board. This discussion can be seen on the Universal Tool Mount page. The summary:
- Plug the vacuum pump for the seed injector into one of the heating element pin pairs on RAMPS
- Plug the water pump/valve into the the other heating element pin pairs on RAMPS
- Plug the Universal Tool Mount's 2 power wires into the fan pins on RAMPS
- Plug the Universal Tool Mount's 2 data pins directly into the Arduino
- Tools will at first have a single function so communication will be general I/O and not require extra electronics
- Eventually tools may have more functions and require an I2C connection and additional electronics in the tool to support this communication
Note: In these photos, there are M3 screws in the mount. I did not have the M5 screws on hand at the time of taking the photo, thought he mount is designed for M5 screws.
SLS Version- The SLS version should NOT be printed using an FDM printer as seen in this photo because it requires the use of support material which can be difficult and time consuming to remove, ultimately leaving you with an inferior part. If you are going to use an FDM printer, do not print the SLS version!
- Note the excessive support material. Again, do NOT print the SLS version with an FDM printer as seen in these photos, it will not come out well.
- The main issue with the V5 Universal Tool Mount is that the three pairs of magnets directly mating with each other is too much force for the z-axis to be able to separate them. In fact, it is difficult to remove the tool from the mount even by hand! We tried making a tool without magnets, instead using washers in hope that the attraction would be weaker. That worked but posed a new problem: the attraction to the tool's washers was not strong enough in comparison to the attraction to the tool's screws for the electrical connections. This resulted in the mount and tool aligning improperly about 50% of the time.
- Only having metal where the magnets are (no screws enticing a misalignment) will help prevent misalignment. And not allowing the magnets to touch each other directly will reduce the holding force.
- Another issue with the magnets is the difficulty of seating them all in the tool mount to the same z-level in order to get good seals between the the tool and the mount. A remedy we tried was supergluing gaskets onto the magnet surfaces of the tool and the tool mount, but that was finicky as a corrective measure, and changed the distances between the tool and mount so the electrical connections no longer worked. That could have been solved with different sized screws or counter bores, but the glued on gaskets we're still not a great solution.
- Not having the magnets ever touch might be a better solution.
- Gluing the magnets into the mount and tool is also problematic. It means that the magnets cannot be easily removed - a major problem if one glues in a magnet with the wrong orientation such that it repels the tool instead of attracts it. In this case, one must take damaging measures to remove the magnet and flip its orientation.
- Screwing in the magnets to the tool and the mount is a much better solution as was done with the V4 design. This will be brought back in V6.
- Last, depending on the quality of the 3D printed parts, the barbs can be easily broken.
- This could be solved by replacing the printed barbs with screw-in metal barbs or with higher quality 3D printed parts.
Electronics
V5 hardware integrates Rotary Encoders onto the back of each of the stepper motors. This is important to ensure that FarmBot always knows where it is in the circumstances when it has been inadvertently moved (by kids or pets) or it tries to move but is prevented from doing so due to some obstruction (rocks, branches, kids, pets). Unfortunately, there are no readily accessible add-on rotary encoders from popular sites like Adafruit or Sparkfun (as of September 2014), however, there are a handful of companies who do produce small, add-on encoders that mount nicely to the back panel of the stepper motor and hook onto a second shaft coming from the motor. The encoders modeled in the renderings below are based on those offered by Schneider Electric.
Electronics RenderingsElectronics PhotosElectronics Issues and Proposed SolutionsSeed Injector
Seed Injector RenderingsNutrient Dispenser
Nutrient Dispenser PhotosManufacturing Files
All of the plates can be CNC routed, laser cut, or waterjet cut. The motor housings, Universal Tool Mount, and Tools can be 3D printed. .STL and .DXF files for manufacturing can be downloaded here.
3D CAD Files
FarmBot Genesis V5 was designed natively in SolidWorks 2014. Using SolidWorks 2014 or a newer version will provide the most seamless experience if you are interested in viewing or modifying the 3D part files. For those without access to SolidWorks, we have converted the files to other commonly used file formats.
All file formats can be downloaded here.
Discussions
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