download SVG laser cut
This is the file needed to laser cut the Printrbot Plus 1311 in plywood. We use Russian Birch Plywood, 6mm thick.
UBIS 13 nozzle
Mcmaster Carr 92716A519 Brass Cap Nut, 1/4"-20
Showing posts with label 3D printing. Show all posts
Showing posts with label 3D printing. Show all posts
Monday, August 17, 2020
Wednesday, November 20, 2019
PETG: Polyethylene Terephthalate with a glycol modification
I thought I knew how to 3D print using PLA, ABS and TPU. Then I met PETG Polyethylene Terephthalate (with a glycol modification). It kicked my butt.
Plastics (PLA, ABS, TPU) strings more as it gets hotter. But, I found out PETG behaves in an opposite manner. It oozes more like other plastics when hotter, but PETG can ooze too in colder temperature. This is not well documented by the filament manufacturers.
1) Bad bed adhesion: sensitive to bed level gap.
I tried all of them. (mirror + alchol, mirror + alchol + Elmer's purple glue, mirror + alcohol + Aquanet hair spray, mirror + alcohol + glue+ Aquanet hair spray, mirror+thick PVA wood glue, mirror+blue tape, blue tape+alcohol, blue tape+glue, blue tape+glue+hair spray on bare mirror, PET film, Kapton film).
my solution: mirror+glue or mirror+hair spray. Here the mirror means perfectly flat glass. If your glass is bent or warped then you are hosed.
my temperature setting: 230 extruder /75c bed
The glass transition point is 85 C so 75 C is good. Any higher you will get an elephant's feet problem. Use extruder temperature of +10 C of mfg's lowest setting. Higher for the 1st layer to stick better. Use wire brush on the nozzle to clean away carbon. Use twizzer to pull out loose strands during 1st layer. Use twizzer to pull out brown blobs during print. Brown blobs means too high extruder multipler or partially jammed extruder, by the way.
Don't try to go for that nice squished first layer look of PLA. If you try, PETG will curl up, and get stuck to the brass nozzle, and lift off the rest of the print job. Get silicone sock. Nothing stock to silicone. If a first layer line curls up, you are too close. If a first layer line drags, you are too far.
my gap setting: 1.5x of PLA gap.
2) Heat creep. I used PLA's 6.5mm retraction distance on PETG. It lead to a partial jam. A partial jam under-extrudes and negates any retraction effort. Under-extrusion prints soft, void parts, and negated retraction leaves bad stringing. But built up pressure during retraction will squirt out brown blobs. Do not exceed the lenght of the nozzle in seting retraction distance.
my setting: maximum 4.0mm retraction on a bowden printer with MK8 extruder.
3) Retraction: Read on.
GENERAL SETTING
Nozzle Diameter: This is the diameter of the tip of your nozzle where plastic is extruded from. A smaller nozzle is great for thin walls, for printing small miniatures and other things that require fine precise details. Large 1 mm nozzles are great for rapid prototyping, creating large parts quickly and efficiently by pushing out lots of plastic.
my setting: 0.4mm
Extrusion Multiplier: The extrusion multiplier will multiply the amount of filament extruded for your entire print. This includes skirts, rafts, supports, perimeter and infill extrudes. The default values in the software are .90 for PLA and 1.0 for ABS.
my setting: 1.0
Extrusion Width: The slicing engine doesn't use your nozzle diameter, but instead uses your Extrusion Width setting. For most cases, keeping this setting on Auto (1.2x your nozzle diameter) is the best route, however for certain cases where you have extremely thin nozzles, you may find it's best to go to Manual and play with lowering the Extrusion Width setting.
my setting: auto (0.48 grayed out) Internet is full of people who recommend 0.40 to match nozzle's 0.40mm diameter. I don't do that. It makes more sense to go 1.2x (0.48), 1.3x (0.52), 1.4x(0.56), 1.5x(0.60)
RETRACTION
It is better to avoid the retractions all together. This way the extruder never has to reverse direction and can continue a nice uniform extrusion. This is particularly important for machines that use a Bowden extruder, as the long distance between the extruder motor and the nozzle makes retractions more troublesome. Vase mode does this. But not everything can be printed in a vase mode.
Retraction Distance: How much filament will be retracted when the software does a retract. For standard Direct Drive, usually .5 to 2.5 mm will work well. For Bowden extruders, 5 to 8.5 mm seems to work well.
my setting: 4.00mm or lower. Keep it down. PETG will jam. It won't clog at the nozzle, but jam up by the throat.
Extra Restart Distance: If you start to notice small defects on the surface of your print, the best way to diagnose what is causing them is to watch closely as each perimeter of your part is printed. Does the defect appear the moment the extruder starts printing the perimeter? Or does it only appear later when the perimeter is completed and the extruder is coming to a stop? If the defect appears right away at the beginning of the loop, then it’s possible your retraction settings need to be adjusted slightly. “Extra Restart Distance” determines the difference between the retraction distance when the extruder is stopping and the priming distance that is used when the extruder is restarting. If you notice a surface defect right at the beginning of the perimeter, then your extruder is likely priming too much plastic. You can reduce the priming distance by entering a negative value for the extra restart distance. For example, if your retraction distance is 1.0mm, and the extra restart distance is -0.2mm (note the negative sign), then each time your extruder stops, it will retract 1.0mm of plastic. However, each time the extruder has to start extruding again, it will only push 0.8mm of plastic back into the nozzle. Adjust this setting until the defect no longer appears when the extruder initially begins printing the perimeter.
my setting: -0.1mm PETG is full of blob and gunk so set it as negative number.
Retraction Vertical Lift: The nozzle will move up in the Z-axis whenever you do a retract. This is particularly helpful with Delta printers and prints that have a lot of islands, since the delta printers can be prone to running into parts when doing rapids.
my setting: 0. Don't lift up in PETG. Will make blobs.
Retraction Speed: The speed at which the filament will be retracted/primed. I think 1800 mm/min or 30 mm/sec is about as slow as I'd want to go for standard retracts, that going quicker will help for print quality in most cases.
my setting: 30 mm/sec
Coasting Distance: If the defect does not occur until the end of the perimeter when the extruder is coming to a stop, then there is a different setting to adjust. This setting is called coasting. You can find it right below the retraction settings on the Extruder tab. Coasting will turn off your extruder a short distance before the end of the perimeter to relieve the pressure that is built up within the nozzle. Enable this option and increase the value until you no longer notice a defect appearing at the end of each perimeter when the extruder is coming to a stop. Typically, a coasting distance between 0.2-0.5mm is enough to have a noticeable impact.
Setting a coasting value can be good if you want to empty out your nozzle before doing a retract. Lets say you're printing a single line that is 100 mm long. If you set a coasting distance of 5 mm, the extruder will be pushing out plastic for the first 95 mm of traveling, but then stop extruding and while it will move over the rest of the line, it will not actually extrude anything for the last 5 mm. It will instead depend on the filaments momentum, and gravity to let the rest of the filament ooze out and fill in the region for the last 5 mm of the line. However, Coasting is not extruding over areas that need filament (you risk under-extrusion voids if coasting value is too high),
my setting: 2.0 mm/sec
Wipe Nozzle: Non-stationary retraction is particularly useful for bowden extruders that build up a lot of pressure inside the nozzle while printing. Typically when these types of machines stop extruding, the excess pressure is still likely to create a blob if the extruder is standing still. Wipe Nozzle will tell the printer to wipe the nozzle at the end of each section when it stops printing.
Wipe Distance: Wiping happens after you've printed your outer most outline (inside-out outline direction). When you print your outer most outline, when it's time to do a retract, there's a good chance that not all of the filament in the extruder nozzle head is going to rise up, that a blob of molten liquid plastic is going to be at the tip of the nozzle still. For this reason, instead of rapidly moving to the next spot right away, you can use the Wipe function, which will wipe over the perimeter and let that filament ooze out, similar to Coasting. Wiping is extruding over areas that have already been printed on (much lower risk of part quality being negatively effected) and coasting is not.
my setting: On at 5.0 mm/sec
Top layer: If you notice that your Top solid layers are not as filled-in as you'd like them to be, I would recommend increasing the # of top solid layers, and if you still think there's an issue then this is the setting I'd recommend changing.
Location of starting point: If you are still seeing some small defects on the surface of your print, Simplify3D also provides an option that can control the location of these points. Click on “Edit Process Settings” and select the Layer tab. In most cases, the locations of these start points are chosen to optimize the printing speed. However, you also have the ability to randomize the placement of the start points or align them to a specific location. For example, if you were printing a statue, you could align all of the start points to be on the backside of the model so that they were not visible from the front. To do this, enable the “Choose start point that is closest to specific location” option and then enter the XY coordinate where you want the start points to be placed.
my setting: Choose starting point 0 / 500
Only retract when crossing open spaces: If the nozzle is not going to cross an open space, the oozing that occurs will be on the inside of the model and won’t be visible from the outside. For this reason, many printers will have the “Only retract when crossing open spaces” option enabled to avoid unnecessary retractions. This is enabled by default for most profiles, since you really only need to do a retraction if you are crossing over an open space, since you would be crossing perimeters and be at risk for stringing.
my setting: on
Force retraction between layers: Forces a retraction from layer to layer.
my setting: on
Minimum travel for retraction: If a movement is below this threshold, it won't retract for that movement. This would be if your printer has a lot of problems with retractions, you may need to tweak this, to limit the number of retractions your print has.
my setting: off
Perform retraction during wipe movement: Next, go to the Advanced tab and enable the option labeled “Perform retraction during wipe movement”. This will prevent a stationary retraction, since the printer has now been instructed to wipe the nozzle while it retracts. This is a very powerful feature and a great option to try if you are still having trouble removing these defects from the surface of your print.
my setting: on
Only wipe extruder for outer-most perimeters: This will ensure that you only use the Wipe feature (Extruder tab) when needed, when it would effect the appearance of your model. Therefore, to save time and be efficient it will only wipe the extruder for outer-most perimeters. It may not be helpful to wipe the extruder after doing Infill, however if you wanted the extruder to wipe after Infill you could do that by unchecking this box.
my setting: on
Avoid crossing outline for travel movement: If your printer is only going to retract when crossing open spaces, then it would be beneficial to avoid these open spaces as much as possible. If the extruder can avoid crossing the outline by changing the travel path, then a retraction won’t be needed.
my setting: on
Tuesday, October 8, 2019
IoT-Enabled Planter System For Urban Space
IoT-Enabled Planter System For Urban Space
By
Daniel Lee
By
Daniel Lee
Professor, College of IT Convergence
INTRODUCTION
Despite our best effort to be active and spend more time outdoors, a majority of our time is spent indoors, whether it’s a home or working in an office environment. The modern building design favors energy-efficient climate-control resulting in reduced fresh air exchange. Indoor air pollution is a health risk either as a concentrated trace chemical or psychological ‘sick building syndrome’.
In addition to indoor air pollution, inhalable particles (micro dust) pollution is an even bigger issue in Korea. The fine particles of 10 and 2.5 micrometers blankets the sky during the winter months.
In 1989, NASA has conducted a Clean Air Study to find the most effective common indoor plants for removing toxins and pollution in the air. Here we present NASA’s recommended common indoor plants in conjunction with my inventions, microsiphon, Veloster, s-trap, and snorkel used in indoor aquaponics planter.
It has successfully gone through alpha and best test stage, and currently being sold at amazon.com, and etsy.com under ‘justponics’ brand. The 3D printing lean manufacturing is performed by lefab3d.com, a member company of PeopleSpace incubator.
Despite our best effort to be active and spend more time outdoors, a majority of our time is spent indoors, whether it’s a home or working in an office environment. The modern building design favors energy-efficient climate-control resulting in reduced fresh air exchange. Indoor air pollution is a health risk either as a concentrated trace chemical or psychological ‘sick building syndrome’.
In addition to indoor air pollution, inhalable particles (micro dust) pollution is an even bigger issue in Korea. The fine particles of 10 and 2.5 micrometers blankets the sky during the winter months.
In 1989, NASA has conducted a Clean Air Study to find the most effective common indoor plants for removing toxins and pollution in the air. Here we present NASA’s recommended common indoor plants in conjunction with my inventions, microsiphon, Veloster, s-trap, and snorkel used in indoor aquaponics planter.
It has successfully gone through alpha and best test stage, and currently being sold at amazon.com, and etsy.com under ‘justponics’ brand. The 3D printing lean manufacturing is performed by lefab3d.com, a member company of PeopleSpace incubator.
MISSION STATEMENT
Through these improvements, we wish to make immediate impacts on people, planet, and profit by offering;
1) small-scale food production
2) tabletop garden and pond, and
3) plant-based indoor air purifier
INCORPORATION
Justponics LLC was formed on 7/29/2019 as a California limited liability corporation
HOW IT WORKS
INDOOR FOOD PRODUCTION
AIR PURIFICATION
NASA study suggested that in addition to absorbing carbon dioxide and releasing oxygen through photosynthesis certain common indoor plants may also provide a natural way of removing toxic agents from the air.
English ivy (Hedera helix)
Green Spider plant (Chlorophytum elatum)
Peace lily (Spathiphyllum 'Mauna Loa')
Chinese evergreen (Aglaonema modestum)
Bamboo palm (Chamaedorea seifrizii)
Variegated snake plant, mother-in-law's tongue (Sansevieria trifasciata 'Laurentii')
Heartleaf philodendron (Philodendron cordatum)
Selloum philodendron
(Philodendron bipinnatifidum)
Elephant ear philodendron (Philodendron domesticum)
Red-edged dracaena (Dracaena marginata)
Cornstalk dracaena (Dracaena fragrans 'Massangeana')
Weeping fig (Ficus benjamina)[5]
Barberton daisy (Gerbera jamesonii)
Florist's chrysanthemum (Chrysanthemum morifolium)
Aloe vera (Aloe vera)
Janet Craig (Dracaena deremensis "Janet Craig")
Warneckei (Dracaena deremensis "Warneckei")
Banana (Musa oriana)
We conducted air quality sampling with a Laser Particle Counter which can detect particles down to 0.5 microns. The large particle size range is calibrated to 2.5 microns and above. It has a PC Interface to capture the air quality data to a PC for graphing and analysis. A room with our Edu Kit was monitored overnight for the PM2.5 level. The result was full of potential (a.k.a. non-conclusive) The room’s PM2.5 level settled down after 6 hours. Due to the PM2.5’s Brownian mobility, the particles might have landed on the leaves of the plants. There is no evidence PM2.5 has true mobility of its own. Electrostatic or other forms of attraction (including gravity) might be at play. We were not able to measure plants’ gas exchangeability with our limited instruments at this time. It would seem plausible a plant with the most leaf surface area should capture the most PM2.5 out of the air. The plant should have assisted or self-cleaning ability to cleanse itself of PM2.5 attracted on its leaves. This needs further investigation.
Air quality monitor used for instant spot monitoring
DECORATION & COMPANION PLANT
Aside from small scale food production and air purifying qualities, Edu kit serves as a beautiful decorative companion plant planter.
RESEARCH
Since we were devising an aquaponics device, we looked into prior work done on hydrodynamics wave propagation but came to learn that the problem was a complicated one, and had not yet been rigorously solved analytically. Instead, a series of assumptions and simplifications were often used in practice. The fluid wave propagation was a three-dimensional problem, but it was simplified from three-dimensional to a one-dimensional problem by using Webster’s horn equation. We got useful information about the behavior with this type of approach. A large number of cases were solved this way with high satisfaction. We got a really lucky break when we made the further assumption that water is a type of high viscous air. It is indeed a lucky break for me because the math on aerodynamics was abundantly available.
(edu kit v2.0 in action. Self-contained eco system)
The following items are invented and manufactured by us.
MICROSIPHON
(This microsiphon is optimized for 1 to 10-gallon tank with an operating flow rate of 10 to 40 gallons per hour )
VELOSTER
Bell siphon Veloster is a specially shaped hydrodynamics device designed to facilitate failsafe starting of siphon by passing a large volume of water into a narrow riser pipe. Without the Veloster, water will attempt to drain simultaneously creating a traffic jam. The science here is a reversal of impedance resonance. The impedance resonance is why a trumpet can carry a tiny lip vibration at the trumpet mouthpiece over a great distance. The boundary layer development was critical in achieving a strong siphon because the high viscosity of water produces high shear stresses, and distorts the inner non-viscous flow. The device achieves compressed entry of water by transitioning slow water to fast water flow. Entering water is smoothed out, and the flow fills the entire pipe area.
Red: slow water
Blue: fast water
S-TRAP
S-trap is a curved hydrodynamics device designed to facilitate minimizing siphon as long as possible so that the maximum siphon is achieved through a sudden jump in the water velocity. It operates fundamentally different from the 90-degree elbow. The scientific method here is Stick and Slip phenomenon. Stick-slip can be described as surfaces alternating between sticking to each other and sliding over each other, with a corresponding change in the force of friction. If an applied force is large enough to overcome the static friction, then the reduction of the friction to the kinetic friction can cause a sudden jump in the velocity of the movement. You can see the water column inside a bell rise in stick and slip motion fashion.
(S-trap showing different water height of inside and outside the bell due to backpressure)
(blueprint drawing of microsiphon)
SNORKEL
A snorkel is a special internal snorkel piping designed to facilitate failsafe stopping of siphon. It passes a large volume of air into a narrow riser pipe without interruption. The science here is Stoke’s Law. A bubble starts out as compressed gas equal to the surrounding fluid pressure when it was first formed. As a bubble rises it loses initial acceleration and reaches terminal velocity while increasing in size causing more drag. This means a bubble at terminal velocity does not have enough kinetic energy to effectively stop the siphon. We want a fast bubble to reach the top quickly so the siphon can stop quickly. The change in the velocity and direction of movement are kept as gradual as possible to attain the highest economy by applying the principle of laminar flow. The specific calculation of the Reynolds number is satisfied by manipulating the geometry of the flow system and flow pattern. The bubble is given the straightest path of least resistance by a snorkel.
DRONE
Used in IoT enabled smart farming. This drone detects and controls pests. We designed two pieces of shells made out of carbon fiber 3D printed shells. The shells are lightweight to increase the payload and flight time of the drone. The drone will carry an AI-based vision system to detect and identify microscopic pests. The future wishlist is to include laser bug zapper for surgical elimination of the pests.
IoT
We developed our own custom board to monitor and collect data from the various custom soil, water, and air sensors.
MOBILE APP
LITERS PER HOUR FORMULA
We are proud to say all bell siphons are fully tested and calibrated before leaving our site. Perfect! But some fans write to us the bell siphon does not work upon receiving. How could this happen? It’s because the bell siphon is used in all kinds of different environments so the water flow rate, measured in LPH, liters per hour, is incorrectly calculated.
Note that calibration is an ongoing process that needs to be performed throughout the life of the growth kit. Without calibration, the bell siphon may not work as designed. If you want better bell siphon experience, we recommend maintaining the optimum water flow rate.
There is a definite science behind it, but we will keep things as plain as possible. Bell siphon itself is a quite simple contraption as far as mechanics go in the sense that there are no moving parts besides water level rising and falling.
The flow rate of a siphon is a function between the diameter of standpipe and S-trap. The equation is as described by Bradbury (1910) gives the average flow rate as
Q = K x A * ((2 x g x h)^(1/2))
where Q= flow rate (L min−1);
K= discharge coefficient;
A= inner area of the discharge pipe (m^2);
h= average head [= average of the maximum and minimum head (mm)], and
g= acceleration due to gravity (mm min−2).
Water inflow is achieved by a 300LPH (80GPH) submerged pump which can be purchased for ~$10.
Because the inflow rate is depended on the capacity of the pump and the pumping height, we determined 300LPH (80GPH) rated pump was achieving 150LPH (40GPH) actual pumping rate when the pumping height was at 280 mm. 280 mm was calculated by assuming stacking two 140 mm height bins. We kept the pump at the lowest part of the lower bin and water outlet hose at the highest part of the upper bin.
MICROSIPHON CALIBRATION
With a perfectly calibrated bell siphon, you should see a constant water level rising and falling. The water may start trickling down the tube, but water inflow should overtake the trickling loss. Then you should see rapid dumping of water to the reservoir signaling of successful siphoning. Once the water level is sufficiently lowered, the siphon should stop with a strong burp.
(nice strong siphon. the water column is way above the Veloster)
There are two main problems a bell siphon can have. The first is where the water flow rate is too low so the siphon does not start, and the second is where the water flow rate is too high so the siphon does not stop.
SIPHON DOES NOT START
1. Trickling sound
Solution: increase the flow rate
The relationship between the pump’s flow rate and the pumping height was a second-degree polynomial. In our calculation, a minimum of 40LPH (10GPH) was required for a successful siphon start. The siphon did not start if the pump inflow could not overtake the inevitable slow trickling down of water. We called this stage a “perma-trickle”.
(water trickles down so siphon does not start)
The grow tank is filled with water so it seems to be ready to start siphoning, but it doesn’t because water is slowly leaking into the reservoir below. The water-in is less than water-out. The drain pipe sucks in the air instead of creating a vacuum to prime the pipe. You can prime the siphon in two ways. Increase the water pump rate or increase the pressure resistance in the drain pipe. The water pump has an adjustable valve. Rotate towards + to increase the flow rate. The water pump needs regular cleanup to remove sludge build-up.
SIPHON DOES NOT STOP
1. Gurgling sound
Solution: decrease the flow rate
The grow tank is drained, but it is not refilling back up. Water-out is greater than water-in. You can break the siphon in two ways. Decrease the water pump rate or decrease the pressure resistance in the drain pipe. The water pump has an adjustable valve. Rotate towards – to decrease the flow rate.
At an inflow rate above 300LPH (80GPH), the siphon did not stop reliably at the end of the discharge. At this high rate, the water inflow rate exceeded the minimal speed which air could enter the bell to break the siphon. We called this stage a “perma-drain”.
We were quite surprised, at least for us, how easy it was to achieve a perma-drain stage. We were achieving this without any calculation. We will revisit why the margin of error was so large to achieve an equilibrium when by definition a rather precise point where inflow and outflow are equal must be achieved.
2. The water pump is getting weaker
The water pump, over time, whether through age, contamination, algae build-up, etc, will slow down. This will result in decreased inflow rate so the siphon does not start properly. You should clean or replace the pump.
3. Overgrowth of roots
Overgrown vegetation root blockage will restrict the water outflow so the siphon does not stop. Clear away the blockage or replace the siphon.
BIN
The container used was SAMLA 1 gallon plastic bin found at Ikea.com.
Width: 280 mm
Depth: 190 mm
Height: 140 mm
Volume: 3.8 liter
Material: Polypropylene (C3H6)n
We designed the Edu Kit for indoor use only so we believe beneficial physical properties of PP such as good chemical resistance with good elasticity and good fatigue resistance outweigh PP’s susceptibility to UV degradation. The replacement bin can be purchased economically from Ikea.com. In any case, please do not use the Edu Kit outdoors or under direct sunlight.
Since it would have been more optimum if the pump was cut off during the discharge, we considered a float valve switch design to cut off the pump when the siphon started. This design was put on hold as a float valve switch would have taken up valuable grow bed space.
OPTIMUM PUMP PERFORMANCE
In our calculation, 150LPH (40GPH) was most reasonable for 3.8 liters (1 Gallon) IKEA samala bin at 280 mm pumping height. The siphon started surely and ended satisfyingly without fail and worry, every single time. We called this a “one-siphon-to-rule-them-all” stage.
As we have calculated and demonstrated, the success of siphon depends largely on correct calibration based on the tank’s volume (width x depth x height, 3.8 liters in our case), the surface area (width x depth), water flow rate (water inflow – water outflow). There was a strong linear relationship between the water flow rate and trigger/break action with a coefficient of determination of 0.99.
One more important dimension of consideration was how fast water rises. This is a derivative of the net water flow rate and bin dimension. For a given net water flow rate and a bin volume, a narrow bin would achieve faster water rise than a wide bin. A faster water rise from a narrow bin will aid in the starting of the siphon. A slower water rise from a wide bin may not be able to start the siphon. A calculation based on actual water inflow rate alone would only be correct if we assume the grow bed is always used empty. The water rise rate depended on how densely medium (sand, pebble, hydroton, etc) was packed in addition to actual water inflow rate which depended on actual pump rate and pump height and in addition to how wide or narrow the bin was shaped.
MACHINE LEARNING
We developed an IoT device to collect data and record pertinent information in managing the edu kit. We anticipate our system will evolve to full integration of automated data recording, data analysis, machine learning, and decision-making into an interconnected system.
ML uses a set of well-defined models that collect specific data and apply specific algorithms to achieve expected results. The recent development of deep learning has expanded the scope of Artificial Neural Network application in agriculture.
Neural Networks are inspired by the human brain functionality and represent a simplified model of the structure of the biological neural network emulating complex functions such as pattern generation, cognition, learning, and decision making. Such models are used for regression and classification tasks
SVMs are binary classifiers that construct a linear separating hyperplane to classify data instances. SVMs are used to predict the yield and quality of crops by classification, regression, and clustering.
Soil Management
Machine learning algorithms study evaporation processes, soil moisture, and temperature. We are interested in detecting balanced fertilizer properties in soil.
Water Management
Machine learning algorithms are used for effective irrigation systems by estimating evapotranspiration and evaporation. We are interested in detecting and maintaining ph level of 6 in water using auto doser.
Yield Prediction
ML can make accurate detection and classification of crop quality characteristics. This is tied to the yield prediction forecast resulting in precision agriculture.
Weeds & Insects Detection
Weed control requirement for indoor planter system is minimum. The spider mite is a huge problem in tomato farming. Computer vision and ML algorithms and robots improve detection and precise discrimination of weeds and insects minimizing the need for herbicides and insecticides.
3D PRINTER FARM
We design and produce our own parts in-house.
VIDEOS
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CONCLUSION
We are on! Currently conducting business on amazon.com and etsy.com with good results.
REFERENCES
Food and Agriculture Organization of the United Nations: small-scale aquaponic food production
https://drive.google.com/file/d/1gm4lVuCDFn4mD2dBWBtSDdZidxvUiZ-t/view?usp=sharing
a smart fish-based solution to growing food using limited resources and little water
https://drive.google.com/file/d/1Xfoz6kPnYO3gZBL1Ud7yj4t4ZmHsW_or/view?usp=sharing
Construction of Automatic Bell Siphons for Backyard Aquaponic Systems
https://drive.google.com/file/d/109N0-ZJgZ-9TJctz_QGtq3aZnA6Gf3f9/view?usp=sharing
EPA Particulate Matter (PM)
https://www.epa.gov/pm-pollution/particulate-matter-pm-basics
NASA Interior Landscape Plants for Indoor Air Pollution Abatement https://ntrs.nasa.gov/search.jsp?R=19930073077
Machine Learning in Agriculture: A Review.
https://www.ncbi.nlm.nih.gov/pubmed/30110960
Study on the Adsorption Capacities for Airborne Particulates of Landscape Plants in Different Polluted Regions in Beijing (China)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4555302/
Through these improvements, we wish to make immediate impacts on people, planet, and profit by offering;
1) small-scale food production
2) tabletop garden and pond, and
3) plant-based indoor air purifier
INCORPORATION
Justponics LLC was formed on 7/29/2019 as a California limited liability corporation
HOW IT WORKS
INDOOR FOOD PRODUCTION
AIR PURIFICATION
NASA study suggested that in addition to absorbing carbon dioxide and releasing oxygen through photosynthesis certain common indoor plants may also provide a natural way of removing toxic agents from the air.
English ivy (Hedera helix)
Green Spider plant (Chlorophytum elatum)
Peace lily (Spathiphyllum 'Mauna Loa')
Chinese evergreen (Aglaonema modestum)
Bamboo palm (Chamaedorea seifrizii)
Variegated snake plant, mother-in-law's tongue (Sansevieria trifasciata 'Laurentii')
Heartleaf philodendron (Philodendron cordatum)
Selloum philodendron
(Philodendron bipinnatifidum)
Elephant ear philodendron (Philodendron domesticum)
Red-edged dracaena (Dracaena marginata)
Cornstalk dracaena (Dracaena fragrans 'Massangeana')
Weeping fig (Ficus benjamina)[5]
Barberton daisy (Gerbera jamesonii)
Florist's chrysanthemum (Chrysanthemum morifolium)
Aloe vera (Aloe vera)
Janet Craig (Dracaena deremensis "Janet Craig")
Warneckei (Dracaena deremensis "Warneckei")
Banana (Musa oriana)
We conducted air quality sampling with a Laser Particle Counter which can detect particles down to 0.5 microns. The large particle size range is calibrated to 2.5 microns and above. It has a PC Interface to capture the air quality data to a PC for graphing and analysis. A room with our Edu Kit was monitored overnight for the PM2.5 level. The result was full of potential (a.k.a. non-conclusive) The room’s PM2.5 level settled down after 6 hours. Due to the PM2.5’s Brownian mobility, the particles might have landed on the leaves of the plants. There is no evidence PM2.5 has true mobility of its own. Electrostatic or other forms of attraction (including gravity) might be at play. We were not able to measure plants’ gas exchangeability with our limited instruments at this time. It would seem plausible a plant with the most leaf surface area should capture the most PM2.5 out of the air. The plant should have assisted or self-cleaning ability to cleanse itself of PM2.5 attracted on its leaves. This needs further investigation.
Air quality monitor used for instant spot monitoring
DECORATION & COMPANION PLANT
Aside from small scale food production and air purifying qualities, Edu kit serves as a beautiful decorative companion plant planter.
RESEARCH
Since we were devising an aquaponics device, we looked into prior work done on hydrodynamics wave propagation but came to learn that the problem was a complicated one, and had not yet been rigorously solved analytically. Instead, a series of assumptions and simplifications were often used in practice. The fluid wave propagation was a three-dimensional problem, but it was simplified from three-dimensional to a one-dimensional problem by using Webster’s horn equation. We got useful information about the behavior with this type of approach. A large number of cases were solved this way with high satisfaction. We got a really lucky break when we made the further assumption that water is a type of high viscous air. It is indeed a lucky break for me because the math on aerodynamics was abundantly available.
(edu kit v2.0 in action. Self-contained eco system)
The following items are invented and manufactured by us.
MICROSIPHON
(This microsiphon is optimized for 1 to 10-gallon tank with an operating flow rate of 10 to 40 gallons per hour )
VELOSTER
Bell siphon Veloster is a specially shaped hydrodynamics device designed to facilitate failsafe starting of siphon by passing a large volume of water into a narrow riser pipe. Without the Veloster, water will attempt to drain simultaneously creating a traffic jam. The science here is a reversal of impedance resonance. The impedance resonance is why a trumpet can carry a tiny lip vibration at the trumpet mouthpiece over a great distance. The boundary layer development was critical in achieving a strong siphon because the high viscosity of water produces high shear stresses, and distorts the inner non-viscous flow. The device achieves compressed entry of water by transitioning slow water to fast water flow. Entering water is smoothed out, and the flow fills the entire pipe area.
Red: slow water
Blue: fast water
S-TRAP
S-trap is a curved hydrodynamics device designed to facilitate minimizing siphon as long as possible so that the maximum siphon is achieved through a sudden jump in the water velocity. It operates fundamentally different from the 90-degree elbow. The scientific method here is Stick and Slip phenomenon. Stick-slip can be described as surfaces alternating between sticking to each other and sliding over each other, with a corresponding change in the force of friction. If an applied force is large enough to overcome the static friction, then the reduction of the friction to the kinetic friction can cause a sudden jump in the velocity of the movement. You can see the water column inside a bell rise in stick and slip motion fashion.
(S-trap showing different water height of inside and outside the bell due to backpressure)
(blueprint drawing of microsiphon)
SNORKEL
A snorkel is a special internal snorkel piping designed to facilitate failsafe stopping of siphon. It passes a large volume of air into a narrow riser pipe without interruption. The science here is Stoke’s Law. A bubble starts out as compressed gas equal to the surrounding fluid pressure when it was first formed. As a bubble rises it loses initial acceleration and reaches terminal velocity while increasing in size causing more drag. This means a bubble at terminal velocity does not have enough kinetic energy to effectively stop the siphon. We want a fast bubble to reach the top quickly so the siphon can stop quickly. The change in the velocity and direction of movement are kept as gradual as possible to attain the highest economy by applying the principle of laminar flow. The specific calculation of the Reynolds number is satisfied by manipulating the geometry of the flow system and flow pattern. The bubble is given the straightest path of least resistance by a snorkel.
DRONE
Used in IoT enabled smart farming. This drone detects and controls pests. We designed two pieces of shells made out of carbon fiber 3D printed shells. The shells are lightweight to increase the payload and flight time of the drone. The drone will carry an AI-based vision system to detect and identify microscopic pests. The future wishlist is to include laser bug zapper for surgical elimination of the pests.
IoT
We developed our own custom board to monitor and collect data from the various custom soil, water, and air sensors.
MOBILE APP
LITERS PER HOUR FORMULA
We are proud to say all bell siphons are fully tested and calibrated before leaving our site. Perfect! But some fans write to us the bell siphon does not work upon receiving. How could this happen? It’s because the bell siphon is used in all kinds of different environments so the water flow rate, measured in LPH, liters per hour, is incorrectly calculated.
Note that calibration is an ongoing process that needs to be performed throughout the life of the growth kit. Without calibration, the bell siphon may not work as designed. If you want better bell siphon experience, we recommend maintaining the optimum water flow rate.
There is a definite science behind it, but we will keep things as plain as possible. Bell siphon itself is a quite simple contraption as far as mechanics go in the sense that there are no moving parts besides water level rising and falling.
The flow rate of a siphon is a function between the diameter of standpipe and S-trap. The equation is as described by Bradbury (1910) gives the average flow rate as
Q = K x A * ((2 x g x h)^(1/2))
where Q= flow rate (L min−1);
K= discharge coefficient;
A= inner area of the discharge pipe (m^2);
h= average head [= average of the maximum and minimum head (mm)], and
g= acceleration due to gravity (mm min−2).
Water inflow is achieved by a 300LPH (80GPH) submerged pump which can be purchased for ~$10.
Because the inflow rate is depended on the capacity of the pump and the pumping height, we determined 300LPH (80GPH) rated pump was achieving 150LPH (40GPH) actual pumping rate when the pumping height was at 280 mm. 280 mm was calculated by assuming stacking two 140 mm height bins. We kept the pump at the lowest part of the lower bin and water outlet hose at the highest part of the upper bin.
MICROSIPHON CALIBRATION
With a perfectly calibrated bell siphon, you should see a constant water level rising and falling. The water may start trickling down the tube, but water inflow should overtake the trickling loss. Then you should see rapid dumping of water to the reservoir signaling of successful siphoning. Once the water level is sufficiently lowered, the siphon should stop with a strong burp.
(nice strong siphon. the water column is way above the Veloster)
There are two main problems a bell siphon can have. The first is where the water flow rate is too low so the siphon does not start, and the second is where the water flow rate is too high so the siphon does not stop.
SIPHON DOES NOT START
1. Trickling sound
Solution: increase the flow rate
The relationship between the pump’s flow rate and the pumping height was a second-degree polynomial. In our calculation, a minimum of 40LPH (10GPH) was required for a successful siphon start. The siphon did not start if the pump inflow could not overtake the inevitable slow trickling down of water. We called this stage a “perma-trickle”.
(water trickles down so siphon does not start)
The grow tank is filled with water so it seems to be ready to start siphoning, but it doesn’t because water is slowly leaking into the reservoir below. The water-in is less than water-out. The drain pipe sucks in the air instead of creating a vacuum to prime the pipe. You can prime the siphon in two ways. Increase the water pump rate or increase the pressure resistance in the drain pipe. The water pump has an adjustable valve. Rotate towards + to increase the flow rate. The water pump needs regular cleanup to remove sludge build-up.
SIPHON DOES NOT STOP
1. Gurgling sound
Solution: decrease the flow rate
The grow tank is drained, but it is not refilling back up. Water-out is greater than water-in. You can break the siphon in two ways. Decrease the water pump rate or decrease the pressure resistance in the drain pipe. The water pump has an adjustable valve. Rotate towards – to decrease the flow rate.
At an inflow rate above 300LPH (80GPH), the siphon did not stop reliably at the end of the discharge. At this high rate, the water inflow rate exceeded the minimal speed which air could enter the bell to break the siphon. We called this stage a “perma-drain”.
We were quite surprised, at least for us, how easy it was to achieve a perma-drain stage. We were achieving this without any calculation. We will revisit why the margin of error was so large to achieve an equilibrium when by definition a rather precise point where inflow and outflow are equal must be achieved.
2. The water pump is getting weaker
The water pump, over time, whether through age, contamination, algae build-up, etc, will slow down. This will result in decreased inflow rate so the siphon does not start properly. You should clean or replace the pump.
3. Overgrowth of roots
Overgrown vegetation root blockage will restrict the water outflow so the siphon does not stop. Clear away the blockage or replace the siphon.
BIN
The container used was SAMLA 1 gallon plastic bin found at Ikea.com.
Width: 280 mm
Depth: 190 mm
Height: 140 mm
Volume: 3.8 liter
Material: Polypropylene (C3H6)n
We designed the Edu Kit for indoor use only so we believe beneficial physical properties of PP such as good chemical resistance with good elasticity and good fatigue resistance outweigh PP’s susceptibility to UV degradation. The replacement bin can be purchased economically from Ikea.com. In any case, please do not use the Edu Kit outdoors or under direct sunlight.
Since it would have been more optimum if the pump was cut off during the discharge, we considered a float valve switch design to cut off the pump when the siphon started. This design was put on hold as a float valve switch would have taken up valuable grow bed space.
OPTIMUM PUMP PERFORMANCE
In our calculation, 150LPH (40GPH) was most reasonable for 3.8 liters (1 Gallon) IKEA samala bin at 280 mm pumping height. The siphon started surely and ended satisfyingly without fail and worry, every single time. We called this a “one-siphon-to-rule-them-all” stage.
As we have calculated and demonstrated, the success of siphon depends largely on correct calibration based on the tank’s volume (width x depth x height, 3.8 liters in our case), the surface area (width x depth), water flow rate (water inflow – water outflow). There was a strong linear relationship between the water flow rate and trigger/break action with a coefficient of determination of 0.99.
One more important dimension of consideration was how fast water rises. This is a derivative of the net water flow rate and bin dimension. For a given net water flow rate and a bin volume, a narrow bin would achieve faster water rise than a wide bin. A faster water rise from a narrow bin will aid in the starting of the siphon. A slower water rise from a wide bin may not be able to start the siphon. A calculation based on actual water inflow rate alone would only be correct if we assume the grow bed is always used empty. The water rise rate depended on how densely medium (sand, pebble, hydroton, etc) was packed in addition to actual water inflow rate which depended on actual pump rate and pump height and in addition to how wide or narrow the bin was shaped.
MACHINE LEARNING
We developed an IoT device to collect data and record pertinent information in managing the edu kit. We anticipate our system will evolve to full integration of automated data recording, data analysis, machine learning, and decision-making into an interconnected system.
ML uses a set of well-defined models that collect specific data and apply specific algorithms to achieve expected results. The recent development of deep learning has expanded the scope of Artificial Neural Network application in agriculture.
Neural Networks are inspired by the human brain functionality and represent a simplified model of the structure of the biological neural network emulating complex functions such as pattern generation, cognition, learning, and decision making. Such models are used for regression and classification tasks
SVMs are binary classifiers that construct a linear separating hyperplane to classify data instances. SVMs are used to predict the yield and quality of crops by classification, regression, and clustering.
Soil Management
Machine learning algorithms study evaporation processes, soil moisture, and temperature. We are interested in detecting balanced fertilizer properties in soil.
Water Management
Machine learning algorithms are used for effective irrigation systems by estimating evapotranspiration and evaporation. We are interested in detecting and maintaining ph level of 6 in water using auto doser.
Yield Prediction
ML can make accurate detection and classification of crop quality characteristics. This is tied to the yield prediction forecast resulting in precision agriculture.
Weeds & Insects Detection
Weed control requirement for indoor planter system is minimum. The spider mite is a huge problem in tomato farming. Computer vision and ML algorithms and robots improve detection and precise discrimination of weeds and insects minimizing the need for herbicides and insecticides.
3D PRINTER FARM
We design and produce our own parts in-house.
VIDEOS
CONCLUSION
We are on! Currently conducting business on amazon.com and etsy.com with good results.
REFERENCES
Food and Agriculture Organization of the United Nations: small-scale aquaponic food production
https://drive.google.com/file/d/1gm4lVuCDFn4mD2dBWBtSDdZidxvUiZ-t/view?usp=sharing
a smart fish-based solution to growing food using limited resources and little water
https://drive.google.com/file/d/1Xfoz6kPnYO3gZBL1Ud7yj4t4ZmHsW_or/view?usp=sharing
Construction of Automatic Bell Siphons for Backyard Aquaponic Systems
https://drive.google.com/file/d/109N0-ZJgZ-9TJctz_QGtq3aZnA6Gf3f9/view?usp=sharing
EPA Particulate Matter (PM)
https://www.epa.gov/pm-pollution/particulate-matter-pm-basics
NASA Interior Landscape Plants for Indoor Air Pollution Abatement https://ntrs.nasa.gov/search.jsp?R=19930073077
Machine Learning in Agriculture: A Review.
https://www.ncbi.nlm.nih.gov/pubmed/30110960
Study on the Adsorption Capacities for Airborne Particulates of Landscape Plants in Different Polluted Regions in Beijing (China)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4555302/
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