Tuesday, July 31, 2012

AutoGardens - Float valve design video

[Looking for recent posts? See below on this page]

New float valve design.

This one has the advantages over the old version of being smaller and easily adjusted.

Thursday, July 26, 2012

AutoGardens-late July 2012 - Video of the Home AutoGardens plumbing.

Home Autogardens video

You will see the siphon tube from the toilet tank, the hose that goes slightly downhill to the upper level autogardens (vegetables), and the lower level autogardens (flowers)

Sunday, July 15, 2012

AutoGardens - Mid July 2012- Goodbye Archimedes!

Goodbye Archimedes!

[see photos near the end of this blog]

While constructing the 13 or so AutoGarden systems for the testing this year, I couldn't shake the feeling that even though I had simplified the system considerably, there must be an even better way.  About a dozen different ideas were jostling around in my brain and it was only in the middle of a sleepless night that I came up with my latest idea.  It is much simpler than the Archimedes water lifter, is easy to make, and requires no motors or batteries.  In the last section of this blog I will describe a setup that should water my plants ALL SUMMER automatically.

If you have ever heard of a pinch valve you already know about the key element of the new system.  A pinch valve is a piece of flexible tubing that allows water to flow through it.  Upon pinching the tubing, the water flow stops.  Simple rubber hose makes great pinch valves.

The new idea in the AutoGardens is the use of pinch valves to act as float valves and maintain a layer of water about 2 to 3 cm in the tray.  The source of the water is a 32 gallon garbage can filled with water and a siphon tube to a horizontal 1/2" PVC pipe.  At each AutoGarden rack, a fitting is located that branches off the 1/2 inch PVC pipe with a small length of rubber tubing.  The rubber tubing goes to the float valve in the tray.

The float valve is made from a piece of 1 inch thick styrofoam board about a square foot in area.  The shape doesn't matter much.  On top of the piece of foamboard is a 5/16" piece of PVC board that serves as a stiffener of the foamboard and the bottom surface of the pinch valve.  The rubber tubing is placed on top of the PVC board and a small piece of 5/16 inch PVC board is held above the tubing.  The board is held in a vertical position and the bottom edge is sanded down to form a fairly sharp edge.  The sharpness of the edge focuses the thrust of the board into a narrow line and minimizes the amount of floating styrofoam needed to shut the valve.

The final element in the system is a wooden beam about 1" x 1" and 24" long that straddles the tray and holds the vertical  PVC board.

Construction of the valve is very easy and uses simple tools.  One big advantage of the new system is that the  water tanks are no longer part of the rack.  Also the trays no longer have to have sections cut out for the Archimedes water lifter mechanism.  They can be simple 24" by 72" trays that are water tight and have side walls two inches high.  No bottom drains are required.
Pinch valve type float valve.  The pink foamboard floats on the water in the tray.  When the water level rises, the plastic board pushes the rubber tube up into the stationary "knife edge" and closes off the water flow.  When the water level goes down again (because of evaporation or uptake from the plant pots) the valve opens.

Connection of the rubber hose to the horizontal feeder tube.  I used a standard coupling fitting, drilled a hole in its middle and then pressed a small length of copper tubing into the hole.  

The connections of the autogarden trays to the garbage can.  

Last note
For my system at my home I have eliminated the garbage can and use a siphon tube that connects the tank of my toilet to the autogarden system.  As water is used by the autogarden racks the toilet tank is constantly refilled so there is no worry about the system running dry.  I anticipate the system should run ALL SUMMER without any concern that the plants will dry out.

Sunday, June 24, 2012

AutoGardens -Late June 2012 - First AutoGarden in Brooklyn! Status photos

Brooklyn gets its first AutoGarden!

AutoGarden rack being prepared for loading into van.  Components (left to right) are bottom support layer, water tank, tray support layer, tray (with float switch, Archimedes water lifter, cover), tray cover (with holes for buckets and float switch)
Installed Brooklyn AutoGarden at 23 Seeley Street.  Rear row is vegetables, flowers are in front.

View from other side of Brooklyn AutoGarden

Status Photos

Today's harvest from seven containers of beans.  This is the  second picking and  probably reflects half of the total yield. Note value on scale - 516 grams
Nyack Community garden plot.  24 June 2012.  

Ripe blueberries

Ripe red raspberries

Monday, June 18, 2012

AutoGardens-Mid June 2012: Inventory

Sketch of AutoGarden on my  daughter's  Father's Day card to me.  Note tray level and tank level (green).  The pots are in brown (a color that she wants me to start using) and are sticking through the tray cover in the usual way.  Note Archimedes water lifter box on the left.  
Inventory-June 13
Name (number of pots)
------Nyack Community garden  (6 racks)-----
-'Early Girl'  (4)
-'Better Boy' (4)
-'Big Boy' (2)
-'Bonnie original' (1)
-'Patio' (3)
-'Roma' (1)
-'Bush Goliath' (2)
-'Park's whopper' (1)
-'Jet Star (3)
-'Husky Cherry Red' (2)
-'Black Cherry' (1)
-yellow bell (3)
-green bell (1)
Turnip greens (3)
Strawberries (1)
Blueberries (2)
Raspberries (1)
Bush Beans (7)
Celery (4)
Beets (2)
Potatoes 'Yukon Gold' (3)
Swiss chard-white stalks (3)
Anise hyssop (1)
Rhubarb 'Victoria' (1)
Grape (1)
-plain (1)
-'Red Russian' (1)
-'Winterbor' (1)
Eggplant 'Black Beauty' (1)
-green (1)
-red (1)
Carrots (2)

--------Side Yard at home (3 racks)-----
Blueberries (12) 
-'Romaine' (4)
-'Iceberg' (finished last week)
Raspberries (2) 
Onion- yellow
Dogwood tree (1)
-'Better Boy' (2)
-'grape' (1)
-'Big Boy' (1)
Goldenraintree (1)
Crabapple (1)
Swiss chard-rhubarb type (1)
Spearmint (1) 
Beets (1) 
Bamboo (1)
Rosemary (1)
Basil (1)
Pepper- green bell

------Step garden on patio at home (1 three-level rack)....
-New guinea (5)
-Regular (4)
Begonia semperflorens(4)
Marigold (4)
-regular (2)
-trailing (1)
Chrysanthemum (4)
-red (1) 
-white (1)
Columbine (1) 
-miniature orange (1) 
-miniature red (1)

-- Auto garden at Pfizer employee plots ( 4 racks)....
Zucchini (5)
-butternut (3)
-straightneck (1)
-'crimson sweet' (3)
-'sugar baby' (1)
cantalope 'Hales best jumbo' (2)
cucumber-'burbless hybrid' (5)
-'Early Girl' (1)
-'Big Boy' (2)
-'Roma' (1)
-'Better Boy' (2)
onion (3)
goldenraintree (1)
grape (1)
blueberry (1)
eggplant 'Black Beauty' (1)

Sunday, June 3, 2012

AutoGardens- Early June 2012- More photos,* videos* and new approach on watering

A pretty picture to start......

Step garden with dianthus (had overwintered in the step garden), New Guinea impatiens (new this year), and regular impatiens (new this year)

Now a few videos to describe the system...

And finally, some more photos.....

Indicator for the amount of water in the tank layer

Flowers in the Step Garden.  Marigolds, begonias, and impatiens

View of water in the tray level and placement of the float switch

Bamboo shoot

View of Autogardens in the Nyack community garden.  Note the addition of green outdoor  carpeting (fake grass) between the racks.  It is hard to tell how much the plants have grown since the last photo but trust me...they have!

First bean pods

First green tomato.  Can you find it?

Saturday, May 26, 2012

AutoGardens-late May 2012 -No Talk - just photos!

Nyack Community Garden......
May 26
Tomatoes with moveable supports and a few scattered marigolds
May 26
Autogarden rack with various plants
May 26

 Side Garden at home.......
Overview of side garden (autogarden with netting in foreground)
May 26
Complete autogarden with AWL, tray cover and watering controller (not visible)
May 26

Almost Blue berries inside netting
May 26

Ripe strawberries outside the pot
May 26
Rotten strawberries Inside the pot
May 26

Patio step garden at home...
Step garden
May 26

Wednesday, May 23, 2012

AutoGardens- May 2012-More construction details, a major design change, and a battle with mosquitoes

Reversion back to Archimedes Water Lifters

In the world of engineering, sometimes the change in one design component opens up opportunities to return to earlier designs of other components.  Such is the case with the impact of a shallow water tank and the method for lifting the water up to the tray.  I had abandoned the Archimedes water lifter  approach in favor of the spiral pump because it can be modified to work with deep water tanks such as garbage cans.  Once I started making the first actual batch of eight AutoGarden stacks though, the ease of construction and reliability of the Archimedes water lifter (AWL) put it back into the race.  A day or two of development and I had the final version of the water lifter concept - a short AWL descending into the water tank and spilling its contents into a drain trough connected to the tray.

The smaller size of the AWL permits the cover to be considerably smaller and unobtrusive.  Pictured below is the cover for the AWL and you can see that it is about the same height as the top of the buckets and takes up only 2/3rds of the width of the rack. The remaining space is used as a place to pour water into the tank as needed.

Mosquitoes and water conservation.

This spring has been quite damp and major swarms of mosquitoes are expected when the weather turns warm.  In that the standing water of the tanks and trays could serve as a nice environment for the larvae, I am making a major effort to restrict the access of the adult pests to the water.  These attempts have the secondary effect of minimizing the water losses through evaporation.  To accomplish these goals I have added yet one more layer to the stack.  This layer (again made of 1" styrofoam) is a cover for the tray.  

The cover has ten large holes cut into it and after the cover is in place, the buckets are dropped through the holes and onto the tray surface below.  The holes are beveled in such a way that the weight of the bucket slightly compresses the edge of the tray cover and creates an air tight/mosquito tight seal.  Although I haven't had enough warm days to test the theory, it is thought that the evaporation of the soil in the pots and the transpiration of the plants will routinely remove all the water in the tray and provide a further detriment for the mosquito larvae survival.

Coming up... construction photographs and step-by-step construction details

My daughter is home from college for the summer and she is acting as my employee for the new business that I am starting (LookAliveWindowShows.com).  Before she starts in earnest with those duties I am having her help me with the documentation.  I am an inventor - not a writer.  Next blog should include early results of her efforts and some photos of early successes in the AutoGardens.  Stay tuned (Do people say that anymore in this digital age?)

Dr Dunc

Sunday, April 22, 2012

AutoGardens April 2012 - Some construction details - Part 1

First part of construction details and some preliminary growing results

 In the full-size Nyack plot.  The shortest stack uses a ground tank.  The next one uses 2x4's in the support layer for the tank.  The tallest four use 1x6's for the tank support layer.  Overall dimensions of all are 2'x6'.  Total height of the whole stack is (top to bottom >3 +2.5 +7 +5.5) 18".  No spiral pumps installed yet.  Note how well the lettuce and cabbages are doing.  Remember that it is only April 22nd. (and New York)

 In the side yard.  Shows the housing for the spiral pump.  They will be painted the same green as everything else

Spiral pump under construction.  Uses 1/2" pvc pipe.  There are two types of pvc pipe.  I learned last night that this type is rated for drinking water and is about twice as expensive as the other - but the fittings are about half the price.  I seem to be able to make two spiral pumps from one 12' piece of pipe so there probably isn't a good reason to change.  Local suppliers don't seem to carry a four way connector  so I had to make my own out of two tee's. The sprocket is made from 3/4 thick vinyl trim board into which I drill 48 holes of 5/16ths.  I then cut out the piece using the band saw and drill a 5/8ths hole for the center pipe.  The center pipe has four 9/64ths holes drilled at 90 degrees at the point where the pipe will be inside the 4-way connector in the center of the spiral.  The center pipe has a cap on one end.  The cap is just a pressure fit so that I can take it off and put it on the other end if I want to pump out the tank instead of directing the flow to the tray.

Pearl River NY  Garden plot under construction.  In foreground you will see some rhubarb.  The racks are at various stages of completion.  First one just has frame for ground tank and tray support layer but no pit dug for the plastic sheet.  Notice the extensive use of weed blocker fabric.  It has been a dry spring but the real test should come this week as we are supposed to get 2 to 3 inches of rain in the next two days.  I must finish covering the ground pronto!  The first four production spiral pumps will go into this garden because at over $4 a gallon of gas, I want to visit these gardens as infrequently as possible.

Friday, April 20, 2012

AutoGardens April 2012 - Introduction to changes from 2011

This should be an exciting year in the AutoGardens.  The experiences from Year 1 are the basis for some dramatic changes.  I am busy making those changes right now so I can't go into too much detail at this time.

Below are the changes and the reasoning for making the changes

1-New style of water lifter.
The Archimedes-style water lifter takes up too much space since it can't stand vertically.  Also the motor that I used to drive it costs around twenty dollars.  The new style of water lifter is based on a spiral pump made from 1/2" PVC piping and took all winter to develop and test.  It is run by a $4 motor and three AA batteries.

2-Individual racks
The issue with the failure of the vertical water lifter while I was on vacation has convinced me that I need a bit more redundancy in my set up.  So now I have developed racks that are 2 feet wide and 6 feet long and each rack has a water lifter.  The high number of racks (currently 13 racks with 10 buckets on each rack) means that I will be able to collect a lot more information for improvements next year.

3-Uniform appearance
Everything is painted in Rustoleum Hunter green oil-based paint.

4-Integral water tanks
Each rack has its own water tank.  This keeps everything neat and tidy.  No need for interconnected tanks and siphon hoses.

5-No solar collectors
The new pumps will run much less often because I will have new style water controllers on each rack.  The three AA batteries are estimated to run for half the summer.  I can buy them for 25 cents each

6-Intensive use of Pink Foam Board.
Wherever possible this light weight insulating material (1" thick) is used for the construction.  It can be painted with the Rustoleum paint and can have nice water-tight seams using silicone caulk adhesive and long decking screws. It isn't strong so I am using various support layers in the racks