MAKER FAIRE - 2019

We’re back at Maker Faire 2019 with some improvements to our award-winning design. First, we wanted to modify the system so that it is easier to build. While the A-frame design (Maker Faire 2016/17) looks nice, some of the materials may be difficult to get and assembly is a bit tricky.  Next, we wanted the design to be flexible enough for a variety of spaces - vertical, horizontal and different sizes. And lastly, we discovered that some physical locations don’t have easy access to electrical power. So, there is an option for a solar powered irrigation system. This page focuses on building a hydroponic system. Go here to learn more about starting and growing leafy greens.

Most often the pipes have a flange at the end to connect pipes to each other. Cut off the flange section, then cut PVC pipes to desired length. Generally, I use either a 10” or 5’ section to maximize use of the pipe. Now, it is time to start cutting the holes in the pipes. Use a 2 ⅛” hole saw with the center spacing about 8” between holes.  Also, for about 1/3 to 1/4 of the pipes, the holes can be cut at a higher density (3 to 4 inches between hole centers) for younger plants. Tips - when cutting holes, once the hole is started, reverse the direction in your drill to give a smoother cut. Also, an edge deburring tool greatly helps to clean the rough edges after cutting the hole.

Connect pipe end caps at the end of each pipe. Tip – instead of using PVC cement to hold the cap in place, try placing a plastic bag or two over the end of the pipe and then put on the cap. Not only will this provide a tighter fit, but the cap can also be easily removed to clean the pipe in the future. Lastly, trim the excess (and unsightly) plastic bag material.

Parts
3” PVC Schedule 20 pipe, 10’ section - Ewing Irrigation - $13.00 each
2 ⅛” hole saw - Home Depot - $10.00
¾" grommet - Amazon- $16.00 for 25-pack
3” End caps - Home Depot - $2.00 each (need 2 per pipe)
Debur Tool - Amazon - $14.00

Vertical system

The vertical system frame is fairly simple to build. Everything can be made from standard 2” x 4” and 1” x 4” wood. The end posts should be about 66” tall if you want 4 levels on one side, shorter if you want 2 or 3 levels. The 44” length supports a 5’ pipe.

• 2 end posts - 66” x 2” x 4"

• 2 span supports - 44” x 2” x 4"

• 2 leg supports - 28” x 2” x 4"

After these pieces are cut, assemble using 3 ½" lag bolts to connect the legs and posts. The span supports can be screwed in place. Also, in the top corners I use a metal tie connector or angle bracket to give added strength.

The next step is to make the pipe braces out of the 1” x 3” wood.

• 2 braces for each pipe,
  4-7 pipes depending on configuration - 10” x 1” x 4"

After the wood is cut, take two boards and clamp them together. Use a 3” hole saw to cut a circle between the two pieces. Be sure to use a scrap piece of wood under the boards to protect your work surface. After the circle is cut through the boards, you will have two supports with a half circle out of each. Sand to smooth. Now mount the braces to the end posts starting at the top, then moving down 15” for each level.

Horizontal system

The horizontal system frame works well when you have more space available. The concept here is to build a box out of 1” x 6” boards. The end pieces will have a cut out of half circles, using the same process describe above. The size of your box depends on how many pipes you want to hold, and the length of the pipes. In general, the 5’ long pipes work fine. If using 10’ pipes, another support piece will be required. Remember to leave about 6” between each pipe.

• 2 end pieces - 32” x 1” x 6"

• 2 side pieces - 44” x 1” x 6"

• 8 leg supports - 30” x 1” x 4"

After you cut the pieces of wood, take the two end pieces and clamp them together. Use a 3” hole saw to cut a circle between the two pieces. Remember to leave about 6” between each pipe and 4” at the end. Be sure to use a scrap piece of wood under the boards to protect your work surface. After the circles are cut through the boards, you will have two end pieces with a series of half circles out of each. Sand to smooth.
Take two of the leg supports and nail them together to form a right angle. Assemble the four legs and then mount the end and side pieces.

Each tube is filled with water enriched with minerals (more on that later) to keep the plants hydrated and fed. The water level in the pipes need to be high enough to touch the bottom of the plants held in 2” net cups.  The height is controled by the height of the ½” PVC drainage pipe inserted into the ¾” grommet.

Tanks specifically designed and sold for hydroponics can be quite expensive. Try using the heavy duty storage bin (about 27 gallons, black with yellow lid) that are available at Costco or Home Depot. These 27 gallon system are sufficient for a 5’ system to operate for 5-7 days, or more. If more water storage is desired to give a larger margin of safety in case of leaks, you can connect two or more tanks togther using Uni-seal grommets and ¾” PVC pipe.

The water pump is a critical component to make the hydroponic system work reliably.  Typically you will use a pump designed for a water fountain. Hydroponic systems typically don’t need a high volume of flow, so don’t get one that bigger than required. The critical specification is the water lift - particularly if using a vertical frame. Get a pumps with specifications similar to this pump. See the section below if your system is not near AC power.

For a vertical system, only a single feed line is required as the water flows from the top pipe to the bottom pipe. The feed line is a standard ¼” drip line hose  The trick is to connect that hose to the pump. Here are the part to make this fixture.
   • ½" slip x NPT Male (threaded connect from pump to ½" PVC pipe)
   • Very short piece of ½” PVC pipe
   • ½” slip X ¾” slip
   • Very short piece of ¾ PVC pipe
   • ¾” PVC end cap
  • ½” top hat grommet (fits ¼” drip line hose)
Drill a ½” hole in the ¾” PVC pipe. That should be large enough to fit in the top hat grommet. Then insert the ¼” drip line. Use a piece long enough to reachthe top pipe. Drill a ⅜” hole in the pipe to hold the hose in place.