Introduction: Greenhouse Test Bench

We are a group of Industrial Product Design students working on a project for hydrodense during the year 2020.

The goal is to make a test setup to study how some crops (in our case rocket) grow best under certain circomstances on a hydroculture, meaning growing crops without proper soil. The results of this test will be used to improve farming and make it more efficient on larger scale.

some essentials for the design were:

-adjustable lighting

-adjustable suport for the roots

-water supply that doesn't counteract growth ( meaning mold, algae...).

Step 1: Part A: the Frame

The frame is build out of 3 three side pieces and three cross pieces.

Some things are easier to attach before glueing so are also in this part


-3x wood panels 400x580x18
-3x wood panels 900x40x18
-8x pvc profile 15x15x340
- dowels
- screws
- paint

Step 2: Step A1: Cutting the Side Panels

-cut out the outher shape

-cut notches in the botom cornes and in the top


Step 3: Step A2: Cutting the Cross Pieces

-cut long stips of plywood

-cut three notches in the wood

Step 4: Step A3: Painting the Frame Pieces

paint the pieces that will be visible from the outside

wait for paint to dry

(we used wood that was pre treathed for moisture. if your wood is not, add a sealing layer at this point)

Step 5: Step A4: Cutting the PVC Side Support

cut the side pvc L-pieces 340mm long


Step 6: Step A5: Attaching the PVC Side Support

-space the pieces on the wood sides

-attach with double side tape

-drill and screw together

Step 7: Step A6: Glue the Frame

put all the parts together

Drill trough the cross and side pieces.

Insert a dowel trough the holes with wood glue.

Make sure everything is squared up.

Wait for glue to dry.

(It might be usefull to get help from some people to hold the frame together while drilling or temporary tape the joints)

Step 8: Part B: the Growing Platform

The growing platform will be build in layers

-the outher frame

-the support grid

-the "soil" growth layer

-cover plates


-2x aluminium profile 15x15x735
-2x abs 340x40x2
-1x abs 600x1000x2 (for laser cutting)
- rivets

Step 9: Step B1: Cutting the Aluminium L- Pieces

cut the aluminium L-pieces 735mm long

( because we are spoiled we used an electric saw but a handsaw works just fine)

Step 10: Step B2: Making the Side Pieces

-cut two pieces of abs around 40mm wide and 340 mm long

-bend a right angle on one side of the piece to mak it stronger (about 10 mm)
you can bend this with a heated wire or heatgun

Step 11: Step B3: Conecting the Frame

put the aluminium L-pieces together with the abs sides using paper tape

check if the angles are straigth and the inside dimensions match your grid size

Step 12: Step B4: Lasercutting

we cut out the grid pieces together with the cover plates.

you can change the spacing of the grid and cut multiple hole patters/distances to test what is best for plant growth.

(you can definitely do this by hand but it's less repetive this way.)

Step 13: Step B5: Assembly

Put the short cross pieces in the frame folowed by the longer pieces to complete the grid.

add the growth medium for the seeds to grow on (this is a sheet of fibers)

put the cover plates in to keep light away from the underlaying layers (you can put different plates on it at once)

Step 14: Part C the Electronics

We will use an light bar and a water pump that are controled by individual timers, we planned on using a dimmer for the light but left it out since it did not arive in time.

The power will be supplied by a separate power brick that will be attach using a connector and switch around the back (this is for safety purposes, main voltage at the side of a moist enviroment could lead to electic schok. The 24V system inside should limit most harm. For this reason there are also no metal srews/bolts on this compartment.

if you want to expand on this by adding humidifiers, sensors, ... you can do this by addin it in the side electonic compartment. (dont forget to use a power supply that can supply enough power for all your appliences.

A video that might be helpfull for the timers we used


-2x timer switch (24V)
-2x electrical connector (F)
-1x electrical connector (M)
-1x light bar
-1x water pump
- wire
- solder

Step 15: Step C1: Electronic Circuit

This is a sketch of how the electronic circuit looks in a schematic way for ease of recreation

Step 16: Step C2: Wire-ing and Soldering

-layout the parts how you want them to be aranged

-solder wires to each part making sure you have enough wire

Step 17: Step C3: Test the Circuit

-connect the circuit wires with lever nuts or by twisting the wires together

-check if the circuit functiuns as intended

-make sure the polarity is right for the devices (conect them and check if they work proparly

-dont forget to set the dc-dc convertor to 12V

-the power plug is not soldered but conected with lever nuts when the sides are closed

make sure you have more than enough cable on the power plug to make installation further on easier

Step 18: Part D: the Outher Frame

the outside will be made of 2mm recycled abs sheets attached to the frame

Step 19: Step D1: Cut Abs Strips

-cut long abs strips to size (measure from front, around top, to back with some tolerance)

1 narrow strip to cover the wood and 1 wide strip for the electronics

Step 20: Steps D2 Drill Holes

-drill holes in the bottom piece for some airflow in the box

-drill holes in the strip for the timers, power input and switch

Step 21: Step D3: Drill Holes in the Frame

drill a hole in the top to pass the light cable trough (we could not splice the cable since we need to return the lamp afterwards)

drill a hole at the botom for the water pump

add a power plug in the hole and bring the cables to the electronics

Step 22: Step D4: Lamp Conection

cut 2 pieces of aluminium

bend them in a L schape so they reach around the lamp

drill two holes for atatching to the frame

dril one hole to attach the lamp

the lamp wil have a treathed rod at one side and a bold at the other side. this way the lamp can be put in place and attached by putting one bolt trough the open side

Step 23: Step D5: Attach the Electronics to the Abs

put the conector and swith at the back and timers (and other equipment for testing) at the front

attach the electronics to the abs with some hot glue (make sure your glue gun is hot) or use the spring lock on the switch and connector.

make sure the electronics faces right side up!

Step 24: Step D6: Attach the Strips

-apply double sided tape to the frame

-attach the strip to the front

-use a heat gun to bend the sheet around the frame

!! when bending the electonic side don't forget to conect the power input to the timers with lever nuts!!

Step 25: Step D7: Seal Gaps

seal the gaps around the timers with silicone, this will also strengthen the bond between the electronics and case, making sure the cant get out

(if your hole is a perfect size for the electronics, we advise to do this on the inside for a beter conection)

Step 26: Part E: the Window Binds

to make sure that the seeds will grow and give roots it is important that in early phases they dont get light

we chose for window blinds to give it a nice look and add some adjustability for the light

-2x window blind
-2x smal aluminium plates
-2x abs sheet

Step 27: Step E1: Aluminium Plates

-cut 2 aluminium plates a bit wider than the size of the 2 window blinds next to each other

-drill two holes in the middle for screwing on to the frame

-drill 2 holes at the side of the plates for rivets

-screw on the frame

Step 28: Step E2: Attachment

-hold the blinds on top of the two plates and transfer the holes to the blinds with a marker

-drill out the two transfered holes

-attach to aluminium plates using rivets

Step 29: Step E3: Test

test your window blinds and figure out that it is not going to work this way

Step 30: Step E4: Fix the Movement

-cut an abs sheet the size of the top curved surface

-cut material away to make sure as much light as possible can go in when the blinds are open

-debur and finish the parts

-make small aluminium brackets for attaching

-bend to shape using heat and rivet onto the frame

Step 31: Step F Water Reservoir

the water reservoir will be beneath the plants. water will circulate using a water pump and divider in the middle


- plastic box 350x650 (aprox)

Step 32: Step F1: Cut to Height

-cut the top of a plastic box (about 350 x 650)

-remove the burs left by the dremel

Step 33: Step F2: Making the Divider

For the divider we will use the leftover from the box

-cut out the four corner pieces so that the length bigger than the side

-glue the corners back together so you end up with a much smaller box than you started with

-cut the height to match the water reservoir

Step 34: Final Model

You should now have a finished system

the timers at the side can be programmed for the light up top and the water pump (see how in this video)

to grow the plants you need to prep the growing plate by choosing a grid type, then puting the substrate on top folowed by the hole plates with the distance you want to test. You will probably start with the plate on the lowest level but you can try some difrent configurations.

In the early stages of growth the plants usualy don't like light so the window blinds can be closed. Later in the proces the blinds can be fully or partially opend. Experimentation is the key here.

Further expansion is certaintanly possible with extra height settings, more electronics or different growing techniques and will make your setup.