Recognition and appreciation to Senior55 for their original concept for a seed starting pot and to IPLOP for his drop in basket thing (which still fits this tray).

My remix attempts to provide several enhancements to Senior55’s excellent design, whilst keeping the core 28x28x28mm ‘plug’. The remix is printed in PETG at 40% hex fill (10% off-set) on a 0.15 layer. Unlike PLA, PETG is naturally waterproof and will have a longer working life (PET is used for plastic water bottles and food trays). This design increases capacity to 21 plugs from the original 12, making it a more useful tool for home propagation.

The main aim of this 21-plug propagator thing was to create a seedling tray that was self-watering and could be left for a good few days without attention, but that would not drown the developing root system. This is achieved by an inverted water reservoir (an old 65mm dia mineral water bottle will do). The base steps allow for a constant 4mm of water in the base of the tray, partial pressures deal with control of the inverted water bottle supply. A clear water bottle would allow you to check on reserves. The central spike gives stability and reduces spillage as the bottle is inverted. A 30mm int dia base is provided to further increase a recycled water bottle's stability (see vid and pictures). A reservoir bottle thing is included, this has a base support built in (base in contact with bed, check angles for your printer so it prints without supports). As above, print in clear PETG to monitor remaining water supply.

< Demo video here: https://youtu.be/5ildijI4YXI >

There is only one water reservoir because there is an aqueduct system running around the edge of the seed tray (in the outer wall). All outer plugs are linked to this water course. When soil is in the plugs this further reduces surface tension and improves water distribution from the aqueduct.

I have designed a less complicated flat-fold basket, that takes less volume, uses less material and is held to shape by the plug cavity. This basket should allow more soil contact with the water and improve irrigation- pictures in situ (Rosti_BasketV1).

Respected Thinger. Partial pressures look after the water supply, gravity and capillary action look after the watering, all you need do is look after the printing (& the tomatoes).

Update1 note: IPLOP's original basket stl can be found within Senior55's original design posting. I have also included it here, but no pictures (IPLOP_Basket - all rights remain with IPLOP)

Update2 note: with all plugs full of compost it takes about 250ml to wet out all of the compost and fill the water ways. Do this before adding the upturned bottle to save yourself an early re-fill.