Watering Spike Bottle Cap

This watering spike is intended to slowly defuse water directly into the subsoil through five 0.015 inch holes near the tips of the spikes. I decided I needed something after losing several plants during the heat of a Texas summer after only being away for a little over 24hr. The concept is that this will slowly and evenly defuse water beneath the surface thereby reducing losses to evaporation and runoff drainage, and hopefully saving plant lives in hot dry conditions.

In my testing it took six to eight hours to empty the bottle reservoir, but it was dense packed soil. Your results may vary due to soil type/depth/print quality etc. In the next version I'm trying a few new ideas to extend the diffusion time out to 24 or even 48 hours if possible. 

Files:

Included are two print files 

• Watering Spike Cap
• Watering Cap Seal

My Print Settings/Suggestions: (Your mileage may vary) 

• Printed at 0.12 mm layer height 
  • The small 0.015" holes may not print if your layers are too thick.
•  0.04 mm nozzle
• Print with spikes facing upward (no supports required)  
• I printed in both matte PLA and black ABS
  • ABS is obviously the strongest, but PLA works fine
• I printed the cap seal in black TPU (not sure what hardness) 
  • 0.08-0.12 mm layer thickness 
  • Cap seal is not strictly necessary if your print quality is good. About half of my prints were leak free without the seal 
  • With or without the cap seal, the cap may leak if print quality is too low. 

Bottle Reservoir:

• The cap is modeled to fit the threads of lemonade and orange juice bottles ("Simply Orange") 
  • but cap threads are normally fairly standered and other wide mouth containers may work as well.
• For correct operation you must poke/drill/gouge/chew, (choose your on method… no judgement) a small hole in the base of the bottle to allow it to equalize pressure.

Modifiable Flow Version

• This is something I'm playing around with to test diferent flow restrictions. 
• Theses added flow restrictors at the base of the cap allows me/you to test diferent hole sizes without having to print a new cap each time. 
• Inserts are 0.3" wide by 0.4" long. They are made to be a press fit.
• Five are needed per cap. 
• They should be easy to create/modify if anyone feels so inclined. I will upload additional sizes as I test them