A two-piece lid for wide mouth mason jars to be used for sprouting seeds. Remixed from "Canning Jar Sprouting Lid" by @AlexEnglish. If you are new to sprouting, there are plenty of instructional videos on YouTube. They are extremely easy and fast to grow yourself. I have found that these lids plus jars and seeds packs make inexpensive and great gifts to anyone that loves sprouts as well.
I would recommend to print both pieces in PETG.
The threaded ring / band and mesh strainer insert are separate pieces, which allows for easier cleaning. Using a plastic ring instead of the original metal ring prevents the issue of rusting that I had using only an insert. If the mesh strainer ever becomes too dirty to safely clean, a new one can be printed quickly with around only a meter of filament usage.
I found that the square threads on the original model were more difficult to print cleanly, so this model uses the ISO-standard metric threads library by Dan Kirshner. I also found that the original model was more likely to trap water around the edges of the lid, so I have modified it to have as large of an opening as possible.
The threaded ring / band can also be used for other purposes, but please note that the dimensions are different than the stock metal screw bands for mason jars.
For the mesh insert, the model is a simple 1mm height cylinder. You must change settings in your slicer to create the mesh. This idea is originally from "Germinator Cover for Mason Jar" by @StephaneRousseau. To create the pictured mesh strainer insert, I used the following slicer settings in Cura:
- Layer Height: 0.2mm
- Wall Thickness: 2.4mm
- Top/Bottom Thickness: 0mm
- Infill Density: 25%
- Infill Pattern: Gyroid
- Connect Infill Lines
- Flow: 120%
Other infill types should work as well, but the density may need to be increased in order to ensure that the holes are small enough so that seeds cannot fall through, but large enough to allow for proper water drainage, and no gaps between layers to trap bacteria. Due to the elongated hole shape created by gyroid infill, it seems to have the proper balance of allowing water to flow easily while still containing the seeds. It also has the added benefits of printing quickly and using less plastic than other infill types.
These are settings for the threaded ring. See Summary section for mesh insert settings!