Replace the band and lid of a standard 24oz jar with this and keep your pickles/sauerkraut/tsukemono/kimchi/whatever under compression and submerged.
Check out this page for some handy info: http://www.theblackmoon.com/Jfood/ftsuke.html
Requires both the jar and a spring (available online or at some hardware stores) - everything else is printable.
Plate can be adjusted downward for more/less food, compression, etc. Max this will take at once is about 15oz/60% full with post screwed all the way in and plate fully compressed. Post can fall out extended all the way out, and plate/knob should be snug enough to stay put but allow disassembly for easy cleaning.
Inspired by existing Japanese pickle presses you can buy at stores... but are pretty expensive.
Samples printed in PLA. The usual disclaimer - use/eat at your own risk. If you've never made pickled anything, then it might be good to practice a bit. Not sure of any long term effects of food contact with PLA, but improperly pickled rotten food can surely wreck you. Don't put the plastic parts in the dishwasher. Hand wash. May try to print one with fda-cool PET some time... when I get my damn printers to not choke on the stuff.
And always use pure/Kosher salt. Iodized salt or other salt with additives can make your pickles ugly and discolored.
First get some Ball mason jars - 24oz/1.5 pint variety.
Then 3/4" OD by 3-3/8" long .047 wire gauge compression spring: http://monsterfastener.com/item/sprc-373?gclid=CNbT5dLlgMECFYdlfgodf0EAeA
Print all parts (I used 0.25mm layers/30% fill/3 perimeters on all but the "plunger" which i made denser - 50% fill).
Spring goes into "lowerpost2" compressed by "plunger" and secured with "lowerpostcap2". "Plate" slips snugly onto plunger end. All that screws into the "upperpost2" which goes through "lid" and is secured with "knob". You will likely need to do a bit of surface sanding on the posts and plunger to make the plunger move easily and the screw action work well.