The importance of curing marijuana can not be underestimated. First time growers all face this formidable challenge: how to turn grass into weed. Get it wrong and at worst your harvest will never impress the goddess, but it may even be unsmokable. The theory is that sugar is present in your buds and if there is allot of it it will make your bud burn into a charcoal lump, instead of white ash of cured marijuana. The art of curing bud has long lived in obscurity, but now the promise that anyone can grow great weed might be here! Using load cells (2kg and 300g) we first load the fresh weed into the dryer with the stem-pincher, which uses a constant force spring. The beginning weight is measured and a target weight is calculated (I haven't run the first series of experiments yet to determine the optimal algorithm). The weed is allowed to dry in the dryer to an intermediate weight. Then it is loaded into the vacuum chamber which utilizes a 12v pump, PHT sensor, and an oxygen sensor.
Somewhere in the pictures you'll find my little weed garden, its winter here so it will be a while before they bud.... but they are autoflowering, so it won't be that long. To bring the knowledge base up to par, curing weed is all about getting rid of the sugar. If you dry too much, the plant dies and stops converting sugar, dry too little, and mold will grow in the jars. This can be accomplished many ways, but none of them actually knows when the plant dies! So I will be killing the rose you see in the picture!! To measure when it dies, I will save the change in O2 concentration in the vacuum chamber to EEPROM, once it stops consuming oxygen the readings from the O2 sensor will stabilize and we will know what moisture conent we should hold the buds at.
Right now, for these pre-experiments, I'm going to wait to publish a complete version that any sophisticated pot head can print on his 3d printer and set up for his grow.