Tested bottle capper. Prototyped mechanism consisting of 3d printed cap wrench and acrylic disk to attach to the DC gearmotor. There is enough torque as low as 7.5 V to twist the cap. We may use a lower voltage than the motor's rated 24 V. See video for results. - Spencer, Rohit
Monday March 5, 2018Tested force sensing resistor. Testing determined the sensor not sensitive enough to detect weight of an empty bottle. Ideas for solving this include adding a "bias" weight to see if the force sensor can distinguish between bias weight and bias weight + empty bottle. Another idea is to build an amplifier circuit that would be built on a separate through hole perfboard and integrated into the PCB if we make a second revision. A second idea is to build the bottle holder in such a way that the notches at the bottom of the bottle translate into a plane, even surface to then press the sensor. - Spencer, Rohit
Wednesday March 7, 2018Noticed that the 3.4 V stepper we ordered (bottle horizontal movement) was not in stock. We are ordering another identical stepper to the bottle rotation motor instead. This will work, but cost $10 more. - Spencer
We received our JST connectors and cable assemblies. The 2-pin connectors fit (used for the 3 pumps and 2 DC motors). But the 4- pin connectors did not fit the cable assemblies (used for the stepper motors). Since these are cheap components, we have ordered one that should fit our board. - Spencer, Rohit