This is a 3D printed robot based on a drinks refill machine at fast food chains. It has simple electronics, just a pump, switch and power socket. It has 6 pieces:
The base - fits the pump, power socket, grill and support for the nozzle + support.
Support - fits the switch and nozzle and has a cut-in for a sticky label for the name of the drink. Print upside down.
Nozzle - fits in the support and guides the tube. Print upside down.
Drip Tray - fits in the base, 80mm x 80mm x 5mm.
PUSH piece- attaches to switch for longer lever
Tube cover - covers the tube on the top of the support.
STL files for 3D Printing: Thingiverse
TinkerCAD Model: Coming soon.
Costs: £2.50 PLA, £15 Parts
(1x) 12v DC Pump - AMAZON
(1x) 8mm int, 11mm ext PVC tubing - AMAZON
(1x) Microswitch - AMAZON
(1x) Power socket - AMAZON
(1x) 12V, 2A power supply - AMAZON
(8x) M3x16mm bolts - AMAZON
(8x) M3 nuts - AMAZON
Glue gun / silicon gun - AMAZON
Cable ties - AMAZON
Empty 1L plastic bottle
Cut a hole in the center of a bottle lid approx 6mm wide. Ensure it fits over the top of the pump, as seen in the picture.
Using a hot glue gun or silicon gun, attach the bottom of the lid to the pump. Once set, fill in the center of the lid to create an air-tight seal.
Using 8mm tubing (8mm internal, 11mm external), cut a piece about 50cm long. Connect one end to the outlet of the pump.
Attach the support piece to the base using M3 bolts. Attach the nozzle rack to the display unit (purple and green pieces in photo) with a push fit. Feed the tubing through each and cut off the excess tube. Attach the hose cover using M3x10mm bolts.
Solder wires on the power supply port and feed it through the hole. Connect the positive wire to the positive pump and the negative wire to the switch. Finally connect the switch (use COM and NO on the switch) to the pump.
Remove the pump from the mount and screw on a bottle, flip it upside-down and put it back in the mount.
Connect a 12V 2A power supply to the power socket. Press the switch to ensure the pump works. Using superglue or a hot glue gun, glue the STOP piece to the switch.
Note: with the current design, the level of the liquid in the bottle cannot be higher than the top of the support piece. You can solve this printing an extender to raise the support height, adding a 12v valve, moving the bottle below the desk and having a long tube (the pumps can lift 3 meters) or using smaller bottles.
Connect the power supply, pump and switch in series.
No coding required.