Powder Auger

thingiverse

I would not use this to dispense anything to any living thing that you do not want to harm. It seems like most plastics are not all that food safe and who knows what you might put in it to dispense. I have had a Sugar dispenser with Ant poison mounted to my lawnmower for years. Just hit a pedal which pushes on the dispenser and causes it to dispense a little bit of poison. Worked fine but I usually had to hit the pedal a half dozen times to dispense the needed amount. So on a Sunday project last year, I designed this battery-powered auger that dispenses the powder as long as you keep the button pressed. I use a DFRobot DF15RSMG 360 Degree Standard Servo Motor that I purchased on Amazon. I removed the electronics and attached the plus and minus leads directly to the motor. The motor runs whenever you close the switch or when the motor is out of notch in the wheel. I mount the servo wheel provided and attach the wheel with a 25mm long 3mm screw. Power is supplied by a 18650 battery mounted in a battery holder that you can find in my design list. I figure it should easily last all summer, so I'll charge it once a year. A schematic is attached, and as you'll notice, there's a 10 ohm resistor that gets applied across the motor. This provides a load for the motor when power is removed, so it doesn't coast so far. Assemble with 3mm screws by self-threading into 2.5mm holes. Don't over-tighten. A 3mm screw attaches the end cap to the auger and is left loose enough to act as the end bearing. You assemble the auger assembly with the exit port closed, and the switch in the notch of the wheel. The auger is closed when the switch is off. Not a perfect seal, but seems to work well. It may dribble a little when it's not in use, so don't keep it anywhere a little powder could cause you any danger to humans or pets. The powder container is glued in place with appropriate cement. This was printed in ABS, and I always use Duco cement. Hope it might be valuable to someone or at least give you some ideas for your own design.