Got tired of waiting, made my own vaccum fed ball hopper. I'll post a wiring diagram at some point. Hardware cost should be around 60-70 bucks give or take. Here is the hardware you need:

6mm M3 Screws
M3 Heat set inserts
HiLetgo ACS758 ACS758LCB-050B-PFF-T 50A Linear Current Sensor
Arduino Nano
Any esc, I recommend something AM32
Greartisan DC 12V 200RPM Gear Motor (100RPM may work better for larger containers)
FLASH HOBBY Arthur 2207.5 Outrunner Brushless Motor, though any 2207.5 motor should do the trick. I have also tested with DYS SUN FUN 2207
Any MOSFET Switch Driver Module or mosfet capable of handling the greartisan motor
a 10k potentiometer
2 XT60 connectors
Some kind of container or bucket
1-1/8 in. I.D. x 6 ft. Polyethylene Bilge and Pump Hose from home depot

Compatible with most OOD accessories. Have fun and ruin as many hvzs as possible!