Being one who likes to build stuff I thought I'd make a homemade powered jobby. After looking at the Dandy two speed($90) and a few other home brews I settled on this design.
Using a pvc table cap for the reservoir was one guy's idea as well as the cell phone vibration motor. One issue with the Dandy and a few others, the powder quantity and it's weight affect their feed rate(s). To combat that problem I fashioned a copper baffle set on a angle to control the weight of the powder and make it's flow more consistent to the discharge tube. The reservoir sets level, the tube at a eight degree downward angle. If you look close just under the feed tube you can see the cell motor offset weight, the motor glued to the bottom on the cap. The tube length 4".
Since I wanted both the slow and fast feeds I put the control together using a tactile breadboard with two 1K ohm pots, one to set the voltage to the cell phone vibration for the slow feed, other for the fast, with a push button for each. At the moment I have the slow feed set at 1.8v, the high at the full 3v.
The project box contains all the control components, breadboard, wiring, battery holder(2x AAs), pots and etc, the cable to the trickler via a cable plug-socket. The box measures 4" x 2.5" x 2"
After use emptying the unused powder is a snap. Tilt the tube upward so any remaining powder in it flows back into the reservoir , remove the baffle then dump the powder back in it's container.from the reservoir.
When testing-tuning I used Varget, H4350, 4166, 4451, H4831(non SC),H4064, IMR 4064, H4895, Benchmark and Unique.With some practice tapping the slow feed buttom I was able to hit the target weight 99% of the time within .02gr weighed on my tuned 505 and re-checked on my Gempro 250.
Cost? $38 and change.