Two photos are attached. Video coming. The finished unloader will be one whole piece. I printed it in a bottom and top section so that I didn't have to print the entire thing every time I wanted to make a change to the top. It took a few tries to get the side shields designed so coal wasn't splashing everywhere. Then getting the spacing right to fit the ties took two tries because I didn't measure twice like the rule says.
So the bottom has the through axle with bearings at each end. The bearings might be overkill but I figured it would eliminate wear and I wouldn't have to think about it ever again. The two gears are meshed and one will be driven. They are what flips the fingers. The fingers will need more work. A lot more work. They don't fold into the base so cars/trains will be unable to pass over them. I'll need to find a spot to tuck them but I think it will be as simple as a printed slot in the base. The unloader is tapered and the coal falls down it nicely. I'll have to see about adding a cavity ok the underside for an oscillating weight to help get the last bits of coal out of the car.
I assume arduino will be the way I'll control it. The main reason for that is I should be able to set stepper motor spin limits so anybody will be able to unload coal without me worrying that they break something on accident.
I took a day off Friday so I can go vote early and I hope I can finalize the design and print it. I'll post if I get to.
The videos show more detail of it working. It I'll have two fingers in time and I plan to make the fingers out of aluminum instead of printed prototypes.
The workbench is a mess because I've been so busy. It's not normal got things.... everywhere.
