Lever or Handle designed for use with the 6mm splined shaft potentiometer of a 3key 1pot chinesium macropad in the vertical position to semi-simulate the throttle or power lever of a train.
I've gone for something based off the Class 150 Sprinter DMU power lever.
Designed to be used vertically, with the macropad in a stand (see my other models) to better simulate the real thing.

Print this one as light as you can, say 10% infill or less, maybe with an extra wall. This lever needs to be light so as not to overwhelm the potentiometer and drop with its own weight but not too flimsy as to break when used, so you'll probably need to do some experimentation with your printer's settings to dial in what is right for you. 
Again, print with support, using a support blocker over the shaft hole.

I've printed mine using an old FLSUN Q5 with matt black PLA, going slow at 40mm/s to try and maximise quality.(!)