Here are 2 videos that show how the 5 gears work:
https://www.youtube.com/watch?v=0s4KS0RHvgE
https://www.youtube.com/watch?v=EV_AAIbVHfw
This is by far the most complex design I've created so far. I thought it would be fairly easy to combine the concepts of https://cults3d.com/en/3d-model/various/reductiongears and https://cults3d.com/en/3d-model/gadget/hypoid-gears, but as I learned pretty quickly, "the devil is in the details".
Every part of 5gears is either new or redesigned. For example, I had to give the 2 vertical shafts (the axels for the horizontal Driven gears) a much larger diameter because of the increased lateral force put on them by the 3 Driven gears that are much higher up. This, in turn, required redesigning the small Driven gear to accommodate the larger axel. And this required changing the spokes for all of the gears, including the fancy Ring gear.
Note that for my print shown here I scaled each part by 50% before slicing. This is because the STL files for the Ring and Pinion gears were developed by someone else who had access to hypoid gear design parameters. I didn't want to risk messing up those designs, so I took them as is and made everything else the same size - which is big.
To get everything assembled you should first attach the Drive gear to the Ring gear. Next, install the combined Drive/Ring gears and the Pinion gear onto the base. Read the last paragraph below before doing this. Then attach the Handle to the end of the Pinion shaft and fit the 2 Driven gears onto their axels as shown in the photos. Note that the Driven gears are all installed with the small gears facing downwards.
If you use PLA to print these parts the best way to join them is with a solvent named Weldon 3. This solvent dissolves PLA and cause 2 joined parts to become a single one. Only a tiny amount of Weldon 3 is needed to make each connection. Most suppliers sell Weldon 3 with a small application bottle that has a long thin metal tube on top. This makes it pretty easy to dispense a very small amount of the solvent in exactly the right place.
Weldon 3 is available from Amazon and many hardware stores. It is particularly nasty stuff, so be sure to only use it in a very well ventilated room (ceiling fan on high), or outside, and never let any of it get on your skin. It is extremely volatile, so keep it's container tightly sealed, and put that inside another air tight container for storage.
The only tricky part to assembling the gears is this: you have to be very careful and patient when installing the Drive/Ring gear and the Pinion gear. The 2 parts go onto the base at the same time - you have to position the Pinion gear part way between 2 of the 4 vertical supports on the Ring gear while you get the Ring gear seated on the Base and at the same time push the Pinion's shaft through the 2 openings of it's supports. It really is possible to do this without breaking either of the supports, but it does require a fair amount of gentle twisting and wiggling. If you do break the inner support you can always weld it back together with Weldon 3.