How many threads about lure turners do we have on TU
Pikeman, I think you waste time, putting your head to work about a false problem. It is obvious to me that head to tail rotation of the lure should be avoided. Let's put it this way: in such a case, epoxy would have the possibility to travel a longer distance until it "settles down". And it could gather around more in some areas compared to others.
So belly to top rotation is the one to choose (JMHO).
But further on, there might be a problem about which nobody seems to care. I have seen big wheels, with 2 rows (maybe 3 sometimes) of attaching points. These rows are in fact circles. This kind of big wheel should be avoided. The further the lure is situated from the shaft axis, the best chances you have that the epoxy sets unevenly.
Theoretically, the best lure turner has only one lure to rotate, and that lure is situated in line with the shaft of the motor (like in the case of a single lure which you would clamp into a hand drilling machine).
But nobody would like to have a turner designed to turn a single lure at a time. So you must choose a compromise. I think that between the 2 wheels of the turner you should attach 3, maximum 4 lures, as close to the shaft as possible. And if you need more than that, I think you should attach a third wheel, in line with the other 2.
By the way, your drawing should be understood as having the shaft all the way between the 2 discs, I think. The second disc will not be driven by the first one, through the lures you will attach in between. (Pardon my ignorance in technical drawing).