AstroHolger I guess the graph has wrong x-axis values and does NOT show full 360 degrees, only 240.
Pieces of paper like that are useless, since ZWO does not even document what they mean. Reminds me of politicians who patch together some technical buzz words to show that they are technically literate.
I suspect that the 360º is the plot of the input angle of the strain wave gear, not their mount, which has other gears and belts and thus other ratios.
Further proof of that is notice that in the first chart on their piece of paper, the start and the end don't even match. I.e., it is not periodic with a period of 360º.
I suspect that what they are measuring is 360º of the input of the strain wave gear shaft. Perhaps ZWO is unaware of is that the full repetition of a strain wave gear (see Harmonic Drive's patent, and also that NASA paper that I have given links to) is two input rotations of the gear, not one rotation!
They are showing 360º. Why? They might as well show 271.3356º and it would be just as useful (or just as useless). But I would love to hear what their explanation is.
Sorry that you received a 288 second mount, Holger.