when the virture axis speed up,those tension also changing quickly

hello,I meet an urgent question :

when the 3 axis are synchronized to 1 virture axis with a fixed setting velocity value,my problem isas below :
I traced each axis speed curve,found that wave fluctuation is under 0.1/60 Degree after my optimization work,but the tension between each axis(paper) are not stable.

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The second problem, when the virture axis speed up,those tension also changing quickly, which method can prevent this bad trend ?

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other questions are splitted to
why the axis synchronized not accurately .
simotion setting problem?.
who can give me the proper answer.Thanks a lot!