How to have regular slope in my spline

 From:  nordzway
8405.1 
Hi,

I try to have a regular slope in my spline course , i think i need a " smooth curve tool " or Something

i try to recreate the course of an water slide

my result is poor, because i connect hélix with another arc curve... is not the best i think :

 

 

thank you

EDITED: 3 May 2017 by NORDZWAY

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