Learn how to adjust with different rotor speeds is not easy.
http://rouletteplace.com/index.php?topic=1510.0
Above you can read about it.
That is one method among others.
With the method i mention above … about how to estimate ball … you can be 10 sec to drop.
As Forester give example off …
When you play with different speeds then scatter patterns become different.
So i recommend playing one speed only at the beginning.
Thats why i think you should pin point out what is the most common speed and play that speed.
You will get the same scatter patterns, ball jumps.
Now you might not play every spin, but get 20 to 40 spins during one evening.
So what should you do between spins.
How about playing a very good wheel signature.
http://rouletteplace.com/index.php?topic=1376.msg11433#msg11433
You need all three reference numbers to match pattern with this method.
You can not use only two reference numbers as some one suggest, because then rotor speed can be very different even if pattern match.
I learn that from Bebidiktus regarding other method.