Hi peteeng,
jackjr is right, do not buy el-cheapo Chinese servos. Its not because they don't work but they typically have atrocious documentation, even worse technical support and no set up and tuning software.
A modern AC servo has many hundreds of parameters, many of which you'll never need or touch but there are many that you will need. In the case of my Delta B2's there are 270 parameters.
You do not want o program those by pushing buttons like a microwave, its just too error prone. Do not do that to yourself.
If you buy a cheap Chinese spindle you'll have a nuclear meltdown guaranteed, and you are only 3000km away.....I don't want to be caught up in the blast!
Most AC servos are very similar, if one manufacturer has a feature all manufacturers follow suit. So within the difference in terminology of each manufacturer if you can program one then its highly probable
you can program another. Your problem is that you have not set up and/or tuned ANY servo....choose a make and model that gives you the best probability of success.
I use Delta, but there are many good brands. The same company I buy my servos from sell ToAuto servos, their own brand. I have no reason to doubt they work and I have good history with
the supplier and they are approx $100USD to $150USD cheaper than the same size Delta B2. Given I've programmed Delta, Allen Bradley, Omron, Yaskawa, Mitsubishi and Schneider
servos I could in all probability handle ToAuto but I vote with my wallet and buy the Delta's.
Craig