energy Ball in Portal 2?
And besides that, in Portal 2 you have missing sounds and materials for the combine ball.
Except one; when ball reaches the catcher, you can't disable launcher. Thats why I transformed it to prefab.
You can't? I got the input "instance:BallLauncher;Disable" for that on the launcher. The catcher instance needs a $relay set and this one gets fired if the catcher gets the ball.
To get the instance in your map, place a func_instance point entity.
There you have the possibility to load a VMF file. Chose the launcher or the catcher.
If you did, you give them a fixup name. Thats the name of the instance and its sub components.
Do control the instance, just make it like with every other entity. Use its name and give it one of the given inputs.
Thanks for instructions Skotty, but I still do not have my energy ball yet.
I'd like to ask you something else...I hope you don't take it bad but, can you please make one fully working energy ball system, then save it as a map and give it to me ?
That will be a template exemple for me to start from and i'd really like if you do it.
You know all the manipulations and it will take just minutes for you. Is that ok for you ? This is the fastest and the more simple solution i'll really appreciate something like this, something that i can use from now and if you do it, then i'll be sure that it is well configured. 
I know what your problem is.
If you chose a VMF in the func_instance sometimes additional keyvalues show up. For the launcher there will appear 4 lines. There you have to enter numbers. For example speed or the lifetime. If you don't enter a number there the lifetime will be 0 and the speed 0. Thats why your ball is exploding just at spawning.
Ah, were wondering about that $relay thing, but thanks hey! Makes map creating way more faster.
Woah skotty, the file you've just uploaded is awesome, the energy ball is well configured, nice job! 
But still as an Hammer begginer I'll ask you the following question :
How to link the energy ball to a door ? I mean, I will need to put the same trigger's conditions between ball<=>door exactly like if it was as example button_floor<=>door ? The same triggers are to set ? I am not sure, because actually I cannot get my door to open yet, this is why I ask. Thanks for answers, you had very much patience until now to answer me!
Also, is there a way to change some sounds ? There is 2 things I hear that I don't like, specific as Portal 2 and I want to change them.
When the ball hits a wall, it makes a noise I really hate and I want bring back the same sound as Portal 1 got. I want same for when the energy ball goes successfully in it's system. I want to add the 2 sounds from Portal 1 into my Portal 2 test map. What can you suggest ?
The sounds the energy ball uses are included in my pack. Because they are not standard in Portal 2 you won't hear them in your game until you didn't pack them into your map with programs, i.e. Pakrat.
Belive me, once you got the sounds in your map and so you got them hearable, the other sounds you hear now will just step in the background. Don't worry about them.
To get a door opened if the catcher catched a ball, you have to give it's $relay keyvalue the name of a logic_relay. Make sure to begin the name of the logic_relay related to this with an @. Thats some internal thing of func_instances.
If you can set in the keyvalues of a func_instance an additional entity (for example here a logic_relay) the instance want to trigger a relay names <fixupname>-nameoftherelay. Means you would have to name your logic_relay here with the fixupname of your instance + a "-" and after that directly the name you entered in the keyvalue.
If you use a @ at the beginning of the name, wether the logic_relay needs the fixup name of the instance in its own name nor the instance wants to add its fixup name to the name you entered in the keyvalue of the $relay.
Ouch...All that is getting too complex for me, definitly! 
I've added a door in the test chamber but you know, I cannot open it.
What I did is, creating my door, i've called it "@door1" and I've set an additionnal value, a "$relay" type with "@door1" as value, all that in my door propreties but it is not working. I know that I didn't understand some part, because you tell me to enter somewhere something like <fixedupname>-relayname but I don't know where to type this. Ok, I think you will be soon gonna be angry with a guy like me who can't understand well what you explain (and i'm sorry about it).
I am about to do it, but I don't understand yet the procedure, these filters to complete by hand is new for me (well, Hammer at all is new for me).
Look at my example map, there I already made what you need.
The $relay is a keyvalue in the func_instance with the ball catcher, right?
There you enter the name of a logic_relay of your choice. Make sure to begin the name of your logic_relay with a @.
This logic_relay gets triggered if the catcher catches the ball. Just tell the relay "OnTrigger exitdoor open".
There you enter the name of a logic_relay of your choice. Make sure to begin the name of your logic_relay with a @.
I am not sure to understand, are you talking about the "func_instance" of the ball catcher itself ? I ask that because my door in not a "func_instance" at all, actually it's a "prop_testchamber_door".
If you are talking about the catcher, then I've let the value you wrote previously, "@EnergieBall_relay".
It gets triggered but why, because you've typed in the options of the catcher "$relay" with the value "@Energieball_Relay" ? (I just want to understand)
And about that "OnTrigger exitdoor open", you then mean I need to replace (or add a new $relay) and then set "OnTrigger exitdoor open" instead of "@EnergieBall_Relay" ? (I will have 2 "$relay" values types then but one for the energy ball and the other one to open the door).
I just want to understand the procedure, as you may notice, I did not understand very well