How to setup a chess engine to play itself? I'm participating in some engines-on correspondence games at ficgs.com.  To assist in my analysis of my games, I'd like to set up a chess engine (probably Komodo9 which I own) to play moves against itself after a certain time interval.  Do any of the UI's like SCID or Arena support this? (Droidfish on my phone does but that won't do)  And if so, what are the steps to achieve this?
Yes, Arena can do what you want.


Download Arena 3.5

http://www.playwitharena.com/?Download
Adding Komodo (or any other engine) to Arena:

On the menu select Engines -> Manage
Open the Details tab
Click the new button
Point it at the executable
Select Ok
If you want it to play itself from a certain position you can set up an 
engine tournament using an epd file to set the position
you want the engine to play from, and then in the settings for the tournament
if you hit the level button you can set a fixed time intveral, or fixed depth
for the engine to play. To create an epd file, you can copy the position from
Scid using Edit->Copy to FEN, and then in Arena using Position->Get FEN from
Clipboard, and then EPD->Save Position in EPD Format. This file would then
passed to the engine tournament dialog.

There might be a way to get it to play itself from a position without using
the engine tournament, but I'm not that familiar with the interface.
If you want to have it analyze a game that has already been played, or what
has been played so far can use automatic analysis under the Engines menu.


Arena seems to have a pretty thorough help file, so most of your questions will
probably have answers in there.

Edit: It was pointed out in another question that the demo button in Arena will
      have the engine play itself. So you can just set up the position, make
      sure komodo is loaded, Go into Level->Adjust to set the time interval you
      want for moves, and then hit the demo button.