Aardvark64
your welcome.
& thankyou for the info on the intended sollution.
I have been updating my maps recently. more to do.
due to unintended sollutions. etc.

First, thanks for that. I appreciate all the help :)
Screenshot: so now I know. I often use F12 in Steam games and currently use my favourite portal shots as a slideshow background for my desktop. After quitting the game the dialogue showing the screenshots I've just taken remains on the desktop and I select show file location. This just takes me to the picture files in windows explorer so I can move the ones I want to a different folder. Now I see the mechanism for uploading them back to Steam for use in comments. Thanks.
Turret: my intention for this turret was to explode it using the available reflector cube, much more fun! I could move the floor button further away I suppose but I don't know if it's worth another update. There's a saying about the best of intentions. Oh well.......

I just made a demonstration & uploaded to youtube for you.
on how I grabed the turret & how to link a screenshot.
to take a screenshot I think default was F12.
but I altered my setting, so not sure for you ?
http://youtu.be/sSk3g1bu2bM

as for linking a screenshot.
you upload them / view them / copy & paste the address bar of the 1 you select,
into the comments.

Aardvark64
to grab the turret on the piston.
I think I went towards it, as it was coming down.
walking while jumping, speeds up your approach.
press e just before it fires.
you can grab it from about a metre away, ish.

Ha ha, very good. I wouldn't have thought of bringing those two out of the cage towards you like that. Actually I'm a bit surprised about the one on the piston platform because I was sure that extending the grating panels outwards would make it impossible to rush in and grab it. Or were you able to grab it through the grating? I tried that of course and couldn't reach it.
I've been wondering how to link a screenshot like this one. There is obviously a mechanism built in for doing this but I'm obviously missing something. Would you enlighten me please?

not noclip for turrets.
grabed the 1st on the elevator /piston, approached it while in sleep mode
& put facing the wall till later.
later put it on piston & rode up with it. (facing away from me of course)
placed it in the corner by the button till I got the other 2.
fired a portal on the floor, as near to me as possible.
stepped back out of sight, untill they went to sleep mode.
fired a 2nd portal under the right turret
& grabed it as it came up the portal on the floor, near to me.
repeated for remaining turret.
then move them to exit, making sure they don't shoot me.
as they are all alive.
I only used noclip, to find out how to get the franken cube.
then quickloaded back to previous progress without noclip, to finish the map.

Ok I give up. Unless it was noclip how did you get all the turrets to the exit alive??