i am looking for some iron frame that is needed for the kayran trap.

Have you done "Indecent Proposal?"

You'll find out when you go to see Loredo at midnight

When you go do the quest, "Indecent Proposal", and you poke around enough, you'll wind up with the iron frame.

EDIT:
As Hanns.g pointed out, my original-ish post may have been a tad bit too spoiler-y. Edited for discretion.

yea i have, Sneaked into the place listened in and talked to loredo afterwards than disabled the ballista and left

Also, make sure you go get it during your trip to Loredo's with Roche

When I tried to get it the next day I could access that area but the frame wasn't there

Some might consider that spoilerish, so I was waiting to see how much info he needed.

Before you complete that quest, don't give up nosing about at the obvious point - keep looking around the place a bit. I sent a more detailed PM to you in the interest of helping while avoiding generalized spoilers for the people that aren't as far as you are.

As for other places to find it, none as far as I know of.

Same here.

There is only one Iron Frame, and one place to get it.

You don't need it to beat the boss. In fact, it gives a very, very, small advantage.

If you are a completionist, read on for SPOILER:











Your only opportunity to get the Iron Frame is when you go to Loredo's compound for "Indecent Proposal." Roche will tell you to sneak around back to check things out. It is possible to fulfill that part of the quest without finding the Iron Frame. If you climb up to the window and listen to the conversation between Philipa and Loredo, you will be told to head back to Roche. When you are safely back to him, the quest moves on.

If you want to get the Iron Frame, you need to make your way into a walled-off storage area. This area is in the direction of the front courtyard, but accessed from where you sneaked into. You can scale a wall or go through a door to get into it. There are many chests, bags and crates. One of the chests has the Iron Frame. You can easily get back to the main courtyard from this storage area.

Regarding the Kayran fight and the Trap SPOILER:









There will be a glowing symbol on the ground to interact with via left-mouse, if you have the Kayran trap. Once you deploy it, it will be difficult to see it, but it is there. The beast may not drop a tentacle in it right away. Seems to help if you stand near the trap and roll away. (This is when you may notice it is hard to see that trap in the grass.)

Anyhow, using the trap saves you slicing one tentacle. Doesn't save you the trapping part, since you have to do that with Yrden any way. So, it buys you 5 seconds. No big gain.

Cheers!

I know this is a bit off-topic, but is there a way to get a key for the part that's locked just before you speak to Loredo?

What part is that exactly ? You get a chance to fully explore Loredo's residence at the end of Chapter 1, only if you side with Roche, though.

That must be it, because OI haven't had a second go at the game yet siding with Roche.