Only two balls?

[zppln]

Hello,

I just solved my Isis and I'm almost sure it only had two balls in it. One in the bottom and the one elsewhere. As I understand it there should be two in the bottom? Has anyone else experienced this? I'm pretty sure I didn't loose one while opening and I always thought I could only hear one ball in it before I could hear the "third".

[LouIsis]

Hi zppln,

Welcome to the forum, and Congratulations on opening your Isis.

Having 'only' two balls is normal for newer Isis puzzles. Only two balls are in there, they are of different size.
I edited your post slightly to prevent giving away too much info.

[Starrie]

Hi!

My friend solved the puzzle looking at some guides online, but I don't want to know about it.
Right now he is attempting to put it back, but he told me that there are also only two balls.

He showed me the two balls... one of them is slightly rusty and bigger.
I found a similar sized ball to the non-rusty one and he had been attempting to put it back.
So given this post...

Should he stick to the original two balls?
Or is it better to add in this third one?
I actually cannot differentiate between the two balls anymore.
Does it matter if the size differ by just a little bit?

Thanks for any replies!

[LouIsis]

It should not matter if you use 2 or 3 balls, The Isis unlocking mechanism works with both numbers, as long as the 3rd ball is small enough for its purpose. Even size 'zero' works fine, hence the possibility to work with 2 balls only
If the 3rd ball is too large for its purpose (or if another part of the mechanism has changed so that only 2 balls should be used), your friend should notice that immediately. He will probably be unable to close the Isis with a too large 3rd ball.
If in doubt, use only the largest and smallest ball that you have.

[Starrie]

I shall attempt to solve it with the current 3 balls then.
Thanks for the information!