Lama bottom rotor sticking

[kenpeacock]

Been happily 'flying' around my lounge with the Lama, until this latest ding. Which I would describe as a moderate ding on the ding-ometer!

Now the bottom rotor is catching on something and flying is a lot less stable - it's flyable, but careering around and I have to make BIG corrections.

At the very lowest revs the top rotor is spinning fine, but the bottom rotor almost does a complete revolution then stops as it catches on something. If I add a little bit more power it starts to spin, but it's making a noise that suggests it catching on something constantly.

Looking at the shaft and co, nothing looks bent or damaged.

It is flyable, but as I say, very much less stable - untrimmable basically.

What do you think experts?!