During lockdown i built my first boat, a nice little wooden model called Diva. I've noticed at part throttle the prop tube vibrates inside the hull. Must be because I have a slight miss alignment between motor and prop. I'm wondering if the standard spring type coupling is not helping so have ordered a rubber coupling to see if things improve. If not, has anyone got any ideas? I'd prefer not to have to do anything too major like drill the prop tube out.