Originally Posted by Melnic
turbo joe, If you have a way of safely securing it to the ground or a picnic table, you can totally remove the head and spin it up. You have to isolate a head vs. tail issue.
If it vibes, it's the tail, then start taking things off the tail.
Remember, a shaft can cause the problem and it won't vibe when you remove blades or head/tail mechanics.
For a long time I've been meaning to get over to Goodwill to see if I can find an old record player for cheap. Several years ago a buddy got one and clamped his 450 bird to it. Made it easy getting the initial gyro setup as well as chasing down vibes. I'd probably have to add a BUNCH of weight to it for testing the 500 once main blades are mounted.