Notchy head on 7HVU

[Shabill]

So I recently finished building my 7HVU and am having an issue where I can't tighten the main grips down all the way without getting a very notchy head. I loosened them a little and trusted the loctite to hold them, but after 3-4 minutes in the air, thankfully I checked and they had loosened up quite a bit. Suggestions?

[eskoskimo]

Tighten them up good with loctite! They will feel notchy when they're static but if you pull out on them while rotating, it will put the load on the thrust bearings, instead of the radial bearings, and they will turn smooth as butter. Same thing in the air.

[Rob43]

I concur. When the dampers are fresh, they impart a great preload. Once they have broken-in a bit, it will be fine. They will always be tight, however.

[squeely531]

Red loctite and make sure you degrease all the threads.

[sewerfly]

And make sure you tighten them on any 700 I've seen them come off in flight and it's not fun

[Shabill]

After 7 years of flying, I had that happen with my X3 last week, and even with 360mm blades, it's pretty spectacular. Glad no one was in the trajectory of the blades (I was the only one at the field, so I guess I'm extra glad about that).

So years in the hobby and red loctite is one of my least used tools, but after an unsuccessful maiden of my 7HV last week due to a slipping pinion, I got comfortable using it on the grub screw in the pinion. So with a 3mm hex head, do you still have to heat up red loctite if you ever have to remove it?

[Rob43]

Yes, expect to use heat. Depending on how much you used, and how clean the threads...could be difficult if you don't. I've broken several wrench tips on those set screws.