Tail boom clamp

[helicraze]

Hi guys, i snapped the long bolt in my frame tail boom clamp and cant get it out. So ordering some new parts to freshen it up. Got me thinking how tight did you do yours up? I used loctite and tightened till the boom was slightly crushed and clamp was touching each other. Frame bolt did not like this.

Are we meant to tighten till the clamp touches together???

Thanks

[Mercuriell]

It's a tricky one Michael - I undertightened mine first off and you witnessed the resulting lack of tail authority at Keilor last year. I feel getting the clamp edges to touch is too tight so the best is somehere in between - matter of feel I think. Maybe you can drill through from the other side after heating the clamp in the oven to denature the threadlock - the right hand drilling should undo the resisual bolt if you can get the drill lined up OK !

[helicraze]

Yeh i remember last year lol. I think you are right about halfway.
Ill get new belt, blocks, 12.9 grade bolts, new clamps and new dampers etc

[DT75]

Hard to explain, but reasonably tight...? Clamps touching sounds too tight imo..

Took a pic instead...

[helicraze]

Thanks

[Mercuriell]

One of those very few instances where a torque drver might be useful.

Michael, I dont have a clamp in my spares box I'm afraid but I'm happy to have a go at getting yours fixed up, certainly be a challenge! That long M3 bolt looks like its 8.8 zinc plated, maybe a 12.9 hign tensile nenwould be better.

[helicraze]

Thanks john i think ill wait for the bits and new boom and belt. I will
Replace all of it.

[helicraze]

New parts on the way! Cant wait to get it back into the air!

[smsodhi]

I tighten it just enough for it to grip the tail boom and unable to move it using reasonable pressure. My clamps do not touch, much like Dumbthumbs pic.

[Mercuriell]

Originally Posted by smsodhi

I tighten it just enough for it to grip the tail boom and unable to move it using reasonable pressure. My clamps do not touch, much like Dumbthumbs pic.

I think it needs just a touch more than this - this is what I did first time and it loosened in flight !

[DT75]

Ok then!

I measured in the middle of the gap , center of bolt, using calipers. It's 0,65mm.
I then "calibrated" my feeler gauges to confirm the same gap at front clamp, 0,6mm blade loose fit, 0,7mm blade don't fit.
Boom has not moved in 82 flights.

I'm not claiming that mine is perfectly tightened, just trying to help out with showing what works (or not...) for me.

So a gap smaller than 0,65mm, but stop before clamps touch...