Twisted Tail Issue

[R1stu]

Now I have this weird issue and its just cost me another set of main and tail blades on the 500, and it effects the 450 too.

For some reason the tail will just twist over on itself! just rebuilt the 500 tail after it sheard a bold and do a test hover when it rotated almost 90o and of course it came down hard braking a tail blade and shreding the main blades.

Now I have got the bolts as tight as I can on the clamp of both the 450 and 500 but it still wants to twist.

Any Ideas on stopping this?

[Mart61]

I've heard of some "pinning" the tail boom on the 500. The 700 I just finished has a fastener on the tail boom mount just for this.

I also have read that, on some 450 kits, it recommended wrapping a little insulation tape around the boom prior to joining the two gearbox halves. This makes for a tighter fit of the boom into the mount.

[p4ddy]

Can you twist the boom by hand?? or is it only once you take off?? I had this the other week on my Logo & so i pinned it.

[asomaro]

Stu,

I assume it is actually the boom that is twisting and not the tail assembly?

The reason I mention this is because that is what happened on my 450 recently, turned out that the "pinch" bolt on the tail housing that secures it to the boom was not tightening up properly. So when it was under load the damn tail would twist.

On another occasion, a couple of the booms (HK specials) have been slightly under size making them a tad loose, so I just put a bit of cello-tape on the boom and this fixed the problems.

Cheers,

[p4ddy]

so I just put a bit of cello-tape on the boom and this fixed the problems.

Brilliant

[millerman]

i have found that the raised locator in the front boom housing can get cut off by the boom if you twist it hard enough and unless you pin the boom it will always twist no matter how hard you do up the screws so best pin it with a short screw

[R1stu]

Stu,

I assume it is actually the boom that is twisting and not the tail assembly?

The reason I mention this is because that is what happened on my 450 recently, turned out that the "pinch" bolt on the tail housing that secures it to the boom was not tightening up properly. So when it was under load the damn tail would twist.

On another occasion, a couple of the booms (HK specials) have been slightly under size making them a tad loose, so I just put a bit of cello-tape on the boom and this fixed the problems.

Cheers,

Nope its the tail box twisting! the Boom itself as pins to prevent this!
There is a locating hole on the box maybe I should just drill a hole and put a screw in there?

[p4ddy]

Hmm?? I know on the plastic case on the S it has a locating lug that pops in the hole at that end. I also have a V1 tail & i cannot see how that will turn as it's so dam tight even after just a couple of screws tightened.