Raptor 30V2 Tail Rotor Question

[cdrking]

I have been helping a friend build and get his Raptor 30 going. We got it all built and then started it up on Saturday. It started great and was hovering fine. I decided to take it up for a couple of higher passes. I decided, "just one more bit of hovering". I was at about 4 feet and the poof, I heard a snap and vibration. I THINK I hit throttle hold. I landed no problem, no further damage.

We noticed that something flew off when it went poof. I was the tail rotor blade and grip. The set screw snapped off right at the hub.

When my friend built it he put the tail together and it was very loose. I rebuilt it with proper loctite and tightened the set screws down more.

I am wondering if I tightened the locknut down too tight and streched the set screw causing it to break.

I really don't know what would cause this. I have built and flown Raptor 50s and 60s and have never seen this. I have heard of it on the 50s but I haven't had a problem.

Any thoughts as to the cause?

Thanks for the replys.

Jeff

[Buzzin Brian]

In most cases it has been found that over tightening the lock nut on the set screw is what causes this. I have also build a few Raptors form the 30's to a 91, and have yet to have this problem. But it is not a new situation. If you tighten the lock nut real tight generally this will be the result. Most times it greaks off flush with the hub. Is this the case? If it is, then I would tend to say that the cause is as I described. But of course I could be wrong. Oh, and yes it would be nice to see the whole system redesigned.

[cdrking]

Thanks for the reply Brian. I thought maybe this could be the problem. I'll try not to over do it next time.

Like I said I've never had any problems with my 50s.

Learn new things everyday.

Jeff

[Dusty]

BB's right.

If the lock nuts are too tight, it will cause it to snap.

Happened to me once as well... got some help from a local guy on that one who also had that issue. Ever since, I've just turned it on until it meets up to lock, then back it off just a tiny bit.

Shawn

[megarckid]

thats no lie my first raptor done the same thing. just over done it on the lock nut

[KevinT]

Does someone make a one piece hub without the grub screws?
This would solve the problem.

[RSL_Mongoose]

There used to be an upgrade one piece hub for the Raptor, I have one, but for the life of me I can't remember where I got it.

[sdixon747]

That happened to me with a Raptor 60. I replaced the hub assy with one from a JR Vigor. It's a much better design.

Steve

[KevinT]

What would happen if you replaced the grub screws with regular allen headed screws? Follow me on this... Just a thought. If you installed the lock nut on the allen screw all the way up, and then used the allen head to tread the bearings on to the assembly untill the screw bottomed out. Then use a wrench to set the load on the bearings. Assemble the to halves of the blade holder, and you have it. The only thing I can see wrong with this is the screws would have to be exactly the right length. If it was to long the allen head would hit the blade.
O well just a thought.
Any of you guys agree?

[PowerGrunt]

I done the exact thing that KevinT said except I used a 3-30mm STD Dubro Bolt, cut the taper in the bottom to insert in the Hub,
screwed the 3mm locknut up to the end then with the bearings on the Hub
screwed the bolt in the hub, do up the 3mm locknut and then cut the bolt about 2-3mm past the end of the nut.

I done this to both my Raptor 50 and 90SE and not had a prob at all.

The weak spot on the std kit bolt is the hole they have for the Allen key as this leaves bugger all meat left on the bolt and thats where they Brake :wink:

Cheers Pete

[WillJames]

Sounds like a good idea Kevin and Pete, or as Steve said, the Vigor STD hub fits perfect on the TT Output shaft, it can be removed for balancing without removineg the grips and tail blades. It also has thrust and radial bearings on it. Only downside is the parts to make the change are about 60.00 and you have to mod the pitch slider to make it work. I did it to my R60 and R90 and never had any problems, and was able to balance the tail on my highpoint balancer.

[Data]

there is nothing wrong with the v2 tail.
the problem is over tightening of the screws.
people pull the blades apart and feel some play and then think they have to tighten the screws until that play is gone, which is not the case, the play doesn't do any harm, centrifugal force takes care of it.

just tighten the screws normal and be happy when you feel a little play when pulling the blades apart.