Torque tube loose

[SDedic214]

Hi guys,

I'm building a 500-size Apache AH-64 that uses a torque tube tail system. There is a small "transfer case" coming out of the rear of the frames that the longer torque tube attaches to. The long torque tube slips into the transfer case and everything is cinched down with a clamp. I have also "pinned" the torque tube into place by drilling a small hole through the top of the transfer case and then inserting a set screw.

My problem is there is still some sway at the end of the tail and I'm afraid that that with changes in the tail rotor speed and torque the tail boom will fail. It seems to pivot at the point where the long torque tube inserts into the transfer case.

I'm thinking about building a "splint" using two hose clamps and a small metal bar. One hose clamp will be placed on the torque tube just beyond the transfer case and the other will be placed on the shoulder or neck of the transfer case. I'll put the small bar between the two clamps and then tighten them down, creating a "splint" between the two.

If you guys have any recommendations or possible solutions please let me know.

Thanks!

[Andy01]

Perhaps try a different boom. Is it a clone boom or Align ?

My Chaos 600 boom was so tight in the SmartModel raised tail gearboxes that I had to sand them down a bit.

Colin

[SDedic214]

The boom was loose inside the tailbox and it seems to be a little smaller than what I'd expect. I've figured out a solution and I am keeping my fingers crossed it will work.

[StripedGear]

On the 500 cobra we first noticed that it was tight and binding a bit. so we had to pull it out just a touch to free it up.. then we drilled a small hole at both ends of the 45 degree gear box and installed a set screw in both sides... You want it a little loose.. not much but not snug tight... This removes drag but doesn't make it sloopy... Just a little free play... Hope you understand..