450 450 Sport.... boom keeps backing out.

[orbi]

Hi Guys , Ive had a new 450 Sport for 6 months and have had to replace the belt and boom a few times because of crashes etc. Now even with the boom box fully tight the boom is slack. This slackness is causing the belt to slip. I have resorted to putting a"boom - brace collar" tight up against the boom box and also pierce the boom with a screw thru the boom box to stop it moving. Its as if the belt may be stretching but im not sure. I wish there was some kind of way I could adjust the tension on the belt properly.
Has anyone else found this problem.

 

[pvolcko]

Scratch a mark into the boom near the front and rear tail box to see if either end is indeed moving or if it is a belt stretch issue.

If it is moving, try wrapping a layer or two of scotch tape around the end of the boom. It should allow it to clamp down on the boom securely.

Lastly, setting tension: I usually just pull on the rear tail box with moderate pressure, using my thumb as a wedge against the front tail box and the boom to prevent it from moving. Then tighten down two bolts to hold things in place. Then release the thumb wedge and secure all the bolts snuggly. When done the belt will allow a bit of play in the tail rotor, flexing a little bit with torque applied, but it will not skip the belt unless I really crank on the rotor.

 

[orbi]

Yeah thanks for that...... the Sport is very forgiving in crash situations as the belt will tend to give and slip on the gearing preventing damage, whereas the Pro would most likely need new gears and torque tube etc.
That collar tightened up against he boom box works a treat all i need is some kind of slot so that the boom wont turn round.

 

[Tony]

Yup, sounds like you need to wrap some tape around the boom for a better fit. Pretty common to have to do this actually.

 

[Lee]

Yep, tape it up and that should hold it. Or for a more permanent fix, you could take off the boom clamps, put the inner surfaces against some sandpaper and sand each one down a mm or so to stop the clamps touching each other before the boom is tight.

 

[orbi]

HEY LEE! just noticed....... you re back from old Espania.

 

[Lee]

Yep back for a month or so now, but it may be short lived. My wife has some potential jobs back in Spain with great prospects. So we may go full circle and end up back in Tarifa where we were before.