trex 450 sport belt tension

[simon1]

This is my monthly daft question that I always seem I need to ask
Just trying to tight up the belt tension on my 450 sport, problem is I don't really know how without having to take the tail all down from the frame, or can I just loosen the tail housing and pull back on it a little?
It does seem slack, and I noticed a little vibration on the last flight, and im putting it down to this.
Cheers

[Weebl]

If it was me I would loosen the boom from the frame, pull back until the tension is right and then retighten the boom mount, remembering to re threadlock. It looks to me like the tail to the boom should be pushed all the way in.

[ROCKET RONNIE]

hello mate, ive got one myself and i hav to tighten mine up must times out ( i seem to hit the tail when landing ) just undo the four boom housing screws and the two on top of the stabalizer bar and pull back on boom, hold it there and tighten boom housing screws. this is how i was told to do it, also ive been told some people put a boom servo bracket at the end of the boom against the boom housing to help this problem. hope this helps

[simon1]

hello mate, ive got one myself and i hav to tighten mine up must times out ( i seem to hit the tail when landing ) just undo the four boom housing screws and the two on top of the stabalizer bar and pull back on boom, hold it there and tighten boom housing screws. this is how i was told to do it, also ive been told some people put a boom servo bracket at the end of the boom against the boom housing to help this problem. hope this helps

Cheers mate, will do this now, it looks slack to me, and I was hitting the deck a little bit the last time I was out so must be that.

Thanks again

[coptermanic]

You don't want the belt too tight, nor too slack. Loosen the boom box screws a little and pull out the boom until the tension in the belt is such that you can squeeze the belt either side of the driven pulley, but they don't touch.

[dam74]

Too tight and you'll be causing the motor to work harder as it won't be as free running. So it'll increase the load and cause the batteries to discharge at a quicker rate. I had this problem up until Monday.

Also I have the tail servo mount hard up against the frame as suggested in the Helituning build videos. This helps stop belt slippage during flight.

[dam74]

If it was me I would loosen the boom from the frame, pull back until the tension is right and then retighten the boom mount, remembering to re threadlock. It looks to me like the tail to the boom should be pushed all the way in.

The only place on the tail that needs thread lock is the tail gear casing as it's metal to metal thread contact. The four screws on the tail boom mount where it enters the frame are metal (screw) to plastic (frame) thread contact so no thread lock is required. If you do however have the servo mount bracket hard up against the frame like I do then when you loosen these off you will need to rethread lock them. But I'd just keep an eye on them and retighten after each flight until you're happy with the belt tension. If it has a bit of dried thread lock already on it, it'll be harder to work out then a clean thread imho.

[simon1]

Too tight and you'll be causing the motor to work harder as it won't be as free running. So it'll increase the load and cause the batteries to discharge at a quicker rate. I had this problem up until Monday.

Also I have the tail servo mount hard up against the frame as suggested in the Helituning build videos. This helps stop belt slippage during flight.

Had a play this afty, tightened the belt up a bit last night, tried to up the gain abit but wags at anything above 35%, so thats where I am with it now.
Bit more of a probelm is the kick of the tail which had happened yesterday and today with it? Even after I had tightened the belt, happened again today a few times during a hover about. It seems to kick about 30 degrees clockwise, very quickly and its over in a flash. Bit worrying, any ideas? im thinking its just the belt becoming slack after im landing, with the tail blades slightly touching the deck and making the tail boom slip.
May have to hover the battery out until and not land to see if thats it, incidently the belt tension looks okay after my flights today, not too slack like it was before.

ANY IDEAS?