Head stiff!!

[handthrottle]

Hi All
Just been out in the garden, put a battery thru it and all went well (just starting out, Trex 450 v2). towards end of battery ( I thought) needed more power, changed battery, seems as tho the head is very stiff, will not turn, tried all the servos and they are working fine, when I tried power just would not turn, the tail started to move about, closed down, turned head a bit to tidy up the rotor blades, very very stiff, pinion is ok and turning. main shaft looks ok, anyway I had a battery thru it before it happened??? Appreciate yr help.

[moonmanflyer]

Tail belt has come of the back pully, and running on the edge at the tail gear box i bet.
If it is change the belt and don't fly it until you have as it will snap.

[handthrottle]

Hi James
Thanks for quick reply.......would there be any difference in the tension of the belt? Went out and the rotors turned a bit then went 'stiff' again, free again, 'stiff' again.?

[moonmanflyer]

could be if it had a kink in it, have a look for any dust deposites around the tail casing that is a sign something happened.
spin the rotor by hand and watch what the belt is doing.
If this is not it, lossen the motor screws, move it awat from the drive gear and see if it still does it, if not then the motor could of had it, if it is the same, might be the one way bearing in the main gear assy

[handthrottle]

Hi James,
Tks again.......bloody hell!! I only had it about 2ft off the ground, practising!!
Tks for advice tho, will go out and have a go. Many thanks

[handthrottle]

Hi James
Looks like you were right in the first place.....had a closer look at the belt and as you look down on to the belt it seems as tho the top of the belt has been sliced off and there is tell tale scrapes of the material belt is made of. Will order a couple of spares. Thanks very much for all your help. Oh! by the way.......is it a hard job, changing the belt??

[andylinney]

Terry, it's not a difficult job but it's a bit fiddly splitting the tail case. While you've got it all apart take the idler out - this seems to stop it happening again.

I found it easier to unplug the tail servo and leave it on the boom - take the boom out and then remove the tail case from the boom. Put that lot to one side and go and find a magnet (old speaker or something similar) then choose a side on the tail case and start taking out all of the tiny screws and popping them on the magnet to stop them disappearing. Then take the old belt out, pop the new one on and then do the job in reverse. Took me about 20 mins flat.

Andy

[tobeornottobe]

Definitely remove the idler pulley. Many people (including me) have had the same problem as you. Removing the idler pulley fixes it. Good thread about it here:

http://www.helifreak.com/showthread.php?t=56627

[moonmanflyer]

As already said it is a nice easy job, strip the tail gear box apart, remove the old belt, tie a bit of string to the new belt, feed that through the boom and pull through the new belt, reassemble the tail gear box and jobs done, i have got it down to about 10 mins now.

[tobeornottobe]

Also check the drive pulley on the helicopter side of the belt. It is only pressed on and the added drag from a snagging belt can yank it loose (don't ask me how I know!) If it is loose glue it on with green loctite.

[handthrottle]

.........you lot are diamonds.....tks again people!!

[chugga-bug]

Put that lot to one side and go and find a magnet (old speaker or something similar) then choose a side on the tail case and start taking out all of the tiny screws and popping them on the magnet to stop them disappearing

Since when has cheese been attracted to magnets!