i just put the jet-cat back together into the pod and boom. i built it with the longer shaft and noticed that the head vibrates between idle and full rpm. has this happened to anyone? if so what can i do if anything to remedy.
01-21-2004 Over year old.
optikaman Veteran Location: EnglishTown N.J.
Rob where do you see the vibration, and what kind of vib? latheral, horizontal, only the tail, the whole heli..... or are you seeing the heli whobble.
Alan...
01-22-2004 Over year old.
rob20rx7 Heliman Location: miami, fl
it starts at the tail. its a wobble side to side then as i throttle up u see the head main shaft start to wobble as well. as i go through the throttle it gets real bad right before it goes away at full throttle. then in flight there is no sign of it until i land then its the same thing only in reverse.
01-22-2004 Over year old.
rob20rx7 Heliman Location: miami, fl
im gonna take a video of it and then i need someone to tell me how to post it
01-22-2004 Over year old.
optikaman Veteran Location: EnglishTown N.J.
Rob it sounds like the problem is in the head or shaft. when you are at full rpm's does the tail still vibrate? it could just be the lead, lag of the blades until they are in flying position from high rpm's. check the balance of the blades and check for run out on the shaft.
Also check the landing gear and frame bolts..
Alan
01-22-2004 Over year old.
rob20rx7 Heliman Location: miami, fl
what do u mean run out on the shaft? how do i check for that? im also leaning towards the landing gear beacause the heli doesnt sit on all four when its down. the right rear stilt is kind of up off the ground like 1/8 inch. this may be it too. i tried to bend it down to where its touching but i dont want to bend it all out of shape.
01-22-2004 Over year old.
heliVoY Veteran Location: NJ
might be a bent torque tube in the tail, or check the main shaft ... the OEM shafts are rather soft, and can bend .. also, is there bearing play in the bearings supporting the main shaft ?
Wojtek
01-22-2004 Over year old.
Phil Cole Veteran Location: Redwood City CA
My jetcopter landing gear doesn't sit flat either. Even if it did, the ground I sit it on mostly isn't. I just rotate the heli until I find a position where it sits without wobbling.
Apart from Alan and Wojtek's suggestions, soft head damping can cause problems likes yours.
01-22-2004 Over year old.
heliVoY Veteran Location: NJ
Phil thats true about the soft dampners ... I had a bit of a wobble till i changed them to the hard ones, and metal blade grips really made the head feel steady ... There is a also a central spindle support bearing that is available that is a good idea ...
