T rex nitro

varagen1 · Posted: Wed Apr 16, 2008 9:38 am Post subject: T rex nitro

Hi I have just put together a t rex nitro with a os 50 hyper,600mm carbon blades,futaba 401 and matched servo,I am getting severe vibration of the vertical stabiliser has anyone else had this problem.Also any ideas for the headspeed on normal,idle1 and idle2,all blades are balanced and tracking true,the headspeed on idle 2 is 2300 rpm.

barney · Member Joined: Dec 27, 2002 Posts: 80 Location: Inverness

Hi varagan 1 Your Headspeed is to high for a 600N..normally its 2100 tops..Most advanced 3D stuff can be flown quite comfortably down to about 1950.

Your model will benefit from using a good Governer if your not already doing so to help keep it from over speeding

Also some blades although carbon can be prone to instability at high headspeeds..is it keeping track OK..

The tail fin is very thin and a little prone to vibrating anyway, but assuming you have the Mixture about right and have lubed Dampners it should be pretty good. Hyper 50 on main is normally about 1-1/4 turns out

Also are you using the Black supplied Kit Dampners (80 Duro)? as even they are quite soft. Align now do a dampner set that includes a plastic tube that sleeves over the spindle and has 90 duro rubbers. Pretty much essential for 3D flying..about £3.00. (note:- it's the tube that prevents the spindle from over travelling and trashing dampners quickly) Wink

On the harder dampners your looking at keeping the H/S 1800ish + to avoid low speed wobbling..
For Smooth 3D 1950 gives good results with +/-12.5 to 14deg depending on what you like and have reasonable pitch/cyclic management.

At 2100 unless your ham-fisted it should handle anything you throw at it.