Throttle/pitch curve experiments

[hookmaker]

Hi all,

I started out hovering on my TT Rappy 50 with all linear throttle and pitch curves (0, 25, 50, 75, 100 on both), works fine.

Then studied a Finless video on curves and tried out the suggested beginner curves of thr: 0, 60, 80, 90, 100 and pitch: 40, 50, 65, 80, 100. The purpose of this is primarily to avoid getting below 0 on the pitch in order to avoid panic situations of setting the chopper down too abruptly + throwing up lots of dirt etc..

However, when I get into hover and have 3/4 throttle, a whole lot of shaking sets in, what is the problem?

Hookmaker
(the Dane in Brasil)

[syn-]

I'm no expert, but it sounds like your headspeed may be getting to high. I've found that most of the suggestions I've came across for throttle curves end up pushing my headspeed way high. That's why I now have a Throttle Jockey governor and an optical tach. :mrgreen: I get the curves close in case the gov. fails and then really get it where I want it using the TJ.

Try your best to get your hands on an optical tach (http://www4.mailordercentral.com/heliproz/prodinfo.asp?number=804260) so you can check what the heli is actually doing... If you follow the suggestions in the manual from TT, you want to get around 1500 on the head for Normal mode. It all really comes down to personal pref. though... whatever you feel comfortable flying is the way to go. For example, my pitch curves on normal, idle1, and idle2 are all the same b/c I don't like to have the heli jumping up or down when I switch modes.

Again, I am FAAAR from an expert. :)


-syn

[BarracudaHockey]

Your pitch curve numbers are meaningless unless you know how many degrees of pitch you are running.

You are probably running too much pitch at hover producing a low head speed, thats the number one cause of raptor shakes, followed by unlubed flap dampeners.

http://www.raptortechnique.com

Even though syn is far from an expert he's on the right track with pitch setups :D

[hookmaker]

OK, I think I understand and I'll dig into that. Tell me more about those flap dampers (to be honest, I don't recall if I lubed them or not on building, but as previously stated it sizzles as a sewing machine on the normal curves), why are they realy so important?

Hookmaker

BTW: will check out for 5-6 days due to holiday

[BarracudaHockey]

Your spindle (the shaft between the two blades) goes through two red or blue rubber plugs in either side of the head. These are your flap dampeners. The spindle needs to be liberally lubricated with silicon dielectric grease or something similar where it passes through the dampeners. The effect of not lubricating them during the build and periodically thereafter is wobbles.

Low head speed also causes them as do training gear.