Maxime

Well maybe just 6 thousands of an inch but it still caused this to happen to my belt. It would slacken enough to move to the left side "ridge" on the tail pulley (shown on the pic).


Anyway... another thing I've seen on two T-Rex is a bit of slop where the flybar goes through the arms (see third pic). Other than that I'm out of ideas. Must be something very simple...

jeff1962

What throttle curve are you running ?, too low a head speed can cause bobbing.

gnd2

The throttle curve is a little tame (I'll have to look at it tonight to get the exact values) but I didn't think it was low enough to cause problems (I wanted to keep it "mellow" for the first flights). I bumped it up a little since I took that video since others commented that the head speed sounded low but I've been afraid to up it too much because I don't want the thing to shake apart. I'll keep it in mind and take a closer look at the head speed if the new bearings don't help (waiting for these things to come in is killing me!).

heartofmadnes

I was asking a simple question, if your not liking the questions then mabe dont aks those who have been flying for years "why" something is doing something wierd. I have the same Heli..Battery is up front..No balance issues...Good luck hope you figure it out.

gnd2

I don't have a problem with questions if they are sincere, but it just sounded to me like you were being a wise ass and criticizing something that was irrelevant for no good reason. If that's not what you were doing and were actually trying to be helpful (or just curious) then I apologize, but a little more explanation about what you were thinking would have helped because I'm not seeing how it could possibly be related to the problem or why anyone would be questioning it.

I have the battery up front, it's just on the lower tray rather than the upper. The lower tray holds the battery forward a little more and the balance is just right this way. If I put it up, it starts getting tail heavy. Like I said, I'd like to put the battery where the SC is, but I don't know how to get the balance right without adding weight which I don't want to do. Maybe the imbalance is small enough to trim out, but I don't know and I just haven't messed with it yet because I've got bigger problems at the moment

Maxime

About the balance thing... RC Heli Mag reviewed the 450SE last year they places the battery just like you did.


I went flying last night at -7 deg celsius with the CF tailboom and the belt didn't get loose, no more wobbling issues for me.

gnd2

wow, I guess six thousandths of an inch really does make a difference. Unfortunately, that's not my problem, plenty nice and warm here, no temperature changes Anyway, glad you got your problem sorted out. I'll take a closer look at my tail and make sure it's lined up properly anyway.

Maxime

Unfortunately here there are BIG temperature changes everyday ( and a bunch of white sh... [:'(]on the ground since this morning... I'm a bit North of Quebec city right now).


Anyway back to trying to figure your problem....Earlier in this thread there was some talk about head speed... Well I don't know if you hover at half or three quarter stick, but let's just say that at 6 degrees pitch I have 78% throttle on my throttle curve in normal mode. 13 tooth pinion. However I have a 430L motor (slightly slower than your XL), but check if you have a very big difference from my setup.... ( and 100% throttle at full 10.5 degrees pitch)

nitro wing

My Feedback: (1)

I am no expert and just starting,but I think that you need to have 100% power already at 6 degree pitch,in fact it may be good to get on the power at 3 degrees.You may get power lag if you pitch up and the motor has to catch up.
Check or change the tailrotor shaft,mine was bent and it caused the belt to favour one side and created a bunch of friction.

Maxime

In normal mode you do not need that much power at 6 degrees.