401 whipping during FF

[big-al]

Anybody here have an explanation for why a 401 will speed up and slow down rotation when the heli is in motion as in forward flight or during stall turns? this is driving me crazy due to its unpredactableness.

Talking with some folks its thought the 9253 doesn't have enough power to move it and hold it where it needs to be and possibly the 9254 can. Heck I've even thought about going back to JR and trying the 500T. I loved how my 5000T handled other than the tail drift problem.

Anyone...Anyone?

[Tom Fiddler]

What heli? and how fast of foward flight?

Give us alittle more to help you with

[big-al]

I've noticed this across all my fleet, a Raven 50 and a Predator Max. it happens in just about any type of motion. I'll do a 540 stall turn and on the second go around, once she starts falling, the tail will whip like crazy. It does the same thing if I'm flying in normal forward flight. I'm running 95mm mahs on my 50 and vblade 105mms on my max. I even noticed it this weekend when I tried a knife edge pirorette. FYI- my piro rate is now about 360 deg/sec.

[Shannon Davis]

Sounds like too much gain to me- but I fly a 601 and have forgotten how to set a gyro. :)

[ChrisW]

I run 401's in both my helis...
Raptor 50V2
and a Fury Extreme :shock: with pretty good results.
What I've noticed about the 401/9253 combo is that it's performance can be greatly influenced by choice of T/R blades...more so than any other gyro I've ever run. I would speculate that this is mostly due to the lower torque of the 9253 servo (just a guess :lol: )

I'm running MS 107mm blades on my Fury. It does really well on 540 stalls...but if you are wanting to pull off additional piros in the stall turn you will start seeing inconsistancies in the piro rate. Now if you were to do the same manuever with the plastic tail blades like come stock with the Fury Expert the "whipping" behavior you are describing is far worse.

I had the same thing with my Rap50...The stock blades stunk, but I found the blue plastic Freya T/R blades helped...not cured, but a heck of a lot better.

As far as truly consistant piro rate in a maneuver you're best bet is the 601. One of my flying buddies is a rep for a major heli/radio brand and top-notch 3D pilot and has spent lots of time trying to make the 401 do exactly what you've been trying. He made some headway but couldn't get it perfect. He's been trying out the new JR500T and has found that it does indeed hold the piro rate better than the 401.
I live with it for now, but I may have to switch to the 601 myself down the road ( or maybe even a 500T :P ).

Hope this is of some help,
ChrisW

[big-al]

Thanks all for the advise fellas, glad I'm not alone in the problem. I haven't really considered going to the 601 mainly because of the cost and the lack of support from futaba.

if money comes up this spring, I want to try the 500T. somebody's got to be a guinea pig! 8)

[plane]

I know this is an old thread but I thought I'd chime in anyway. I just installed a set of Align Carbon Tail blades in conjunction with a 401/9253 and my piro rate is ballistic. I thought I was flying a Trex450 that's how fast it is.

Before with the stock plastic blades it was really slow so I can vouch for blades making a big difference.

I'd estimate my piro rate at 540 per second. I guess that's pretty good considering the servo is only 28oz's of torque.