RC Groups

RC Groups
    Electric Warbirds
        Discussion FMS 1400mm BF-109

#1 Tman57 Sep 12, 2011 09:04 PM

FMS 1400mm BF-109
 
I recently purchased this FMS BF-109 foamy and found that it flys great and very scale like.. It does, however, like to chase its tail, nose over easily and has a terrible tendancy to roll/turn to the left on take off. I have watched many videos of testing of this warbird and also many still photos of take offs and they all show the same thing ... a bad tendancy to go left on take off. If I take off on our grass field just after it has been cut, the nose over issues is not a severe, but I must still hold full up elevator until signifigant air speed is obtained before I can ease up on the elevator. Flying and landings do not seem to be an issues and they are both typical 'warbird' style of flying. I added an ounce of weight up front as I felt the model was a little twitchy for my taste and that helps smooth things out, but of course it made the nose over problem even a little more of an issue. These models sport retracts and this makes it almost impossible to re-position the landing gear to ease some of the nose over tendanceys ... I am curious if anyone that may have bought this model is experiancing the same issues and if so did you find any solutions.

thanks guys,

Tman:cool:

#2 TripleW Sep 12, 2011 09:17 PM

I don't have this bird, But you might find these thread interesting.
http://www.rcgroups.com/forums/showt...t=fms+109+bash

http://www.rcgroups.com/forums/showt...hlight=fms+109

TW

#3 Tman57 Sep 12, 2011 10:33 PM

Hey TW,

I read the two links you offered up, but judging by the dates of these entries, I believe what they are discussing is the old BF 109 which I also believe was smaller.. not 100% on this though ... I believe the 1400mm size is fairly new addition ....


Thanks for your input ... always appreciated !


Tman

#4 Tartago Sep 13, 2011 12:01 AM

Quote:

Originally Posted by Tman57 (Post 19300875)
Hey TW,

I read the two links you offered up, but judging by the dates of these entries, I believe what they are discussing is the old BF 109 which I also believe was smaller.. not 100% on this though ... I believe the 1400mm size is fairly new addition ....


Thanks for your input ... always appreciated !

Tman

Tman, try more right rudder on take offs and add forward angle to your landing gear (rake).

#5 Tman57 Sep 13, 2011 12:18 AM

Hi,

The right rudder is a given ... I have been flying RC since the early 80's ... and as far as the landing gear goes, and as I pointed out this model comes with retracts and because of the design and the fact the plane is foam, adjusting the forward angle or any other angle is not an option, but thanks for the suggestions. What I would really like to discover is why this particular model is pulling so hard to the left to begin with. I suppose it could be engine torque, but the FMS 1400mm P-51 does not show this trait and it has the same motor setup.

Tman

#6 TallyHo1956 Sep 13, 2011 06:33 AM

As far as REAL Bf-109s are concerned, more were lost in take-off and landing accidents than in combat.

The reason? Propeller torque, coupled with the narrow track undercarriage and a smallish fin and rudder. This caused a marked torque-induced swing on take-off.

...Just like the model.:cool:

#7 Tman57 Sep 13, 2011 12:55 PM

Hey Tally Ho,

I feel that you are on the right track and following my thinking about this issue ... possibly this winter (providing the plane make it until then) I will look into putting some offset on th motor to see if that will help compensate the torque issue a bit without causing other issues ... always comprimises it seems

Thanks,

Tman

#8 Tom Hunt Sep 13, 2011 01:19 PM

Quote:

Originally Posted by Tman57 (Post 19300875)
Hey TW,

I read the two links you offered up, but judging by the dates of these entries, I believe what they are discussing is the old BF 109 which I also believe was smaller.. not 100% on this though ... I believe the 1400mm size is fairly new addition ....


Thanks for your input ... always appreciated !


Tman

No, if you bought a 1400mm Airfield/FMS model recently, then you have the "old one" just like those two threads are about.

The "NEW" BF-109F is not out yet and the thread can be found here:
http://www.rcgroups.com/forums/showthread.php?t=1357270


All times are GMT -5. The time now is 04:23 AM.