What Would Cause A Plane To Want To Pitch Up

[Piers Bowlan]

It is also interesting that Nigel says that he has had to add weight to the tail to achieve the published C of G (75mm from LE). Quite a few references to this online but not everyone has this problem, indicating some inconsistency in the foam density used during manufacture. Most 3S 2200mAh LiPos don’t differ vastly in weight. In any event,  many people fly with a c of g at 65mm with no ill effects, by all accounts.

if you do find the fuselage very flexible Nigel it is easy enough to reinforce it with thin carbon strips, as I have done with several of my foam models over the years. 
Using a steel ruler as a straight edge, carefully cut a slot down the belly of the model, no deeper than 10 mm. Push the strip (8mm x .5mm) into the slot so that it is buried. Now run thin cyano along the slot - job done. If there is excess lateral movement another strip can be inserted into ONE side of the fuselarge. Just ensure the fuselage is completely straight before applying the cyano!

Just to confirm the strip is half a millimetre thick, not 5mm!)

 

Good luck?

[Nigel Heather]

I took the tail and tailplane off.  Refitted and tried again.  Flew fine after that.  Can only think it couldn't have been seated properly.  Even able to remove the tail weight without any adverse effect.

 

[GrumpyGnome]

Glad it's sorted...... a nice easy fix!

[Nigel Heather]

5 hours ago, GrumpyGnome said:

Glad it's sorted...... a nice easy fix!

 

Yes.  Weird one though.  There wasn't any obvious misalignment, everything looked good.  It has been doing it since new not just after the crash.  I can only think that when I first assembled it the fin and the tailplane didn't seat quite right but not in a way that was evident.

 

Cheers,

 

Nigel