Multiplex Twin Star II
02-26-2006, 01:41 AM
#1
Junior Member
Thread Starter
Join Date: Jul 2005
Location: Mission Tx
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
Multiplex Twin Star II
Can anybody out there give me a cure to a barrel (rather than an axial) roll?I progrommed differential (50%) down into the ailerons & it still does a wide roll. It really likes two Axi 2208/34
02-26-2006, 02:31 AM
#2
Join Date: Oct 2002
Location: Chilliwack, BC, CANADA
Posts: 12,425
Likes: 0
Received 22 Likes
on
19 Posts
RE: Multiplex Twin Star II
A barrel style of roll comes from having a lot of pitch stability in the trim. Chances are that if you dive the model and release the sticks it'll pull up on it's own. If you move the CG back and retrim the elevator to compensate until it only pulls up from a dive with a gentle pullup that requires you to save it before hitting the ground then it'll do rolls that are more axial. This is called the "dive test". Folks use it as a way to figure out just how close to a neutral handling model they can get. Trainers, on the other hand, need to have a fair degree of built in pitch stability so moving the CG back so it's near the neutral point is not something that you want to do.
But the Twinstar is not really intended for these sorts of shenanigans. I suspect that it'll always have some odd behaviour traits. I doubt that it'll ever do a nice clean axial roll. But with some fine tuning of the pitch trim you can likely make it better than it is.
But the Twinstar is not really intended for these sorts of shenanigans. I suspect that it'll always have some odd behaviour traits. I doubt that it'll ever do a nice clean axial roll. But with some fine tuning of the pitch trim you can likely make it better than it is.
03-11-2006, 11:30 PM
#3
My Feedback: (85)
RE: Multiplex Twin Star II
Well you may or may need the differential. what i do is get up high push the nose straight down to the ground. pull the throttles back to idle. make sure all sticks are nuetral. in other words you are not holding any up-down. aileron rudder etc. then do one roll with ailerons only. then pull out think to yourself was this roll axial. Yes it's your fault you are probably holding in elevator while rolling. No is a little tougher. you will really have to pay attention if you are rolling right see if the plane is moving off line to the right or left. if it is moving to the right while rolling right you have to much differential. if it is moving to the left you do not have enough differential. Make sure you do this both directions to discount any effect from the wind.
For what it's worth i can do multiple axial rolls on the twinstar with 25fx's. A key word is you need to use some rudder. picture this. if you roll right as you start rolling to the right add left rudder as you start coming around to inverted get off the rudder and feed in some down elevator as is continues around let off the elevator and feed in right rudder as it continues around let off the rudder and feed in some up elevator. It's tough to get all the controls correct at first. if you roll left reverse the rudder inputs. second thought is do not roll so fast to give you the time for the corrections.
Next thing is if you have aileron and rudder coupled you will never be able to do a axial roll see the rudder corrections needed and you will see what i mean. Most of the problems i see about not getting axial rolls are from somebody giving it up elevator before entering the roll and not nuetralizing the elevator before starting the roll.
Dennis
For what it's worth i can do multiple axial rolls on the twinstar with 25fx's. A key word is you need to use some rudder. picture this. if you roll right as you start rolling to the right add left rudder as you start coming around to inverted get off the rudder and feed in some down elevator as is continues around let off the elevator and feed in right rudder as it continues around let off the rudder and feed in some up elevator. It's tough to get all the controls correct at first. if you roll left reverse the rudder inputs. second thought is do not roll so fast to give you the time for the corrections.
Next thing is if you have aileron and rudder coupled you will never be able to do a axial roll see the rudder corrections needed and you will see what i mean. Most of the problems i see about not getting axial rolls are from somebody giving it up elevator before entering the roll and not nuetralizing the elevator before starting the roll.
Dennis
