trim question
08-26-2012, 08:14 PM
#1
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trim question
I have a trim question, my Edge 540 keep turning to the left when I pull up as in a loop or vertical. The plane is trimmed in straight and level flight, but as soon as I pull up it starts banking to the left. Could I just not have the rudder and ailerons trimmed right or could the plane not be balanced left to right? Any insight would be very much appreciated.
08-26-2012, 08:40 PM
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RE: trim question
Could also be "gaps" in the elevator and the ailerons.
How close are they?
Are they sealed with covering?
If not.
Do it.
Biggest single improvement that can be made to most all planes.
How close are they?
Are they sealed with covering?
If not.
Do it.
Biggest single improvement that can be made to most all planes.
08-27-2012, 02:43 AM
#3
RE: trim question
Check the throw of the elevators. For whatever the reason, when I mix two elevator servos, the slave always has more throw and requires a 94-96% setting compared to the primary. I find the number is critical... one percent up or down will manifest the tracking problems in a loop.
08-27-2012, 10:30 AM
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RE: trim question
It's all in the details....
Start by seeing if the wing itself is balanced along the center line. If they are plug in wings and you can't slide the joiner rod/tube/blade out then make up a temporary joiner from soemthing so you can check for span wise balance. Weigt the lighter side as required to balance.
At the same time check the wing for warps and correct them as required. Note that you want to NOT INCLUDE the movable ailerons in such a check. Offset trims in the ailerons will mask warps in the actual fixed portion. You may need to get creative with finding and building up some way to test for such warps.
If you didn't find anything to fix in these first two things than the stuff the guys are suggesting above are the next things to look at. But you want to confirm that the basics are correct, namely balanced and straight.
Start by seeing if the wing itself is balanced along the center line. If they are plug in wings and you can't slide the joiner rod/tube/blade out then make up a temporary joiner from soemthing so you can check for span wise balance. Weigt the lighter side as required to balance.
At the same time check the wing for warps and correct them as required. Note that you want to NOT INCLUDE the movable ailerons in such a check. Offset trims in the ailerons will mask warps in the actual fixed portion. You may need to get creative with finding and building up some way to test for such warps.
If you didn't find anything to fix in these first two things than the stuff the guys are suggesting above are the next things to look at. But you want to confirm that the basics are correct, namely balanced and straight.
08-27-2012, 01:47 PM
#5
My Feedback: (15)
RE: trim question
ORIGINAL: 1320Fastback
Could also be ''gaps'' in the elevator and the ailerons.
How close are they?
Are they sealed with covering?
If not.
Do it.
Biggest single improvement that can be made to most all planes.
Could also be ''gaps'' in the elevator and the ailerons.
How close are they?
Are they sealed with covering?
If not.
Do it.
Biggest single improvement that can be made to most all planes.
How much of a gap is too much? Please elaborate. Thanks.
Kurt
08-27-2012, 04:15 PM
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RE: trim question
For my planes I seal them all reguardless.
I'd say that in general that if you can measure it or if it's bigger than 1/16" I would seal them.
Take the ailerons for example in a high speed pull up from level flight.
If one side is 1/16" and the other Aileron is 1/8" obviously one is going to let some air slip thru more than the other.
This air is your lift or pressure and the difference will cause a roll motion.
Elevator will have the same issue. Causing a roll to one side or unevenness.
Rudder is not as critical.
Sealing can be as simple as tape or even clear covering for planes with trim schemes.
I'd say that in general that if you can measure it or if it's bigger than 1/16" I would seal them.
Take the ailerons for example in a high speed pull up from level flight.
If one side is 1/16" and the other Aileron is 1/8" obviously one is going to let some air slip thru more than the other.
This air is your lift or pressure and the difference will cause a roll motion.
Elevator will have the same issue. Causing a roll to one side or unevenness.
Rudder is not as critical.
Sealing can be as simple as tape or even clear covering for planes with trim schemes.
08-27-2012, 05:38 PM
#7
RE: trim question
All the stated suggestions so far are good one in order to get the most out of any airplane. With that said usually on a scale aerobat such as the Edge you uasually have to apply a slight amount of right rudder as you ' Round the corner" to vertical. Reason for this I beleive is that the engine gets slightly loaded and the torque value goes up. Torque is a very broad term and forces that apply here could be P factor, spiral slipstream but for the past decade and a half when speaking to IMAC and pattern pilots of all levels the force requiring right thrust and right rudder has always been refered to as torque.
So try this next time out. As you round the corner to vertical, apply a touch of right rudder and the slowly back out of it when vertical. If your airplane has enough right thrust it should continue strait. Now you get to worry about it pulling or tucking LOL.
So try this next time out. As you round the corner to vertical, apply a touch of right rudder and the slowly back out of it when vertical. If your airplane has enough right thrust it should continue strait. Now you get to worry about it pulling or tucking LOL.
