Ultimate thrust angle question
#1
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From: Wisconsin Rapids,
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Hi
Ive had a few more days at the field with my New Ultimate and I have some questions. as a rule i like a tad of up trim in a plane but this years Ultimate seems to need a bit of down trim to stay level. I dont have an incedance meter and i just built the kit like i do any ARF and she does fly very well. I allways have a bit of wind so good flight trimming has been a problem. Well the other day we had a calm one and the amount of down trim i needed was more than I think we should have the counter balance was almost above the stab when i landed I shook my head. I spend most my flights hovering around with my jaw open going OMG look what this thing is doing why would anyone fly this thing streight and level?
So I have a few days where we wont be flying the rain has come. I want to see if i can make some adjustments to this thing before I go out and burn up my lifes savings in fuel flying it. Right now it has a Evolution 58 and a 24-10 prop i was considering the prop thrust angles as a place to start. Any Ideas? next was a reafermation of the incedance of the top wing in inches so I can use a tape measre I know its a bit ctude but we aint flying a space shuttle. other than this Im open to any and all Ideas. thank you all for your time
Ive had a few more days at the field with my New Ultimate and I have some questions. as a rule i like a tad of up trim in a plane but this years Ultimate seems to need a bit of down trim to stay level. I dont have an incedance meter and i just built the kit like i do any ARF and she does fly very well. I allways have a bit of wind so good flight trimming has been a problem. Well the other day we had a calm one and the amount of down trim i needed was more than I think we should have the counter balance was almost above the stab when i landed I shook my head. I spend most my flights hovering around with my jaw open going OMG look what this thing is doing why would anyone fly this thing streight and level?
So I have a few days where we wont be flying the rain has come. I want to see if i can make some adjustments to this thing before I go out and burn up my lifes savings in fuel flying it. Right now it has a Evolution 58 and a 24-10 prop i was considering the prop thrust angles as a place to start. Any Ideas? next was a reafermation of the incedance of the top wing in inches so I can use a tape measre I know its a bit ctude but we aint flying a space shuttle. other than this Im open to any and all Ideas. thank you all for your time
#2
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From: Flower Mound (near Dallas),
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The upper wing TE shoule be 1/4" higher than the LE. Just measure between the top and bottom wings, the rear should be 1/4" farther apart than the front.
TF
TF
#3
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From: Wisconsin Rapids,
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Im close to that I will check that again after the last little repair things may have changed I didnt know if the thrust could be checked as well I know thats built in. But sometimes a little tweaking can be a good thing
#4
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From: Flower Mound (near Dallas),
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Thrust can be checed as well but it's unlikely to be off. You can try changing it but that can be a pain. Whatever you do do a little at a time.
TF
TF
#5
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My Feedback: (1)
Balance will also have an influence on trim quantities. Start at 6-1/2 " aft of the top wing point and move bach to 6-3/4" aft and see how that works for you. If the wing incidences are close, and the c/g falls within that range you may want to experiment with up and down thrust a little. I wouldn't go more than two degrees either direction in the attempt to find what you seek.
Bear in mind that the 24" prop you are running due to a larger engine is having an impact of it's own that you will have to factor into the trim equation.
Bear in mind that the 24" prop you are running due to a larger engine is having an impact of it's own that you will have to factor into the trim equation.
#6
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From: Wisconsin Rapids,
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the prop size was on my mind. I have it at 6 and 1/2 back now maybe just a touch farther back. I cant see moving it any further back till i know why she is taking this much down trim I still have to recheck the top wing incedance may get to that today.



