Gs 540 Flutter Problems
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Gs 540 Flutter Problems
i 'am having problems with my gs 540 , the elevator flutters in knife edge attitude. the hinge's are all sealed, and i can't find any slop in the linkages the servo's are new hs 225's mg. what could be possibley be causing this ? i would apreciate any help!
Chad
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Gs 540 Flutter Problems
Is it taking alot of speed to hold knife edge ? You have 2-225's on the elevator ? All I can figure if you've checked all the obvious is that your airspeed is too high, but that doesn't help much..not like you can slow it down if it won't hold knife edge. Maybe a higher torque servo would be in order. Nothing like throwing money at a problem. One other option might be braces or flying wire on the tail...the whole stab might be oscillating and not just the elevator.
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Gs 540 Flutter Problems
Originally posted by RCU
Don't despair, there's something causing it. Can you post a pic of the linkage so we can see the setup?
Thanks,
JW
Don't despair, there's something causing it. Can you post a pic of the linkage so we can see the setup?
Thanks,
JW
hear are the pics , it has 2 hs 225's on the elevator. running on 6 volts= 67oz.
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Gs 540 Flutter Problems
Originally posted by AtomHeartMother
Is it taking alot of speed to hold knife edge ? You have 2-225's on the elevator ? All I can figure if you've checked all the obvious is that your airspeed is too high, but that doesn't help much..not like you can slow it down if it won't hold knife edge. Maybe a higher torque servo would be in order. Nothing like throwing money at a problem. One other option might be braces or flying wire on the tail...the whole stab might be oscillating and not just the elevator.
Is it taking alot of speed to hold knife edge ? You have 2-225's on the elevator ? All I can figure if you've checked all the obvious is that your airspeed is too high, but that doesn't help much..not like you can slow it down if it won't hold knife edge. Maybe a higher torque servo would be in order. Nothing like throwing money at a problem. One other option might be braces or flying wire on the tail...the whole stab might be oscillating and not just the elevator.
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Gs 540 Flutter Problems
What size plane is that ?
I'd bet money your control rod is flexing. Almost looks like 2-56 in the picture. If so, I'd go with 4-40's and ball links for connectors. Just a thought.
I'd bet money your control rod is flexing. Almost looks like 2-56 in the picture. If so, I'd go with 4-40's and ball links for connectors. Just a thought.
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Gs 540 Flutter Problems
Originally posted by AtomHeartMother
What size plane is that ?
I'd bet money your control rod is flexing. Almost looks like 2-56 in the picture. If so, I'd go with 4-40's and ball links for connectors. Just a thought.
What size plane is that ?
I'd bet money your control rod is flexing. Almost looks like 2-56 in the picture. If so, I'd go with 4-40's and ball links for connectors. Just a thought.
another thing is you can also see the elevator surface flutter in a hover, that is really stange to me , it doesnt do it much in a hover but you can see it from time to time.
the flying wires are an interesting thought !!!! maybe the whole surface is oscilating , how do figure out if it is ????
thanks
Chad
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Gs 540 Flutter Problems
Originally posted by Flyindoc
Try moving the clevis to the outer most hole on the control horn. Hopefully this will solve your problem.
Andy
Try moving the clevis to the outer most hole on the control horn. Hopefully this will solve your problem.
Andy
thanks
Chad
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Gs 540 Flutter Problems
Originally posted by coony2787
if i move the clevis out i will lose alot of throw, doesnt 3d well with less throw. however this may solve the problem. i really want to keep all the throw i have now because i was actually looking for some more!!!!
thanks
Chad
if i move the clevis out i will lose alot of throw, doesnt 3d well with less throw. however this may solve the problem. i really want to keep all the throw i have now because i was actually looking for some more!!!!
thanks
Chad
Try it, it might work.
Andy
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Gs 540 Flutter Problems
Normally it's hard to actually see the stab fluttering. It'll usually transfer it's oscillation to the weakest link..being the elevator.
Bracing is a good option, but I'd hate to see you drill holes and what not in your stab for anchors and discover it didn't help.
4-40's look small on a big bird aye ?
I would still seriously think about ball links instead of z-bends at the servo arm. It'd be an easy fix. They may feel snug but the extra precision in a ball link might just be enough to eliminate the flutter. What servos does the guy have you mentioned ?
Bracing is a good option, but I'd hate to see you drill holes and what not in your stab for anchors and discover it didn't help.
4-40's look small on a big bird aye ?
I would still seriously think about ball links instead of z-bends at the servo arm. It'd be an easy fix. They may feel snug but the extra precision in a ball link might just be enough to eliminate the flutter. What servos does the guy have you mentioned ?
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Gs 540 Flutter Problems
he has futaba 9002 or some 9000 number not real sure wich one but i think he said that they have around 70oz of torque so about the same as mine.
i have never fooled with ball link conectors, this is just my secound big plane. so i'am pretty new to all this bigger stuff so i'am leaning as i go. where do i get the ball link connectors?
i really apreciate your all's input
thanks
Chad
i have never fooled with ball link conectors, this is just my secound big plane. so i'am pretty new to all this bigger stuff so i'am leaning as i go. where do i get the ball link connectors?
i really apreciate your all's input
thanks
Chad
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Gs 540 Flutter Problems
Dubro makes a good set. I've got 4-40's and ball links on my big gasser. Tower or your local hobby store should have them. You'll just need to get 4-40 rod threaded at both ends, the right length. Might only be able to find a full length thread. I have a 4-40 die but quickly found that your can't run threads on 4-40 sized rods. The ball links won't fit...grrrr. The threaded rod you buy at the hobby store has rolled threads which are just a tad bigger in diameter. Anyway, that's what I'd do. Also, I run hitecs in a lot of my stuff and I've been happy with them, BUT I'd say the futaba's have less slop around center which is really critical when you'r talking speed and 3D type control surfaces. I'd try the ball links first, if that doesn't work-either brace the tail or drop some coin on some higher end servos.
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Gs 540 Flutter Problems
Originally posted by AtomHeartMother
Dubro makes a good set. I've got 4-40's and ball links on my big gasser. Tower or your local hobby store should have them. You'll just need to get 4-40 rod threaded at both ends, the right length. Might only be able to find a full length thread. I have a 4-40 die but quickly found that your can't run threads on 4-40 sized rods. The ball links won't fit...grrrr. The threaded rod you buy at the hobby store has rolled threads which are just a tad bigger in diameter. Anyway, that's what I'd do. Also, I run hitecs in a lot of my stuff and I've been happy with them, BUT I'd say the futaba's have less slop around center which is really critical when you'r talking speed and 3D type control surfaces. I'd try the ball links first, if that doesn't work-either brace the tail or drop some coin on some higher end servos.
Dubro makes a good set. I've got 4-40's and ball links on my big gasser. Tower or your local hobby store should have them. You'll just need to get 4-40 rod threaded at both ends, the right length. Might only be able to find a full length thread. I have a 4-40 die but quickly found that your can't run threads on 4-40 sized rods. The ball links won't fit...grrrr. The threaded rod you buy at the hobby store has rolled threads which are just a tad bigger in diameter. Anyway, that's what I'd do. Also, I run hitecs in a lot of my stuff and I've been happy with them, BUT I'd say the futaba's have less slop around center which is really critical when you'r talking speed and 3D type control surfaces. I'd try the ball links first, if that doesn't work-either brace the tail or drop some coin on some higher end servos.
Andy
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Gs 540 Flutter Problems
If it's an ARF check the tail construction. Flew my Model Tech SU-29 ARF Sunday (probably had 50 flights on it) and put it into a 90 degree left bank to enter a knife edge pass. Heard about two seconds of flutter (never fluttered before) and before I could cut the throttle the tail blew off. Pretty impressive actually, the vertical and horizontal surfaces came off in about five pieces and fluttered to the ground while the rest of the plane went into a nice spin that I could actually slow down with the ailerons. It hit the ground fairly slow so the damage was minimal (didn't even break the prop). When I looked at the mounting surface for the tail surfaces on the fuse the glue had only been applied to two small areas front and rear (about 10% of the mounting area). Didn't like the tail anyway.
Mike
Mike
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Gs 540 Flutter Problems
Cooney, are you running 6 volts? I'm just checking - I realize you are an experienced flyer and you probably know that the 225 doesn't have enough torque for an 80" with standard voltage.
Just checking.
Just checking.
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Gs 540 Flutter Problems
For diagnostic purposes, move the clevis out to the farthest hole on the control horn. There is a possibility that the setup ie. servo arm / and servo that you are using, coupled with the inward hole on the control horn, could be the culpret. You are fine with a Z bend and a straight shot with a clevis (like you have). I know it isn't what ball link fans want to hear, but ball links can cause flutter by twisting the control horn. Many flyers only use them on throttle because of this. If you feel comfortable to fly it after the linkage adjustment, let me know and we'll go from there. If not, I suggest a larger servo. I'm almost done framing a GSE540 now.
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Gs 540 Flutter Problems
I would be concerned that the 225 would be on the verge of being too small on a plane this size with 3D throws, even at 6V. An elevator that size at 45 degrees of throw requires some substantial holding power. It may be too much for the little Hitec mini. If you have zero slop in your linkages and they are not flexing, you have the linkages setup properly mechanically and electronically if using a computer radio, used enough hinges, and the hinge line is sealed, then I would suspect the servos.
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Gs 540 Flutter Problems
I just looked at the photo you posted. I think Flyingdoc may be right. You definitely have the rod inboard on your control horn. I'd try putting it in the last hole outboard as Flyingdoc suggested. I doubt this servo could deal with a mechanical disadvantage like that. Just a thought.
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Gs 540 Flutter Problems
Originally posted by aftcg
Cooney, are you running 6 volts? I'm just checking - I realize you are an experienced flyer and you probably know that the 225 doesn't have enough torque for an 80" with standard voltage.
Just checking.
Cooney, are you running 6 volts? I'm just checking - I realize you are an experienced flyer and you probably know that the 225 doesn't have enough torque for an 80" with standard voltage.
Just checking.
i was talking to one the veteran club members today about the problem and mentioned to him about the flying wires and he agreed that it could be oscillation of the tail. since you can kinda notice it in hover every once in a while. i think i'll move the clevis out on the control horn a few notches and add the flying wires they look good any ways so even of they don't help i will still like them.
if that don't fix it then i'll try the ball link. but there is really no slop in the linkage now. maybe some carbon fiber rods with ball links if all else fails!!!!
thanks for all the input guys it really helps
Chad
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Gs 540 Flutter Problems
I would change servos...see if you can find someone to let you try a couple higher end servos and see if it fixes the problem......i had 2-225mg's on the v-tail of my pilon plane with a ttpro40 and lost the plane due to the servo's......i had one crap out on me and since i just bought them my LHS just swapped them out for me for the same servo....when i flew it again another servo went out and i lost the plane....not saying 225's are prone to failure and definately not bashing but i wouldnt trust another plane to these servos.....just my .02
P.S. Im still running 925mg's on my chopper with no problems....so im not bashing hi-tech
P.S. Im still running 925mg's on my chopper with no problems....so im not bashing hi-tech
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Gs 540 Flutter Problems
Originally posted by Flypaper
Dynamic balancing of the stab will help control flutter also.
Dynamic balancing of the stab will help control flutter also.
Chad
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Gs 540 Flutter Problems
Originally posted by CrAzYfLyEr
I would change servos...see if you can find someone to let you try a couple higher end servos and see if it fixes the problem......i had 2-225mg's on the v-tail of my pilon plane with a ttpro40 and lost the plane due to the servo's......i had one crap out on me and since i just bought them my LHS just swapped them out for me for the same servo....when i flew it again another servo went out and i lost the plane....not saying 225's are prone to failure and definately not bashing but i wouldnt trust another plane to these servos.....just my .02
P.S. Im still running 925mg's on my chopper with no problems....so im not bashing hi-tech
I would change servos...see if you can find someone to let you try a couple higher end servos and see if it fixes the problem......i had 2-225mg's on the v-tail of my pilon plane with a ttpro40 and lost the plane due to the servo's......i had one crap out on me and since i just bought them my LHS just swapped them out for me for the same servo....when i flew it again another servo went out and i lost the plane....not saying 225's are prone to failure and definately not bashing but i wouldnt trust another plane to these servos.....just my .02
P.S. Im still running 925mg's on my chopper with no problems....so im not bashing hi-tech
thanks for the input and i hope the servo's hold up for me, i know they are on the low end for this aplication but they seem to hold very good in all other flight attitiude other than knife edge .
thanks
Chad
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my tail pictures as promised
Here are the pictures of my set-up that works very well. By the way what engine do you have in it? I dont think I have seen that yet. I am running the saito 180 on 30% morgans fuel. Awsome hovers and rolling herriers!!!!!