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Old Apr 01, 2011, 11:59 AM
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HouseOf4Doors's Avatar
United States, CA, Richmond
Joined Dec 2007
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Thanks!

G.P.: It requires not much, just a normal amount of up elevator while inverted when trimmed for level, so I know it is not a cg issue.

I get you about putting the necessary trim in via the linkage, but my gut tells me that this is still just not right.

I hope the photos tell the tale. Note the dx7's trim display is the vertical readout at the extreme right edge of the tx screen. I attach the photos of the flying surfaces in their slots for reference. NOTE: the flying surfaces are absolutely dead straight, no twist, warp, etc. at all.

I'll report back when I get my incidence meter sorted.
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Last edited by HouseOf4Doors; Oct 12, 2012 at 12:25 PM. Reason: clarity
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Old Apr 01, 2011, 12:08 PM
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United States, LA, Moss Bluff
Joined Nov 2008
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Quote:
Originally Posted by HouseOf4Doors View Post
Thanks for trying to help with my trim/rig problem. Let me start over so I'll clear up any misunderstandings due to my lack of clarity.

I am using the Hacker A50-12s, 16x10 APC, thrust is factory-set, no mods.

Condition 1 - No elevator trim, cg @ recommended 7", elev. properly centered:
Result: Severe nose-down tendency. When inverted, severe nose-up tendency.

Condition 2 - 95% up elev. trim, cg @ 7":
Result: plane flies normal upright and inverted, but I've lost nearly 50% of up elev. travel, plus, I know that's not right!!!

I have not checked incidence but am putting together a homemade meter and should have results in a couple of days.

If you can think of anything that could cause this other than an incidence issue, please let me know.

Thanks!

Interesting, so you have it trimmed to hold the nose UP during upright flight. Which inverted this trim (just as a statement), would make the nose go down, but yet it climbs. WOW, I think I'd start over and use MAntas advise.
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Old Apr 01, 2011, 12:44 PM
iumop ap!sdn w,I
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Joined May 2005
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Quote:
Originally Posted by robj View Post
Interesting, so you have it trimmed to hold the nose UP during upright flight. Which inverted this trim (just as a statement), would make the nose go down, but yet it climbs. WOW, I think I'd start over and use MAntas advise.
We've been through this already....once trimmed it does not climb when inverted.
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Old Apr 01, 2011, 12:49 PM
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Cleveland, OH
Joined Nov 2007
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Originally Posted by johnnyrocco123 View Post
Anyone fly the GP sequence?

I can get it shipped for $140 right now. Just wondering if it's worth it for a pattern plane for the trunk (practicing at work.)
46" Osiris on the way....
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Old Apr 01, 2011, 12:57 PM
iumop ap!sdn w,I
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Quote:
Originally Posted by HouseOf4Doors View Post
G.P.: It requires not much, just a normal amount of up elevator while inverted when trimmed for level, so I know it is not a cg issue.

I get you about putting the necessary trim in via the linkage, but my gut tells me that this is still just not right, and I'm kind of a perfectionist.

I hope the photos tell the tale. Note the dx7's trim display is the vertical readout at the extreme right edge of the tx screen. I attach the photos of the flying surfaces in their slots for reference. NOTE: the flying surfaces are absolutely dead straight, no twist, warp, etc. at all.

I'll report back when I get my incidence meter sorted.
Remember that it is going to take more trim in the radio to get the same amount of control deflection as a 3D or aerobatic plane. The Osiris has much less throw, so each step of trim doesn't move the surface as far.

Here's what the owner of 3DHS says about the subject:

Quote:
Originally Posted by blucor basher View Post
mbritt -

It's not your incidence. the incidence on ARF aircraft is set by laser-cut fuselage sides that, if they were incorrect, would prevent them from being assembled. It's not the incidence. And no, you won't find very many small 3d aircraft with the wing at a whole degree positive, no.

The CG position in the manual will require both up elevator trim and a healthy push of down elevator when inverted.

The angle your elevator is sitting at when the plane is at rest on the ground will change with different CG locations. the more nose-heavy a plane, the more up elevator trim it will have. The more tail-heavy a plane, the more down elevator trim it will have.
Quote:
Originally Posted by blucor basher View Post
I think there is some guy out there...I call him "Johnny Incidence-seed". He goes around the country convincing people that if their airplane's elevator is not perfectly level at rest, the airplane is mis-manufactured. I don't know how else this idea could have become so widely propogated all over the hobby.
Quote:
Originally Posted by blucor basher View Post
Exactly Rob. That's what I was noting above, a lot of people get sabotaged by an incorrect piece of information, the idea that the elevator should always be perfectly level at rest.

The elevator will only trim out to level at one particular CG location...that may happen to be the one that a given pilot wants, or it may not.
Quote:
Originally Posted by blucor basher View Post
...and wherever the elevator trim ends up for your particular CG, that's where it ends up.

Looking back through our records, it appears you've been messing with incidence on your 3DHS planes since early December, and we explained this all to you back then. Looking through what you posted today, I again diagnose an incorrect trimming and balancing procedure, very specifically that you are trying to achieve a certain elevator position as a goal. This is not correct.

If you take several popular aircraft that thousands of people are flying and enjoying, and if you find that yours do not fly the way you want them to, and other people tell you that your trimming procedure is wrong and this is why, do you think it is more likely that:

1.Your trimming procedure is wrong.

or

2.All of your airplanes have incidence problems.

If you have decided that all your airplanes need their incidence changed (which apparently you did back in December) then go do it. However, the advice you'll mostly get in internet threads about a plane is going to be about that plane as designed and shipped.
And those are just the most recent posts on the subject. Short story long:

If you want to have your elevator more in line with the stab then move your CG aft.

If you like the way the plane flys and don't want to move the CG, then fly it.

I'm guessing that it'll fly fine with the CG where the elevator and stab line up, as that's most likely how AJ designed it. I'll know for sure in a month once the snow melts!
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Old Apr 01, 2011, 01:05 PM
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Manta1's Avatar
USA, GA, Cochran
Joined Jun 2008
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agreed.move the battery back, re-trim. Incidence is not the answer here.It is kinda hard to get the incidence wrong on these arfs.You kinda gotta be trying to.
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Old Apr 01, 2011, 03:16 PM
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San Diego
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Originally Posted by wedgewing View Post
46" Osiris on the way....
Is it safe to say that it will run on all the same components as the 48's, and is there a guess on arrival?
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Old Apr 01, 2011, 04:05 PM
AJ Addict
Toledo Ohio
Joined Jun 2008
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3dHS has the 46 Osiris on display at the Toledo Show It has a sign that said coming in MAY.. Its a nice look plane It also said 4s 2200 packs on it..
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Old Apr 01, 2011, 04:15 PM
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San Diego
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Originally Posted by ronmad02 View Post
3dHS has the 46 Osiris on display at the Toledo Show It has a sign that said coming in MAY.. Its a nice look plane It also said 4s 2200 packs on it..
Cool, thanks! Time to start saving.
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Old Apr 01, 2011, 05:37 PM
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United States, CA, Richmond
Joined Dec 2007
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Quote:
Originally Posted by G.P. View Post
Remember that it is going to take more trim in the radio to get the same amount of control deflection as a 3D or aerobatic plane. The Osiris has much less throw, so each step of trim doesn't move the surface as far.

And those are just the most recent posts on the subject. Short story long:

If you want to have your elevator more in line with the stab then move your CG aft.

If you like the way the plane flys and don't want to move the CG, then fly it.

I'm guessing that it'll fly fine with the CG where the elevator and stab line up, as that's most likely how AJ designed it. I'll know for sure in a month once the snow melts!
And I guess this is where the internet fails us. You'll just have to come over and fly my plane to see what I'm talking about. Because if I moved the cg back, I'll have to pull like hell on the elevator to keep from going up when inverted.

I appreciate the skepticism from Ben and everyone on incidence issues, and the bit about "Johnny Incidence Seed" is funny. That said, I'm pretty sure planes that need a more aft cg do not tend to climb when inverted!
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Old Apr 01, 2011, 05:37 PM
Advocating for RC Aviation
USA, NJ, Phillipsburg
Joined Jul 2010
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Quote:
Originally Posted by ronmad02 View Post
3dHS has the 46 Osiris on display at the Toledo Show It has a sign that said coming in MAY.. Its a nice look plane It also said 4s 2200 packs on it..
Probably why TH put the GP Sequence on sale! What color scheme(s) were they showing?
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Old Apr 01, 2011, 07:07 PM
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United States, CA, Hayward
Joined Aug 2004
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motrolfly 4320's are up on ken's website (subsonicplanes.com) now! perfect motor for an osiris on 6s
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Old Apr 01, 2011, 07:49 PM
iumop ap!sdn w,I
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Joined May 2005
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edit: Nevermind.

The plane climbs inverted, then it doesn't, then it does again.........see red writing in post #1815 and tune the plane as required.

Done.
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Last edited by G.P.; Apr 01, 2011 at 07:57 PM.
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Old Apr 01, 2011, 09:40 PM
Use the 4S Luke
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USA, TX, Euless
Joined Aug 2003
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Finished mine tonight. Maiden AM.
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Old Apr 01, 2011, 09:56 PM
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Gilbert, AZ
Joined Apr 2008
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Originally Posted by feathermerchant View Post
Finished mine tonight. Maiden AM.
Good luck Feather. Welcome aboard!

Cheers,

Jim
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