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Author Topic: Nobler preset tip weight?  (Read 4180 times)

Offline bruce finley

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Nobler preset tip weight?
« on: July 27, 2015, 08:13:10 PM »
Anybody have a naked nobler to see just how much tip weight is buried underneath the plastic covering?  I think I have a tip weight issue and want to know from where I am starting, before I go and add lead. ??? ???

Bruce

Offline Paul Walker

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Re: Nobler preset tip weight?
« Reply #1 on: July 27, 2015, 08:46:56 PM »
Why not add modeling clay to the tip until it is right? Then you can weigh that and then add the same weight of lead inside.

Offline Randy Ryan

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Re: Nobler preset tip weight?
« Reply #2 on: July 28, 2015, 08:05:31 AM »
Why not add modeling clay to the tip until it is right? Then you can weigh that and then add the same weight of lead inside.


Maybe too much already.
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Offline Bob Reeves

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Re: Nobler preset tip weight?
« Reply #3 on: July 28, 2015, 09:02:41 AM »

Maybe too much already.

That is when you start adding clay to the inboard wing so you know how much to remove when you open it up.

Offline bruce finley

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Re: Nobler preset tip weight?
« Reply #4 on: July 28, 2015, 09:47:07 AM »
Here's the story guys. on my inside Square after the second turn the plane takes off sailing away at a 45° angle. Outside squares no problem, sharp and crisp. what do you think?  Looking for warps or issues, not seeing anything. Could this be an issue with fixed lead outs and the CG?

Offline bruce finley

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Re: Nobler preset tip weight?
« Reply #5 on: July 28, 2015, 09:48:10 AM »
I've already added about three quarters of an ounce, seem to help. That's why I was asking about the total weight involved. Thanks to all who replied.

Offline Randy Cuberly

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Re: Nobler preset tip weight?
« Reply #6 on: July 28, 2015, 11:20:49 AM »
I've already added about three quarters of an ounce, seem to help. That's why I was asking about the total weight involved. Thanks to all who replied.

Three Quarters of an ounce is a lot of weight to have to add to a (ARF Nobler).  I strongly suspect that there is another issue.  Most probably (no garuntees) there is a warp either in the wing itself or a flap, or misalignment in the stab to flap hinge line.  It's just about impossible to trim an airplane from remote locations by typing on a keyboard but those are the things I would look for first.

One question...what engine and prop are you running and do you have any engine offset.

Paul Walker provided some time ago a trimming check sheet, you can probably find it on line or from Paul.  It's an excellent guide line for trim problems.

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Offline Randy Ryan

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Re: Nobler preset tip weight?
« Reply #7 on: July 28, 2015, 11:25:01 AM »
That is when you start adding clay to the inboard wing so you know how much to remove when you open it up.


Ah good point Bob.
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Offline Tim Wescott

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Re: Nobler preset tip weight?
« Reply #8 on: July 28, 2015, 11:58:21 AM »
Here's the story guys. on my inside Square after the second turn the plane takes off sailing away at a 45° angle. Outside squares no problem, sharp and crisp. what do you think?  Looking for warps or issues, not seeing anything. Could this be an issue with fixed lead outs and the CG?

If it doesn't do it on the outside squares, then look harder for warps or issues.  Look for warped wings, flaps not in alignment, and the tail twisted with respect to the wing.  If you don't find any such, look for the airplane rolling toward the inside or the outside -- basically, if it always flies with the same tip up or down then it's a tip weight issue; if it always rolls in the same direction (meaning, if it's tip up while upright and tip down while inverted) then the plane is rolling.  If the wings are dead flat, or always tip down, and it misbehaves on insides and not outsides, then chances are the elevator is tilted.

If it does have a problem with misbehaving more in one direction than the other then you can paper over that problem with more tip weight -- at the expense of hinging.  It's something to be done as a last resort, but you really want to find the root cause.
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Offline bruce finley

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Re: Nobler preset tip weight?
« Reply #9 on: July 29, 2015, 11:50:02 AM »
If it doesn't do it on the outside squares, then look harder for warps or issues.  Look for warped wings, flaps not in alignment, and the tail twisted with respect to the wing.  If you don't find any such, look for the airplane rolling toward the inside or the outside -- basically, if it always flies with the same tip up or down then it's a tip weight issue; if it always rolls in the same direction (meaning, if it's tip up while upright and tip down while inverted) then the plane is rolling.  If the wings are dead flat, or always tip down, and it misbehaves on insides and not outsides, then chances are the elevator is tilted.

If it does have a problem with misbehaving more in one direction than the other then you can paper over that problem with more tip weight -- at the expense of hinging.  It's something to be done as a last resort, but you really want to find the root cause.

So when the plane flies off after that second turn of the inside square, I'm thinking it may be yawed out(?) and flying on one line--the up line--and that is why it is not responding to input(down) and allowing some control.  Not at home looking at my Nobler, but it seems the up line is at the rear.  Is this what a Rabe rudder might correct?

Engine is L&J Fox 35 running the RSM 10/6 prop and engine is set at approx 2 degrees out.  Maybe need to take some out(?)

Offline Bob Reeves

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Re: Nobler preset tip weight?
« Reply #10 on: July 29, 2015, 01:28:38 PM »
I would just about bet on a warp or misaligned flaps. Try tweaking the outboard flap down in reference to the inboard flap and see if that doesn't help.

Offline bruce finley

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Re: Nobler preset tip weight?
« Reply #11 on: July 29, 2015, 01:30:45 PM »
Thank You Bob, tried that and didn't have much effect

Offline bruce finley

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Re: Nobler preset tip weight?
« Reply #12 on: July 29, 2015, 01:32:41 PM »
Check that, I tweeked the imboard flap.  Will tweek outboard and see

Offline Tim Wescott

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Re: Nobler preset tip weight?
« Reply #13 on: July 29, 2015, 01:36:35 PM »
So when the plane flies off after that second turn of the inside square, I'm thinking it may be yawed out(?) and flying on one line--the up line--and that is why it is not responding to input(down) and allowing some control.  Not at home looking at my Nobler, but it seems the up line is at the rear.  Is this what a Rabe rudder might correct?

Engine is L&J Fox 35 running the RSM 10/6 prop and engine is set at approx 2 degrees out.  Maybe need to take some out(?)

Rabe rudders are there to correct itty bitty problems.  If your Nobler is yawed out enough to be flying on one line you'll know it because you'll be looking at the ass end of the plane.  Ditto yawed in, except you'll be looking at the spinner (and, possibly, reviewing significant incidents in your life).  I would not classify enough yaw to cause you to hang on one line as "itty bitty".

Thank You Bob, tried that and didn't have much effect

How much tweak did you give it?  Have you looked at the plane in upright and inverted flight to try to sort out weight/warp issues?  It's really a must-do at this point.  If you know how to do it -- do it and report back.  If you don't -- ask.
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Offline bruce finley

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Re: Nobler preset tip weight?
« Reply #14 on: July 29, 2015, 01:45:22 PM »
Looks very level upright and inverted.  No lost tension on a regular inside loop.

Just an issue when banging inside squares, triangle etc

Offline bruce finley

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Re: Nobler preset tip weight?
« Reply #15 on: July 29, 2015, 01:45:56 PM »
Have it about 3/16 diff in tweak

Offline Tim Wescott

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Re: Nobler preset tip weight?
« Reply #16 on: July 29, 2015, 01:51:09 PM »
Looks very level upright and inverted.  No lost tension on a regular inside loop.

Just an issue when banging inside squares, triangle etc

Have it about 3/16 diff in tweak

Inspect the alignment of the tail and wing very carefully then -- if the elevator is tilted with the top toward the inside of the circle then that's your problem.  If it isn't then your issue is beyond my pay grade.

It doesn't take much -- if you can see a 1/32" difference from tip to tip of the elevator to wing distance while sighting down the tail of the airplane, then you need to cut it up and fix it.
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Offline Brett Buck

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Re: Nobler preset tip weight?
« Reply #17 on: July 29, 2015, 03:43:40 PM »
Inspect the alignment of the tail and wing very carefully then -- if the elevator is tilted with the top toward the inside of the circle then that's your problem.  If it isn't then your issue is beyond my pay grade.

It doesn't take much -- if you can see a 1/32" difference from tip to tip of the elevator to wing distance while sighting down the tail of the airplane, then you need to cut it up and fix it.

  Same thing for the "skew" axis. The hingelines must be *exactly* parallel, even as little as 1/64" can completely screw everything up.

   The hinge lines are already sealed, right?

    Brett

Offline bruce finley

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Re: Nobler preset tip weight?
« Reply #18 on: July 29, 2015, 04:20:25 PM »
Hinge lines are sealed.

Brett elaborate on skew axis pls

Offline Tim Wescott

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Re: Nobler preset tip weight?
« Reply #19 on: July 29, 2015, 04:44:33 PM »
Hinge lines are sealed.

Brett elaborate on skew axis pls

He means that the axis upon which the elevator rotates needs to be parallel with the horizontal stab.  Even if the stab and elevator are parallel with the wing, if the hinge line is tilted to the stab then it'll have the same effect as if the hinge line were straight on a tilted stab.

For the amount of drama you're experiencing you should have a really visible tilt, like 1/4 inch from side to side or some such.  Smaller stab tilts will show up as odd behavior, but not to the point of needing 3/16" tweak in the flaps to compensate.
AMA 64232

The problem with electric is that once you get the smoke generator and sound system installed, the plane is too heavy.

Offline Tim Wescott

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Re: Nobler preset tip weight?
« Reply #20 on: July 29, 2015, 04:45:39 PM »
Both elevator halves do travel together, yes?  If your horn were loose in the outside elevator half it may cause this.
AMA 64232

The problem with electric is that once you get the smoke generator and sound system installed, the plane is too heavy.

Offline bruce finley

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Re: Nobler preset tip weight?
« Reply #21 on: July 29, 2015, 06:02:12 PM »
Both elevator halves do travel together, yes?  If your horn were loose in the outside elevator half it may cause this.
[/quot

Yes all is tight.

Pic....

Offline bruce finley

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Re: Nobler preset tip weight?
« Reply #22 on: July 29, 2015, 06:03:08 PM »
Another pic

Offline Target

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Re: Nobler preset tip weight?
« Reply #23 on: July 29, 2015, 07:31:42 PM »
Do both flaps have about equal torsional stiffness?
What if the outboard flap was not stiff, and the inboard was? On a hard pull command the outboard flap might blow back and the inboard would cause a roll out of the circle.
Just guessing, and I'm a newbie.
All of this is very intriguing to me.
Hope you get it sorted.

Regards,
Chris
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Offline bruce finley

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Re: Nobler preset tip weight?
« Reply #24 on: July 29, 2015, 08:03:21 PM »
All stiff and normal y1

Offline Brett Buck

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Re: Nobler preset tip weight?
« Reply #25 on: July 29, 2015, 08:07:50 PM »
Hinge lines are sealed.

Brett elaborate on skew axis pls

   Parallel looking from above. Measure from the hingeline at one tip of the stabilizer to the flap hinge line, same from the other tip. They need to be exactly the same.

   Sealed hinge lines?

    Brett

Offline Gordon Van Tighem

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Re: Nobler preset tip weight?
« Reply #26 on: July 29, 2015, 10:10:11 PM »
How does it balance? Tail heavy, by chance?
I had one that hinged on inside squares and triangles and a slight addition of nose weight cured it.
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Offline Tim Wescott

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Re: Nobler preset tip weight?
« Reply #27 on: July 29, 2015, 10:40:49 PM »
   Parallel looking from above. Measure from the hingeline at one tip of the stabilizer to the flap hinge line, same from the other tip. They need to be exactly the same.

Gahh!  Sorry for putting words into your mouth, Brett.

Yes -- that, too.  I prefer to measure from a point on the center of the fuselage instead forward to the TE, but it's accomplishing exactly the same end.  I can't remember this stuff to talk about, but you can bet that it gets measured about ten different times before I ever even get the glue bottles out.

I don't think this can be screwed up on an ARF Nobler, but if you check the tail against the fuse the way I do it, then be sure to check the wings, too -- Brett's method will tell you if they're correct with respect to each other: mine will tell you if each one is correct to the fuse (and then if the fuse is straight you know they're correct to each other).
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Offline Tim Wescott

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Re: Nobler preset tip weight?
« Reply #28 on: July 29, 2015, 10:43:44 PM »
Another pic

Well, to the resolution of your camera you're OK there.  Picky perfectionist PA pilots might care about getting it closer than can be seen in a picture, but unless you're very picky in flight you'd probably be complaining about it getting "a bit light" in a square corner, not going totally uncontrolled.
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The problem with electric is that once you get the smoke generator and sound system installed, the plane is too heavy.

Offline bruce finley

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Re: Nobler preset tip weight?
« Reply #29 on: July 30, 2015, 10:42:09 AM »
   Parallel looking from above. Measure from the hingeline at one tip of the stabilizer to the flap hinge line, same from the other tip. They need to be exactly the same.

   Sealed hinge lines?

    Brett

Yes sealed.  Hinge line to hinge line was spot on.

How does it balance? Tail heavy, by chance?
I had one that hinged on inside squares and triangles and a slight addition of nose weight cured it.



Balances at about 1/2" in front of spar at the fuse.  I think I will increase tail weight and then adjust handle spacing--now set at 3 3/4"

Offline EddyR

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Re: Nobler preset tip weight?
« Reply #30 on: July 30, 2015, 11:05:26 AM »
There are a lot off fixes here but what do you mean? "takes off sailing away at a 45° angle" Please explain.
Ed
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Offline bruce finley

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Re: Nobler preset tip weight?
« Reply #31 on: July 30, 2015, 11:58:17 AM »
There are a lot off fixes here but what do you mean? "takes off sailing away at a 45° angle" Please explain.
Ed

When trying a inside square, after the 2nd turn--level flight to vertical, after the next turn the plane should be horizontal and level--it never makes hori inverted.  It is not responding to "up" imput.  After the 2nd corner, it flies out of the corner at 45 degrees(it doesn't turn).  Thoughts?

Offline Steve Helmick

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Re: Nobler preset tip weight?
« Reply #32 on: July 30, 2015, 12:43:32 PM »
Looking at the pictures, I was wondering if the outboard tip of the right side elevator centerline might be a bit above the stabilizer centerline?

Improved line tension will fix a lot of things. Not meaning more, but more consistent. Is there 1 >1.5 degrees or so of out-thrust in the engine? That would help, IMO. When the lines go slack, they get tight again much quicker. You'll need to adjust LO guide forward slightly to get the plane tracking tangent again. You do have adjustable LO's, right?   ??? Steve
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Offline EddyR

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Re: Nobler preset tip weight?
« Reply #33 on: July 30, 2015, 08:15:40 PM »
 Now I understand. I think the 45 degree thig was throwing people off. You do not have enough turn. This is rather common on the ARF Nobler. I had the same problem. It is a alignment problem. The motor ,wing and stab all need to be on the same line. One of these is off on your model. I bet the stab is at a angle. You will not be able to see it you need to measure is somehow. I had to add more down to mine to correct it. The motor may not be level to the wing. Some of the ARF bodies are very bad. I had a early one and did not check it very well when I put it together.  Mine would not turn outside well until I fixed it. Also the CG needs to be correct. Yours may be nose heavy.
Ed
Locust NC 40 miles from the Huntersville field

Offline tom brightbill

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Re: Nobler preset tip weight?
« Reply #34 on: July 30, 2015, 08:42:23 PM »
Starting CG is 7 1/8" from the TE/flap hinge line.
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