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All Forums >> RC Airplanes >> Profile and Fun Flying Planes >> OMP - Ohio Model Products Support Forum >> hybrid wing problem
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hybrid wing problem - 1/3/2008 5:10:18 PM   
outssider


 

Posts: 1107
Joined: 1/18/2002
Status: offline 		seems like R2 doesn't want to touch both jigs. all the rest seem right-on or very close. I tried fitting it upside down (just to check how it touches the jigs) and it's much closer, the other R2 does the same thing. gap looks like almost 1/16 inch. looking at the rib i can see something is wrong, exactly what is going to take a much closer examination. Any suggestions....

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RE: hybrid wing problem - 1/3/2008 8:03:48 PM   
AFSalmon



Posts: 3739
Joined: 5/24/2002
From: Beavercreek, OH,
Status: offline 		Not sure as all the parts are laser cut and nothing has changed with this kit for 3+ years. The wings are built upside down so obviously the slots for the aileron mounts should face up as you have them in the picture. Slide in the wing tube socket to double check that you have these ribs properly oriented. Only the wing tube socket is asymetrical given the tapered wing however the outline of the rib is symetrical so even flipping it over would not matter. The only thing that comes to mind that would offset the rib would be the position of the main spar on the board of which the rib fits over. make sure it is pinned over the plans properly. Other than that just make sure the rib trailing edge rests on the jigs provided. If you have to move them in a little and pin in place.

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Mike (Salmon) Pilkenton, Chief Slab Designer
Ohio Model Planes, Team OMP Captain

(in reply to outssider)
       Post #: 2

RE: hybrid wing problem - 1/4/2008 1:59:21 AM   
outssider


 

Posts: 1107
Joined: 1/18/2002
Status: offline 		I figured out what is not right. As you can see from the picture below, the rib is not straight, it is actually a little concaved. all the other ribs are straight at this same area. I can add a bit of balsa to correct this on both sides on both ribs (both R2 ribs are bowed in like this. should i make the correction or is it supposed to be bowed in as the picture indicates ????

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       Post #: 3

RE: hybrid wing problem - 1/4/2008 1:16:15 PM   
AFSalmon



Posts: 3739
Joined: 5/24/2002
From: Beavercreek, OH,
Status: offline 		Outssider,
There is no way that slight amount of curve will affect the overall length of the rib or alignment on the jigs. We are talking probably hundreds of an inch relative to overall length and spar locations. My recommendation is build per the instructions and weight the wing panels (per instructions) while you sheet. Also, the instructions recommend tack gluing the ribs to the jigs as you progress.

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Mike (Salmon) Pilkenton, Chief Slab Designer
Ohio Model Planes, Team OMP Captain

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       Post #: 4

RE: hybrid wing problem - 1/7/2008 6:45:52 PM   
Crash90



Posts: 2315
Joined: 10/5/2002
From: Cressona, PA, USA
Status: offline 		Believe it or not I have the exact same problem. Rib R2 just isn't right. I tacked all of my ribs to the wing template. Exactly 90 degrees in perfect alignment with the plans. When I eyed up the TE of the Ail. I could see that something just wasn't right. R2 was sitting too low. What I did was drew a centerline on rib 2 and set it in place so that the measurements were the same from LE to TE. I then ran a straight edge from R2 to R10 at the TE. of the ailerons. I clamped all the ribs to the straight edge. As far as I can tell, as long as the end ribs are sitting parallel to the table and all the rest are straight in line with these 2 ribs then everything should be fine.. Mine was off by 5MM. I checked it with the other R2 thinking that maybe it was just a coincedence but both R2 are the exact same size. I wish I took a picture. My only hope is that when I turn the wing over to finish off the top everything is lined up.
Something tells me that the second wing will have the same troubles. If so, I will post pics early on so maaybe Mike can tell me whats going wrong.

EDIT: I will note that the wing tube phenolic was a perfect fit.

Edit 2. Outssider. My suggestion is (mike correct me if I am wrong) mark a center line on rib R2. Make sure that line is parallel to your building board. If it isn't make adjustments as necessary. I believe that is the most important part.

< Message edited by Crash90 -- 1/7/2008 6:52:00 PM >

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       Post #: 5

RE: hybrid wing problem - 1/7/2008 9:18:03 PM   
AFSalmon



Posts: 3739
Joined: 5/24/2002
From: Beavercreek, OH,
Status: offline 		Yes please post some pics on the second wing but you are right in that all the ribs must be parallel to the building board at all times. So if you draw a center line on the rib from le to te and check against the board just make sure it is parallel. That is what the jig does for you and why it is tapered from root to tip. If the wing tube does not fit into the holes then you have one of the ribs upside down. They are marked and the tube should also be parallel to the building board (i.e the top of the wing).

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Mike (Salmon) Pilkenton, Chief Slab Designer
Ohio Model Planes, Team OMP Captain

(in reply to Crash90)
       Post #: 6

RE: hybrid wing problem - 1/7/2008 9:41:52 PM   
Crash90



Posts: 2315
Joined: 10/5/2002
From: Cressona, PA, USA
Status: offline 		Mike. Here is a picture that i took last night. At this point I was in the middle of trying to diagnose the problem. This picture was taken after I saw that there was a problem. I layed a straight edge in the large groove where I will be cutting the ail. away later on. Initially, R2 was way below the rest of the ribs. I also clamped a straight edge all the way at the TE of the ail. I then raised R2 so that the cutout was in line with the rest of the ribs. As you can see, in this position, the TE of the Ail. is 5mm above the straight edge . R2 was also up off the wing root template at this point. It was very confusing.

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       Post #: 7

RE: hybrid wing problem - 1/9/2008 4:41:47 PM   
outssider


 

Posts: 1107
Joined: 1/18/2002
Status: offline 		This is what i did to fix. I added some material as can be seen on the photos. sr1 is also off (added material to it also but not in photos). r2 is now about the same size toward the trailing edge as the root and r3. I believe that the root rib should be a little larger at the trailing edge also, to completely correct this problem. This would make the root the largest (the way it should be). I am starting the second wing today with the corrected r2 and sr1. Mind you , this is not a perfect fix but much better than it was...with the fix the aileron cap fits very close. without the fix the aileron will narrow at the root and the cap would not fit right (could easily be sanded though)

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< Message edited by outssider -- 1/9/2008 4:47:39 PM >

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       Post #: 8

RE: hybrid wing problem - 1/9/2008 6:36:48 PM   
Crash90



Posts: 2315
Joined: 10/5/2002
From: Cressona, PA, USA
Status: offline 		Outssider. Just a quick question. The aileron jig. Is it placed all the way at the end of your ailerons or is it inset a bit. It seems that it would be difficult to install AS2 without gluing everything to the template.

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       Post #: 9

RE: hybrid wing problem - 1/10/2008 12:10:26 AM   
AFSalmon



Posts: 3739
Joined: 5/24/2002
From: Beavercreek, OH,
Status: offline 		This thread is starting to overlap with the other Hybrid Edge thread:

http://www.rcuniverse.com/forum/m_6682446/tm.htm

See my answers there regarding the wing jigs. But yes you can inset the jigs slightly if you want to to prevent gluing to it. That would be a builder's preference. Again it is important to keep the ribs parallel to the board as measured along the center line of the ribs. Outsider, the ribs are all laser cut and the profiles are designed for a specific reason. Modifying the ribs is not necessary. Build per the plans and follow the instructions and you will have no problems.

_____________________________

Mike (Salmon) Pilkenton, Chief Slab Designer
Ohio Model Planes, Team OMP Captain

(in reply to Crash90)
       Post #: 10

RE: hybrid wing problem - 1/10/2008 3:23:05 AM   
Crash90



Posts: 2315
Joined: 10/5/2002
From: Cressona, PA, USA
Status: offline 		Sorry Mike. I will try to contain myself to this thread. I began construction of wing 2 tonight. I ran into the same problem. I took some pics along the way so maybe we can figure this out. I don't think R2 is the problem. It is either builder error OR R 3&4. I want to stress up front that my building table is perfctly flat.
I will skip the prep work as laminating R1 and R1A doesn't have any bearing.
I will post this in multiple threads.
Let's start with pic 1
In pic 1 I have pinned the main spar to the board in perfect alignment. I have also pinned down the wing template. The templase is mounted flush with the root and in alignment with the plans. This is also sitting flush with the building board.

Pic 2 just shows the center lines on R1 and R10. I also marked the center of the other ribs in case I needed to check them.

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RE: hybrid wing problem - 1/10/2008 3:26:25 AM   
Crash90



Posts: 2315
Joined: 10/5/2002
From: Cressona, PA, USA
Status: offline 		In pic 3. I have glued all of the Ribs to the main spar. I used a square to ensure that they are 90 degrees to the board. I also lned the TE up with the plans using a square and tacked the ribs to the wing template.

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RE: hybrid wing problem - 1/10/2008 3:34:42 AM   
Crash90



Posts: 2315
Joined: 10/5/2002
From: Cressona, PA, USA
Status: offline 		At this point I installed the 2nd spar. No pics but I installed the spar then used my square to ensure they remained at 90 degrees to the building surface before gluing.

At this point, everything shoulod be fine. However once again, when I look down the TE of the Ail. It is clear that I have a problem. This pic was taken from the first wing I built and I am using it here because I had a real good picture showing the problem. I believe this is the same problem noutssider has. As you can see in the pic. R2 seems to be sitting to low. Actually, when I put the straight edge on the wing, R2 is 3/16" below the straight edge as the pic shows.

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RE: hybrid wing problem - 1/10/2008 4:13:12 AM   
Crash90



Posts: 2315
Joined: 10/5/2002
From: Cressona, PA, USA
Status: offline 		So by now im thinking to myself **** is going on. I then decided to take center line measurements of ALL the ribs. Here is my findings. I am measuring in MM for accuracy.

R1 - LE 53mm TE 54MM
R2 LE 50MM TE 49MM
R3 LE 46MM TE 49MM
R4 LE 43MM TE 46.5 MM
R5 LE 40MM TE 42.5 MM
R6 LE 38MM TE 40MM
R7 LE 36 TE 36.5MM
R8 LE 32.5MM TE 34.5M
R9 LE 30.5MM TE 32MM
R10 LE28.5MM TE 30MM

I realize that we need to allow for a little warping in the balsa and for the most part, all of the ribs are within 2MM front to back but you can see that something is wacky in R3,4, and 5. Not sure how to handle this. The only way I can get all of the center lines to be the same is if I begin reshaping ribs or cutting notches in the template. None of which are desireable.
Sooooo. Any idea on what may be going on?

(in reply to Crash90)