SSE Incidence issue during build
#1
Senior Member
Thread Starter
SSE Incidence issue during build
I'm about the mount the stab to the fuse per the old instructions. With the wing mounted I aligned the stab trailing edge with the wing trailing edges (again per instructions). Before I epoxy the stab to the fuse I tossed an incidence meter on the wing and stab. The wing relative measurement is 4 degrees positive and the stab is 1 degree positive. They should be the same. To achieve 4 degrees positive on the stab it will be necessary to raise the forward edge of the stab 7 mm (over 1/2"). Of course the rear can be dropped the same.
OK peanut gallery, how would you approach achieving the same incidence on the wing and stab?
Thanks for you learned feedback.
OK peanut gallery, how would you approach achieving the same incidence on the wing and stab?
Thanks for you learned feedback.
#2
Senior Member
Thread Starter
RE: SSE Incidence issue during build
OK - some days ya just shouldn't get out of bed!
SSE wings can be mounted upside down. With the wings mounted with the servo bays facing DOWN the incidence angle of the wings is now 1 degree positive.
Never mind ...
[:@][:@][:@][:@][:@]
SSE wings can be mounted upside down. With the wings mounted with the servo bays facing DOWN the incidence angle of the wings is now 1 degree positive.
Never mind ...
[:@][:@][:@][:@][:@]
#3
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RE: SSE Incidence issue during build
I don't know for sure but I thought the horizontal stabilizer centerline should be parallel to the engine crankshaft centerline.
Bill
Bill
#4
Senior Member
Thread Starter
RE: SSE Incidence issue during build
And it is - the thrust line is the datum line. The engine crankshaft, wing and stab are all at 0 degrees incidence. I was just about to go ballistic when I thought I assembled the plane so that the wing or stab was waayyyy out of whack.
#5
RE: SSE Incidence issue during build
If you ever run into a problem like that, it is an easy fix.
The stab incidence is very hard to change. Usually, you'll have a flat plate that is built into the fuse and that's where the stab will mount. Not easy to change without major surgery to the fuse.
But, the alignment/incidence of the wing is easy to change. Simply hog out the holes in the side of the fuse so that the alignment pins from the wing can move up and down. Cut some 1" round plugs of lite ply and drill a hole in the center to fit snugly over the wing alignment pins. Now block up the tail and get the fuse level so that stab is sitting at 0 degrees. Slap the incidence meter on the wing and adjust it up or down until it's set where you want. Hold it in place and use some thick CA to secure your new lite ply donuts to the side of the fuse. Maybe wax the wing alignment pins or put some KY jelly on them to prevent gluing them inside the ply donuts.
Easy fix.
The stab incidence is very hard to change. Usually, you'll have a flat plate that is built into the fuse and that's where the stab will mount. Not easy to change without major surgery to the fuse.
But, the alignment/incidence of the wing is easy to change. Simply hog out the holes in the side of the fuse so that the alignment pins from the wing can move up and down. Cut some 1" round plugs of lite ply and drill a hole in the center to fit snugly over the wing alignment pins. Now block up the tail and get the fuse level so that stab is sitting at 0 degrees. Slap the incidence meter on the wing and adjust it up or down until it's set where you want. Hold it in place and use some thick CA to secure your new lite ply donuts to the side of the fuse. Maybe wax the wing alignment pins or put some KY jelly on them to prevent gluing them inside the ply donuts.
Easy fix.
#6
Senior Member
Thread Starter
RE: SSE Incidence issue during build
Em, RC - that sounds very familiar to a post when I was looking for a fix to a "up elevator" trim issue with my previous SSE (may it RIP).
RC - it appears that when the j-hooks have tension placed on 'em the root of the wing behind the tube tends to pull away from the fuse leaving a bit of a gap. Have you ever solved this? Or does it even need solving?
Did you make it out to the field this morning?
RC - it appears that when the j-hooks have tension placed on 'em the root of the wing behind the tube tends to pull away from the fuse leaving a bit of a gap. Have you ever solved this? Or does it even need solving?
Did you make it out to the field this morning?
#7
RE: SSE Incidence issue during build
ORIGINAL: SeamusG
Em, RC - that sounds very familiar to a post when I was looking for a fix to a "up elevator" trim issue with my previous SSE (may it RIP).
RC - it appears that when the j-hooks have tension placed on 'em the root of the wing behind the tube tends to pull away from the fuse leaving a bit of a gap. Have you ever solved this? Or does it even need solving?
Did you make it out to the field this morning?
Em, RC - that sounds very familiar to a post when I was looking for a fix to a "up elevator" trim issue with my previous SSE (may it RIP).
RC - it appears that when the j-hooks have tension placed on 'em the root of the wing behind the tube tends to pull away from the fuse leaving a bit of a gap. Have you ever solved this? Or does it even need solving?
Did you make it out to the field this morning?
Ask Pete Weller about the SSE.
#8
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RE: SSE Incidence issue during build
I just finished my first wing on the SSE build and actually wrote "right" on the face of the root rib for this very reason. I know when it is all finished it will be obvious but I figured until then, better to label.
#9
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Thread Starter
RE: SSE Incidence issue during build
There is no issue with my wings - I didn't pay attention to the servo trays and just mounted the uncovered wings upside down. Just a brain fart.