RCU Forums

RCU Forums (https://www.rcuniverse.com/forum/)
-   Kit Building (https://www.rcuniverse.com/forum/kit-building-121/)
-   -   AMR Trainer 26 - Problems fitting the wing - advice sought (https://www.rcuniverse.com/forum/kit-building-121/11606919-amr-trainer-26-problems-fitting-wing-advice-sought.html)

grosbeak 11-20-2014 01:58 AM

AMR Trainer 26 - Problems fitting the wing - advice sought
 
You may have come across my AMR Trainer 26 build thread. I have run into a problem and am starting a new thread in the hopes of reaching more people.


During the build up of the wing I test fit it to the fuselage a few times; in this instance I pinned the front of the wing using a couple of transfer punches. All was good.


https://farm6.staticflickr.com/5610/...fd53c437_z.jpg


It's when I got to the step in the manual where the wing is finally fit to the fuselage that I started running into problems.


First of all, the wing pin holes didn't line up like they had before. The front of the wing was properly centred with the port dowel in place...


https://farm8.staticflickr.com/7536/...fae154d1_z.jpg


... but the starboard hole did not line up.


https://farm6.staticflickr.com/5609/...73e23c7a_z.jpg


I wracked my brain for a reason but couldn't figure out why. This is still nagging at me. Since the pin holes are already part of the wing (not just the balsa leading edge but the underlying structure as well) I figure I had no choice but to relocate the hole, which I did (I don't know how the new hole ended up lower than the original but it doesn't seem to affect fit and can be addressed later if need be).


https://farm6.staticflickr.com/5605/...c20ee2a3_z.jpg


With this done the fit at the front appeared to be fine.


https://farm6.staticflickr.com/5610/...809c03aa_z.jpg


At the back I centred the wing using the method described in the manual - measure from each wingtip to the tail, adjusting the angle of the wing until the measurements are equal. I did that - both wingtips are 1331 mm from the tail. However, now the wing alignment at the rear is off - the centre line of the wing is a few mm to starboard of the fuselage centre line.


https://farm9.staticflickr.com/8630/...20172951_z.jpg


This is where I stopped. Things are not right at this point and I have not yet come up with a way to fix them. Your advice would be appreciated.

TomCrump 11-20-2014 02:46 AM

Is the wing centered in the fuselage, measuring from the wingtip to the fuse, at the wing root ?

sensei 11-20-2014 04:01 AM

Are both wings exact in length at the leading and trailing edges?

Bob

grosbeak 11-20-2014 06:27 AM


Originally Posted by TomCrump (Post 11921616)
Is the wing centered in the fuselage, measuring from the wingtip to the fuse, at the wing root ?

Tom, I will check. I will take three measurements for each wing - leading edge, main spar, trailing edge.


Originally Posted by sensei (Post 11921633)
Are both wings exact in length at the leading and trailing edges?

Bob

Bob, could you please give me a little more detail? Are you asking if the wings are exactly the same length?

sensei 11-20-2014 09:47 AM

Yes but measured for length at both the leading edges and both the trailing edges.

Bob

grosbeak 11-20-2014 10:31 AM


Originally Posted by sensei (Post 11921804)
Yes but measured for length at both the leading edges and both the trailing edges.

Bob

Ah, yes. I will check that.

box car 11-20-2014 03:25 PM

I bet you did not use a square to build your wings

jeffo 11-20-2014 03:27 PM

Is your fuse straight?Construct a straight line from the leading edge center line to the center line at the end of fuse.See where the trailing edge center line ends up.Personally,your worried about nothing.As long as the wing is straight,and set at the proper incidence in the saddle.If the rotation is with in a few mm,you'll never notice it.jeffo

grosbeak 11-21-2014 05:50 AM


Originally Posted by box car (Post 11922001)
I bet you did not use a square to build your wings

Care to make it interesting?

grosbeak 11-21-2014 05:50 AM

I have heard back from Dany at AMR and he had some very nice things to say about my build. He also said, "... you could have the wing off/crooked by 1" at the saddle section and you would not even see a difference when flying. Make the wing fit so that it looks nice for you."

I checked the fuse and I'm satisfied it's straight and true. I squared the wing to the fuse using wingtip-to-tail measurements and marked the anchor plate for the wing bolts. There's plenty of room for the starboard wing bolt (and T nut if I choose to use one).

https://farm8.staticflickr.com/7503/...037d72b3_z.jpg

Thanks for your contributions, everyone. I'll be back on the build shortly!


All times are GMT -8. The time now is 03:59 AM.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.