RE: gp lancair wings snapping
 

TIANCI:

Make sure that the aileron servos are securely mounted. The recommended method is not very reliable and if one of the servos comes loose the aileron will flutter, usually tearing a wing off. To be safe, build a 1/4 square balsa box around the servos to hold them in place when they break loose from the top sheeting.

Jim

RE: gp lancair wings snapping
 

yes you are correct I was thinking of the dreamliner! the a380 is composite in the rudder and tail cone. Its going to be a real sight to see one in the air! what is the hold up on the 787 test flights? have they found problems in the design. Thbe prototype had beautiful shaped wings the production models will not have that feature. Still a beautiful plane.


see i can admit when im wrong;)

RE: gp lancair wings snapping
 

Hi,
Here are the modificaitions I did to combat any potential wing failures. Its a thin wing and and additional strength is advantageous.
I didn't like the light ply joiner that came with the kit. It wasn't thick enough and wobbled front-to-back and up-and-down in the joiner socket. I believe this has a lot to do with the wing failures...no solid mechanical bond. I decided to fabricate my own out of aircraft ply. I sandwiched three layers of carbon fiber, the middle layer at a bias to the outer layers, between aircraft ply with 30 minute epoxy and clamped overnight. I traced the outline of the original joiner and cut out the new joiner. I sanded it to snug fit the joiner box with just enough room for epoxy.
Also, if the covering is not removed from the wing roots, they won't make solid contact with each other during epoxying. There isn't much surface area to begin with since the ribs have lightening holes. A razor plane made quick work of this. I estimate 1/4 of the wing root surface has covering on it. I used rubber bands around the leading edge dowels and around the flap openings at the trailing edge to clamp the wing together during epoxying.
The split landing gear also contributes to wing failures. A hard landing directs all force to the wing root. I made some straps out of aluminum to connect the two gear sections together. Now all I have to do is fly it. Hope this information keeps other Lancairs from suffering wing failures.
Thanks
CAsniffer

RE: gp lancair wings snapping
 

cas i did the same mod on the joiner for my Midwest 300 S but went the other way i got rid of the aircraft ply and went with light ply with carbon fibre between it held up for about 6 years till the guy i sold had his radio lock up and the plane went in . the way you did the joiner is the way to do it good idea on your part

as far as the landing gear i think a few other guys said the way the gear was designed it was trying to pry the wing apart . looking at the picture there absolutely right Mickey Mouse desigen

JIM

RE: gp lancair wings snapping
 

My friend's plane has been glassed but I think I shall get him to put on the UC plate. Me getting one? I had one and I sold it, its pretty as heck but I love to just fly and throw my planes around, I have no finesse! Hahahahaa ...

RE: gp lancair wings snapping
 

Wow SDCrashmaster.

Nice Video. Wish my L. EP looked as good. Though I fly mine occasionally I’m still fiddling with adding the cool features that you have put in yours, so mine is on the ground more so than in the air.

Since 2003 threads have been reporting the same topic in spite of varying expertise, build concerns, crash pics examinations etc. And yet the same problems seem to plague this model while others don’t seem to have any issues.

Since we are still freely giving our opinions here;
I looked back at my comments, and while I sounded like a bit of an idiot, a little over the top with some of my comments, I found then as I occasionally still find now, there is a manufacturing flaw that in my opinion needs a different design to remedy.

Every time I see one of these either in the box or built I look at the webbing Box spar assembly. Some look fine and nicely glued where as others don’t. In fact some had glue in the right places and some were just lacking in different places most of which were very hard to see and even harder to fix. There is no continuous member except the LE and TE to deal with wing flex. If the entire wing is glued properly the glued webbed boxes should take up the flex. Do a poor glue job and you have several different points of failure that show up in different ways.

You never know who builds your ARF but I’m kinda thinking some are not putting these together within the tolerances needed for this design. That shouldn’t be my problem since ARF’s are not supposed to be a spin the wheel and take your chances; though we all know this is always a possibility.
This intern strains GP’s reputation and their responses. I would have thought GP’s Q&A would have picked up on this since this design (thin long wing) puts additional demands on the materials used. Even light gliders use long carbon fiber spar and their wing loads are so much lower.

I haven’t found a crash attributed to flutter and most know about this before hand. The split landing gear is easily solved, the Spar and how it is installed, how the glue sets, reinforcing the sheeted wing to act as an exoskeleton taking much of the overall strain…. All of these become factors having to compensate for how the wing structure was assembled, with flaws hidden away in a number of places.

I wish GP would redesign cause it really is a nice looking plane.

RE: gp lancair wings snapping
 

SD...I was trying to use your pics as an example of
gorgeous Lances but, I didn't know how to forward the
pics to this thread so I'm glad you chimed in![8D]

That looks sooo good in Columia 300 garb. That hatch
has got to be the #1 most useful mod I have ever seen.
Would definitely help with the battery placement during balancing
as well as better access. Great job on servo placement as they all seem to come
out a little nose heavy. My battery was actually wrapped in foam and then
zip tied to the rear bulkhead. I still wonder how the original builder managed this
but, couldn't figure out how to join a wing!:eek:


PS...I really enjoyed the video. Had a hard time telling
when they transitioned from the full scale to the model!...[8D]

RE: gp lancair wings snapping
 

Nice joiner Casniffer.[8D]

I'm surprised to see lightening holes in the joining ribs![X(]

Did anyone plug up the voids to get more adhesion area ?.

RE: gp lancair wings snapping
 

Hi Paul
Your posting on the Lancair was rather a long time ago, but I was completely enthralled with the job you did on the second aircraft.
I live in U.K. and am currently piecing together the Lancair ARTF kit. I am finding that the position of the battery/rx tray will be difficult to get to on a flying day basis and I was intrigued to see that you had made the baggage door openable.
Any tips that you may have, on how you so neatly cut this door out of the fuselage, put a trim round the inside and installed some form of hinge and locking mechanism, would be greatly appreciated.
May I also know what engine you used and from the photographs, it would seem that you reworked the nose oleo, so any tips there would be equally welcome.
With kind regards and thanks.
John Sangster - Berkshire UK.

RE: gp lancair wings snapping
 

Ok Guys - A little help please. I am changing out the last 72mHz receiver to 2.4 (JR) and it's in my Lancair. Have you guys used the standard 2.4 Rx's with the short antenna's or have you gone ahead and bought the special Rx's for composite fuselages that still stick out through the fuselage? If you have used the standard 2.4 Rx with the satellite Rx did you do anything special as far as where you mounted it so it got the optimum signal?

Winter is here I'm afraid so it's back into the shop for most weekends fixing the few odd hangar rashes some of the planes developed during the summer.

Thanks

RE: gp lancair wings snapping
 

I've been away from the hobby for 14 years, and all these ARF's have come about in the interim.

But when we were building airplanes, YOU WOULDN'T think of building a wing without glassing the center section.

I'm really surprised it doesn't happen more often.

RE: gp lancair wings snapping
 

Whoa, I'm sorry I never saw this post. Here's how I did the baggage door. Most importantly, I had a wrecked fuse from our first Lancair:D that was undamaged in that area.
So I was able to cut out the door from that fuse, and not worry about damaging the area around it. Then I was able to hog out the door area on the new fuse, and wasn't worried about
saving that door. Then I took the "good" door and covered it with duct tape on the inside and around all the edges to the outside, and taped it in place from the outside of the fuse.
Then I glassed over the inside of the fuse in that area with several layers of fine (don't know the exact oz. weight anymore) fiberglass. After that set, I removed the door (resin doesn't stick to duct tape)
which revealed a full glassed over recessed opening. Then I used a sanding drum on the dremmel to hog out the opening and shape the door stop. This could all be done without a spare fuse by either cutting the door out very carefully, or making a mold of the hatch area of the fuse, then laying up a new hatch in that mold. The hinges are offset gear door hinges (either Dubro or Rocket City brand I believe), and the latch is a BVM Hatch latch (www.bvmjets.com). If you cut out the hatch and have funky gaps or insightly irregularities in the corners, etc., just cover the door with duct tape and tape it in place completely covering all the cracks from the outside of the fuse. Then fill the gap from the inside with an epoxy/micro balloons or baking soda mixture. When you remove everything, the opening will be the exact shape of the hatch door with a gap the thickness of the duct tape you applied to the door prior to taping it in place from the outside.

Hope that helps, if not too late:D
Paul