Hai-Lee
Old and Bold RC PILOT
Over the years I have struggled at times with getting a wing folded and warp free. It took me a fair while but I managed to develop techniques, (all FT inspired), to get my wings to look identical to the FT videos.
It could take quite a bit of time and effort. One problem I often had was the tearing of the LE where the fold started leaving the tip piece starting to straighten. This tear does often cause a premature wing failure and is a weak spot in the event of a crash.
Again I developed methods to make the wing LE more sound but then they were not always effective.
Well today I traced the problem down to the grade of the foam and the fact that often the foam density is not as uniform as it would appear. The way I found out was because I was forced to select a different supplier due to stocking issues and the new foam is much firmer and the paper much lighter and weaker. Well I bought the material to fill an order and the first effort to make a wing had been a disaster even though I used the same plans as I had used almost 100 times before.
The order cannot wait so I investigated and managed to find a way of using the stiffer foam and get the wing folded in a way that leaves NO wing weakness and does not leave the wing with the serious internal stresses that some of my builds had suffered from in the past. The results of those stresses included delamination and even warping with age.
What did I do different? It is so simple that I am somewhat amazed the FT doesn't already use it because it is so CNC friendly and gives almost perfect results without trying. It has reduced my labour input to the wing assembly by over 50%. The only real change required to the wing FB piece is to increase the depth/cord of the wing underside panel by the thickness of the FB material.
At the wing fold line I just cut a channel which is the same width as the thickness of the FB, into the wing bottom panel and removed all of the foam in the channel. Then I marked a line or cut the paper only on a line which was 10mm from the edge of the newly cut channel, (on the wind underside panel). From the 100 line back to the edge of the newly cut channel I bevelled the foam.
To fold the wing I just apply glue and wrap the paper, of the channel, around the LE. Then I apply glue to the bevelled foam, the spar/s, and the wing TE and then fold the bottom panel to its final position. PLEASE NOTE: The wing profile cuts and curve are already formed and the spars fitted in the required position before the wing is folded into its final form.
A large amount of the previous internal pressures are gone and I actually was able to manually mark, cut, and fold a wing in less than an hour and I use a liquid glue for my assembly.
Just what is now to become my wing fold of preference!
have fun!
It could take quite a bit of time and effort. One problem I often had was the tearing of the LE where the fold started leaving the tip piece starting to straighten. This tear does often cause a premature wing failure and is a weak spot in the event of a crash.
Again I developed methods to make the wing LE more sound but then they were not always effective.
Well today I traced the problem down to the grade of the foam and the fact that often the foam density is not as uniform as it would appear. The way I found out was because I was forced to select a different supplier due to stocking issues and the new foam is much firmer and the paper much lighter and weaker. Well I bought the material to fill an order and the first effort to make a wing had been a disaster even though I used the same plans as I had used almost 100 times before.
The order cannot wait so I investigated and managed to find a way of using the stiffer foam and get the wing folded in a way that leaves NO wing weakness and does not leave the wing with the serious internal stresses that some of my builds had suffered from in the past. The results of those stresses included delamination and even warping with age.
What did I do different? It is so simple that I am somewhat amazed the FT doesn't already use it because it is so CNC friendly and gives almost perfect results without trying. It has reduced my labour input to the wing assembly by over 50%. The only real change required to the wing FB piece is to increase the depth/cord of the wing underside panel by the thickness of the FB material.
At the wing fold line I just cut a channel which is the same width as the thickness of the FB, into the wing bottom panel and removed all of the foam in the channel. Then I marked a line or cut the paper only on a line which was 10mm from the edge of the newly cut channel, (on the wind underside panel). From the 100 line back to the edge of the newly cut channel I bevelled the foam.
To fold the wing I just apply glue and wrap the paper, of the channel, around the LE. Then I apply glue to the bevelled foam, the spar/s, and the wing TE and then fold the bottom panel to its final position. PLEASE NOTE: The wing profile cuts and curve are already formed and the spars fitted in the required position before the wing is folded into its final form.
A large amount of the previous internal pressures are gone and I actually was able to manually mark, cut, and fold a wing in less than an hour and I use a liquid glue for my assembly.
Just what is now to become my wing fold of preference!
have fun!
Last edited: