Building the fowler flaps and fibre-glassing
I have bumped into another road-block as i got some feedback from other hobbyist in rc-groups pointing out that the outboard Fowler Flap won't work according to my design if it was directly attached to the fairings as hinges. The A350 Fowler flap system is unique compared to other types of Flaps such as the A330, A320, B777s as it retracts down and parallel to the fuselage compared to other flap systems which retracts down and perpendicular to the trailing edge. (See picture before for visual reference).
Also view post #69 to post #80 for the in-depth discussion on the A350 Fowler flap: http://www.rcgroups.com/forums/showt...2263665&page=5
Had been a long time since I have done something productive to my A350. I have been using the past few days to do primary 2 things:
1) Figuring out a good solution for the Fowler Flap system - I have decided to use cwrr5 solution to solving the Fairings and Fowler Flap conflict. Right now the flaps and fairings both move independently of each other without any foreseeable issues.
2) Been reading up and practicing on how to fiber-glass with different type of mediums as i have never fibre-glassed anything before in my rcplane scratch-building history. One of the useful links i have searched:
and also back in 2005 in Daddy-hobby forums:
I have tested 4 different type of mediums to bond the fibre-cloth to the surface and made the following observations:
1)Marine Poly Urethane - Easy application,Dries hard, bonds cloth to the surface but not as strong as epoxy, Glossiest of them all.
2)Epoxy - Gets very messy at times, Stiff and solid once cured , bonds cloth to surface extremely well , but heaviest of them all.
3)White Glue - Easy application, not water-proof ,Dries milky color,the weakest bond of cloth to surface of them all.
4)Water-Based Poly Urethane - Easy application , Dries hard and slightly glossy, might need to apply 3-4 layers as the viscosity of the urethane is extremely thin which i foresee the longest to work with compared to the rest.
I eventually chose Epoxy to be used on parts that needed strength (Flaps and other moving surfaces) and Marine Poly Urethane to be used on large area surface skin (General area of wings and fuselage).
As i'm new to fibre-glassing, i recommend all of you not to follow my techniques in this thread as i'm honestly a newbie in this field and probably already made some mistakes. I just kept a few general rules at the back of my head while working with fibre-glass.
1) Always a glove to prevent rashes, Always wear a mask for health purposes.
2) use a squeegee to remove "shiny" blobs before it cures on the surface as those are unwanted dead weight.
3) Always start from the center of the work piece and work outwards to prevent cloth from moving in one direction.
4) Keep surface well sanded and clean at all cost before application of the 1st or 2nd layer and so on.
Below shows the step-by-step instructions on how i work on the fibre-glass and Fowler-flaps.
And here is the video on the Fowler flap system.
I have bumped into another road-block as i got some feedback from other hobbyist in rc-groups pointing out that the outboard Fowler Flap won't work according to my design if it was directly attached to the fairings as hinges. The A350 Fowler flap system is unique compared to other types of Flaps such as the A330, A320, B777s as it retracts down and parallel to the fuselage compared to other flap systems which retracts down and perpendicular to the trailing edge. (See picture before for visual reference).
Also view post #69 to post #80 for the in-depth discussion on the A350 Fowler flap: http://www.rcgroups.com/forums/showt...2263665&page=5
Had been a long time since I have done something productive to my A350. I have been using the past few days to do primary 2 things:
1) Figuring out a good solution for the Fowler Flap system - I have decided to use cwrr5 solution to solving the Fairings and Fowler Flap conflict. Right now the flaps and fairings both move independently of each other without any foreseeable issues.
2) Been reading up and practicing on how to fiber-glass with different type of mediums as i have never fibre-glassed anything before in my rcplane scratch-building history. One of the useful links i have searched:
and also back in 2005 in Daddy-hobby forums:
I have tested 4 different type of mediums to bond the fibre-cloth to the surface and made the following observations:
1)Marine Poly Urethane - Easy application,Dries hard, bonds cloth to the surface but not as strong as epoxy, Glossiest of them all.
2)Epoxy - Gets very messy at times, Stiff and solid once cured , bonds cloth to surface extremely well , but heaviest of them all.
3)White Glue - Easy application, not water-proof ,Dries milky color,the weakest bond of cloth to surface of them all.
4)Water-Based Poly Urethane - Easy application , Dries hard and slightly glossy, might need to apply 3-4 layers as the viscosity of the urethane is extremely thin which i foresee the longest to work with compared to the rest.
I eventually chose Epoxy to be used on parts that needed strength (Flaps and other moving surfaces) and Marine Poly Urethane to be used on large area surface skin (General area of wings and fuselage).
As i'm new to fibre-glassing, i recommend all of you not to follow my techniques in this thread as i'm honestly a newbie in this field and probably already made some mistakes. I just kept a few general rules at the back of my head while working with fibre-glass.
1) Always a glove to prevent rashes, Always wear a mask for health purposes.
2) use a squeegee to remove "shiny" blobs before it cures on the surface as those are unwanted dead weight.
3) Always start from the center of the work piece and work outwards to prevent cloth from moving in one direction.
4) Keep surface well sanded and clean at all cost before application of the 1st or 2nd layer and so on.
Below shows the step-by-step instructions on how i work on the fibre-glass and Fowler-flaps.
And here is the video on the Fowler flap system.
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