Mini Sophisticated Lady

[joe yap]

Not exactly a new project, but rather something I'm picking up again which I left off earlier to design and built the Corina.

Folks who loved the Carl Goldberg Gentle Lady will know the Sophisticated Lady, an offspring of the ever popular previous kit, which thousands have been sold, built and flown around the world.

The earlier 'Die-crushed' kits were later replaced by laser-cut kits, and recently the manufacturer produces the ARF version of it. I bought the laser-cut version from NTC but feel like changing the airfoil to something more modern and proven. I wouldn't want to bash the kit yet and at the point when I thinking of building, I only have a mini Hi-start. And thus, I re-design it at 1.5 metre to accomodate my mini Hi-start and at the same time, change the airfoil to Selig 4083, which I have many very succesful designs with it.

I don't want to give a blow by blow report on the build since many things are pretty standard. Weeks before I started on the Corina project, I already got the wings built. I want the wings to be strong and stiff enough for the Hi-start and so I have the full D-box LE section throughout the full wingspan. Spars are CF strips and balsa shear webs are glued between them after sheeting.

[joe yap]

The tail end is in 'T' configuration and so the elevator control cable linkage needs to be built within the vertical fin. The LE section of the fin is made up of 3 laminations of thin balsa sheets, which the nyrod sheath is installed within. The rest of the vertical surfaces are typical balsa built-up trusses construction.

I spent about 1/2 hour for these, but yet to be sanded down to correct cross-sectional profiles.

[Ghostfit]

Woah ! ...Another lady ? ...Joe, ya' da' man !

[joe yap]

The fuselage is partially constructed. It is almost exactly scaled down from the original kit, except that I use 1/64" plywood doublers on the fuselage side panels. So far, all alignments are straight and true.

[Vortices]

Great project again. Just thought I will share something with you. When I built my Lear 45, It has a T tail as well. It was fluttering a bit airbourne. It needed a D box Leading or a centre spare box to stop the fluttering. Just thought I will share this with you since you a reducing the plan of the original.

I though of building something similar. Anyway after the high start yesterday, I have decided to install a hook on my DG for bungee launch, just for the fun of it.

Cheers

[joe yap]

Great project again. Just thought I will share something with you. When I built my Lear 45, It has a T tail as well. It was fluttering a bit airbourne. It needed a D box Leading or a centre spare box to stop the fluttering. Just thought I will share this with you since you a reducing the plan of the original.

I though of building something similar. Anyway after the high start yesterday, I have decided to install a hook on my DG for bungee launch, just for the fun of it.

Cheers

Thanks, Kevin.

Most lightweight gliders will encouter tail flutter when they are flown too fast. The idea is to rig the towhook and trim the elevator to achieve the steepest climb without popping off, with the Hi-start, so that most of the energy of the bungee will be used to climb the plane and not to accelerate the forward speed.

This morning, Sunstorm's Fling HLG also encounter tail flutter ( conventional cricifix tail), initially when the elevator trim was set too much 'down'. The bungee accelerates the plane speed more than what it needs, the climb angle was much shallower than normal and needless to say, the climb rate wasn't really impressive as well. He gets the tail flutter everytime he launches the Fling with this setting until he later put some uptrim to the elavator, which immediately sees the differences. The tail doesn't flutter anymore and the plane can really reach impressive launch height. Needless to say, the rest of the unpowered flight does not see any flutter on the tail.

[Vortices]

Great!...saw your glider flying passing TPE this morning. Are you free during weekdays for the next one week. I am off. Can go fly.

[joe yap]

I'm planning to fly on either this coming Wednesday or Thursday. Not adviseable to fly too high though.

[joe yap]

Most of the fuselage is done. The nose reminds me of the Jart.

[joe yap]

I carved the canopy plug from laminations of balsa sheet. Once done, I covered it with Oracover and waxed the surface. Then I laid several glasscloth over it with epoxy resin to make a female mould.

[joe yap]

The plug is easily removed. Candle wax do good here. It trimmed the female mould and waxed the inner surface with candle wax again and sprayed Tamiya Gun metal paint over it, before laying a few layers of lightweight and medium grade fibreglass cloths with epoxy.

I hope it turns out well, as I never try pre-painting the mould before.

[joe yap]

To expedite curing, I placed the canopy mould over my Lead Acid battery charger. So much about recycled energy.

[Raven]

lol... you put the glass cloth in good use. Great to see you started on female moulding. Anytime you need more glass... just let me know. I remember I had a spare tub of mould release... will try to dig it up for you if I can find it.

Guess the rain today is causing our fingers to itch

[joe yap]

lol... you put the glass cloth in good use. Great to see you started on female moulding. Anytime you need more glass... just let me know. I remember I had a spare tub of mould release... will try to dig it up for you if I can find it.

Guess the rain today is causing our fingers to itch

Thanks Raven. The cloth comes in handy when making a female mould. Anyway, I found that candle wax, if used properly, can do the job really well.

First, I rub the mating surface will candle wax. Next I heat it up with a hairdryer and when it starts to melt, I use a piece of tissue paper or cloth to spread it evenly. I repeat the same for another 2-3 rounds and make sure I really got enough wax on it. Lastly, I use the tissue paper or cloth and polish the surface until the wax really shines.

When the resin has cured, I just need to pull the female mould a little and the moulded part will nicely seperate from the female mould.

[joe yap]

While waiting for the resin to cure, I used the time to build the horizontal stabilizer. The tailplane is built entirely out of 1/8" balsa sticks, plus a little 1/8" balsa sheet.

Anyway, here's the result of the moulding. the Tamiya acrylic paint doesn't stick to the glasscloth and resin well, but it doesn't impede the seperation or marr the moulding surfaces either. The female mould popped off the female mould very easily, with just a bit of pulling. Most of the paint still stay on the female mould.

After popping, I cleaned away the paint with paint thinner and trimmed the moulding to shape, before spraying the Tamiya Gun metal paint again. The result is very satisfactory.