1200mm Dragonfly

I've been using my 3D printer recently to make various parts as I think I've posted before but now I've started to actually build my 1200mm span Dragonfly based on the Model Shop one.
outerzone.co.uk/plan_details.asp?ID=15454
I've scaled up the OZ drawing to give the 1200mm span & am doing the fuselage sides in the conventional manner in balsa on the plan but have printed out some spacers to make it more likely the 3D printed formers will fit.
I'll be sheeting the nose in 1.6mm balsa but intend to cover the rest with laminating film.
 

Has anybody tried this?



 

It would not stand a chance with my clumsy mitts 

I've got the front end built up ready to sheet but I'll wait until I've got the wings & tail done so I can work out the best place for the battery to go for balance although the middle section of the top of the nose lifts off so there's plenty of access.
After spending a whole day trying to do the windscreen I discovered the Lofting utility which apart from sometimes giving weird shapes generated a thin (2mm) shape which fits a treat. It needed alot of support on the printer which was fiddly to clean off.
The stringers on the nose give it alot of strength but I still intend to sheet it.
 
 

I couldn't resist sneaking a joke in!

I've got the Vee-Tails built up.

I've got the Vee-Tails built up.
The front former/dihedral brace isn't sitting level.

This is the calculations to size the V-tail from the conventional tail & fin.
theampeer.org/ampeer/ampapr23/v-tail-design.pdf
 
 

 

I have not waded through ampeer's maths but the one thing I can say is that a V tail with the same total side area as a vertical fin does not behave the same. Even a V tail with each side of the V tail equal to the fin still behaves differently.
In my own design example despite its quite steeply inclined V tail it did not work well until I added quite substantial vertical fin "plates" at each end.
 
Only when they were fitted did the nasty nose drop "yaw" with any sort of bank become readily manageable.

Looks like a nice bit of hybrid design (balsa & printed braces) on the tail. 

How did you guys learn to build planes like this. I always cut myself every time I use a junior hacksaw or a stanley knife. I am good on a sewing machine though but even then sometimes I get an injury.

Jannine
You have to excuse us as most on this forum have been doing model planes for a very long time and in many cases not only planes! Some of us have even done some full size as well.
So the "how" we learned is just by "being around" with quite a bit of "trial and error" along the way. Obviously following a web site like this and asking questions helps too. A benefit we did not have pre internet!

Don't get me started on sewing machines!
I bought a vintage "folding" 15K Singer treadle machine at a car boot. Restored it to working condition. 35 years on it now sits, still in full working order, as our hall table. It also amazed quite a few kids (mostly lads!) at my son's junior school "open day" by allowing them to have a go at sewing up a little pouch.
It did not end there as I now have a collection of 13 vintage sewing machines!
One of them is even my mother's hand crank Singer that was a wedding gift. An important item for a young couple starting out in 1931. How times have changed.
 

I can't remember exactly when I started building balsa models (my short-term memory loss goes back a long way) but it must be about 66 years ago.
Here's me at my 78th birthday party yesterday. My wife has a photo from 3 years ago & she says I'm wearing the same clothes. Some things don't change!