TOPIC: New Models for 2020

One day I'll get mine back in the air!

Roger adds:

Promises, promises!

But, with the Tender L-2L, we do seem now to have the 'right' motor for this large model, so there are no excuses!

Hi Guys,

some progress with the Grumman F-11 Tiger:



The flying surfaces were built following my usual practice: composite leading edge (hard balsa outermost) with webbed main spar and an extra spar at the front. The diagonal ribs add stiffness and 1/16" washout is built in. The tail feathers are essentially 3/32" sanded to a symmetrical aerofoil.
It's nice when things begin to 'take shape':



The interesting shape of the tail end is mimicked with a 1/64" ply former.

Next: doping the structure and covering with pre-printed tissue.

Does this photo deceive or is this actually similar to the Talon with small wing area compared to fus size? If so it could be another great performer. Looking good.

Looks beautifully built!

Thank you for your comments - very encouraging, which is what I need as I've hit a snag. I was planning to cover the Tiger with pre-printed tissue (like I did with the Cutlass), however, the tissue I now have is very different from the tissue I used then, and takes the ink much less well, and you end up with a pale imitation of what I wanted.

I've looked for a different dense but lightweight tissue 'on line' and we will have to see what arrives through the post. If it is equally useless for my purposes (it's a great tissue for covering, but there is no depth of colour) it will have to be 'Plan B', i.e. spraying and decals. Ugh!

As to the Tiger being similar to the wonderful T-38 Talon, I'm afraid the semi-profile version is, in contrast to the Talon, one of my trickier models and (confession time) I don't think I've yet had a 'complete' flight from it!



Above: it's a lovely 'looker' but needs taming!

There is about 30-32 sq in of wing area (a bit more than the T-38) so if I keep it light (the bare structure is about 21 grams) there is a chance the built-up Tiger will be a better flier, especially with a TSP L-2L in its tank!

I hadn't noticed before but the CG looks to be behind 50% of the overall fus length. I've had lots of trouble trimming long nosed models, maybe that's the issue. My first Comet 4c was the worst and would spin down around the nose at the slightest provocation. I trimmed the nose down so that it became a Comet 2.5!, that worked. Maybe some catapult tests with a rough and ready simpler profile model with a changeable wing position would tell you what is going on. Either that a bigger fin might work?

Roger adds:

as usual, Howard has good advice. Oscar Wilde said, " I love good advice and pass it on whenever I can"!.

However, in this instance, I have (thinking on the same lines as Howard) brought the wings as far forward (from scale) as I dared and made the fin as big as I could without it looking desperately 'out of scale'.

Whether this helps remains to be seen. The semi -profile version needed a very forward CG before it behaved predictably from a catapult launch.

We do these things not because they are easy but because they are difficult ....