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Posted by Swissflyer | Mar 12, 2010 @ 11:34 AM | 3,249 Views
After months of intermittent work & two house moves, the re-engined F117 took to the skies this afternoon.
It now flies easily out of my hands with a gentle toss. Then the EDF units pull it gently away. Since these are low cost brushed units, there is no stunning sky-burning.
However, the model has a great shape and the sideways silhouette against a hazy sky is quite unique.

The CG was too aft on the first flight, after correction things were much better.
There is still some in flight experimentation with CG to do as it still flies too tail heavy for my liking.

Still, it was a great day for flying and a great shape to see in the sky

Posted by Swissflyer | Apr 22, 2008 @ 07:06 AM | 4,843 Views
Well I finished the model last Saturday but it was too windy to think about flying. On Sunday the early morning was calm so I took the F117 for a first flight:
- Wow, those fans wrecked the calm of a Sunday morning... It looks like EDF will kill my reputation for flying nice quiet model aeroplanes!
- A Frisbee launch had the F117 in the air, sort of:

There is clearly not enough thrust, the F117 managed high angle of attack slow flight for about 200m.
I tried again but still the same even after a harder throw, we clearly were not going to get on the step.
Still, I established a few things:
- Range of the Corona synthesized receiver is OK
- No interference problems
- F117 is controllable and flies nicely
- BUT need more thrust (and ideally less noise)

From the photos you can see that I have not fitted nice inlets or a good exit tube. Subsequent (it is always that way) reading shows me how much thrust I am throwing away by just sticking the EDF units there with no plumbing.

On this link:

There is an excellent article by a very competent person in EDF, I will follow the advice he gives, especially on page 13 & 14

- Smooth air intakes (120% of inlet area)
- Yoghurt pot exhaust duct to give an 80-90% vent area.

I will give a yogurt pot update later.

Posted by Swissflyer | Apr 11, 2008 @ 10:12 AM | 6,022 Views
Well the rainy weather this week gave me the chance to build something that looks like my Avatar
Yes, the French are really good at Depron and the F117 by Lionel Bernardin seemed simple and fast to build, it is!

There is a nice photographice build sequence pdf here

Half way through I stopped and wondered why I hadn't bothered to fit EDF fans. I have two GWS units that have been sitting there for too long...
Luckily things hadn't gone too far so here we are

So this is the build so far. Won't be able to do any more for the next week, maybe the rain will have stopped by then