More RFFS-100 Fun

[Dave Robelen]

Hi All,
Meet my latest little Pal, P-Nut. She has a wingspan of 13", an area of 30 sq. in., weighs 22 grams and is powered with a KP-00 re-geared to 6-1 and driving a 5-4 prop. The controls are RFFS-100 of course. The battery is one 170 mah Li-Poly, and the actuators are my dual push-pull modification of the RFFS-100 unit.
With a static thrust over 26 grams, I am beginning to see the performance I have longed for in a little bitty model. It will actually do a presentable Cuban eight from level, and multiple rolls are right in there. I still have a ways to go with the tinkering, maybe coupled ailerons and an airfoil mod for some streamlining, but it really does look promising.

[Dave Robelen]

Hi,
Just for kicks, here are the P-Nut "guts".
Dave

[t-turley]

Dave,

:eek: :eek: :eek: That's amazing!!

Tony

[Mike Taylor]

Very nice, Dave, a very 'classic' look. I especially like the rounded cowling and fairing into the wing; nice touch.

[MINIRCPLANES]

Dave,

That is a really neat plane. Love the classic lines. Are you using turbulators on these RFFS-100 controlled models?

Happy flying,
Felix
MINIRCPLANES

[Dave Robelen]

Hi Felix,
Thanks for the nice words. No, I am not using a turbulator. Generally, they are not all that effective on a thin curved sheet wing. Also, in the case of P-Nut, the flying speed is high enough that I doubt a turbulator would be needed. Now that you have raised the subject, I really ought to at least give it a try to make sure.
Take care, Dave

[pease1]

Is that a trim tab on the left wing? To counter torque?

[Dave Robelen]

Hi Al,
You caught me! That is a trim tab, just a pinch of masking tape, but it is there to counter a warp in the wing. I have not noticed any thrust effects, and the thrustline is 0-0.
Regards, Dave

[FLB]

Hi Dave,

Great job. The "monochrome" finish and the round design of the plane match very nicely together... Did you scratch the prop to fit it in the set? ;)

I will try soon to do something on my side with the D-27

Regards

Frederic

[mike nill]

my hat comes off to you Dave, very nice work.What about a solid balsa wing sanded to shape or have someone do it on a CNC.i bet that would give good performance outdoors, wouldnt it ? just a thought:)

[Dave Robelen]

Hello Frederick,
Yes the prop is a scratch job. However, you can get a very good match in the GWS line. I simply enjoy watching a propeller emerge from a block of wood. Of course, there are times when I kid myself into thinking "my" prop performs better, but I doubt that is the case.
Mike,
The situation with the wing has been one of shooting for the absolute minimum weight initially. The curved 1/32" wing weighs 2.3 grams complete, and a thin coat of color w/o sealer would add another .2 grams or so. P-Nut is still "raw" because I am actively making changes every few flights and do not want to be inhibited by a colorful finish. Finding a material (including balsa) that can be cut to an airfoil with more depth, and still stay within a reasonable weight is a neat challenge. Possibly milling it from very low density balsa and then cutting a large amount of the middle away and replacing that with light ribs and very thin covering will be a practical approach.
Regards, Dave