This will be my first build log. My bench has been covered in other projects unrelated to airplanes for over 3 years now, far to long. Time to get back to the JR Aerotow in 2013, hopefully with a completed Nomad. The one-of-a-kind Nomad was built by Robert Stanley over a period of years in the late1930s and flown in the National Soaring Event in Elmira NY in 1938 & 39. The only Nomad ever built now hangs in the National A&S, Udvar-Hazy Center near Washington DC. Unfortunatley, the location in the gallery where the Nomad hangs does not make picture taking very easy. If anyone happens to have additional information, specfic to the Nomads use of spoilers, airbrakes etc. I would appreciate a post with details since my inquires to the A&S have not been answered.

Parts cutting has begun, this will be a fairly basic wooden build the intent is to keep the structure very simple thus maybe able to complete over the next few months.

Nothing like a Dead-Line to get one motivated!

General model specs are:
Span - 22.2ft (6.8 m) ~40% scale
Length - 7.9ft (2.4 m)
Estimated Flying Weight - 20 lbs
Controls - Semi Flying V-Tail, Ailerons, Spoilers
Airfoil - NACA 23018 root, 23012 tip (these are scale why change them)

EXCELLENT choice! Can't wait to see it at the upcoming JR!

Nice looking subject. Looking forward to the progress.

Originally Posted by Whiplash46

Airfoil - NACA 23018 root, 23012 tip (these are scale why change them)

Because this is a model and not full size.......

Originally Posted by szd16

because this is a model and not full size.......

+1!

I would be inclined to use a proven model airfoil.....something like the HQ3518 at the root.....so you can keep it to the same thickness as full size and then taper to HQ3512 at the tip.....here is a overlay of the NACA airfoil and the HQ
NACA = yellow
HQ3518 = blue
HQ3512 = red
You can see just how "fat" the NACA airfoil is....this thing wont penetrate worth a damn and will be down on the ground sooner then the tug....IMO. The HQ airfoils have been designed from the gitgo for models and are used on a wide variety of scale sailplanes.

One other thing....20lbs?? Not so much...at 40% you are going to need mass for this thing to even fly.....30 - 35 lbs. should be your goal. At 20lbs and with the NACA airfoil I predict that not only will it beat the tug back to the ground but do it in record fashion.

Thank you for the airfoil suggestions SZD16. I do have some experience with the 5 series NACA airfoils in powered models up to 12' spans and 25-50 lbs. The 18% root is a monster and your advice to use a proven model section would be a wise choice. Based on the information I can find concerning the full scale Nomad it had exceptional performance for its time. Of course that could be wrong. Robert Stanley was most likely (big guess on my part) inspired to use these sections at the time because they had just been developed and I suppose were state of the aerodynamic art in the mid 1930's. At a minimum, a thinner root section would still allow for a simple and easy to build spar. Thanks for the advice but you have cost me some hours drawing new wing sections.

Sorry! I would hate to see you invest time and money into a build that turns out to be a dog....do you have compufoil?

Whiplash 46, I would be inclined to go with SZD16, as he has quite some experiance with big gliders. The airfoil you chose may work quite well wirth a power model (while the fan is going) but on a glider it would not have a whole lot of "sayupability", and as for souring... forget it. Even on an aerobatic glider it would be too fat.
Good subject, by the way, guess the other challenge will be the polished ali.
Best wishes
Col

Looking forward to the progress. I have to wholeheartedly agree with Tom, ( SZD16 ) on the airfoil and weight. Too many times I see guys try to build a very light large scale model sailplane, ( 6m or more ) and then have to add 5 or more pounds of ballast only to get it to fly decent.
Its better to put the weight into the structure.


LEN
www.RcAerotowing.com
www.RcAerotowing.com/forum

Cool build whiplash!

Looking forward to seeing it in Monticello. Will you be coming to the Cumberland MD Spring Soar For Fun in March?

http://www.rcaerotowing.com/forum/sh...d-Soar-for-Fun

I have Compufoil but do not use it. OK, it looks like the HQ foils are the ticket, with some of the under-camber at the trailing edge removed, of course then it is no longer an HQ foil. The ailerons on this bird are big enough to compensate with some down trim, maybe. Cumberland in March would be a good target finish date and it's only 3 hours away. Airfoil discussions never get old, do they? Thanks for the advice everyone and Colin I love Flite-Metal, this thing will need a Ton of it. I found a source for 3" 7 mil AL tape on the web. looks like they sell direct in small quantities http://www.uline.com/Product/Detail/...e-3-x-60-yards

Originally Posted by Whiplash46

I have Compufoil but do not use it. OK, it looks like the HQ foils are the ticket, with some of the under-camber at the trailing edge removed, of course then it is no longer an HQ foil.........]

Leave the under-camber....that's what gives it its lift generating properties. HQ airfoils are proven to work time and again in models....Chris Williams uses them pretty much on every model he builds....and he builds A LOT of models! My 40% K8 uses a HQ35XX airfoil and flys like a dream at 35 lbs.........it may not be built very well but it flys fantastically well.

come on whiplash48 just take the advise these guys give you , they know what they are talking about and get on with the job in hand.
I to am building a large vintage glider and Chris Willams has suggested to me the aero sections to use and that is what I am going to do.
Models are different to full size.
will be watching your build. cheers