A glider, name to be determined

[Mac82]

So... there I was looking at this pile of pink foam in my scrap box, it's in a couple chuncks and of somewhat odd shaped. Wondering what the hek I'm going to use it for. Then it hit me, why not use it for a fuselage.
What I had left wasnt enough for a full size plane but it's just enough for a pod shaped fuselage with a tail boom. So here are some progress pics.



It took most of a morning to sculpt each side

The internal cavity



Booth halves


With the hatch

The wings are going to be using the foam ribs balsa spars and poster board covering method that I'm using on my camel build.

I still haven decided on how I want the tail. Weather a V tail, traditional or dlg. style. I want y'alls input on that part.
The next thing I haven't decided on yet is weather or not to add arilons or to keep it a 2 ch
In case your wondering about the specs
I'm looking at a 50 in. span and at most a 31in leinght

 

[jamboree1]

That Pod looks a lot like my easy star 2 pod, so go with, that build rest like the FT explorer, use it's wing and tail and motor mount

 

[Mac82]

Not a bad idea jamboree1, but I'm past the point where I can designe in a motor mount or move the tail boom and I had plans on this being a non powered glider

 

[albertomellado163]

Cool Man!

 

[Mac82]

Here are a couple more profile shots of the fuselage pod

I have the tail boom roughed out. There is still more material to be removed.
I've decided to go with a a V tail to keepb the weight down and for astetic reasons.
Originally I didn't intend for the tail feathers to be sculpted from the pink foam but swing as I had just enough to do so I figured why not. Well that's all for today. Next step the wings.

 

[Craftydan]

Hey Mac,

Neat build

Don't get me wrong on this -- I'm lovin' the scratch-it-out vibe on this build -- but if you don't mind a few suggestions . . .

- The fuse is VERY wide for a 50" glider -- if this is a glider, even a easy-star-ish power glider, a wide fuse is a lot of drag. If you don't need the space inside, I'd suggest cutting the middle inch or so out of the pod to narrow her down. You might also consider glassing it to give her a hard-but-light crust so the foam walls can be narrowed even further.

- If you can find a CF arrow somewhere, I'd replace the boom with that. They're dirt cheap at Walmart (~$3, last I checked) and a ~30" arrow shaft should more than suffice (and they make great wing spars ). The less weight that ends up in the tail, the less ballast you need to put in the nose . . . and the lighter your glider will be. Epoxy or a foam safe CA are probably the best way of mounting CF to the foam.

- Tailfeathers . . . Thin. How thin? How thin can you make 'em? I'd consider thinning to between 1/8" and 1/4", and probably add a light layer of glass for strength and rigidity. Again, it's that drag and balance.

- V-tail . . . you've chosen it, so I won't suggest pros and cons, just be aware: While they have a lower drag, they also tend to like more airflow than standard tails and get mushy at near-stall-speeds. This isn't a fault, it's a behavior -- Just be ready for it.


Hmmm . . . I seem to be suggesting a lot of glass Honestly, glassed planes fly nice

. . . but by all means, keep building her as you like. You're the one doing all the work, and you're the one who's going to live with her. I'm perfectly happy watching you build her out -- Keep it up

 

[Mac82]

Thank you Craftydan.
-Glassing with a little epoxi is a given, it's really the lightest and smoothest way I can think of to seal the foam for painting.
-I had considered using the carbon arrow shaft, especially seeing how much weight the do well that I have is adding.

Now to the V tail. Lol yes would could be here all day discussing the pros cons. But I have done my research, but this is a new chalange I've never built or flown a V tail.

- Thinning the fuse I agree there I may be able to thin it out a little bit but seeing as I already have the wing rest sculpted I can't make that part much thinner but.... we'll see.

Again thanks Dan, your advice is invaluable


I just had another thought.
Dan you mentioned that the 50 in wing span was a little short for the size of the fuselage. What would you say would be the optimal wing span should be?

 

[jamboree1]

Mac im including a few pics of my easy star with a few dimensions to give you an idea and some guidelines, AUW is 1 lb 14 oz with 2200 3 cell.

 

[jamboree1]

Also, Im with CraftyDan on the vtail, if you go vtail make sure you have ailerons, reason being that in glider mode with no air passing over the control surfaces the plane becomes quite sluggish, my easy star can be too even with ailerons, as they never get prop wash.

 

[Mac82]

Thanks jamboree. Yes I had came to that same conclusion and I will be incorporating ailerons I have even considered adding flaps but that's still up in their air (pardon the pun)

 

[Mac82]

OK jamboree I've done some comparison measurements. Your fuse is at what looks like 3 1/4in I'm at 3 1/2in your tail boom is at 1 3/4 I at 1 1/2 in just in front of where I intend to place the tail fins. Your fins are 4 in mine are 4.5in so we're fairly close on most mesurements.
Lets compare the rest.
Easy star ws: 54in mine:50in
Leinght: 38in mine 31in

Now I can see how my wing span could be a little short for the designs that's not a problem since I haven't built them yet. The question remains. How much longer to make the wings. 10 or 20 inches longer? For a 60 or 70inch span. The thing to remember is I'm using a 7in chord. Its my understanding threw observation that the gliders/ Sailplanes with the longer wingspans generally have a more narrow chord.

 

[jamboree1]

I believe you are correct with the thin wings, I'd try the 70" wings, if they don't work right, and that might be because of the short fuse in proportion, you can cut them down. The Radian has 78" wings with a 45" fuselage if I recall correctly. I mention the Radian to give you a size reference. I believe the Calypso has v-tail if you want to check that out.

 

[Craftydan]

FWIW . . . The Carl Goldberg Gentle Lady is an iconic trainer glider, and has a 78" span and a 9" chord. Moving upward in the classic's food-chain, Dave Thornhurg' s Bird of Time is 118" with a 10" span. Jump up to the "throw Money at it" performance bracket, the Pulsar Pro 2M is at 78" with a 7.25" chord (a bargain at $460, but at that point, why not spring for the 3.5m model ).

I don't see anything wrong with moving to a 70" span with a 7" chord, just so long as your tail surfaces are large-enough or far-enough-from-CG to still have good authority. Keeping the wing light and strong with a good airfoil will do more for performance than aspect ratio.

 

[Mac82]

OK great points from both. I have already started to plan out the mid wing extension of 20 in, and it looks like I may have to increase the area of the tail fins by about another 10% witch isn't a problem but I will end up going with using foam board to do so.
More updates as I build