Some Wings I built....

I know I have showed these before. But I have seen alot of pics from Robert S. Really nice stuff. I have seen his weights and they are really good.

Here is three wings I built.

All are Geo-Bolts. One is the Geo Dedic style and the others are laser cut straight ribs. I just sent the tip and root to the cutter and he turns out a set of ribs in a flash.

The wings are ready to go into the fuse at this point. They are complete with tips, TW boxes, LO guides, BC, LOs, gear blocks and covers, Pushrods and horns.

The wing in the foreground weighs 8.5 oz. The middle wing weighs 9 oz. and the geo dedic wing weighs an even 10.

I think they are all very usable weights. The one thing I did do on all of them is use c grain heavy wood (I dont know the specific weights) It was just tough stuff. The TEs are extremely straight.

I am curious on your inputs for these weights.

>I know I have showed these before. But I have seen alot of
>pics from Robert S. Really nice stuff. I have seen his
>weights and they are really good.
>
>Here is three wings I built.
>
>All are Geo-Bolts. One is the Geo Dedic style and the
>others are laser cut straight ribs. I just sent the tip and
>root to the cutter and he turns out a set of ribs in a
>flash.
>
>The wings are ready to go into the fuse at this point. They
>are complete with tips, LO guides, BC, LOs, gear blocks and
>covers, Pushrods and horns.
>
>The wing in the foreground weighs 8.5 oz. The middle wing
>weighs 9 oz. and the geo dedic wing weighs an even 10.
>
>I think they are all very usable weights. The one thing I
>did do on all of them is use c grain heavy wood (I dont know
>the specific weights) It was just tough stuff. The TEs are
>extremely straight.
>
>I am curious on your inputs for these weights.

Doug they are all acceptable weights. Very nice as well . It surprises me that the geodetic is the heaviest.

The weight is in the sheeting. The ribs of both types of wings weigh within a couple of grams of each other.

Being geo dedic doesnt really make it any lighter. Just looks cool. Yes there are less full size ribs but there are just as many half ribs. In the straight ribbed wing there are more full size ribs but there is no half ribs. It takes the same amount of sheets of balsa to get all the ribs cut out. It really is a wash.

>The weight is in the sheeting. The ribs of both types of
>wings weigh within a couple of grams of each other.
>
>Being geo dedic doesnt really make it any lighter. Just
>looks cool. Yes there are less full size ribs but there are
>just as many half ribs. In the straight ribbed wing there
>are more full size ribs but there is no half ribs. It takes
>the same amount of sheets of balsa to get all the ribs cut
>out. It really is a wash.

The geodetic wing should be stiffer. I should have asked are they lost foam C tube wings? Are they made of 1/16,3/32 or 0.77 balsa?

EDIT: Any time you build a wing ready to go @ 10oz Thats a good weight. IMO

Yes the Geo wing seems to get stiffer earlier in the process of building. But after I get all the sheer webbing in the spars and along the TE sheeting they feel very much the same. But just feeling the geo wing stiffen up earlier in the process tells me that it can handle more torsional stress.

I use 3/32 sheeting.

These are all biult in the same lost foam jig. Just one uses ribs from the templates that Bob cut. The others use striaght ribs cut from the root and tip that Bob cut.

When you have your ribs and landing gear doubler cut by the laser. And you prep your sheeting while you are waiting for ribs to arrive. Once you get your ribs you can be in one peice inside of 4 hours. And that is if you take it slow. The lost foam jig is truly the best way I have ever seen or heard of to build built ups. It is just too easy to get it straight and repeat over and over and over again. Wouldnt you agree?

>Yes the Geo wing seems to get stiffer earlier in the process
>of building. But after I get all the sheer webbing in the
>spars and along the TE sheeting they feel very much the
>same. But just feeling the geo wing stiffen up earlier in
>the process tells me that it can handle more torsional
>stress.
>
>I use 3/32 sheeting.
>
>These are all biult in the same lost foam jig. Just one
>uses ribs from the templates that Bob cut. The others use
>striaght ribs cut from the root and tip that Bob cut.
>
>When you have your ribs and landing gear doubler cut by the
>laser. And you prep your sheeting while you are waiting for
>ribs to arrive. Once you get your ribs you can be in one
>peice inside of 4 hours. And that is if you take it slow.
>The lost foam jig is truly the best way I have ever seen or
>heard of to build built ups. It is just too easy to get it
>straight and repeat over and over and over again. Wouldnt
>you agree?

YEP!

It took 2 days to build my wings and I'm waiting for sheeting to dry now. So in a couple more days I can put it on the wing. In the mean time I'm doing my fuse and stab.

Robert
"waiting for the sheeting to dry" Does this mean that you pre bent the sheeting? If so do you have a picture?

>Robert
>"waiting for the sheeting to dry" Does this mean that you
>pre bent the sheeting? If so do you have a picture?

Doug I don't want to HiJack your thread. But in reply to your question of sheeting the pics will be on tomorrow's thread on my T-Bolt.

>Robert
>"waiting for the sheeting to dry" Does this mean that you
>pre bent the sheeting? If so do you have a picture?

Actually you make a foam buck of the leading edge area and then mold the leading edge sheeting around this. On some designs you don't use any other leading edge this way.

Matt is building his new Stuka design this way and will be including a pictoral of it as well (Fuselage done, wing in the process right now).

Doug,
If you use a lost Foam jig to build the wings,is it possible to use a set of lasser cut rib with the lost foam? My Tony wing weight was 13oz.with all the controls and hinges and flaps.Wish I could get it down to 10oz..Total wing area including the flaps is 743sq.

>Doug,
>If you use a lost Foam jig to build the wings,is it possible
>to use a set of lasser cut rib with the lost foam? My Tony
>wing weight was 13oz.with all the controls and hinges and
>flaps.Wish I could get it down to 10oz..
>
>Gordy

Doug's wing WITHOUT flaps is 10 oz.

3 oz for flaps is quite a bit unfinished, but may also be the reason your airplane turns so well.

>Doug,
>If you use a lost Foam jig to build the wings,is it possible
>to use a set of lasser cut rib with the lost foam? My Tony
>wing weight was 13oz.with all the controls and hinges and
>flaps.Wish I could get it down to 10oz..Total wing area
>including the flaps is 743sq.
>
>Gordy

The lost foam technique is a way to get a pattern for each rib and then to have a "fixture" upon which to build the wing on a flat board. But, in answer to your question, there is no reason you could not have the ribs lazer cut and still use the lost foam cradles.

Len,

'Thank you for the info.

Gordy,

I used laser ribs on the two wings that are straight ribbed wings. I simply traced the root and tip and sent it to my laser guy. Then I told him the span of each panel and the spacing from center to center of each bay and how many ribs there needed to be. Then a three days later I had a perfect set of ribs that lay in the craddle just like they are supposed to. Saved me many many hours of tracing and sanding ribs from templates. Tracing and sanding wasnt so bad the first couple of times I did it. But after the 10th or 11th time you just dread that part. The laser is just toooooooo easy!

Yeah it is 10 oz without flaps and I consider that one to be the HEAVY one. The 8 oz.er is more like what I usually get at that stage. 8 to 8.5 with everything in ready to install is what I like to get. Just couldnt get the balsa I wanted and went with some heavier stuff.

The real weight savings is in the sheeting not the ribs.

Gordy, I would say 13 including flaps on that size wing would be great. My foam Saturn was 13 with flaps and it flew great. And it is way smaller than your plane.

My flaps have weighed all different weights over the years. I built them up on my Geo Bear and they seem to be great. I found some nice quater and used that on my Furias flaps. They weighed about the same. They both are and were very good flying planes. I do not like to taper the flaps. I like them to be big planks just sticking out there. I remember an article in SN years ago about flaps. It said that non tapered flaps were the most responsive by far. Makes sense. Non tapered are not going to wash out at the TE of the flap. They will stay stiff where they NEED to stay stiff.

I saw how Al reinforced his flaps with a carbon ron on the LE. ??? Why on the LE they are already supported by the hinges and the TE of the wing at that point. It would seem to me that the TE of the flap is where you need the most support. This is the area where it will flex and you wont get the response. Just what I have observed.

Moved to a new post, subject flaps.

Hi Doug!
A fully assembled wing including flaps and all the hardware should be in the 12 to 13 ounce range assuming the wing area is around 680 to 700 squares. So I think you are well within the ballpark on all of the wings you built. Good Job.

Thanks Mike.

How do you go about finding someone to laser cut ribs. Also approximate cost and do you supply the wood? -DOC

Here you go,

www.tanks-hangar.com

Hi Doug,
IIRC, Aaron's Geo bolt wing was about 10 oz. complete (tips, flaps, hinges, b/c, etc.) and ready to cover. Had very good 3/32nd wood for the sheeting, and good wood for the flaps.
Bill <><

i used the .077 we had ordered from riley around 1998 when i first got the wing.
i really dont think there is that much total diff in the weight if you use .077 and 3/32 because we have used both and i am sure it was less but the 3/32 seemed to be a little stiffer and stronger, i will use 3/32 next time even if it does weigh a touch more because weight in the wing kind of seems to be null and void at times right?

Doug,
Thanks for you help. I wanted to do the lost foam wing,but like you making the ribs is very time consuming.

Hi Gordan,
I have found that making the ribs for the lost foam set ups takes only a *little* bit longer (a couple hours max) than stack carving/sanding a set, and they are as perfect as you can get with out laser cutting. But we get impatient when building several.
Of course, laser cutting IS faster, but I can have a set ready long before I can get a set from Tank's, and he has exceptionally quick service.
Bill <><

>The wings are ready to go into the fuse at this point. They
>are complete with tips, TW boxes, LO guides, BC, LOs, gear
>blocks and covers, Pushrods and horns.
>
>The wing in the foreground weighs 8.5 oz. The middle wing
>weighs 9 oz. and the geo dedic wing weighs an even 10.

Doug,

What do expect the flaps to generally weigh? I try to count that weight in to the total wing weight.

I do believe they will all be very "useable".

Bill <><