Author Topic: I-Beam wings vs conventional... (Read 11280 times)

Joe Yau · « **on:** September 18, 2008, 11:05:48 AM »

I been thinking of building either a Cobra or an Ares stunt ship, but they uses an I-beam design wing. so I'm just wondering, what's the real advantage of using the I-beam design?

Thanks in sdvance.

Jim Thomerson · « **Reply #1 on:** September 18, 2008, 11:36:28 AM »

I-beams are quick and easy to build, easy to build straight, and probably lighter than some other methods. They look good when covered. They depend on the covering for a good bit of their strength so are not designed to be covered with film only.

Joe Yau · « **Reply #2 on:** September 18, 2008, 01:07:26 PM »

Hi Jim,

I thought they were tougher to build, cause you need to build them right into the fuselage.

Randy Powell · « **Reply #3 on:** September 18, 2008, 01:46:27 PM »

Joe,

No, they are pretty easy and easy to keep straight. The jig setup allows it to maintain a more consistent taper and if you build a rib cutting jig, it's pretty easy to cut out all those rib strips. I use a very modified I-beam sort of construction in my planes and it's pretty easy to do.

Dennis Adamisin · « **Reply #4 on:** September 18, 2008, 05:39:01 PM »

Having just framed up my second-ever I-Beam, what I like is that it requires FEWER sheets of good wood for the ribs. The strip ribs use up almost very square inch of a sheet of wood with much less waste. All you lose is the ends you cut off.

My first I-Beam responded well to film covering, my second will get likely get micafilm - either is light and strong, but neither will impart as much strength as a SGM & dope finish will...

Tom Niebuhr · « **Reply #5 on:** September 18, 2008, 06:04:53 PM »

Dennis,

Another I-beamer. Are you going make us wait or are you going to tell what you are up to?

Leester · « **Reply #6 on:** September 18, 2008, 06:14:54 PM »

And don't forget to get the DVD that Bob Hunt puts out of Billy Werwage and his construction of I Beam Wings.

Jim Thomerson · « **Reply #7 on:** September 18, 2008, 06:22:19 PM »

I don't use my best wood for the ribs. I am clumsy enough that when I did use really good wood, I spent as much time repairing broken ribs as gluing in new ribs. Also, you are not using that much wood for the ribs so going to a little firmer wood won't hurt.

Joe Yau · « **Reply #8 on:** September 19, 2008, 08:23:12 AM »

Thanks for all the replies..

Looks like a good design after all. I think I'm going to have to give it a try.

Robert W · « **Reply #9 on:** September 19, 2008, 10:03:41 AM »

Ty

What is the issue with polyspan on an I-beam? Does the covering relax after the dope is applied?

james dean · « **Reply #10 on:** September 19, 2008, 11:07:03 AM »

Robert,

I'm going to take a chance and put my two cents worth in on your question. I've used polyspan on four airplanes(wing and fuse) Polyspan is tremendously strong and stable ounce the weaveis filled. The one thing you have to watch for is over tightening the cloth. I use an covering iron to tighten the cloth at a medium heat setting that is just enough to get the wrinkles out. Polyspan will keep shrinking till it pulls apart and creates small tears if you use to much heat for too long.
I crashed my new Gieske nobler (dust devil got me)

breaking the fuse in four pieces, but the wing that was covered in polyspan suvived the ordeal with only scratches and the structure was completly intact, no tears or cracks! I will use this wing in another Nobler fuse this next season.

Brad B · « **Reply #11 on:** September 19, 2008, 01:26:42 PM »

Who sells a Cobra or Ares kit with instructions? The Cobra is my all time favorite plane. I love the way it looks. I like the Ares ain't too bad either! Thanks in advance...B

Dean Pappas · « **Reply #12 on:** September 19, 2008, 02:33:50 PM »

Hi Brad,
You know that they are the same airplane aerodynamically, right?
Dean Pappas

Randy Powell · « **Reply #13 on:** September 19, 2008, 02:42:18 PM »

>>You know that they are the same airplane aerodynamically, right?<<

Not the same. Close though. The Ares has a bit more thickness to the airfoil and a slightly blunter leading edge (at least the one I built from plans long ago - there have be several renditions) and the Cobra has a slightly (like 1/4") longer tail moment. Aesthetically, they are similar, but not the same. The Ares has a bit more side area aft of the CG also. There are some other slight differences. But ultimately, they are very similar.

Dave Adamisin · « **Reply #14 on:** September 19, 2008, 06:44:52 PM »

Quote from: Tom Niebuhr on September 18, 2008, 06:04:53 PM

Dennis,

Another I-beamer. Are you going make us wait or are you going to tell what you are up to?

Hi Tom. I'll drop in on this and say that it's not from the Ares or Detroiter school........

Mark Scarborough · « **Reply #15 on:** September 19, 2008, 07:11:11 PM »

FWIW Bill Sawyer has Kitted the Argus, its a well done kit, laser cut, and from my breif drool when I pulled the parts out of the box, the intstructions are well done. It may be what yhou are looking for

Joe Yau · « **Reply #16 on:** September 20, 2008, 07:55:59 AM »

Quote from: Brad B on September 19, 2008, 01:26:42 PM

Who sells a Cobra or Ares kit with instructions? The Cobra is my all time favorite plane. I love the way it looks. I like the Ares ain't too bad either! Thanks in advance...B

Hi Brad,

Pat Johnston has the plans and ribs for the Cobra, but I'm not sure if its available in a kit.
http://brothersofthering.com:80/index.php?productID=670

The Ares is available in a Brodak kit, and I believe SS Hobbies have them.

Mark Scarborough · « **Reply #17 on:** September 20, 2008, 08:55:44 AM »

Pat has the plans for the Cobra, and he has a laser cutter, he can custom cut one at a time kits or short kits for you. Plus hes a great guy!
I think Bill has the Argus kits in stock, laser cut, you can find him here, my understanding wasnt the Argus the forerunner to the Cobra?

john e. holliday · « **Reply #18 on:** September 21, 2008, 07:53:00 PM »

I have built three I-Beam airplanes and find that once they are jigged up it is faster than a conventional wing. Besides if you follow Billy's advice the fuselage is almost done before you ever start the wing. I covered my Sheeks Spitfire with poly span with base coats of dope. To me it is just a rigid as a D-Tube wing. In fact I would not be a bit afraid to use Monokote on an I-Beam as once the ribs are glued to the spar, trailing edge and leading it is very stiff. The strength is in the spar as well as the leading/trailing edge. Have fun, DOC Holliday

Joe Yau · « **Reply #19 on:** September 22, 2008, 10:51:49 AM »

Thats lots of great infos.. Thanks guys.

Just wondering does anyone have some pics of the I-beam wing being built?

Bill Little · « **Reply #20 on:** September 23, 2008, 06:28:34 PM »

Hi Ty,

Been out of town and missed this one. I LOVE I-BEAM MODEL AIRPLANES!!!!!!!

I think everything has been covered. I spent many many hours talking to Billy. I do rank him as the I-Beam MASTER. His video/DVD is a great introduction to building I-Beamers. He is the main reason I *admonished* Denny for using Moneycoat. His instructions to me was to never, ever, under any circumstances use anything but silkspan or silk. And NEVER leave out the rear spar on a USA-1 (right Randy P??) But $coat worked out fine for Mr. Adamisin.

Mongo

Joe Yau · « **Reply #21 on:** September 25, 2008, 06:27:53 PM »

Quote from: Ty Marcucci on September 22, 2008, 09:26:00 PM

There are photos of them being built in the Classics section. Look for "Colossus". Also in Wind "Dancers site, he has some of his Tucker 4 as do I in the Classic section.

Thanks Ty,

Nice pics of the I-beam construction of the Tucker 4.

Author Topic: I-Beam wings vs conventional... (Read 11280 times)

Dave Adamisin