Make a tail out of aluminum?

[KDOG]

I was think of constructing a tail from aluminum tubing and aluminum sheet for the skin. What thickness for the skin do they normally use for such parts? Also I was thinking of using 1" tubing for the framework, .190 thickness - agree?

Barry K. was going to take some pictures and write out the specs for his tube and fabric tail, but I haven't heard anything and don't want to bug him so I'll use the extra time to investigate the other options!

 

[gyroblackwell]

Alum. Tube,foam,-n-covering.

Alum. Tube,foam,-n-covering.

I built my vertical Stab, and Rudder using this method, and I am very happy with the results.

On the stab I used 1" tube for the trailing edge (with .090 wall), a 2" main spar tube with .062 wall, and a 3/4" tube with .062 wall for the leading edge.

I used "blue" foam for the filler, so that the skin does not "oil-can" if pressed on.

My Vert. Stab is pretty large, so I don't think you would need to use such heavy wall tubing.

1/16 wall tubing would work just fine for your application.

I made thin walled plugs for the ends of the tubes so that i could rivet the skins to the ends of the tubes for strength, and so that I could enclose the ends.

The rudder is made from a single 1" tube .09 wall. rapped with skin over a foam core. I used AN eye bolts for the hinge points (3)

these are really easy to build.

 

[KDOG]

Hmmm thanks for the info. I'll have to design one up. I would like to know dimensions of some of the other tails, like starbee, and the such or at least how tall can I go safely, etc...

 

[helipaddy]

Hi.
Has anyone used Hexlite for tail surfaces, Its an aluminium honeycomb core with aluminium skins. looks light and strong.
www.hexcel.com
Heres a link to the specs:
www.hexcel.com/NR/rdonlyres/ 0FEF7BD8-88D2-4A1A-81A2-B872ACD7305B/0/HEXLT220.pdf


Paddy

 

[martylunsford@h]

My last (unfinished) project was a Zenith CH-801. That is an all aluminum airplaned held together with "pop" type rivets rather than the solid, bucked rivets that are used in airplanes like the Vans RV-8. I was amazed at how easy it was to build with aluminum, and I'm planning on making my tail out of it. I've built with fiberglass (a Q2, unfinished of course, and I also used to build surfboards), and I've built with wood and fabric (Woodhopper, unfinished of course) but nothing is as forgiving and easy to work with as aluminum.

I don't have a design yet, but I was planning on doing something similar to the Zenith CH-601 tail. Check my website in a month or two: home.earthlink.net/~martinlunsford

 

[Doug Riley]

I've used .025 for this type of construction, but it's thicker than you really need.

 

[junkyardbear]

Hi All,
I also would like to learn how to build a tail. Watching very closely.

 

[Doug Riley]

Get one of the EAA's how-to books on metal airplane construction. Their Web site lists books for sale.

 

[Brian Jackson]

I've been told that Aluminum Tail design can in fact be much lighter than composite. I was hesitant to believe that at first, but learned epoxy garners mass and weight from more than one source.

My original hesitance of using AL skin was in not knowing a good way to wrap leading edges of airfoil shapes. Can this small radius be formed without a brake press somehow?

 

[Doug Riley]

Brian: Yes, it's actually pretty easy. You bend the sheet over double (still within its elastic limit -- no creasing yet) on a smooth piece of plywood. Clamp together the edges that will become your trailing edges. Lay a 2x4 over the doubled-up sheet. The 2x4 should be parallel to the leading edge and long enough to overhang the span at both ends. Move the 2x4 closer and closer to the leading edge, pressing firmly and checking the resulting radius of bend 'til you get the L.E. radius you want.

This works with either 2024-T3 or 6061-T6 sheet. Both are quite springy and resist permanent creasing, but both will bend eventually if you keep at it. Of course, don't over-do the bend into a sharp crease (you're not mailing a letter here).

 

[KDOG]

We have these plastic-nylon tier sheets at work that we put on the pallets. They are, of course, 40"x48", which I'm going to use to get the shapes down and then use as a template on the aluminum.

Fantastic information! Getting excited!

Marty, you have an unfinished CH-801?!?! I love that plane! What are you going to do with it, or did you sell it already?

So how tall can I make the tail safely? How long at the base? How wide is the hstab usually? 4ft?

Also, where can I get a hand riveter and rivets? Are there certain rivets that you use, etc....?

I'll take myself out behind the woodshed to await my beating for all these questions....

 

[martylunsford@h]

When I built the tail on the CH-701 I was at the Zenith factory in Missouri. The rudder skin was pre-bent, but that would be easy to do using the method that Doug has described above. We used a simple plywood jig to hold the skin tightly against the leading edge of the wing ribs while we drilled the holes and installed the clecos. It was really very simple, but it's rather hard to explain without pictures. I'll try to post some pictures when I get home this evening.

On the CH-801 we actually used two skins; the first one was creased, and it formed the trailing edge of the rudder up to the spar. The second wrapped around the leading edge of the rudder and overlapped the trailing edge skin. The rivet holes along the spar were match-drilled through both skins after everything was lined up and held in place with clecos.

KDOG, I have a finished rudder for a CH-801. I went to the workshop in Missouri to build it, and I learned a lot about building with aluminum. It is much easier to work with than fiberglass or wood. And it's cheap, too. Anyway, I realized after building the rudder that i really just didn't have the funds to build the -801. It would have cost me $35k to $50k to build. It is an awesome plane, though. I got to ride in the factory demonstrator and the pilot did a short field takeoff. On takeoff he gave it full power with the brakes locked up and the stick full aft. As soon as he released the brakes the nosewheel came off the ground and he accelerated with a nose high attitude for about two seconds until the mains lifted off. Then we climbed at an uncomfortably steep and scary (for this Cessna pilot) angle. The ground roll couldn't have been more than 200 feet.

 

[KDOG]

Oh boy. What are clecos? I know NOTHING about riveting!

 

[martylunsford@h]

KDOG,

I edited my last post for you, so you might want to go read it again.

Clecos are just little clamps that go through the rivet holes and hold the pieces together until you rivet them. Basically, you drill a hole then stick in a cleco. You drill a few more holes, then stick in another cleco. You continue to do that until all of the holes are drilled and the the part you are building looks like a pincushion. All of the clecos are then removed, you deburr all of the holes, put it back together with clecos ,and then start putting in the pop rivets. As you come to a cleco, you just pull it out an put a rivet in it's place.

 

[martylunsford@h]

To answer your other questions, KDOG, you can get everything from Wicks. I really suggest an air powered riveter, though. It takes three of four squeezes of a hand riveter to place a rivet, but with the air riveter, you just squeeze the trigger and two milliseconds later the rivet is set. As far as the dimensions go, I have no idea. I was going to find out the dimensions of someone elses tail and just kinda make a copy.

 

[KDOG]

Doug: What thickness to you recommend?

What size rivets do you use? I'm gonna look around at wicks...

At Wicks they have several different versions of the same thickness/size aluminum sheet....

Wicks Aluminum Sheet

They vary WILDLY in price. What version would you get?

 

[John Henry]

PADDY I looked at the Hexcell site. What particular product are you suggesting? I'm looking to make my tail out of a light weight composite or foam core or prepreg type material. The compound curves would be too hard in aluminium and I hope to find something lighter than ply. I have seen cored fiberglass sheet samples in several thicknesses, but never found what the brand name was or where to find it. I believe it's very expensive but still want to know more about it.

 

[REDHORSE556CES]

Oh boy. What are clecos? I know NOTHING about riveting!

Cleco: A spring loaded part, compressed with cleco pliers; when fully compressed and before inserting into the hole drilled in the aluminum skin, snap out of the pliers and are usually last seen sailing across the shop into the most inaccessible corner behind several heavily loaded crates.

 

[GyroRon]

I've used .025 for this type of construction, but it's thicker than you really need.

Doug, that must have been in your Pre-Grey days!

 

[Dean_Dolph]

KDOG, the use of clecos requires the use of cleco pliers. Clecos come in specific sizes for the size hole they are used in. The size of hole is determined by the rivet size. Do a google search and you should come up with a ton of info on the use of blind rivets (use aviation ones and not the the POP brand!) and cleco pliers. All the major aviation supply houses carry these.

I've said it before and I'll say it again (my favorite statement!), if everyone had a copy of Carroll Smith's 'Nuts, Bolts, Fasteners and Plumbing Handbook' they they would have all their questions of this nature answered. Yes, it is an automotive race engineers book but the difference between formula race car construction and aircraft is virtually indetectable and the two disciplines trade innovations. The only difference seen in the past few years is more use of composites in the race car frame. But the hardware use and apps are still the same.

Try it, you'll like it!