Stickbuilder

At 1/4 scale, you will only have 10.1 inches to deal with. Boy, whatever you use in the way of a gas twin will be tight. Have you considered something like the Seidel Radial? Talk about scale.......[8D] The cool factor would be over the top as well. A friend of mine put one in a T-28, and the performance and sound was awesome. So is the price.

Bill, AMA 4720
WACO Brotherhood #1

lazyace

My Feedback: (126)

hi guys finaly got my cowl & pants from stan's realy look good now down to the shop and work work work or is that build build build

Stickbuilder

Make sure that you check the cross section dimension of the wheel pants. I had to section 1/4" out of mine to get them right. It's easy, and can be done in about one hour.

Bill, AMA 4720
WACO Brotherhood #1

SuperCub Man

Pix #1
The cabanes are 1/8" aluminum strips covered with 3/8" K&S tubing and filled with epoxy. They are attached to the fuse with steel clips and 4-40 button head steel screws into Tee nuts. Steel clips and Tee nuts in the wings with 4-40 socket head screws will facilitate removal and/or installation at the field. The top of the rear cabanes are filled with KBWeld. I put a correct sized vaseline covered wire in when stuffing in the KB and it pulled out easily after drying allowing me to tap for a 4-40 bolt. Then I Silver Soldered a steel clip to a 4-40 threaded rod and that made the rear cabane strut adjustable. I just could not get the wire cabanes as bent from the plans to line up with the wing so I cut them off, built my own. They are rough yet and will be filled at the joints with auto body filler to finish off before painting. They are quite sturdy!

Pix #2
The interplane strut will also be adjustable. In an attempt to copy the look of the full scale aircraft, I made straps that will run on either side of the main strut at the top and bottom. A 4-40 bolt through them and the aluminum strap in the wing, will hold them in place. I used my favorite "brake line tubing" to make threaded inserts which will slide into the adjustable struts ends. They will be held in place with JBweld as well. The struts will have an epoxy covered dowel run through them for strength. I notice on my photos of the plane I'm modeling that the cabane stuts are smaller than the interplane so I selected the 3/8" size for cabanes and 1/2" for the struts. Not quite as close as I'd like, but close enough. The normal tabs on the wings as shown on the plans will be used except I made them of 1/8" aluminum. The straps are still too long and will be cut to fit nicely when I build the struts.

Pix#3
The "main" gear struts are of aluminum and they operate as scale with a strong spring installed. The bottom portions are turned and cut at an angle with 10-32 steel bolts as axels. The axel bolts have large unthreaded shoulders for the wheels to ride on. They are not trimmed and finished yet as I have to figure out how to attach the wheel pants. The rear gear supports as well as the centers are steel brake line tubing. They are made as the century gear with the spreader supports forming an "X" at the top. The gear alone weighs in at 10.5 oz. without the wheels. I now have to figure out how to cover them. There is a gear hatch in the belly that splits to open in two parts so it would fit around the gear struts. A very "fiddly" job! The camber and toe-in may look a little extreme but they are still a little loose and awaiting adjustment.

And so the battle continies. Have to figure out how to get those cabane wires that run between the front cabanes installed yet. At least with the removable cabanes it will be a lot easier to cover. Waiting for more K&S 1/2" tubing before I can finish the struts.

Happiness is a Waco nearly finished!!

pimmnz

Jim, FWIW, I don't like using ally for struts, it tends to work harden and crack, those centre section struts of yours will be better served with steel inners. Biplanes don't have 'cabanes', they don't need them, a cabane is a triangular support structure usually above the wing, to which the wing bracing wires are attached, so generally found on monoplanes. Pedantic I know, but in the interests of accuracy...Can't actually think of a biplane that has a cabane... Anyway it is interesting to note that all the struts on a biplane are in compression, hence the use of tubular members, if they were in tension the they could be wires. That is assuming, of course, that the flying and landing wires actually work, and that the wings are not cantilever. I note that on the models generally discussed here the wings don't really need the wires and struts by their design, so it pays to decide whether to make the struts decorative (light) with cantilever wings, or working, with the bracing wires, and make the wing structure lighter.
Evan, WB #12.

WacoNut

Jim,
I like how you tackled the gear and cabanes. Can I get a drawing of your gear?? I would like to build something similar for my 1/4 scale. I really want to build nice scale gear fairings but it will be very difficult to do without having scale functioning gear such as you have built. I for one think you have done an excellent job, congrats!!!
Anthony

RICKSTUBBZ

Jim,
I enjoyed your post on the cabane and interplane struts. I like your way of thinking for tackling that issue. What I have rolling around in my head is very simular to what you have done. Once you put the finishing touches on them I have no doubt, they will be sweet. [8D]
Question--What do you have in mind for flying wires?
Keep up the good work and please do post more pics and info.

SuperCub Man

RICKSTUBBZ - For flying wires I intend to use the method described on Page 180 Post #4499. Plastic braiding !!! I bought some - it looks good and should be easy to install and maintain.

Cubnut - I will try to put something on paper. I was given the main strut tubes with the spring installed. I simply took them and using the plans for size, built around them to suit. I had to turn the lower leg segments myself as the ones supplied were for another style of gear, but other than that it went quite simply. Attachment to the air frame is not shown so I will draw that up for you. Give me a bit of time though as I'm trying to get the plane finished for a Club Meeting "show and tell" next Monday!! Also I may change the supplied tubes for some heavier side wall 6066T6 (or something!) that I have lying around. Also I may get a slightly lighter spring. The chap that buuilt them made the spring on his lathe and it may be too much. The way the leg assembles, it is easy to slide the bottom portion out and change things. We'll see later!

pimmnz - the shaped aluminum on the struts is just dressing, The support will be hardwood dowels epoxyed inside them and the ends will be reinforced with JBWeld at the connection points. As far as the ally tabs in the wing, I've never had a failure in the many years I've been using them. However, thanks for the info and the other comments. I'l post as I get along.

WacoJoe

It's very common for the center section struts on a biplane to be called "cabane struts". The definition of "cabane" as found in the Dictionary of Aeronautical Terms is;

"An arrangement of struts or other supporting structure that holds the wing of an airplane above the fuselage"

That would seem to be broad enough to include the center section struts on a biplane (note that it doesn't specifically say anything about a triangle), and this is the term that is most often applied to those struts. When you talk to biplane restorers/builders, they'll all know what you're talking about when you mention "cabane struts". (They should also understand "center section struts" as well!)

The term "cabane" is also applied to the "v" strut under the fuselage of a Cub type aircraft that provides the upper attach point for the landing gear shock struts. Even though this little "V" doesn't have anything to do with the wings, it's commonly called the "landing gear cabane".

Technically correct or not, that's how we talk in the world of "full scale" airplanes!

Cheers!

Joe
WB #54

Thomas B

My Feedback: (4)

NASA uses the term cabane strut officially, per this link. It IS the correct term.

http://www.hq.nasa.gov/pao/History/SP-468/app-d.htm

I wonder where the gentleman in NZ got the idea they were not called cabane struts......

RICKSTUBBZ

Evan (pimmnz),
I would like to constructively debate your statement about Biplane struts being in compression. Particularly in the case of a WACO U/YMF.

Mind you, I am no aeronautical engineer, but in the case of this biplane, both wings are carrying a percentage of the load (weight of aircraft) and obviously both wings are creating lift. Therefore the “cabane� center struts holding the top wing, would be in tension. Yes there are situations were these struts could be in compression but not in strait and level flight.

Theoretically the interplane (outer) struts will oscillate between compression and tension with varied angle of attack and wind direction/speed. If both wings are equal in lift there would actually be no tension or compression. They actually supply support against torsion as well.

All of the struts perform the function of maintaining structural integrity. Meaning the struts maintain the distance between both wings and the fuselage up and down, side to side, as well as fore and aft, not to mention preventing varied twist between the wings.

On a full scale plane of this type the flying wires are there as much as anything else to help spread the load of all these varying forces. In our models, in many cases, we are able to build with such strength that the flying wires are not needed structurally.

Again, just a friendly debate.

khodges

My Feedback: (1)

To add to Rick's excellent treatise (? right word ?) The wing wires are split into "flying wires" and "Landing wires"; the flying wires support the weight of the aircraft under the wings in flight and prevent the wings from folding up, as most bipe wings are not cantilevered, and unable to support their own weight, much less that of the aircraft in flight. The flying wires are the ones from the lower part of the forward fuse to the upper end of the interplane struts. In flight, these are under load and the interplane struts transfer this support to the bottom wing. On landing, or just sitting on the ground, the landing wires are loaded, supporting the lower wing and preventing the tips from dropping under inertial loads when the plane touches down. This support is transferred to the top wing by the interplane struts; the landing wires go from the top of the cabane struts down to the lower ends of the interplane struts. Together, they form a very strong truss structure that keeps the wings in precise position throughout the flight envelope. Both the cabane and interplane struts experience both compression and shear (stretching) forces, dependent on what's going on within the flight envelope.

pimmnz

Yes, sorry guys, I think perhaps I shouldn't have said anything... But if it makes us think about how these things are stressed then we can make better decisions about our structures. As Khodges sez, the wing struts and spars and wires make a very strong and rigid `box girder'. I believe that, in model sizes, built following the full size practise, that struts are always in compression. I can offer no other proof other than having had a wing strut fail on the UPF sometime through a demo flight, (rear outer wing strut) and not knowing until the landing circuit when you could see it trailing in the breeze... Had this failure allowed the wings to move apart then I reckon the pilot would have known, as it was the flying wires still managed to maintain the correct rigging angles and the strut was taken home and repaired. As for `cabane', well that came from a very old WW1 riggers book, and only Bleriot, Fokker 'E' and Morane 'Parasol' types, followed by the Bristol monoplane actually had them, as described. So it seems that time has changed the usage and common understanding of the word. It seems that will have to catch up with modern times :-).
Evan, WB #12.

skylarkmk1

You guys are all correct;

Cabane

From Wikipedia, the free encyclopedia

A Cabane is a historical term for the tripod, pylon, or struts, usually at the centre-section of a biplane or upperwinged monoplane.
----------------------------------------------------------------------------------------------------------
From The Oxford Essential Dictionary of Foreign Terms in English, 1/1/1999.

cabane noun M19 French . 1. M19 A hut, a cabin. French Canadian. 2. E20 A pyramidal structure supporting the wings of an aircraft.

Garthwood

Hello Khodges.................Hope your new year is to a good start. Reference your post # 5040 pictures. Your spring assembly to reinforce the landing gear of your Waco, Is that spacer a piece of hard vynal tubing (or hard vynal washer) ?. Also what sort of struts material did Jim use in his modification ?. His looks like the K&S round aluminum tubing, but that would be too soft, unless there is a 4-40 pushrod wire inside the tubing. I like both of you guys idea.

I started on the mod. but it will be a while before it is finished. I'm working on another project. But I should have it completed by the spring. I have not started cutting into the fuse yet. I'm just gathering all the information and looking into the plans. Your pictures are really helpful, thank you both. I cannot see how Jim connected his struts to the bottom of the gear at the wheel base. Wonder if he has any pictures that are close up.

Charles.
Brotherhood #87

Jim Henley

Charles,
You are correct, there is a 4-40 threaded rod inside the tubing. I used ball links that fit a 4-40 thread but the ball end is 2-56, in an attempt to keep the ends of the struts as small as possiible. I do not think I have any photos of the attachment on the gear leg set up, but perhaps I can draw something up, and post it for you.

Jim Henley

Charles,
Hope this gives you some help, if not send me a PM.
This was drawn off the 1/5 scale plan so the L/G is accurate, the other drawings you can size to your application.
The brass is silver soldered to the outside of the L/G wires. (You will cover them with balsa sheet when you get the
strut attachment bolted to the inside of the brass stock.

khodges

My Feedback: (1)

Charles--the white spacer on my spring assembly is a nylon spacer, sold in several sizes in the specialty hardware section at Lowe's. The inside diameter is just larger than the bolt that passes through it. I forget the exact dimensions.

Where Jim used 4-40 rod inside the tubing, I used carbon fiber rods. I had some 3/16 square rods and glued them side-to-side to make a rectangular rod, and used brass sheet to make looped ends, riveted in place.

Garthwood

Hello Jim.................thanks for the drawings and explanation. If it worked on your larger Waco I'm sure it will work on the 1/6th.
I have used that same idea on the airfoiled tubing inserting 2-56 pushrods on the Waco's ailerons, centering the rod and then epoxy it in place. In this case it's just more for looks. In your case the tubing also adds strength and looks. I will be working slowly on this mod, so my reporting will be later. I will try to take some pictures while doing this. Thanks again.



Khodges...........thanks for the pictures and info. I will just have to visit Home Depot and look for the aluminum channel. The brass plating I have some on hand. Lowes just moved in Canada and opening their first store soon, just half hour North of me. But Home Depot is a big competitor.

If any snags come up I'll be asking you guys for help. Thanks

Charles.
Brotherhood #87

Thomas B

My Feedback: (4)

Ran across an interesting for sale ad on R/C groups. How about a decent looking 1/4 scale Waco for......$400.00:

http://www.rcgroups.com/forums/showthread.php?t=799337

Needs some cowl work and new cabane struts.

You can definitely see a few "warts" in the pictures, but it looks like it has some potential as a great fixer upper for the price.....wish I lived in Mo....

Garthwood

Very nice Jim..........like what you did.

Charles.
Brotherhood #87

khodges

My Feedback: (1)

Skylark Mk1, where are you? Check this out, can't be too far away from you.

skylarkmk1

Ken,

Sent him a note, just waiting for his reply to see where he is. It may pose a storage problem for me as well (90" wing is about 2' more than I really want and will have to find a place for the fuse []), will have to think this one out.

Stickbuilder

NEW BROTHER ALERT

We have a new Brother. George Werber is now Brother #90. Welcome George, and good luck with your model.

Bill, AMA 4720
WACO Brotherhood #1

PacificNWSkyPilot

My Feedback: (19)

I've been trying to get through to the guy for days to buy it from him, he hasn't answered me at all.

I'd do a road trip or get a friend to pick it up for me and make arrangements, but he doesn't even respond.

Jim