Wing Q & A

Revised: February 04, 1999

From Danrihn@aol.com
The rear spar will require you to first set the wing in the fuselage to see where the rear spar will lay.  You may have to add plywood doublers to get it to line up or offset  jog) the steel spar plates to get the line up you want.

From: SKYBOLT55@aol.com
Spruce spars are great but hard to come by! Most people are building fir spars ....it's easier to get I'm building spruce spars but the 2 ...18ft boards were on order for 4 months.
As far as I know either wood works very well. Don't be affraid either way.

 

From: SKYBOLT55@aol.com
The only wing tank at this time is a small smoke tank that goes in the left rib bay between nose rib at WS12 and nose rib at WS24.I don't know of any plans for a fuel tank in the wing.

 

From: SKYBOLT55@aol.com
You sure make it sound confusing with your section this and section that...basicly the rib thickness at the trailing edge of the long ribs are wrong on the plans. You should make the the same thickness as the aileron ribs at the trailing edge, to achieve the thick trailing edge that has proved superior in aerobatic performance. Boy that sounds good. In laymans terms make part A fit part B. The wing should have the same width trailing edge all along the wing.Don't forget the thickness of the plywood covering when calculating the thickness of the trailing edge. I've built my wing and it works great....press on.

 

From: ACRO240Y@aol.com
In reference to the epoxy used on the inside of the wing it does not weigh any more than a couple of good coats of varnish. IT IS VERY IMPORTANT TO PROTECT THE WOOD ON THE INSIDE OF THE WING FROM MOISTURE VAPOR. This another reason to use the epoxy instead of varnish,it is much better at keeping out moisture vapor. As for the glass on the outside of the wing , 1.4oz.to as light as
3/4oz. per square yard should be used this will be the lightest way to finish the wood. DO NOT USE DACRON ON THE WINGS. The dacron fabric STITS, CECONITE, etc, are a slippery material like nylon and glues do not bond to them very well. There was a lot of problems in earlier times with the Stephens Akro type airplanes with fabric separating from the wood. If you want to use dope as a finish on the wing you should use good old fashion cotton.Imagine what would happen if a one or two foot section of the fabric decided to ballon at high speeds. I have seen the results, it was fatel.

 

From: Wilyum yum@aol.com
Inside of wing on bare wood. 3 coats of epoxy varnish should be applied until surface is shiny.
All wood aircraft I have had any experience with have had some sort of cloth cover on the exterior of the wings. very light glass or dacron. Don't forget to put an extra strip on the leading edge to provide wear resistance. Bugs Rain crap in the air etc.
If you don"t you will wish you had in a few years.

 

From: RIHNAIRCO@aol.com
After the aileron is completed including all covering and paint and definitely before flight put weight in the aileron nose board channel until the aileron balances. Measure that weight by removing it from the aileron. Add ten per cent to that amount and that is the amount you want to put in permanently. Most people are using lead shot in west systems epoxy.

 

From: Outlaw 406@aol.com
I agree that Doug Dodge has nice components as I have been to his shop but I am a welder and fabricator myself , since posting the question on the bell cranks I have finished them using 1x1 .065 just thought I would ask in case someone had experienced the same problem.

 

From: PMorgan001@aol.com
What exactly was the problem you had using the 1 x 1 x .049 that the plans call for, was it
not strong enough ?

 

From: Outlaw 406@aol.com
I just thought after milling the slots out that there was not enough materiel in the 049 tube strictly my opinion as I am a dreamer not an engineer so I went to 065 wall and I am satisfied now with the end results.

 

From: PMorgan001@aol.com
The best way I have found for getting a fast smooth finish is a bit messy but works Great!
What you do is lay up your glass, paying extra attention to edges, etc, (remember glass is hard to sand when fully cured). squeegy it down well to remove the excess epoxy. When you have a layup that looks good, while the expoxy is still wet but starting to gel a bit, pour glass bubbles over your layup. (wear a good mask). this is a bit messy but the results are worth it. Brush the excess glass bubbles back into a plastic bag, they can be reused on your next layup. When the layup is half cured 4 - 5 hours, trim trailing edges, ect with a sharp blade. this will save Hours of work. When your layup is fully cured, you will find a light sanding with only little more filling is required for a great base to work with.

 

From: RIHNAIRCO@aol.com
There is no reason to burden the aircraft with the extra weight. I have seen the prototype pull 10 G s with a 235 lb pilot plus parachute etc. There was no problem and the aircraft has flown hundreds of hard aerobatic hours on it since with heavy pilots. Stick to the plans it is safer, and cheaper in the long run.That occurred because the builder had planned on spruce and completed his ribs when he switched to fir. He was willing to take on the extra weight rather than build new ribs. He didn't do this to create greater strength. This is a rather stiff wing as it is and is plenty strong. Remember adding weight to an aerobatic airplane is more serious than standard aircraft. Every pound added is going to be like 10 pounds at 10G.
 
From: DanRihn@aol.com
Aircraft quality lumber usually has a moisture content of 12%. It should not be less than 8%, this would make the wood too brittle. Good reading on wood and wood building techniques-
EAA Aircraft Building Techniques WOOD; available from the EAA. This is the best book I have seen. I highly recomend it for every One Design builder.
Government issue books-
CAM-18
AC 43.13-1 A&2 good general guides, this is a modern version of CAM-18
Airframe and Powerplant Mechanics Handbooks- Airframe, and General
These last two were published by the Forest Products Laboratory. The data in these books were used for the design of the One Design wing. Copies of thiese books are hard to get. They contain mostly test and engineering data.
ANC-19 Wood Aircraft Inspection and Fabrication
ANC-18 Design of Wood Aircraft Structures
Remeber to monitor the humididty of your work place while building your wing. An inexpensive humidifier works great when conditions get too dry. A good rule is to keep your humidity at about 75% (or higher) during the construction process, especially during skinning of the wing.

 

From: ddavila546@aol.com
Wing ribs--use staples or nails to hold gussets in place, otherwise they slide around. air powered nailers are under $75 and you can tell your wife its for her new kitchen cabinets(someday)

 

From tfabian@netrix.com
Answer to C - Raka Fiberglass carries .75 oz cloth. They have a web page  at www.raka.com.

 

From Danrihn@aol.com
The lightest I have found is 1.4 oz/sq. yd. 1.45 Deck cloth is fine.  The lighter cloth is very hard to find these days.

 

From:  Danrihn@aol.com
The wing attach set up you describe sounds good

RIB DRAWING
From: SKYBOLT55@aol.com
In order to make the first 3 long ribs match the aileron you need to make them a total of 5/8 wide at the trailing edge. Including the 3 mill ply wing skin. It runs in a straight line from the back of the rear spar. This was pointed out to me by Doug Dodge. He built the prototype. The plans are wrong.

 

Aileron Hinges
Date: 95-01-19 20:01:02 EST
From: SKYBOLT55@aol.com
I have spent several days with Doug Dodge at Acro Specialties. He has a better aileron hinge and belcrank assembly for the 1D. The plans belcrank makes it nec. to enlarge the lightning holes in the ribs for the ail. push-pull tube. This design eliminates the problem.

 

Todd W. Ashcraft
I can't afford a good fine wire staple gun, so I clamped each rib (to glue on the capstrips/gusstes/etc.) in my wing. A person can quickly go broke buying enough spring clamps for this, and spring-loaded clothespins are too weak and don't open wide enough. I found a company (ACCO) who makes what they call "BINDER CLIPS" in various sizes. The large size, which come about 6 per box, work well for the thicknesses of these parts. Made from black painted spring steel (or Iconel?), they are strong enough to get a good hold, but don't squeeze out all of the West Epoxy. They can be found at any office supply store, and are far cheaper than the made-for-woodworking clamps. Try them.
Also, using these clamps, a long/slim work table(closet door) covered in plastic sheet, and the 1/2" acid brushes plumbers use for pipe cement, you can work in assembly-line fashion and crank out all the ribs in about two sessions.

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