AMF 14H MARANDA SN:1026 Making Sawdust April 11, 2014
Well, it is spring and, even though I did install the engine on the fuselage a couple of weeks ago, you are probably wondering what I have been doing all winter. I have been working on the ailerons and elevator. All of them are nearly done, but the ailerons are the farthest along. That is probably because I had some help with them.
A group of young men from church spent a couple of Sunday evenings working on the spars for the ailerons and on the skins for the elevator. Then my son, Nathan, came from California for my birthday and we installed the aileron ribs. The rest of the process I did by myself. Oh, and I did take some pictures.
This shows the aileron spars with the ribs sort of attached. The locations for the nose ribs are being marked.
The trailing edge of the ailerons is being made the same way that I made the trailing edge of the wings and elevator, rather than the way the plans call for. The plans call for the trailing edge to be cut at the appropriate angle with a notch cut lengthwise to accept the gussets. What I have done is to cut a piece of 2mm plywood to run the full length of the aileron, then I marked the desired location of the aileron ribs and glued them in place. Once that much was assembled I cut fir strips to be glued on each side of the plywood. Later I shape the trailing edge with a planer and sander.
All of the aileron nose ribs are identical. I rough cut the ribs, then stacked them together and sanded them to make them identical. I used my little pull saw to cut the notch for the leading edge stringer.
The locations of the nose ribs were marked. These are not all placed directly on the other side of the spar from the rear ribs.
To make gluing the nose ribs into place a bit easier, I clamped a couple of boards across my bench to allow me to hang the ailerons with the front of the spars up. I could mix up some T88 and glue the nose ribs pretty easily. Of course, I stapled the nose ribs as I glued them and pulled the staples once the glue had cured.
Before I glued the trailing edge strips I marked where I wanted to cut out the plywood. This results in some weight savings and makes everything look like the plans. However, I think it makes things a bit more durable and secure.
After the first trailing edge strip is glued to one side of the plywood, I used my pull saw to cut out the area ahead of the trailing edge strip. The areas of the plywood that I left correspond to the gussets that the plans call for. I cut the angles to 45 degrees because it was easier to mark that angle with my combination square, than to mark the 30 degree angle called for in the plans.
The center rib for each aileron was built just a bit differently than the plans as well. The plans call for two ribs to be positioned in the center. These ribs needed to have a gap between them for the aileron horn. Since I plan to use push-pull cable to activate the ailerons, the aileron horns will only protrude above the ailerons. Therefore, the horns can be inserted from one side. Therefore, I used 3/4″ fir in place of the two ribs. Then I cut a notch in the rib to accept the horn.
Partial plywood skins are glued on the top and bottom of the ailerons. Holes needed to be made in the skins to allow the horns to be inserted and bolted into place.
The bottom skin is flat, but the top skin is curved. There is a solid fir strip on the leading edge to hold the top skin while the rest of it is bent to the contour of the aileron top surface.
The way that I did this was to glue the fir strip to the plywood first, then I smeared glue on the top of the ribs and spar. As I positioned the skin assembly in place I glued and stapled the gussets in place to hold things securely. Once all the gussets were in place I could staple the skin to the nose ribs, spar and aileron ribs. I had to carefully work things to fit the required curve. I used enough staples to hold things securely.
When the glue cures things should look nice. Then the trailing edge strips were planed and sanded to the proper shape.
The next step will be to cut the piano hinge to make the hinges for the ailerons.
on August 17th, 2014 at 5:32 pm
beautiful work.
I’m buying the plant from Chris, I believe that soon I start mine.
manoelzeferino@gmail.com.
I want a little help if possible.
on August 18th, 2014 at 7:29 am
Where are you located? I am always willing to provide my opinion and explain why I did things the way I did by email.
on August 18th, 2014 at 11:58 am
I’m in Brazil..
He was very pretty, I’m buying the plane Chris.
I hope I can do it.
I wonder, is easy construction?
on August 18th, 2014 at 1:10 pm
The construction is not difficult. You never build an airplane, you only make pieces. Then you fit the pieces together into bigger parts. When all the parts are finished and fitted together you end up with an airplane.
Plan on spending the first several months studying the plans. Figure out where you will start and proceed from there.
on August 18th, 2014 at 2:36 pm
all wooden parts were manufactured for you? Or have to buy a kit?
on August 18th, 2014 at 2:40 pm
I saw it used T-88 Structural Epoxy Adhesive. How much?
on August 18th, 2014 at 3:39 pm
I made all my own wooden parts. I ordered the wood from a local lumber yard and the plywood from Aircraft Spruce and Wicks.
My initial order was about 300 board feet of Douglas Fir from a local lumber yard. This was enough for all the longerons and spars. The remainder of the lumber I got from Menards by hand selecting pieces of Douglas Fir flooring. That worked out very well and was MUCH less expensive than ordering Sitka Spruce.
I like the T-88 and have ended up purchasing several gallons, however, I only order it in quart volumes. The quart quantity comes as two pint bottles with squirt ends on them. These are easy to use when mixing. I tried ordering a half gallon (two quart containers) to use for refilling the pint bottles, but that got to be way to messy for my liking.
Other glues are available as well. Find a glue that you are comfortable with and use it to make some test joints. Then break the joints. What you want is for the wood to break instead of the joint. If you can consistently create good joints that are stronger than the wood, you are doing things right. The particular glue is less important than the quality of the joint.
Chris doesn’t call out any particular glue, but other members of my EAA chapter who were also building airplanes were having good luck with the T-88, so I just followed along. That gave me some others to ask when I had questions about how to use it.
on August 20th, 2014 at 8:17 pm
please tell me how much hp is your engine.
I talked to a specialist here in Brazil, he told me that this aircraft does not fly with less than 120HP engine, because it has too much drag.
Do not believe it. I want to know if your aeronove is already flying, or if you know someone who has some flying.
Thank you.
on August 21st, 2014 at 7:55 am
I am building the 14-H model which is designed to meet the LSA requirements. The engine that I have is a Continental C-85-12 which is 85 HP. The specifications that Chris put in the plans is for an engine between 50 HP and 120 HP.
Randy at http://mywoodenairplane.com is using a Corvair engine in his 14-H. Patric is building a full Maranda and has a Lycoming O320 that is rated at 150 HP, I think.
Most of the larger versions use at least a 120 HP engine, but I was looking for something lighter and more economical.
on August 21st, 2014 at 10:18 am
First of all, I want to thank your attention.
Well I saw the design of your aircraft, I believe that it should be very light both on the ground, as in flight.
Here in Brazil, the construction of aircraft, is not common. There are not many people with whom we exchange information.
Here, we have a huge shortage of aircraft engines.
Is no choice of automotive engines, such as the Subaru 2.2 or 2.5.
We have a VW AP 2.0 engine water cooled.
Both engines are used with reducers. See attached photo.
When it comes to automotive motoro have much fear about safety.
This AP 2.0 engine was widely used in cars in the 80s and 90s in Brazil, is an engine with high reliability.
I really want to build this aircraft, but we have the problem as aeronáticos engines in Brazil.
Quaker new aircraft engine of 100 hp in Brazil costs around U $ 30,000 to 50,000.
Used when you think in make a U $ 20 30,000.
vide http://www.altaircoelho.com.br/grande/AC16MotorAc53.jpg
http://www.altaircoelho.com.br/grande/Fotos%20da%20Maquina%20027.jpg
http://www.altaircoelho.com.br/grande/AC%2054-1.jpg
on August 21st, 2014 at 11:25 am
Just because I am using a C-85 doesn’t mean that it is the only engine that could be used. There are quite a number of auto conversions being used in aircraft. However, a plane with like the Maranda would work best with an engine that could swing a long prop at a slower speed. Something like a 74″ diameter propeller with a 41″ pitch at about 2300 RPM. That means that any auto conversion would need a PSRU to meet that requirement.