The connection of the fuselage to the wings was very similar to the tail pieces with the exception that i also needed to cutout a place in the wing for the motor. Again mainly this involved lightly clamping things together and measuring over and over comparing both sides on top and bottom before cutting away the laminate and cutting thru the wing. I probably cut a little bit more than i needed off of the wing, but after seeing how well epp glues to itself and plastic i knew i could just fill these spots in later and have a solid connection.
In one of Jeremiah’s comments on either facebook or youtube, he had mentioned that he liked to fill in the cutout spaces with some shoogoo, as this gives a very nice surface to stick things too like velcro. I have tried this on a couple planes and sticky back stuff LOVES shoogoo surfaces. Works awesome. So since i had to wait for e6000 to dry i added shogoo to the compartments facing up.
Its a little hard to see whats going on in this picture, but what i have done is placed a scrap piece of carbon fiber flat stock across the top of the motor so that the motor is pushed down on to the bottom plate of the fuselage. When i initially tried just sandwiching the motor plate between the top and bottom fuselage pieces it made the motor have a very strong downward angle. After this dried for a few hours i went back and applied glue to the top fuselage piece and glued it down. I also took some scrap pieces of epp and glued the edges of the wing to the motor plates.
This picture shows how close the tail booms are to the 9×6. Probably have 1/8 to 2/8 of distance. I have spun up the prop with no problem and the booms are pretty stiff, but in a crash i have no doubt its going to make contact.
It was at this point in the build where i started getting a little nervous. Connecting the various parts wrong, from this point forward, would make a big big problem in flight. If the parts are not aligned it could cause all sorts of issues in flight, as i have found from building foamies. Also, although i haven’t seen exactly how others build epp/laminate planes i was assuming that you wanted it glued foam to foam not glue to foam. So first thing was to get the parts mated up and measure, measure, measure every distance between parts. When i was happy i clamped everything down and measured again, before tracing out the laminate to be removed. Even with all this measuring, i was off about 1/8″ to 1/4″. Not noticeable really but i have no idea the impact this will have on flight. It was also around this point that i had run out of welders glue (copious amounts!). I had recently picked up some E6000 glue and after testing this on some extra epp i decided to use it in place of welders. It was also at this point that i started getting worried about the distance between tail booms as i had NOT made sure my 9×6 prop was going to fit inside that space.
The connection between the tail booms and the tail section is a pretty simple thing to accomplish, but i almost made a mistake that i didn’t realize for several days later. In mocking up the connections i knew it had to be square but i wasn’t sure exactly where i should put them on the horizontal stabilizer. I knew they went outside the vertical stabilizers, but even with that you have several inches to play with. The other connection on the wing is the same angle all the way out so it didn’t really matter on that side (i thought!!More on this in a later part). So making my decision based on aesthetics, i decided to line the outside edge up with the spot right where the 45 cut starts on the horizontal stabilizer, not only using a 90 degree for reference but also measuring the distance between booms all the way down.
As the booms are one of the weaker points on the plane I didn’t want to weaken them any further by making cuts into the foam to hide cables. So i used packing tape to attach it to the plane. Packing tape sticks extremely well to laminate. After i did this i definitely added this in my mind as an option for the rest of the plane if i don’t want to cut into it.
The Motor mount is made of 4 pieces of thick plastic. The holes and tabs fit tightly together. Not hard to get together but tight enough that with some glue there is no fear of it coming apart. The kit comes with several motor mount plates so that you can fit a number of different bolt patterns depending on what you are using. The large hole is for threading a plastic bolt thru the top of the fuselage, thru the motor mount, and into a plate in the bottom of the fuselage. This would make it easily removable. I am going to mount it permanently with the bolt and glue.
As i stated in the beginning posts, the tail section is not touched on specifically in the build videos. In hindsight i see now that the cuts in the horizontal stabilizer were the relief cuts for the elevator. The vertical stabilizers get installed NEXT to that cut, not on it like i did. This caused me to have to make my own relief cuts. The hinge in created by removing one layer of plastic on the bottom of the coroplast. If you haven’t worked with coroplast before, it is very strong. Although it is easy to bend and deform it is very hard to tear or rip it without something sharp to start a cut, so this should hold up to alot of abuse. The control horn is made of a top and bottom plate held together by screws, which i also glued.
The aileron control horns are something new to me, having only used wood glue in horns in the past. They have one plate that slides up and goes on the top of the aileron and another that goes on the bottom. There is alot of force needed to squish the foam enough to slide the locking plate on. This combined with glue on both surfaces should ensure it never comes off in an accident.
Gluing the pieces is pretty straight forward. The only “issue” i guess is that in Alex’s video (here) he shows that if you wait 10 minutes for the welders to set, when you push the pieces together they stick together. In my experience this is NOT the case. They do bind together very well, but it has a lot of play in the weld. So i have been gluing and then clamping the pieces or putting something heavy on them for a few hours. No big deal, just FYI. As a test to see how much space i had for batteries and CG i put a 5000mah 3s pack in. Pretty tight fit. Not bad, should keep things from moving around. Will probably put a piece of Velcro at the very front just to keep it from shifting the CG.
The wing took a little figuring out as far as the jig to keep pressure on everything and make sure it didn’t warp at all. The next day it was pretty solid.
The tail section is a very simple concept, but the lack of instructions cause me to make a couple mistakes. The kit does not come with ANY documentation. Now this inst a surprise, i knew this already, but there are few things that are not specifically touched on in the videos. Specifically there is no detail on how the vertical on horizontal stabilizers should be placed. I noticed a slit in each piece and wrongly assumed they mounted to each other using it. So now i not only had my vertical stabilizers about an inch farther than they are supposed to be, i have also used the relief for the elevator. No big deal, i just cut some new slits next to the stabilizers and made my hinge per Alex’s instructions.
The final parts for the body are to install the wing and motor screw mounts. If you like you can remove the wing for travel. I am going to glue everything together, but this will add some good reinforcement to everything.
My plan was to do a first flight before any finishing work. That way if i totally pwn it i could save myself some time. Unfortunately my RX is going to take longer than i thought to be delivered, so i decided to try painting. I put Minwax on the paper first and let it dry for a couple hours. I Put masking tape on the duck tape. In the future i may double up on the tape and i am not sure what effect having paint on top of the tape will do to the next layer sticking on it. Basically i just grabbed some glossy paint i had on hand. Black and Red.
If it flies i will clear coat the top and put clear packing tape on the bottom.