GREAT PLANES EXTRA 300S, 60 SIZE, ELECTRIC CONVERSION, 2019 BUILD ALONG

nhk750

Aviation Enthusiast
Finished the fin, now just need to build the rudder then cut hinges and sand edges round. Then I decide to start on the wing or the fuse, I really want to work on the fuse but you need the wing to do some finish work on the fuse, but the fuse is the meat of the conversion project and I can hardly wait to get busy with that.
 

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nhk750

Aviation Enthusiast
So, I started working on the rudder and accidently cut a piece of wood to short (the rudder base) and of course I had none of this size around. So, off to the LHS to buy some, guess what, no one around here carries any 5/16" x 1" stick or any 5/16" for that matter, and if I order a $2 piece on line it will cost $15 for shipping (Balsa USA and National Balsa) arrggggg! For some reason 5/16" is a rare cut of wood, so I took some 3/16" balsa and laminated some 1/16" sheet to both sides, then cut it to size and there ya go, made my own wood! Back to building the rudder, which is actually the hardest part so far.

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nhk750

Aviation Enthusiast
I finished the rudder today and just need to cut hinges and sand the edges round per plans. Wow, this plane has a large rudder, bigger than all my 60 sized aircraft. I did the calculations and this is a 1/5 scale plane. The fuse looks to be really large also, what a fun plane to build, too bad they don't make the kits any more...


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nhk750

Aviation Enthusiast
I decided to build the wing next as it’s needed to align the fuse during the build. I like using Great Planes plan protector plastic as it works great and doesn't stick to Titebond. Everything is layed very flat, tight and ready to start on a nice wing build. Got some basswood layed out for tomorrow.
 

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nhk750

Aviation Enthusiast
Working on the wing spars and gluing the doublers on. I like to use a really good straight edge and press the spars very straight when working with them, I will also press them straight when I put them in place on the plans and begin the wing.

In the mean time, the spinner from TrueTurn showed up and it looks really nice. They are very expensive, but I wanted this plane to be a special build as it's my first Extra 300 and it needs to be super duper...


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Chuppster

Well-known member
Question: what are the black weights you are using to keep your pieces in place, and where did you get them?
 

nhk750

Aviation Enthusiast
I use film canisters filled with lead shot, the steel blocks are called 123 blocks (with holes and without), the little black things are latch magnets with the steel and without. Amazon carries all this stuff. I'm building on a steel board so I can use magnets.
 

Chuppster

Well-known member
I use film canisters filled with lead shot, the steel blocks are called 123 blocks (with holes and without), the little black things are latch magnets with the steel and without. Amazon carries all this stuff. I'm building on a steel board so I can use magnets.
That's a really cool idea! I may have to get those instead of t-pins when I give balsa a try.
 

nhk750

Aviation Enthusiast
Yes, building with magnets opens up a whole different world of possibilities to build airplanes. It’s expensive to get set up, but you can use the jigs and stuff to perform repairs and build anything, including foam airplanes, boats, whatever. I cant even imagine using pins ever again.
 

Chuppster

Well-known member
Yes, building with magnets opens up a whole different world of possibilities to build airplanes. It’s expensive to get set up, but you can use the jigs and stuff to perform repairs and build anything, including foam airplanes, boats, whatever. I cant even imagine using pins ever again.

How do you hold down pieces (commonly done by "crossing" T-pins over your piece of balsa)?
 

Chuppster

Well-known member
Ah, that's what those are doing. It all looks really neat, just kind of expensive. Still, I bet I could 3d print some similar stuff.
 

Joker 53150

Mmmmmmm, balsa.
Mentor
There are already some 3D printed designs available, but it certainly wouldn't be hard to custom-design some pieces like he's using.
 

Joker 53150

Mmmmmmm, balsa.
Mentor
Heck, I'd have to do some searching to find them. They were all on the common 3D printing design websites - I think I searched "balsa" and they came up. There was also a thread on the balsa forum here about 3D printing tools which probably has the info as well.
 

nhk750

Aviation Enthusiast
Im looking at the dihedral gauge (rib gauge, G1) and measured the angle of it which is only about 1 deg off of 90. So I see no reason to install all the ribs at 91 degrees like the directions suggest. The only rib that needs an angle is the root rib on both wing halves, so when joined there will be a slight amount of dihedral. I'm a little lost on this one so if anyone has built this before or has some advice?
 

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nhk750

Aviation Enthusiast
After figuring out the dihedral angle (I like to research the build as much as possible before starting), I laid down the spar and cut/popped out all the wing ribs. I learned how to get the spar exactly straight from Airfield models website building tips and experience from my past builds, refining a good method for myself.

Using a good quality straight edge, the spar is pressed against that and everything held secure with magnets, then remove the straight edge and apply magnets to that side of spar. I'm using magnets to press the spar flat against the building board to start with and as ribs are installed and glued will switch to vertical presses and weights. Using a straight edge instead of a line on the plans assures a very straight wing build as sometimes plan lines can be off a bit. It's very IMPORTANT to have a straight spar as its the main building block of the wing.
 

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