Forward nose assembly and bottom glass

It took a lot of work to get to this point (NG30 panels, floor pans, side panels, nose wheel, nose strut, electric actuator, strut cover, nose wheel well, etc) - and it has finally come time to install the forward nose assembly and glass the nose bottom.

First, I had to assemble the forward nose assembly. This composed of the F-7.75 bulkhead and what I call the 'mini NG30' panels. I made these way back when I made the rest of the nose bulkheads. (See nose bulkheads)


I started out by clamping the mini-NG30's into a precisely cut foam block to a width that made sure they would align with the big NG30 panels.


I then measured out and drew the lines of where the mini NG30's needed to be mounted onto the F-7.75 bulkhead... I then predrilled two holes and inserted nails to act as positioning pins.


I mixed up some flox and bonded them in place.


I kept the excess flox to act as a fillet... and applied two plies of BID tape to all four corners.


Clamped everything together and let it cure. (Ok, you caught me! You noticed the NB nose wheel box sitting on my worktable! How can that be if I already installed it?! Well that's because I had made the forward nose assembly a while back! Any who, moving on...)


So I trimmed the overhang glass...


And sanded everything nice and smooth...


I then drew the lines of where the assembly needed to be mounted onto the forward face of the F1-3 bulkhead... predrilled two holes and pinned it in place.


Now she's starting to look like a missile! ::whistle whistle:: Or a radar dome...


I had previously bonded the middle foam piece in place to keep the mini NG30's straight and parallel... so I had to notch out a 3" gap to allow me to bond the BID tape between the mini NG30's and F1-3...


Mixed up some flox...


And used the nails as locating pins to put the assembly back into the exact location I wanted. Again, I kept the excess flox to make a nice fillet...


Applied 2-ply BID tape to all four corners and let cure...


Next day, I trimmed everything up being careful not to hit the nails which would be bad for two reasons: a) my blade and b) would make it difficult to remove the nails stuck in place.


Taaaaa-daaaa! Forward nose assembly bonded to F1-3.


It was now time to bond foam pieces to it. I started out by bonding the bottom floor pans. At first, I was very concerned about making sure I got a tight fit on all mating surfaces, but that was very difficult to do where the foam mates with F-7.75 - since the bonding area is so small. I then realized as long as it was properly bonded to the mini NG30s and the forward face of F1-3, the rest could be filled in later with micro. So I clamped it in place and let cure overnight. Notice I put shims on the outside of the foam so that the clamps would not harm the foam.


Bottom view.. made sure all surfaces were nice and parallel with each other... and that they overhung below the mini NG30s' waterline.


Now to make the forward nose side panels. I knew getting the correct shape would be difficult - so I used the cheap home depot stuff to practice getting it right... and good thing I did since I went through not one.. not two.. but THREE iterations. Once I got the pink foam to work, I built an exact replica out of the good blue stuff (2" thick divinycell).


Notice how I angled the side panels a bit to maximize the foam volume; however, the bottom face mated perfectly flush with the floor pan foam piece. Never mind the giant clamp in the back of F1-3.. I'll explain that in a minute...


Oooooo! That is starting to look like a nice battery compartment!


Being happy with the side panels, I micro'd them in place. I should have made a thicker micro to keep it from oozing out.


Remember that giant clamp I mentioned earlier.... I used it to hold the forward wedding cake onto the forward face of F-7.75 while it cured. I stacked 3 layers of 2" foam... micro'd each layer and added a wooden slab to keep the foam healthy and clamped everything together. It worked like a charm!


After cure, I removed the clamp and flipped the fuselage over. By the way, I should mention that I removed the main landing gear since I knew I was going to have to flip the fuselage over multiple times.

Here's a shot just before starting to carve the nose. My girlfriend walked in and asked, "That's going to be the nose?! Are you SURE you know what you are doing?!" And I said, "What... you don't like it?"


So let the carving games begin!


I started out with a knife... and went to town with it! Slicing away thin slices at a time..


Ok, not quite what we are looking for but getting closer... less Lego'ee


I then switched over to a surfoam.. $16 for this thing but man was it worth it!


I then brought out the big guns... 80 grit hand held portable belt sander! Had to be VERY careful with this guy since he would eat up the foam like butter. But it was very helpful at starting to smooth everything out...


Ok ok... better... but still not there.


I then had to flip the fuselage over again to carve the top nose shell. In order to make sure I had a proper spline, I used a tape measure and clamped it to the aft bulkheads.


Hmmmmm... I see a problem here. Notice how the spline hits the top of F1-3 but not F-7.75.


No problem... just had to make the nose cone steeper... so I shaved some more foam off...


And bingo! Notice how the spline now transitions smooth between F1-3 and F-7.75....


Ok, NOW she is starting to look like a missile! ::whistle whistle::


Flipped the fuselage over... again. But before we can glass, I had to plug up that hole just forward of F1-3... remember, this was so that I could install the forward nose assembly earlier.


So I filed everything nice and square... and prepped the sides for bonding foam to it by sanding everything dull....


Made a plug...


Test fitting the plug...


Micro'd the plug...


And stuck the plug in! Notice how I taped the perimeter so that it would keep the rest of the existing foam nice and clean...


The next day, I sanded everything nice and smooth. Can you even tell there is a plug there? I don't think so...


Ok... so we are now about ready to glass the nose bottom...





But first... some prep work. I knew the glass was going to overhang and wanted to control how far the glass actually bonded with the nose. So if you look close, I installed a strip of clear tape along the side of the nose. This way, I can trim the cured glass along this line later.



Remember that ramp I made just forward of the nose strut? Well I wanted to have a nice strong edge there... so I used my dremel to remove some foam to make a flox corner... it's a bit crooked, but I will make it nice and square when I install the nose bumper later on.


I mixed up some flox and applied it nice and thick. I also used some flox to make a ramp to transition the strut cover with the bottom NG30 edge.


Mixed up some dry micro and filled in as many voids as I could...


Just about ready for glass....



But first, let's discuss the glass schedule. The plans say "2-ply BID - orientation optional". So I made some measurements and decided I could save a lot of glass by cutting 4 trapezoids with dimensions as shown...



 Since the BID roll comes in 38" width, this was perfect!


 
So I cut 4 of the following...



I did the following layup schedule. Notice how the first two plies share a common middle (so that the middle part gets its 2 plies... and then the 3rd and 4th ply butt up against each other but do not overlap. This gets rid of any unwanted bumps in the middle and makes sure all surfaces have at least 2 plies.

 


I then mixed up some slurry and got the bottom left side surface ready for glass...


Ply #1...




Wetting ply #1 out... notice how I left at least a 2" overlap onto the fuselage...


Slurried the bottom right half...


And applied ply #2....


Wetted it out and applied ply #3...


And finally, ply #4...


I then trimmed the fuselage overhang to exactly 2" so that I could apply peel ply and get a nice smooth transition...


Peel plied applied...





After cure, it was time to trim the overhang glass...


I started out by trimming the strut channel.


Then the skirts. Remember that piece of tape I put underneath? Here is where that came handy... I drew a line where I knew the edge of the tape was...


And trimmed along the line...


Taaaaa-daaaa! I now have a nice straight transition line between bottom and top nose shells. I made sure to remove the tape after.


And there you have it! Nose bottom all glassed up! A little sanding work later on and she will be ready for paint... but that is a long ways away!









Although this doesn't complete the nose work... I am considering this chapter (Chapter 13) more or less complete. I will incorporate the top part of the nose work into Chapter 18 (the canopy).




8 comments:

RUdea said...

As always very interesting. Forward to continuing to build.

Javier Lopez Nieto said...

Excellent

Jose hernandez said...

Very nice, Ary
Thank you.

Jose said...

Thank you, Ary.
We follow you til the finish.

Ary Glantz said...

Thanks guys for the wonderful messages! Keep'em coming and I'll keep posting! Happy New Year and all the best for 2015!

Dario Zapata said...

Dear Ary,
I want to thank you for sharing the details of the construction process of your plane. I always review them so I can learn tips for the construction of my own airplane. This blog encourages me in the difficult job of constructing my airplane, because you make it seam simple. I am always looking forward to seeing your new posts. Regards, Dario

Alex Sabbatini said...

Such progress - such wow; Seriously though Ary saw the recent time-lapse of the nose build, you are setting an example for us all to follow!!!

Capt Meatballs said...

Ditto