I believe as per Shawn's last post.... He potentially has a fuselage half. Might possibly get stuck in the mold and be ruined as it comes out???? LOL


Ken

Ha ha, I have two fuselage halfs done! Right now I am figuring out the internal structure. All the formers, doublers, and gear plate need to be in before I can join them. I'm planning on getting the halves seamed over the coming weekend. Scott, the slimmer is next in line, I promise.

Shawn, you plan on adding some carbon to both sides of that cardboard or just gluing it in the way it is??????

Scott

It's " special " cardboard!

Ooooooo Ahhhhhh "special cardboard" That is the real stuff right there. That should add extra lightness and strength to the fuselage. I hear it is like Unobtanium to get a hold of! LOL

Looks good Shawn!

Ken

Ok you two, enough nonsense! I did cut out a couple formers from the actual material that is being used. It is a laminate of 1/8" Divinicell with 5.7 oz carbon cloth on each side. This is some of what I have been selling to other guys as well as the fiberglass material as well. Over the next few days I will be cutting formers and getting them glued into place.

That is some interesting material. Had to look it up. The Smaragd I had used a bunch of the honeycomb stuff for formers and servo mounts and such. It was light enough but I felt was a bit to fragile. This looks better to me. Looking good and nice progress!

Ken

Yup, that is the same laminate I use. I need to make some more since Chris lost 2 426 planes at Phoenix last weekend...
Are you going to do the inner laminate and seam in 1 piece or tape the seam later?

Scott

Scott, I'm going to go ahead and tape seam but if you notice there is a small twist. I'm sure that you have noticed that there is an edge flange molded onto the fuselage seam. This is only the last layer of 3.1 oz cloth. A thin bead of paste adhesive will be applied to this flange, some straight resin applied to the edge of the fuselage and then the molds will be clamped together. I will then apply a 1" tape across the seam. I will be posting pictures of a fuselage early next week.

Hi Shawn, Scott,
I was curious about Divinylcell and googled it. Wow, that stuff is lighter than contest balsa. What do you think about using it in all balsa construction? I was thinking of laminating 1/16 balsa to the outside and using it for fuselage sides; I'd reinforce the inside too depending on the location in the fuselage either with open framework or more 1/16 balsa or maybe ply around the firewall/landing gear areas.
Thanks for your thoughts!
-Will

I used carbon honeycomb for formers, tank tray and servo mounts in my Xareltoo and it's plenty strong enough. I put ply hard points in for screws etc.
This Divinicell does sound good though. Probably would still need hard points for screws though?

Yes, I would not put any screws in it. For things like servo mounts I lay up a panel made from 2 sheets of 1/32 ply and 3 sheets of 5.7 oz CF cloth. I also use this for gear plated and firewalls. Ken has seen some of this. The Divinicell material I use anywhere you would use balsa or lite ply. I'm not a big honeycomb fan, it's only real strength is in compression. As far as using a Divinicell laminate for fuselage sides and such, I think it would be better to just stick with balsa, but to be fair I have not experimented with it in this fashion.

I fit pieces of 1/8th aircraft ply for hard points between the carbon , about 10mm wider than the servo and 1 layer of 200 gram carbon each side.

I've also used the same for gear plate, but 1/4" thick and 3/8" hardwood dowel for hard points.

Works fine.

Productive day today. Got all the formers in and parted the hatch mold.

I just realized you have some balsa sheet in the mold. Is it being used for extra stiffness? Sound dampening? I guess I assumed the glass alone would be "good enough".

Ken

Ken, a fuselage this large needs a core material to stiffen it up. To do that with just fiberglass would make for a heavy fuselage. I chose 1/32 balsa because of every type of foam that could have been used, balsa in this case gave the best strength to weight ratio. Hopefully tomorrow I will have a final weight on this fuselage. The max I was shooting for is 30 oz.

Makes perfect sense. My Smaragd was Kevlar with a 1/16 layer of white bead foam with 3/4 oz.?? glass cloth over it. It was very fragile. IMO. I think part of that was using Kevlar. While Kevlar is very tough it seems epoxy does not really seem bond to it. The epoxy just seems to encapsulate it.

Thank you for posting your build and putting up with all my questions. I'm learning a lot!!

Ken

And now I have an actual fuselage. Now the real build can begin.

Hi,
Great work.
Can you give us a weight for it at this stage, please.

Brian

Brian, with all the formers, gear plate and root ribs for upper wing and stabs the weight is 39oz. Not as light as I was wanting but not unreasonable either.

I would say, not bad for a first pull from the mold. I see the DLG guys modifying their layups all the time looking for that magic weight to strength ratio. I predict as time goes the layup will get lighter and stronger.

Great job!

Ken

Yes, I have already come up with a few changes. If I can get this one under 11 lbs I will get it flying and then start on a new fuselage.

Hi,
Yes at 39oz it is a little on the heavy side.
What weight were the balsa sheets ??
Rohacell 51 is very good in a fuz,, sandwich - a little pricy - but light.

Brian

Brian, I used 1/32” contest balsa. Should have been lighter then a foam core. I think I just ended up with too much resin.