Love it! How could I get My hands on molds?
Seba

I think next they go to Mark C in the UK, he has waited long time. Marcus T is almost done with them.

Hi Dave, I'm still here and absolutely enjoy watching the progress.

biber

Oh boy! Not only is this the birth of a new Mubu, it's a totally new process for me to build wings: https://www.rcgroups.com/forums/show....php?t=1721451

Looks very nice.
And interesting build.

I've seen the polyurethane foam core thread before, but now I've even more reason to closely watch you pioneers working.

biber

Nice Troy
I'd be worried about sanding in to the mold flange. Too bad you can't hotwire it off without the nasty poisoning yourself bit.

Is it 2 lb density foam Troy?
Yuri

Yuri, this is 6lb density foam. It is very stiff in compression and dent resistant while still making a relatively light wing (200g). Not having a full shear web I won't be going to full F5D power but closer to 500-600 watts max. I have to see how the control surfaces feel once I cut them out.

Steve, I did the open expansion and sanding to show the worse case scenario. I figured I could do this faster than making custom lids to cast the foam in a closed-mold situation before joining. I had these skins sitting in the mold for several months so I had to just go for it while I had the opportunity. I had little issue with getting close to the flanges but it is still not ideal. With some forethought I could have put down some thick tape on the flanges to protect it better but I actually had glass over-hanging the edges. That gave me my warning to stop when I began to hit it.

My leading edge looks good and the trailing edge is surprisingly sharp. I was expecting some thick edges. If this wing works well I would be willing to spend the time to make lids and process the foam properly. Back pressure and vents would produce better quality foam in regards to cell consistency.

Hey Troy,

very interesting work!

Do you think it would be eneugh support to build it w/o beam-bars for a full performing F5D wing?

Thinks with the lids it will be hard to bring the material in and to get the right distribution... specialy at trailing edge.

Did you sand the foam to zero at the flangearea or do you keep some interference?

Very interested in your judgement about the control surface stiffness...

Christoph

looks nice Troy.

How do you plan on running the cables for your servos? did you put in tunnels or are you tunnerling afterwards?. What did you ise to bond the 2 halfs together as it will be a mostly foam bond?.
I was going to ask s the foam going to be strong enough for a shear web but you have answered that one.

I bonded the 2 halves together with Gorilla Glue (polyurethane glue) and put a little water on to make it foam and expand. This helped to lower the density and forced adhesive all around the surface area.

With regard to servo wires, I will have to make a tunnel for the aileron servo wires. It's not a very far distance to go (just past the inboard elevators). In fact, I may install them in a groove forward of the elevator hing line once that area is cut open. Next time I would pre-install some wire. This wing was an experiment that turned out better than expected so not a lot of pre-planning for the usual necessities.

Some progress today cutting out the ailerons and elevators. Control surfaces feel pretty stiff in torsion but I will know more when I hook up servo linkage.

Hey Troy

that look really nice. Could you please make some close look pics to see the details

Regards

EZ

Ed, there is not a lot of detail to show yet but here you go

I started on installing the aileron servos and making a recess for the servo wires and wipers in the elevator hinge line. You can see where I will put the wire for aileron servos in the pic.

Nice,nice, nice Troy.
Thanx for shearing.
Yuri