Looking forward to following your progress

Then came the sheeting. This was the number one reason I built the heavy, rigid jig last year .

I knew then that no matter how nice I applied the bottom sheeting---the top sheeting can change everything and locks in all the incidence, angles, true vs warp, etc that I needed. Without the jig who knows how it would come out?. My goal is to not only have things true, aerodynamically correct, etc---but to be the same as the Prototype so its Maiden Flight performance will be more familiar to me.

And a better chance the Maiden flight won't be the last flight.

Next step was to add top and bottom light ply covers for the gap between the 2 halves

But first I custom fitted these fillers to handle the major compression loads when the bolts go through this removable stab and are tightened down.

Although the fillers are from very light (and weak) contest balsa I think they will provide the strength needed because they are on end.

Finally the top sheeting is applied with overnight foaming polyurethane glue and "tons" of sand bags and model airplane magazines curving over the surface to apply even heavy pressure.

Finally the stab is rigid and strong. Best of all its light too

What a monster build ! ;>}

Now that I have the Stab, how do I attach it to the jet?
First problem is the frail fin frame projects out behind the fuse. This makes it tend to compress or distort when the Stab is placed on top. That changes the incidence, threatening everything.

Solution. A CF square tube glued to the TE to support the fins top rib where the stab mounts, plus Rigging under the LE. The rigging pulls the fin up straight and holds it there. The turnbuckle enables fine tuning, one notch at a time until the Incidence meter says 1.5 degrees. This should hold everything in true position until the sheeting goes on and adds strength to the fin, then it will provide additional strength in flight.

Although the rigging is Kevlar (Don's Hobby), this is basically WWI Biplane technology. Except that I won't have the drag penalty since the rigging is internal.

Next Challenge----They don't seem to make aluminum bolts longer than 3 inches..............So I made my own

I hack-sawed this 1/4-20 all-thread stock to the right length , then thin CA holds a nut on top to be the head of the bolt. For good measure I drilled a hole through and glued in a piano wire retainer. The slot on top was then made by dremel and cut-off wheel.

I made my own blind nuts too since the alignment with the Stab Bolts must be perfect and I doubted my ability to do that with normal "pronged" nuts. A piece of 1/4 inch lite ply provides a wide area of support and gluing surface. After drilling a 1/4 inch hole I use a small file to make it a Hexagon. The nuts are then glued in and trapped in place by a piece of 1/8 liteply. The 1/8 has a 1/4 inch hole drilled in it. Large enough to let the bolt pass through but not the nut.

Heres how it turned out. The aluminum bolts hold the stab and the nylon bolts hold the top rib its mounted to.

Sorry about that.

With the Swept back spars in the Hstab which also has some dihedral,
I was fresh out of ideas and just happy to be able to get the Rib shapes accurate.

The YB is nuttier at the shoulder. a real struggle.

Bird of Play...................Whats in the water in Indiana that makes people so humble?

You have nothing to feel "sorry" for. You did nothing wrong--quite the opposite, in fact..

XR-1 is a difficult subject which proved too much for even the great Werner Von Braun. Thanks to your CAD genius, and knowledge of everything from 3D printing to Full Scale flight, we actually got an XR-1 in the air for the first time ever. Watch it soar and gleam in the video above. Reflects the sun and reflects well on you.

I have enjoyed following and watching your progress on Von Braun's fictional spaceplane but really what makes it worth watching is the excellent video work of whoever is doing the shooting. Really, some of the best that I have seen.

Jim

The pre-build will take longer tahan the build

Though the pics above show the fuse maybe ready for sheeting, it was only trial fitted together. Everything had to be disassembled and drilled full of lightening holes, then sub systems like the removable cockpit and landing gear designed and fabricated,

Here's how I prep the main stringers and sheeting--pre-formed after 50 seconds water soaking to the correct shape. Many stringers can be bent to shape on the frame. The Rack is only for the 4 strategically placed spruce stringers and 4 harder balsa ones.

I will once again use Trailing Link Trucks--although I'm not aware of anybody else ever using them---cause they performed so well on the Proto. Robart steel on the mains and Electron aluminum on the nose.

Heres my mock up of the Main system before the trucks are replicated in aluminum with lightening holes. And this is how I lightened the Electron nose strut by drilling major holes throughout and covering them with lightweight aluminum tape. Lighter wheels throughout also help.

But I decided go beyond normal with lightening and try mating a Nose Retract rated for smaller planes with Main retracts rated for a 50 Pounder. This may prove to be a mistake. Flight and taxi tests will tell the truth, whether I like it or not. But my belief is that nose retracts don't have nearly the stress on them--and don't need to be nearly as heavy or strong--as Main Retracts. It seems this is against mainstream or industry practice to use all three retracts the same size. So I may have an embarrassing failure here. But I'm going for it as I have before on other cutting edge planes, mostly successfully.

Here is a pic of the smaller nose retract I will attempt to use next to the "right size" nose retract. Tests show it has no trouble lifting the gear even without the wind which will assist its rearward retraction after takeoff. If anyone is bold enough to attempt this before I get flight test results, be sure to have Electron Retracts do special programming for you in the controller so the disparate size retracts can work in unison. Electron was most helpful . I like those guys.

The root ribs are put together from many parts of light ply, light balsa and the aluminum platform to hold the incidence meters.

The platform must be glued exactly on the RR centerline. It will be the reference authority when it comes time to set the critical stab incidence.

This pic also shows a new idea I'm trying . Strengthening a former by adding a lightweight 1/8 x 1/4 brace perp to a vertical light ply brace--instead of using a stronger brace made of CF or stronger wood,. Alone, the lightply vertical support cannot handle much load. Same for the balsa brace. But together there should be strength Magic---as the balsa brace saves the stronger liteply strut from its great weakness--bending,

Impressive - even the weights holding down your spars have lightening holes!

Another way to make a stiff former would be to use two thin ply faces glued to a foam core. The sandwich construction would keep the thin ply faces from buckling.

Thanks, Tspeer

Your idea seems a sound way to get strength with less weight. Those holes in my steel weights are some kind of metal workers standard. But they do look a lot like lightening holes. Maybe their presence will inspire the wooden parts of the plane .

Speaking of lightening holes. I took everything apart and drilled all the lightening holes, and designed and built all subassemblies I can forsee, so now I am finally putting it all back together for "real". Once this is complete I will break out the glue. Imagine I havn't even reached the gluing stage yet.

At the EAA's Airventure in Oskosh, they build an entire full-scale airplane during the week of the show,............At the other end of the Speed Spectrum, there's the XR-1 Build.

Now that’s what I call a “space”plane