Ben Harber's XB-70 (wings, engines and wheels!)

by FliteTest | January 2, 2018 | (5) Posted in Projects

Here at Flite Test, we just love sharing community projects. As one of the most epic airplane builds we've seen for a while steadily takes shape, we wanted to give you an update on Ben Harber's giant scale RC Valkyrie. Before you jump into this article, however, be sure you read more about the real XB-70 and and the first steps of this undertaking in part 1 here (if you haven't already). Okay, let's get going!

The Wings

At first glance, you may mistake this shape as a rather large cardboard triangle. However, on further inspection, you'll see that this is, in fact, a very carefully engineered delta wing complete with a sweeping airfoil and separate wing tips (shown more further down in this article). As you can see, Ben is using our Flite Test Waterproof foamboard which is a good idea for an RC aircraft this large; if you're thinking of building a giant scale RC plane, you're probably going to want it to stick around for a while.

Here you can see how the internals of the wings were constructed: spars and wing formers were cut from foam board and glued to the inside of the wing to establish the curves of the Valkyrie's airfoil. 

Once folded over, much in the same way as our far smaller FT designs, the wing takes shape. 

Just like the real XB-70, this model features folding wing tips. It probably won't help to trap a sonic shock wave under the belly of the craft as the real XB-70 did (as this one won't be travelling quite that fast despite the six EDF's), but it certainly looks the part. 

The Engines

These are six 70mm EDFs almost ready to create some serious power. Mmm... lovely motors. 

Adding the thrust tubes takes the build that one step closer to Flite Fest where Ben will debut the finished XB-70 aircraft. 

With big motors come big ESCs! It must have been a relief that all of the electronics here have bullet connectors. Just so you know, our power packs in the FT Store all come with bullet connectors which means you don't have to do any soldering. As a top tip, it's worth looking out for this feature in your electronics when you're looking to invest in some new ESC's or motors. 

The Undercarriage

Check out these 3D printed components of the landing gear. Just like the real XB-70 Valkyrie, this model needs a hefty set of wheels to carry the weight of the plane. When complete, the mass of the finished model will be around 20lbs/9kg - so it's a little more than most of our foam board planes! 

These aluminium components add an element of realism to the aircraft. It's aesthetics and functionality all rolled into one.  

Hopefully, you can take some inspiration from this article to get out there and start your own marathon builds! All you need is some materials, some electronics, and a vision of what you want to make. So build it, share it and fly it like you stole it. 

Find out more about the Valkyrie:

The Flite Test forum thread featuring Ben's Valkyrie

NASA article on the real Valkyrie 

Article written by James Whomsley Editor

Instagram @jameswhomsley


elijahf111 on January 4, 2018
is he gonna show it at ffw or ffe
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Anthony Evans on January 7, 2019
One of the coolest r/c planes I've ever seen. Just the landing gear alone were pretty much a work of art.
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jwc4520 on July 26, 2021
Many time I have walked around and under the XB-70. on trips to WPAB. Fct is I met some of the engineers that built this marvel. Parked nearby was the model that has beaten my efforts, the YRF-4E, upon retiring I went to photo every detail of the plane. Equipped with enough camera to take a thousand detailed photos I drove the 60 miles and went directly to the planes spot. It was missing? I ask if it had been moved, no it right here... as we went to the empty spot the search began. The plane was missing and the staff had no idea where it went. I went home and made a joke about it being lost on FB, gosh the AF got mad, in a terse email it was explained it was out for repaint. 7 years latter I checked still out for paint. Once more on FB, i had to share, even offered to come up and help since I had some old paint brushes in the shed .....Next day it was relisted as in storage .... I suspect it was made into a special QF-4 mod. Any how I saw your F-4 ....want to add canards?

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Ben Harber's XB-70 (wings, engines and wheels!)