Hmmm this thread is making me hungry!
Looks like you’re doing an excellent job taking care of this flapjack. I don’t envy he prodigious use of filler on the intake, or fiddling around with those itty bitty prop spinner pieces. I don’t know if I’d throw those against the wall, or spend hours trying to perfect them, dropping them on the floor, and spending hours to find those bits again.
Thanks for sharing, looking forward to seeing this one progress.
Once you did that, someone would have them out on Shapeways!
Very nice model. Look forward to progress.
Yup, the XF5U-1’s intakes needed a lot of Green Putty - and my tube had dried out! The putty had to be softened by mixing it with Testors liquid cement.
The V-173’s spinner parts were just made for the carpet monster.
Thanks!
Major assembly and parts prep completed for both planes. Ready for masking, primer, and paint. All I need now are some nice days with no rain, wind, or high humidity. (I do all my spraying outdoors.)
Both planes can be seen as either one big wing or one big fuselage. So how would they be classified? Flying wings? Lifting bodies? Something completely different?
Well, I guess a flying wing is a sort of a lifting body. The thing that makes the two planes unique is their way to improve performance.
Many lifting bodies have a lot of drag that limits aerodynamic performance because of the low aspect ratio (ratio of wingspan to wing chord). The lower the aspect ratio, the more the tip vortices are strengthened which induces more drag. By putting the props out on the tip of that very low aspect wing, and turning the props in the opposite direction to those vortices, the tip vortices were partially cancelled out by the propwash. This made the plane act like it had a larger aspect ratio, resorting in better performance, so they were indeed unique.
I have often thought one could make a manpowered plane using this technique, and avoid the super-high aspect ratio the current designs have, and save the tremendous complex lightweight but high aspect ratio wings.
Look up Charles Zimmerman, the concept was his.
Geez, the more I see this thing come together, the more I want one!
The Flying Pancake was also known as “Zimmer’s Skimmer.” Here’s something I just discovered yesterday: the plane that inspired Zimmerman, Cloyd Snyder’s Arup S-2. It first flew in 1933, and was demonstrated around the country. (Zimmerman’s V-173 flew from 1942 to 1947. The XF5U-1 never flew.) I’m no expert, but the S-2 appears to address the issue of tip vortices in its own way. Mr. Stauffer?
The Arup S-2 looks like something that Williams Bros. should produce a 1/48 kit of. It would look great next to their PCA-2 Autogiro.
Obviously there are no props at the tips to counter the vortices. Winglets are the modern way to do it- the winglets are slightly canted outwards to create small vortices of their own to cancel the wing vortices.
If that tab-like thing on the tip were at a negative angle of attack, I could see how it might reduce wing vortices. However, that view makes it look like the tabs are at a positive angle of attack, and hence strengthen the wing vortices. I assume those tabs take the place of ailerons. I would think this low aspect flying wing would have very poor aero efficiency. Looks like a lot of wing area, however, so landing and takeoff speeds may be quite low.
Canopies assembled and test fitted. The XF5U-1’s canopy was a simple job. The V-173’s windshield needed careful sanding on its bottom edge to make the whole unit of three pieces fit tight to the wing/fuselage. The V-shaped locating ridge behind the pilot’s seat was sanded off first.
Looking really good!!! [Y]
Checked my old kit and it is the Sword version. Guess I’ve built enough Classic Airframes kits by now that I call every limited run model that brand…
Thanks Gamera!
The Special Hobby V-173 Flying Pancake is labeled “Limited Edition.”
I noticed a patent drawing for an aircraft designed by Zimmerman, on page 3 of Ginter’s book about the Pancakes. Dated 1938, it’s an earlier aircraft design than the V-173, and it appears to owe a lot to Snyder’s Arup S-2. Those tab-like things on the S-2 are also present on Zimmerman’s 1938 design, and are designated by him as “floating wing-tip ailerons.” Their function(s) is described in the patent. Here’s the link:
Changing horses in midstream.
I originally planned to make the XF5U-1 a whiffer, and the Kitty Hawk kit provides parts and decals to do that. Then I decided that what I really wanted was a model of the plane that actually existed - prototype #2. But the kit doesn’t give you this option, straight out of the box. You have to perform a few mods.
I removed the bomb racks I had already installed, and filled in the channels for the tail hook mechanism - located on top of the plane. The channels and covers for the tail hook mechanism don’t appear in photos of the two prototypes (as far as I can tell), so it’s likely the tail hook was never installed - though the Vought engineers had produced drawings of it.
The Kitty Hawk decal sheet doesn’t provide tail markings for prototype #2 (“Navy, 33958, XF5U-1”). Propagteam used to offer a decal sheet for the KH kit, and it included the tail markings, but I’ll be darned if I can find one anywhere. No luck, either, finding waterslide alphabets and numerals that will work (I’ve never had good results using dry transfers). And my graphics program doesn’t have a typeface that’s close enough (the “9s” and “5s” and “8s” are all way off) so I can’t go the custom route. Hmmm … interesting problem. Stay tuned.
Oh gee, good luck with your modifications. Looks cool so far.
BTW: Have you checked the model railroad section of the hobby shop for the letters and numbers? You might also look in a regular craft store too.
Thanks Gamera. I think I’ll be using the custom decal service from Bedlam Creations. All they require is a photo(s) of the real plane.
Here is another Arup with a different control configuration.
It sure looks like Amarillo to me, here’s a jpg. I can send you a dxf file as well.
That’s the Arup S-4, with the S-2 behind it. The Wikipedia article about the S-4 says the plane was scrapped during WWII, but then also says it went to a museum in Texas in the 1970s. ???