21st century Volksplane?

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Topaz

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Topaz, you're right about some people thinking (thousands of hours of sanding). I've built two Long EZ's and the actual hours of sanding is closer to 250. It just SEEMS like thousands of hours because it's the only part of building a moldless composite airplane that isn't interesting and fun.
Yep. Exactly. Unfortunately, now, "everybody knows" that it takes "thousands of hours" of sanding. It's become "group knowledge." You see it pop up here on HBA every time someone mentions a moldless project, and we have to go through the same arguments and examples over and over to show that what you've described is the actual reality.

Can you spend thousands of hours sanding and filling a moldless composite airframe? Have some people done it? Sure. Don't pay attention to core shapes from the first cut, pause during a hot-wire cut and put a gouge in your core, don't pay attention to peel-ply'ing overlaps and joints - just "get on with it and worry about finishing later." That'll get you into "thousands of hours" of sanding very quickly. If, on the other hand, you worry about fit, finish, and shape from the very first hot-wire cut, the actual "finishing" is hugely reduced.
 

Bigshu

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Well said, VB, so if we choose blindé-riveted aluminum tube and gusset covered in fabric as the preferred method, how best to tackle a simple, constant-chord, squared off, cantilever wing using that construction style?
Talk to Bob Baslee. His airdrome aeroplanes replicas are easy to build, inexpensive, and use VW or similar hp engines with great success. Everything he offers is strut braced or parasol, but he could probably puzzle out a cantilever wing as well.
 

Hot Wings

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If you set up your shop to build a sheet metal fuselage, then you have to set it up differently to build a wood or composite wing, there will be some net loss in efficiency,
Correct - mostly.
For something like a CNC tube and gusset fuselage or a Fold-a-plane composite fuselage there could be very minimal shop reorganization needed to convert to another building material/method for the wings. Both systems are essentially big model/erector set kits. The downside of these options are that they are best accomplished with a kit.
 

robertl

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I have built all the aluminum parts for 2 Bearhawk wings (4 panels) and enjoyed it. Repaired C-172 wings and reskinned, stab, elevators and ailerons.

Picture of all parts for a bearhawk wings except for the spar webs and skins.
It's amazing what you can do from scratch with a few tools.
Bob
 

Pops

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Just to let Mathew know that the price of lumber on the wholesale market is plummeting. Lumber PRICE Today | Lumber Spot Price Chart | Live Price of Lumber per Ounce | Markets Insider

Unfortunately, it still has a long ways to go to be inexpensive.
Stopped at Lowes box store to get a quick dose of sticker shock. Getting land ready to build a cabin and having the septic system installed.
Have a list of common size of lumber that I have been keeping track of. Plywood is even higher that a month ago, at a all time high, framing lumber about the same sky high prices, treated decking boards are ( 1"x6"x12') down to $12+ from a high of $18+ a few months ago.
Going to hold off the build for a while to see how the prices go.
 

cluttonfred

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Yes, the Pataplume 2 and Siebel Hummel are both close to what I have in mind despite being separated by more than half a century. It comes down to how slow you want to go, how much power you can afford, and how simple you want the build to be. Something the size and weight of a Pataplume 2 but squared off and simplified is a good starting point.

The Pataplume 2 would offer a great base for a VP21
 

Bigshu

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A Pietenpol replica made of the tubing like the Baslee models, that would wake me up.

The Pataplume 2 would offer a great base for a VP21
Yeah, I think there are lots of old wood designs that could translate to tube and gusset aluminum. A tri gear Pataplume would be very interesting to me.
 

Chilton

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Thanks, Topaz, for all the feedback. I am deliberately staying lighter than LSA limits to keep things affordable and get the most out of modest power: 1320 lb on a VW is very different than 1100 lb on the same engine. Target would be 600 lb empty for 500 lb useful load knowing that keeping an enclosed two-seater that light would be a challenge.
The weights you are looking for sound very like Piper's PA15 Vagabond, the original Lycoming O-145 claims 65hp and like the VW conversions probably does not quite make it! The clip wing Piper does fit a 20ft container from memory and can produce reasonable performance but if you want to make the weights it must be no frills, adding dual controls and sprung gear will be heavy!!
 

Victor Bravo

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Well said, VB, so if we choose blind-riveted aluminum tube and gusset covered in fabric as the preferred method, how best to tackle a simple, constant-chord, squared off, cantilever wing using that construction style?
Forgive my predictability... the answer is fairly clear. Blind riveted tube and gusset truss ribs (stealing from Kolb and others), with a Zenith style spar, using blind rivets for attaching the ribs to the spar, and squeeze rivets in the caps where they are well worth the extra effort. The tube ribs should be 3/8 or so behind the spar, and 7/16 or 1/2" in front of the spar (instead of the 5/16) that Kolb uses, this allows you to rivet on a structural leading edge D-tube skin through the forward tube ribs.
 

cluttonfred

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By squared off I meant dead flat like a Volksplane (minus the aileron balances) or a basic MiniMax. Wingtips are optional.

As was mentioned earlier in this thread, folks today seem to have a skewed perception of wingspan and aspect ratio. 34’ (10.36 m) is exactly the wingspan of a Piper Tomahawk and more than a foot shorter than a J-3 Cub. I wouldn’t do a one-piece wing that long just because of shop space requirements but in two or three sections, no problem.

Tube and gusset makes a lot of sense for a fuselage and simple tail surfaces and for wings braced with struts and/or wires. Jury is still out for a cantilever wing but it’s worth exploring.
 

cluttonfred

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Other than the original Ercoupe, there aren’t a lot of light aircraft with fabric-covered cantilever metal wings that come to mind. I suppose that might be an argument for a stressed-skin wing even if the rest is fabric covered.
 

Victor Bravo

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A reasonable wingtip is worth the extra two hours and two pounds it takes to put on, even if it's just one bent tube bow covered in fabric like an antique.

A properly shaped wingtip can measurably improve handling, climb, drag, etc.

If it wasn't worth it, they wouldn't have done it on all the older airplanes.
 

cluttonfred

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What was the signature line that Pops uses again? "If its not there, it cost nothing, weighs nothing, and is 100% reliable." It also takes no time to build.

"A properly shaped wingtip can measurably improve handling, climb, drag, etc." For low speed aircraft at low wing loadings, I think that's debatable compared to building the square-cut wing out to the span of the wing + tip in the first place.

In any case, some folks will certainly put tips on, but eliminating that part (ditto the tips of the tails) is part of the psychology leading to, "Hey, I could build *that*!"
 

Sockmonkey

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I'm leaning in this direction, where you have a nice high AR strut-braced high wing.
Tandem seating for two.
Center mount is a universal pivot so you can rotate the whole wing easily by unhooking the side struts from the fuselage.
Has to be two-axis, but that comes with a benefit.
With no pedals, you can slide the front seat back when flying solo so you keep the same CG.
Just have an extendable bit on the yoke so you can still comfortably reach it.
There ya go.


 

Geraldc

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For a spar you could make one out of aluminium angle like these gin poles.Pops would probably have used these.
1624482439647.png
 

blane.c

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Other than the original Ercoupe, there aren’t a lot of light aircraft with fabric-covered cantilever metal wings that come to mind. I suppose that might be an argument for a stressed-skin wing even if the rest is fabric covered.
The Bearhawk uses a aluminum with aluminum skin wing and fabric covered fuselage and is lightweight and rugged. Of course it uses more hp, and is heavier than proposed VP-21 it also has cantilevered wing but it is not overall a bad perspective to look at for a light weight design as it could be much lighter if it had a VW engine constraint.
 
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