Thoughts on an all metal Jodel D9, Falconar F10 or Druine Turbulent Derivative? For Taller pilots!

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addicted2climbing

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Hello All,

I am planning to buy an Avid CNC router before year end as I need to get my list of tools I need together as I will need the write-off. I already have a Tormach PC1100 I plan to finally set up this winter and a 100W laser cutter not for metal though. Anyhow, I was thinking it would be a good project to design something I could cut on the Avid that uses either the small Briggs type engine, half VW or O-100. I have always been a fan of the Druine Turbulent and the Jodel D9 but being tall it would never work for me so the thought came to mind to mod it a bit to work in metal and stretch the cockpit a bit for a taller pilot. Headroom is not an issue in either but a roll over bar would need to be made regardless.

I was thinking to buy a few sets of plans to study that are similar.
A set of the D9 and F10 for sure as geometry guides.

For the metal airplanes to study I was thinking:
Hummel H5 or Hummelbird
Teenie Two
BK-1 (designer passed away so no plans available other than 2nd hand)
Would love to buy a set of Onex plans off a builder who finished.
Thatcher CX4 ( I already have these)
Any others to consider?
Anyone have any on my list that is willing to sell?

If the polyhedral wingtips were retained in the D9/F10 it would be cool to have them fold up like on a Onex and also use the paddle aileron connection.

I will be in France for Christmas and if there are any plans built aircraft similar that are not sold in the USA (for litigious reasons as usual) I could buy them while there.

Marc
 

Geraldc

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Jodel D9 would not be too hard except for wing spar.
I think the Falconer variant is already wider.
 

addicted2climbing

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Jodel D9 would not be too hard except for wing spar.
I think the Falconer variant is already wider.
I know the D9 has some crazy spar layout per the research I have done, but being a new design and just made to resemble the D9 or F10 I could modify the spar as needed in metal.
 

Dan Thomas

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Thorp T-18. Bushby Mustang II. Davis DA-2. Zenairs. The RV series. Pazmany PL-2. There are lot of aluminum low-wing two-seaters already. Converting an airplane from wood means designing 95% of a new airplane, with all the engineering calculations involved. For instance, the Jodel uses a box spar, with plywood glued/nailed to spruce strips. It's entirely enclosed. How does one buck the rivets on the last sheet going onto the spar? You can't, and you'd have to use pulled rivets. That's a no-no in certified aircraft. No pulled rivets in spar construction. They work loose too easily.

Aluminum also weighs much more than wood. You'd have to minimize structural extrusions or the airplane would be much too heavy. Can't just substitute aluminum for wood. Get into a Cessna someday when it's being thoroughly annualed and has all the interior stuff out, and see that almost everything is just folded or bent sheet. Extrusions are limited to the main wing spar caps, struts, the fuselage strut carrythrough, and a few small brackets. A few castings carry the main landing gear.
 

TFF

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I’m a fan of T2s for the simplicity. They are not very pretty. Utilitarian. My opinion not a lot to CNC, or at least a little overkill.

A metal Jodel is interesting. A T-18 and Mustang 11 are essentially the same type of platform in metal. I can see routing tooling bucks for ribs and bulkheads along with stock. Is the plan to cut shapes or also rivet and bolt holes.

With these smaller engines, I think CLTs, Cub Like Things, are better platforms. Low wings tend to be small and hot performers. You might get a Davis DA5 to work with the O-100
 

Geraldc

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A successful wooden single seater adapted to metal is the Corby Kestrel
an aluminium version of the Corby Starlet
 

don january

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I don't know a thing about a Avid CNC tool and the other stuff your thinking of doing but if its home built and fly's I'm with your goal 100%
 

Hephaestus

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I was thinking it would be a good project to design something I could cut on the Avid that uses either the small Briggs type engine
Pik 26 comes to mind. But you'd have to adapt it to fit bigger pilots. It's definitely on the small size for even the FAA standard size pilot.
 

karmarepair

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The MONI plans are online, and the design used a lot of castings and fabrications that are no longer available, as well as a spar extrusion that John kept the dies for. And it would fly with a V-twin, without question. There is also an Italian alternative spar built up from more common extrusions. As Dean Willson will testify, aircraft DESIGNS cannot be copyrighted, although Plans can be. A MONI-like airplane that can fit within the British "Single Seat DeRegulated" rules and/or the JAR Microlight regs and/or the Canadian Basic Ultralight rules might have a market.

I second the DA-2 idea, maybe shrink it to a single seater so it would fly with a V-twin. Plans are also available online for inspection, via IO.Groups. Leon used 2024 extrusions for the spars, so maybe redesign in 6061-T6?
 

cluttonfred

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Perhaps take a look at Henri Nicollier’s designs for some inspiration. The Ménestrel II is pretty but the straight lines of the Weekend II would be easier to recreate in a new metal design. Last I checked, Nicollier has no objections to selling his plans in North America.

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Random thought…spruce is expensive and difficult to source these days, plywood less so. Why not take an existing fabric-covered wooden design and adapt it to CNC fabrication with metal or composite spars and lingerons to eliminate the spruce or resize small pieces for cheaper wood?
 
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karmarepair

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One more idea - a clone of the Strojnik S-2/S-4. He practically tells you what size extrusions to use for the spars in his books. He DOES tell you what size tubing to use for the boom. I'd do the wings using Dick Schreder/Michel Columban aluminum skins over closely spaced foam ribs, vice Strojnik's fiberglass skins laid up on plexi then formed while still "green" over a male mold.

You could do it open cockpit even. Either as a pusher, or a mash-up with the unbuilt DL-5 as a tractor.
 

crusty old aviator

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In the late 70’s, I thought it would be an interesting exercise to build an all metal VariEZ and looked into it. Then I flew one: her handling was so disappointing, given all the hype about Rutan and his design, that I no longer thought about it...until now.
 

Riggerrob

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In the late 70’s, I thought it would be an interesting exercise to build an all metal VariEZ and looked into it. Then I flew one: her handling was so disappointing, given all the hype about Rutan and his design, that I no longer thought about it...until now.
How quickly we drift off thread.
Burt Rutan's early sketches used the curved aluminum fuselage panels of a Bede 5 with sheet metal wings, but he soon abandoned that concept for the all-composite Vari-Eze.
 

BJC

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In the late 70’s, I thought it would be an interesting exercise to build an all metal VariEZ and looked into it. Then I flew one: her handling was so disappointing, given all the hype about Rutan and his design, that I no longer thought about it...until now.
You flew an all metal VariEZ?


BJC
 

Victor Bravo

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What about just leaving the (really good) size and shape and aerodynamics of the Baby Jodel alone, and simply using a better semi-supine (sailplane) seating position? Addicted2Climbing is 5 or 6 inches taller than average, but he's not an NBA basketball center.

1) Move the firewall and rudder pedals a few inches forward, and compensate with a shorter engine mount or a shorter engine (Chip Erwin's V-twin, the O-100, a Verner radial).
2) Recline the seatback several degrees and move the forward end of the turtle deck (the rollover bulkhead) rearward to wherever the pilot's head will be.
3) Redesign the instrument panel to allow the pilot's knees to be a few inches higher.

This can be executed in metal by simply borrowing the structure of the Thatcher, or the Teenie, or several other similar single seaters... then having a qualified person fine tune any structure to account for minor differences in shape of parts.
 
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