Bouwverslag Junkers Ju-87 B2 Picchiatello ⇨ W.Nr.0353 | 236 Sq. 96 Gr. Aut. B.

Ramses zei:
Ik hoop ondanks de kleine schaal toch de Junkers vleugeleigenschappen te krijgen op dit model. Door de naar achter liggende scharnierlijn t.o.v. de tekening varieert de spleet wanneer de ailerons en flap`s uitslaan net als bij de orginele Junkers vleugel. Ik ben ook erg benieuwd of dat op dit model in deze schaal in praktijk zal gaan werken!

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A very interesting flap is the "Junker" type. It is a separate small airfoil under the wing trailing edge and hinged in such a way as to always create the "funnel effect" to reactivate the upper surface boundary-layer.

The Junker flap is especially interesting when used as ailerons. As already mentioned the usual boundary layer is quite thick over the rear part of the airfoil and 'normal' ailerons need a certain minimum deflection to be effective. This is usually small "ineffective" roll control deflection from its neutral position. With the Junker type aileron, this is not the case if full advantage of the possible "funnel effect" is achieved by careful design of the hinge point location and careful construction.

The drawback of this flap is that at high speed the funnel is always consuming some energy so that the drag coefficient is slightly higher than for a conventional flap.
But the 'Junker' flap is a very good compromise when excellent low speed in aileron controllability is desired, associated with high lift/low drag in climb configuration, and the top speed end is not so important.

The 'Junker' flap always, and the 'Fowler' flap when extended, provide a certain 'boundary layer' control, be cause they 'trim" this layer out by blowing accelerated air into it, thus allowing the airflow to adhere to the solid airfoil up to substantial deflections (30 to 45 degrees) without local stalling of the airflow

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Ik weet het, het getal van Reynolds kan me in deze schaal tegenwerken... ;)
Klik om te vergroten...
Hier een mooi plaatje met de scharnierlijn zoals toegepast bij de originele JU-87:

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Groeten, Ramses
 
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Die motorkap is echt gaaf geworden zo ! vakwerk. Ik ben benieuwd hoe je de landingsgestelpoten gaat aanpakken.

Mvg,

Bart
 
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@ Bart: Bedankt! :D
De wielkappen ga ik denk ik ook van balsa (en litho) maken, helaas zijn de wielen welke ik nu heb voor de Picchiatello te breed. Moet even wachten op andere wielen voordat ik met de wielkappen begin.

Ik heb het stukje romp onder de vleugel klaar en heb alles licht nageschuurd:

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De Picchiatello is op het landingsgestel na ruwbouw klaar. Als ik tijd heb begin ik morgen met het bekleden van de romp en vleugels met tissue en PU-lak.

Groeten, Ramses
 
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Update

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Begonnen met het bekleden van de onderkant van de vleugel met tissue en PU-lak. Eerst de tissue met wat overmaat snijden:

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Dan de tissue er oprollen dmv een kortharig lakrollertje. Ik maak de tissue niet nat met water maar rol het er "droog" op. Vanuit het midden opzetten en dan strak naar de randen vastzetten want het tissue trekt zelf niet strak (geen spanlak). Met een penceel zet ik de tissue vast bij de randen en de achterlijst bij alle scharnierpunten:

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De andere kant:

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De onderkant is klaar en ligt nu te drogen. Verder met het bekleden van de romp

Groeten, Ramses
 
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tessue

Ramses zei:
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Begonnen met het bekleden van de onderkant van de vleugel met tissue en PU-lak. Eerst de tissue met wat overmaat snijden:

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Dan de tissue er oprollen dmv een kortharig lakrollertje. Ik maak de tissue niet nat met water maar rol het er "droog" op. Vanuit het midden opzetten en dan strak naar de randen vastzetten want het tissue trekt zelf niet strak (geen spanlak). Met een penceel zet ik de tissue vast bij de randen en de achterlijst bij alle scharnierpunten:

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De andere kant:

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De onderkant is klaar en ligt nu te drogen. Verder met het bekleden van de romp

Groeten, Ramses
Klik om te vergroten...
Ramses ,waar mee zet je de tessue vast [geen spanlak] vastzetten van de randen met een kwastje .
Vogelman
 
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Hoi John,

Ik rol de tissue direct vast met de PU-lak. Ook met het penceeltje duw ik de tissue direct met de PU-lak vast, deze gebruik ik waar het rollertje niet goed bij kan. De Picchiatello heeft nogal wat scharnieren aan de achterlijst uitsteken en dan is zo`n penceeltje erg handig.

Het is deze PU-lak, gewoon uit de DHZ-zaak: Syntilor Vernis Extreme Protect Polyurethaan

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Het is een geel/beige achtig goedje, maar droogt transparant op.

Groeten, Ramses
 
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Update

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De vleugel is aan beide kanten bekleed en ik ben begonnen met de romp. Dit doe ik in 2 delen (zijkanten) en werk van de neus naar de staart en van de hartlijn naar buiten. Omdat de romp bijna overal dubbel-krom is werk ik nu alleen met het penceel:

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Een rompzijkant klaar:

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De andere kant:

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en de romp geheel bekleed met 2 stukken tissue:

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Inmiddels zijn ook de staartvlakken bekleed en alles moet nu goed drogen

Groeten, Ramses
 
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Vind ik ook Serge!

De tweede laag PU-lak zit op de Picchiatello en nu moet alles goed uitharden.
Vast eens kijken naar wat details en hoe deze te maken.

Groeten, Ramses
 
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Op zoek naar detailfoto`s kwam ik deze 7/10 schaal Stuka tegen. Voor de duidelijkheid, deze is niet RC maar hier kan je instappen en mee wegvliegen ;)

Junkers%20JU-87%20replica-XL.jpg


Junkers Ju 87 B-2 Stuka scaled replica [1979] N87LL Owls Head Transportation Museum, Rockland, Maine - July 2005

This 7/10 scaled replica of the famous Stuka dive bomber took Louis Langhurst 8000 manhours to build, and is painted in the color scheme of famous Luftwaffe Stuka pilot Hans Ulrich Rudel.
An interesting note: Hans Rudel was once offered the opportunity to fly this very airplane, which of course he was most happy to do.


Groeten, Ramses
 
Ah zo!
Dan valt hij in een andere klasse en gelden er hele andere eisen.

Groeten, Ramses
 
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@ Femmo: en natuurlijk de kosten!

Voor de liefhebber meer info over deze in mijn ogen prachtige Junkers Ju-87 B2 Replica en zijn ontwerper/bouwer:

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Louis Francis Langhurst (22 Jan. 1907 - 17 May 1995) was an American engineer and inventor. Born in Cedar Rapids, Iowa, he is best known for building a 7/10-scale flying replica of Germany’s feared Junkers Ju 87 Stuka dive-bomber.

Birth of an idea

In 1970, while living on a 70 acre farm in Carriere, Mississippi, Louis Langhurst first got the idea of building a replica Junkers Ju-87 Stuka, a two-seat monoplane dive-bomber used by Germany’s Luftwaffe (Air Force) during WWII. With no original plans available, Langhurst spent the next three years gathering and studying research materials on the aircraft and making the necessary aerodynamic calculations in order to draft plans for a 7/10th scaled-down version. By April 1973, he had enough drawings completed to actually begin cutting metal. Langhurst opted for all-metal construction based on the parameters he had set for the scale replica and also because he felt his metal-working skills were superior to those he had working with wood.
Langhurst chose to build a replica of the Ju 87B-2 as this version was in production at the outbreak of WWII and constituted the largest number of all Stukas built during the war. He housed the project in a shed on his farm and was later granted permission to clear a 1,700-ft grass airstrip on his property from which to fly the completed aircraft. By his own estimation, Langhurst spent 8,000 man-hours working on his Stuka.
After much consideration, Langhurst painted the aircraft in the same scheme and unit markings as that of Germany’s most highly decorated Stuka pilot, Oberst Hans-Ulrich Rudel, who commanded III Gruppe/Stuka Geschwader 2 Immelman (III./StG2) on the Eastern Front during WWII. The plane was assigned the official FAA registration tail code N87LL and sports the registration code T6+AD along the fuselage.

Flight Testing

By July 1978, Langhurst’s replica Stuka was complete and ready for flight testing. Following an inspection of the aircraft, the FAA agent in Jackson Mississippi issued temporary airworthiness papers so that testing could begin. Initially the plane’s wheel pants, dive brakes, machine guns and dummy center line-mounted bomb were left off so as to conduct testing of the aircraft in a “clean” condition. Later in the program, these items were individually added back on to determine how they affected the plane’s overall handling characteristics.
Among the initial problems encountered with the aircraft were flight controls out of adjustment, inadequate braking action and shimmying of the tail wheel. None of these posed any serious impediments to the aircraft’s basic aerodynamic performance, however, and all were eventually corrected. A flight accident occurred when one of the test pilots applied the brakes too hard upon landing, tipping the aircraft nose first and wrecking the plane’s propeller. Langhurst had to wait eight months for the manufacture of a new custom-made propeller.
By July 1979 the flight testing and necessary flying time were finished and the FAA lifted the temporary restrictions. Langhurst had long planned on taking the plane to the annual EAA Fly-In at Oshkosh, WI and, with his friend Col. Reggie Braddock at the controls and Langhurst occupying the backwards-facing rear gunner’s seat, made the 900 mile trip that summer. Langhurst had attended the Fly-In for the past 15 years but this was the first time he had his own home-built aircraft to bring along.
In talking over the Ju 87 Stuka’s actual flight characteristics with several former Luftwaffe pilots, who had flown them during the war, Langhurst felt his replica shared many similarities, chiefly the quick responsiveness of the controls and the need to “…fly the airplane all the time you are in it” and the ability to land it three point or on two wheels with equal ease. In November 1980, former Stuka pilot Hans-Ulrich Rudel himself had a chance to fly in Langhurst’s replica and declared that its flying characteristics closely hewed to the original.

Junkers%20JU-87%20replica-XL.jpg


Ownership history

In 1981, after 175 hours of flight time, Langhurst loaned his home-built Stuka to the San Diego Aerospace Museum (now the San Diego Air and Space Museum) where it was placed on display for the next ten years. The aircraft was then sold to newspaper editor Roland Weeks of Biloxi, Mississippi. In 2002, Weeks sold the plane to Mitch Sammons of Augusta, Maine where the plane now resides and is a frequent performer at local air shows.

Other Stuka replicas

A second flyable Stuka replica, based on Langhurst’s drawings, was completed by Richard H. Kurzenberger of Horseheads, NY in 1987. It was given the FAA registration code N87DK and sported the fuselage registration code T6+KL. Kurzenberger's Stuka was based in nearby Elmira for the next twelve years until he sold it in 2000 with an accrued flight time of 354hours. The new owner's father, Amos Faux-Burhans, making his first familiarization flight in the aircraft, crashed upon take-off from the Faux-Burhans Airport in Urbana, Maryland on 26 May, 2000 and died from his injuries. His son had purchased the plane just two weeks earlier. The aircraft was so badly damaged from both the crash impact and subsequent fire that it was written off.

Vladimir Nesonov, a retired Ukrainian army pilot, built a 3/4-scale replica Stuka from scrap and powered it with a four-cylinder engine. He flew it for the first time in June 2002 at an airfield in Dzhankoi, Ukraine. The plane is currently on exhibit at the Central Air Force Museum at Monino Airfield, just east of Moscow.

800px-Junkers_Ju-87_replica.jpg


As of 2012, Jeff Willoughby was still working on a 5/8-scale Stuka replica in Pennsylvania, a project he began in 2003. Construction is primarily wood with an aluminum main spar and aluminum skinning for the wings and fuselage. The plane will be powered by a 110hp converted Corvair automobile engine.

Langhurst Stuka Specifications

Data from Military Aircraft Replicas: A New Era in Flight

General characteristics


  • Crew: 2
  • Length: 7.3 m (24 ft 0 in)
  • Wingspan: 9.9 m (32 ft 6 in)
  • Height: 2.3 m (7 ft 6 in)
  • Wing area: 35.40 m² (164 ft²)
  • Empty weight: 760 kg (1,680 lb)
  • Loaded weight: 1,032 kg (2,275 lb)
  • Powerplant: 1 × Lycoming GO345-B air cooled, 160 kW (220 hp)

Performance


  • Maximum speed: 220 km/h (119 kn, 137 mph)
  • Rate of climb: 5.6 m/s (1,100 ft/min)
  • Wing loading: 158.9 kg/m² (13.8 lb/ft²)
Armament


  • Guns:
    • 2× 7.92 mm (0.312 in) dummy machine guns in wings
    • 1× 7.92 mm (0.312 in) dummy machine gun on flexible mount, rear cockpit
  • Bombs:
    • 250 kg (551 lb) dummy bomb mounted along center line of fuselage
    • 4× 50 kg (110 lb) dummy bombs mounted near wingtips
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Groeten, Ramses
 
Update

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Het machinegewehr gemaakt voor in de achterste cockpit.

Een aluminiumbuisje, wat aluminiumtape, balsa, triplex en een pianodraadje maken dit:

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Iets meer detail:

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Gunmetalgrey en de minutiedrum erop:

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Druktankje en leren handvat op de minutiedrum gemaakt:

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En zo is `t geworden:

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Iets meer dan 10cm lang:

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Groeten, Ramses
 
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Mauser MG 81 7.92 mm (dat moet het tenminste voorstellen. Niet helemaal schaal, is op het oog nagebouwd, maar het gaat om de indruk = sportschaal)

MG81.jpeg


Groeten, Ramses
 
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