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Macchi Castaldi MC72


JimInOz

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G'day lads and lasses, started this one. Delata 2 1/72 MC72 kit of the 1934 record breaker.

Some pretty major surgery required to straighten this one out but I don't think it is a basket case. 1st problem was straightening the fuselage, which I achieved by wedging a piece of plastic card down the entire length of the fuselage. Then I simply bent it! You can see the stress marks just bellow the cockpit walls. It appears to have stayed "straight", we shall see.

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Also had to add wedges of plastic strip between the fuselage and wing assembly to fill the canyon there. The gills behind the pit will be filled and I will replace them with something I haven't thought of yet :blink:

Next drama was the floats, these also had major fit problems. I obliterated the surface detail with 120 grit and have backfilled the gaps in them with super glue.

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I'm gunner beat this bugger into shape, lets see how it goes eh?

Cheers and beers. Jim :drink:

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Much swearin n cussin going on round ere but............................ I'm startin to get this little mongrel to come around to my way of thinking :wicked: I have ripped into this thing with 120 grit whipass paper, (I kid you not!). Sanded, filled, sanded, filled and sanded again. Jim 1 MC72 nil. Next we wil try some colour :pray: Cheers. Jim :D

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She dreams in colour she dreams in red.................................

MC03018.jpg

The 3x Coats of MM Italian red have taken to her like a duck to water! A couple of toothpiks are keeping those floats jigged right and a dry fit of the struts show that this all might just work. I am still wondering what to do/use for the radiators, I'll work it out and hopefully wont FUBAR the whole thing in the process.

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Those lines are just way to sexy, gotta love those continental types. OK OK Supermarines lines make me hard all over like a chocalate frog too. :lol:

Cheers, thanks for looking and ondward into the unknown. :hobbyhorse: Jim

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Thanks Mish and welcome to BM.Nice to see the Ladies having a dabble :D

Righto.............. thought long and hard about the radiators and what to do. Make up some decals, form them out of thin plastic sheet, paint some tape etc. etc. But after applying the KISS principle I decided to paint them on. I think they turned out OK, maybe not brassy enough but I think they will do. It is startin to look a bit more interesting now we have the contrasting colours. A few more touchups here and there and I reckon I'm on the home straight. Thanks for looking. Cheers. Jim :drink:

MC7003.jpg

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Thanks Keefr and Steve :D

Gettting damn close now, gloss coat and decals on. Down to the windshield which I am making from clear sheet and framing with decal strips. Then I'm calling her done. Ohhhhhhhhhhhhhh soooooooooooooo close. Cheers and beers Lasses and Lads, I'm stuffed and off to bed, thanks for looking, goodnight all .Jim :sleep_1:

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MC08004.jpg

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Wow my eyes hurt! Keep up the good work - this one's gonna stand out!

Man, that is so right. You did a great job on something I wouldnt have even tried. I just cannot see those 1/72 wel enough to do them up. It looks wonderful. So what was the deal with the radiators? Surface area dissipators?

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Cheers Lads :D , thankyou for your interest and comments, hopefully the next shots I post will be "Ready for Inspection".

Dahut: I think you may be right about the radiators, I have scouted around on the net for a bit more techy stuff but the majority of intel is on the engine and the speed record. Not so much on other aspects of the aircraft, maybe someone here could enlighten us both??? I do suspect you are on the right path with regard to the radiators working on heat dissapation through surface area, rather than them being veined and using forced air.

Once again, thankyou for the interest. Cheers Jim :)

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Dahut: I think you may be right about the radiators, I have scouted around on the net for a bit more techy stuff but the majority of intel is on the engine and the speed record. Not so much on other aspects of the aircraft, maybe someone here could enlighten us both??? I do suspect you are on the right path with regard to the radiators working on heat dissipation through surface area, rather than them being veined and using forced air.

Has to be, right? Actually that is the full meaning of the word, radiator, as I reckon it. What is needed is a larger model of the plane so that can be explored more fully. More on that in a bit. Heres what a bit of "googling" found

"Macchi-Castoldi MC 72 (edited from the Italian translation)

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The decision to trust in a single type for 1931 edition mobilised resources never available before, allowing to build sophisticated devices to test the tricky FIAT AS-6 engine, conceived by Eng. Tranquillo Serbi. To avoid the problems created by huge propeller torque, Zerbi decided to adopt a double, counter-rotating fixed-pitch propeller. Not only efficiency was some 15% higher, but rear propeller was immediately flooded by air flow and was efficient even during take off.

In the difficult floating phase, torque absence should allow to have a balanced load on the floats: an important aspect, considering that, with 1800HP engine, the left float was loaded 23% more than right one. In 1931 Supermarine S-6B with 2650HP was 32% overloaded, while MC-72 barely reached 3% even with 3000HP. Behind the propellers stood a singular twin engine - two 12V, 60 degrees engines directly coupled on the same shaft, each moving a propeller through two coaxial crankshafts passing through forward engine banks. Air intakes were in the centre, between both engines, while breathing system, composed by a centrifugal compressor and a bank of 8 aspirated carburettors, was single for the whole plant.

There are plates labeled "Front Engine" and "Back Engine", still in the cockpit, showing that each engine was independent, as confirmed by run-up scenes in the famous movie of the record. It seemed the simplest solution, but, as often happens, AS-6 promises were harder to win than expected.

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Once the engine solution was had, airframe realization proceeded rapidly and without problems. The aircraft emerged as a steel tube frame, acting both as engine mount and forward fuselage, complete with mounts for wing, floats and rear fuselage. Wing structure was metal, with rectangular shape, covered with flat surface radiators, while tail unit, with empennages and cockpit, was a monocoque wooden structure. Under the tail a further radiating element was envisioned.

The floats, used as fuel tanks and also covered with flat radiators, were initially metal but were eventually changed to wooden, lighter and smaller ones. All above gave a very nice and sleek aircraft, whose main section was lower than the preceding MC-67, giving no flight problems even if control surfaces were not dynamically balanced as surprisingly happened in all Schneider's planes.

Entry into the 1931 Schneider Cup was abandoned due to tuning of the AS-6 engine, which emerged as difficult beyond any provision: 18 months testing, first on loose parts, then on subassemblies, finally on the whole engine, running for only one hour on April 20, 1931. It offered 2200HP only, and burned two valves in the process.

It took two months to solve this, with no less than twelve different valve combinations and 1000 valves in 10 different steels. Reached at the end of May, the 2400HP AS-6 was mounted on the first MC-72: But all optimism seen in testing was frozen on June 22th, shortly after first take off. Detonations and flameouts, strong enought to crack the compressor, obliged Monti to land immediately.

While the test flights continued, the necessary modifications were implemented. Then on August 2nd, 1931, Pilot Officer Monti crashed on take off and died. Next in line, Ltn. Ariosto Neri and Stanislao Bellini took over with the second MC-72: only 40 days were left before the race, but no solution for the troubles was in sight.

On September 3rd, Ministres of Aeronautics of Italy and France asked British Royal Aero Club to postpone the race one year: the Britons refused with typical pragmatism, because their participation was paid for by sponsors, and retiring that year could mean forever. So, on September 12th the British Supermarine flew alone.

A record attempt was held also in Desenzano, on September 10th, with Ltn. Bellini at the controls. It concluded dramatically: more flameouts, detonations and then the MC-72 simply exploded in flight. No escape for Ltn Bellini; he was killed immediately. That's two pilots killed in the efforts to win the Schneider Cup

To resolve the carburation troubles, a third engine test bed was set up, filling a whole hangar where two 400- and 700HP engines simulated wind up to 750Km/h. The device was used to verify proper functioning of RAV-26 carburetor system, fitted with transparent elements to observe fuel flow.

On February 26, 1932, a 2400HP AS-6 simulated on the test bed a record flight on 3Km basis: to get an ideal fuel "Rod" Banks, the British wizard of fuel mixtures, was enrolled. He created a mix of 55% gasoline, 22% benzol, 23% alcohol and 0,15% lead. Engines were prepared with 3000HP for record runs and with 2500HP for endurance, working mainly on supercharging.

Ltn. Neri and new program test pilot pilot, Warrant Officer Francesco Agello, recommenced flying in June: On 15th Neri experienced terrible flutter problems, landing safely only thanks to his skill. Unfortunately, Ltn. Neri was killed three months later while on an unrelated training flight, flying a CR-20.

Now, only Warrant Officer Agello was left. The assault on 700Km/h was nearing, with Agello as pilot. After several aborts, the first attempt was held on May 13th, interrupted for flameouts. Second attempt on June 22nd, aborted for compressor failure. Third try on July 4th, with strong vibrations insurging. Agello had scored an unofficial record of 664.078Km/h on June 4th after only 8 minutes, but it was unverified. Then, a long stop until autumn.

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Another unsuccessful flight on October 1st came and went. On October 13th, other flameouts and further delay. On October 23rd, take off at 14:56 floating, light mist, then the four official passes. Landing at 15:11, with Agello unaware he had beaten his own record set back in June. After the calculations, average resulted of 709.209Km/h, with the third, fastest pass at 711.462Km/h. Finally, decorations, promotions, celebrations came, with the immediate storage in a museum of the third, and sole remaining, MC-72. It never flew again.

MC7225.jpg

W.O. Agello's absolute speed record stood four and a half years, then was beaten two times in a month: by Hans Dieterle in a Heinkel 100V8 at 746.450Km/h on March 30th, 1939 and by Fritz Wendel in a Messerschmitt Me-209V1 at 755.1Km/h on April 26.

In the seaplane category, the record wasn't overcome until August 7th, 1961 when the Soviet jet plane, Beriev M.10, flew at 912Km/h. For piston engined seaplanes, the MC-72's record STILL stands, down to this day."

2. And now as promised, here's a link to Scott Aiken's review of the Noix resin MC72 in 1/48: http://modelingmadness.com/scotts/civil/racers/m39.htm

3. This is from Wikepedia:

"The design of the Macchi M.C. 72 was unique with a fuselage partly metal to the cockpit and wood monocoque bolted to the front tubular portion by four bolts. The streamlined nose contours enclosed an oil tank with its outside wall exposed to the airstream. The wing was all metal with flat tubular water radiators smoothly faired into the wings. The twin pontoons had three smoothly faired radiators on the outer surfaces, the forward radiator for water and the centre and rear radiators for further oil cooling. The float struts also featured water radiators and another radiator was fitted during hot conditions under the fuselage running from cockpit to tail. "

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