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Airfix 1:72 Spitfire Mk Vb canopy wanted

Started by steelpillow, March 18, 2020, 10:40:04 AM

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steelpillow

#30
Quote from: PR19_Kit on March 22, 2020, 05:04:13 AM
Most likely the PM kit that Lee mentions above. Best avoided.

Actually, rather handy if you want to knock up a thin-wing Spit as an alternative to the Spiteful wing. Each is moulded as a single piece. Just need to cut out the u/c wells - redesigned or not to taste - and re-skin the upper surface.
Oh no, here I go again. I swear, sniffing snorting and inhaling have nothing on whiffing when it comes to addiction.  :wacko:
Cheers.

The Wooksta!

No, it's not fit even for that.  Best filed in something metal and circular.

TBH, the Spitfire wing was fairly thin anyway, hence the issues fitting cannon, and capable of quite high Mach numbers below supersonic - IIRC at least one was doing near supersonic dives.
"It's basically a cure -  for not being an axe-wielding homicidal maniac. The potential market's enormous!"

"Visit Scarfolk today!"
https://scarfolk.blogspot.com/

"Dance, dance, dance, dance, dance to the radio!"

The Plan:
www.whatifmodelers.com/index.php/topic

steelpillow

Thickness-chord ratio was 13.75% if I remember correctly. That was thin for 1936, not so much for 1944 when the Vampire was coming out at 14%. The follow-up "thin-wing Vampire", renamed the Venom, was reduced to 10%. What would that have done for the Spit?
Back in the days of the Schneider Trophy racers, Supermarine's prop designers had been estimating transonic compressibility drag for the propeller tips. It remained the ultimate nemesis of the quest for greater prop speed. Staggeringly, the S.6B's Rolls-Royce R engine delivered much the same horsepower as the late-mark Griffons. The Griffon's max RPM was lower and its reduction gearing changed from 0.605:1 to 0.51:1. Prop diameter was ca. 10 ft compared to the Fairey type on the S.6B at 8ft 6in, making tip speed per engine rpm almost identical. (Amazing that the six-blader needed only the same power as the earlier two-blader of less diameter - now there's some aerodynamic advance for you!).
But h'mm, so either the reduction gearing would have to be around 0.75 or the Griffon's max revs greatly increased to start hitting those compressibility effects again. Over-stressing a glycol-filled block just in front of the pilot is a bad, bad idea and my protagonist would have had that rubbed in by the Darwin experience. So it has to be a revised prop design leveraging the old Supermarine knowledge base (cos the UK did not do transonic test facilities), together with a new reduction gear from R-R. I just love the way these whiffs design themselves and their story lines, once you know the score.
Cheers.

zenrat

#33
Quote from: The Wooksta! on March 22, 2020, 03:09:58 PM
No, it's not fit even for that.  Best filed in something metal and circular.

TBH, the Spitfire wing was fairly thin anyway, hence the issues fitting cannon, and capable of quite high Mach numbers below supersonic - IIRC at least one was doing near supersonic dives.

PR XIX at Kai Tak piloted by Flt Lt Ted Powles achieved an unconfirmed Mach 0.96 during a meteorological flight.  Others may have done so deliberately during testing.

Quote from: steelpillow on March 23, 2020, 02:21:49 AM
...Staggeringly, the S.6B's Rolls-Royce R engine delivered much the same horsepower as the late-mark Griffons...

The R was pure racing engine running, IIRC on special fuel which may have included nitromethane.  Griffon had to hold together for longer than a few races.

<edit>  not Nitro but a mix of benzene, methanol and acetone. https://en.wikipedia.org/wiki/Rolls-Royce_R#Supercharger_and_fuel
Fred

- Can't be bothered to do the proper research and get it right.

Another ill conceived, lazily thought out, crudely executed and badly painted piece of half arsed what-if modelling muppetry from zenrat industries.

zenrat industries:  We're everywhere...for your convenience..

steelpillow

Quote from: zenrat on March 23, 2020, 02:49:25 AM
The R was pure racing engine running, IIRC on special fuel which may have included nitromethane.  Griffon had to hold together for longer than a few races.

<edit>  not Nitro but a mix of benzene, methanol and acetone. https://en.wikipedia.org/wiki/Rolls-Royce_R#Supercharger_and_fuel

Indeed. But when you look at their props, it is hard to believe just the same.
Cheers.

zenrat

Fred

- Can't be bothered to do the proper research and get it right.

Another ill conceived, lazily thought out, crudely executed and badly painted piece of half arsed what-if modelling muppetry from zenrat industries.

zenrat industries:  We're everywhere...for your convenience..

PR19_Kit

Quote from: zenrat on March 23, 2020, 02:49:25 AM

PR XIX at Kai Tak piloted by Flt Lt Ted Powles achieved an unconfirmed Mach 0.96 during a meteorological flight.  Others may have done so deliberately during testing.


There was a PRXI that lost its prop during a max speed dive while testing from Farnborough during WWII, and that reached some horrendous Mach No. The pilot managed to land it too!  :o
Kit's Rule 1 ) Any aircraft can be improved by fitting longer wings, and/or a longer fuselage
Kit's Rule 2) The backstory can always be changed to suit the model

...and I'm not a closeted 'Take That' fan, I'm a REAL fan! :)

Regards
Kit

The Wooksta!

"It's basically a cure -  for not being an axe-wielding homicidal maniac. The potential market's enormous!"

"Visit Scarfolk today!"
https://scarfolk.blogspot.com/

"Dance, dance, dance, dance, dance to the radio!"

The Plan:
www.whatifmodelers.com/index.php/topic

steelpillow

#38
Pah! Doing it in a steep dive is child's play. The Thin-Wing Spit reckoned to do it in level flight.  ;D

Of course, that might have depended on little things like max airspeed and Mach number at any given altitude. With the late three-stage supercharger fitted and lower temperatures at altitude bringing down the Mach number, that is where it would have first happened. Probably going not much faster than the Spiteful Mk 16, say around 490-500 mph :blink:
Cheers.

The Wooksta!

One of the Spitefuls topped 492mph, which was faster than the Me 209 record breaker.  And that held the record for a good 30 years.

Supermarine could and should have went for the speed record, if only to piss off the Germans.
"It's basically a cure -  for not being an axe-wielding homicidal maniac. The potential market's enormous!"

"Visit Scarfolk today!"
https://scarfolk.blogspot.com/

"Dance, dance, dance, dance, dance to the radio!"

The Plan:
www.whatifmodelers.com/index.php/topic

steelpillow

Quote from: The Wooksta! on March 23, 2020, 10:38:44 AM
Supermarine could and should have went for the speed record, if only to piss off the Germans.

Cue the Thin-Wing Spitfire project, ta-daa!  ;D
Cheers.