Yes sir, I am and can attest to the quality of them. I actually used a set to create the model for the Do 335...but I didn't use them for the FW-190 as the factory drawings I had were accurate down to the millimeter (to spec at least, their jigs might have been tweaked during production for whatever reason).Radicaldude,
Are you familiar with the Arthur Bentley drawings for the FW190 series? Excellent, super detailed, well dimensioned drawings, well worth ordering.
The beauty of Kronk's bird is that it kept the profile of the single seater, but seats two. the trainer version of the FW is (cough, gag) HORRIBLE! I'm the "94%" man, but my wife is only 5'2 for the 2nd seat I really want to build a two seater like Kronk's, but not brave enough to design the whole thing myself.. Rv8 is my design bogey.Took a look at what Mr. Kronk did (may he rest in peace), and it seems that he enlarged the entire cockpit and canopy. It's really hard to tell unless an original was parked right next to it, but the canopy is longer and taller proportionally than the original. He's also able to fly it with the canopy open, which is puzzling as this is strictly verboten in the full size model due to buffeting...
I was also planning a two seater version, though more in the style of the modified trainer version of the original than an enlarged cockpit version like what Mr. Kronk did. The problem is that the canopy rails taper back; in the original, the cockpit rail width was about 25" at the instrument panel and 22.5" where the pilot shoulders are. In my version, its about 26" at the panel and 24" at the shoulders.
The good news is that a trainer version could be accomplished by only redesigning the rear fuselage. The canopy width at where the forward fuselage terminates is about 22". Of course, the rear cockpit width would be limited at that width (which is similar to the cockpit width of an RV-4), but it wouldn't necessitate redesigning the entire fuselage sub assembly. There will be a strange bulge followed by an aggressive taper to meet the tail, though.
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CAD-wise, I also put the pilot in to see how he/she fits in the cockpit. The guy in the pictures below is a 95th percentile sized man, so 6'3 and 245lb. Personally, I'm 11 inches shorter and more than a hundred pounds lighter, so I'm at the 5th percentile, which means I'll design the cockpit to fit between the 95th and 5th percentiles. I'll be able to fit comfortably (since if this thing gets built, I'll be the only sure customer...); the 6'3 guy, probably not so much as though he'll still be able to operate it safely, the plane will probably fit him like a tight glove. I'm going to try to find a 50th and 5th percentile virtual mannequin to further verify.
I also did the same for the 109, as seen below. The good thing about the 190 is that the cockpit widens as it gets lower. No such luxury exists in the 109, which is consistent with pilot reports of it being barely spacious enough to operate the controls. Of course these are scaled down replicas, which certainly does not help alleviate the problem...almost makes me want to go full scale, until I look at the increased construction and operating costs, that is...
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This isn't a replica Fw-190 though... at some sub-scale, its a new airplane that looks like a Fw-190.. I presume it won't be 9,000+ lbs and won't have 1,700 or more hp so given that its all new, I would think there wouldn't be too much gained by the internal design review of the real thing? Terry in Au did a pretty convincing replica from what I understand using the Rv planes design as a baseline? seems like figuring the target weight then using a proven design around that might be a good starting point... e.g. Titan T-51?Just a few observations on the FW190 wing mount: The bolt runs through the forward part of the spar cap. It looks aft in the drawing because there is substantial incidence in the design and the cap itself is pretty far aft—about 35% (?) chord. Second the firewall structure to which the wing attaches is very stiff. If I’m not mistaken the firewall frame is a one-piece forging with many other stiffening structures riveted to it. Third, the neutral axis of the spar is probably closer to the upper spar cap than appears. The spar/wing structure is a pretty complex beam that certainly results in non-obvious deflection. Fourth, look at the size of the bolt. It is much too large if designed only to handle tension. So it seems to me that it is also designed to take some shear. And lastly, this is a WW2 weapons platform with a very short useful life. A structure that looks bad to somebody who designs stuff to last 10,000 hours may be just fine for one that must last only 200 hours.
Which engine can you best afford? I've always liked the D9 myself.Just been working on stability so far, not much to show other than just numbers. It did, however, force me to do components placement, the weight distribution is needed for dynamic stability analysis.
I've also been working on cockpit ergonomics. As a sport plane masquerading as a fighter, cockpit comfort is essential for getting that "one with your machine feel" that people expect. To that end, I'm going with a bracket swivel (swings forward as as you increase seat height; found in British fighters like the Spitfire) and adjustable rudder pedals.
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I'm intending the airframe to weigh ~1400lbs, leaving 3 options in terms of engines:
Option 1 would be to mount a ~500lb engine like M14P (default choice), O-520/540/550, O-720 in short nose configuration. M14P and O-720 should give performance pretty close to the Radial Rocket and Bear 360 (180-200kt max cruise); performance with the O520/540/550 is going to be a bit anemic (think T-34). (Empty Weight: ~1900lb)
Option 2 would be to mount a larger diameter radial like the R985 Wasp Junior (450-525hp/670lb) in a slightly enlarged cowl. At 85% scale the cowl only needs to be widened by 1.5" to take this engine. The holy grail for a short nose FW-190 at 85% would be the double row R1535 Twin Wasp Junior (825HP, ~1000lb; powered the H1 Racer), which would give speeds well into the 220kt range...if only more than 2 of the engines existed. Performance with R985 would probably be similar to Option 1, only with slightly improved climb. (Empty Weight: 2200-2500lb)
Option 3 is to mount a liquid cooled engine like the Falconer V12 (640-1200hp; 700lb dry, guessing ~1000lb with cooling system & accessories) in long nose configuration (FW-190D; TA-152), which should push performance into the 350kt (400mph) range. (Empty Weight: 2200-2500lb)
All three options are designed to mounted on an unmodified fuselage; in fact, the only airframe differences will be the engine mounts, cowling, and a different tail unit (lengthened) for Option 3. The wings, fuselage, and landing gear are standard for all 3 versions.
Allison powered Spitfire...there's something blasphemous about that phrase :roll:Sounds like you've been busy. Images?
And for inspiration, here's a hi-dollar Spitfire replica with an Allison and an original (needs TLC) 190D for sale ....
The cheapest engine out of the mix is actually the M14P. Engine/Prop combo is about $40K, which is quite a bargain for 360-400HP.Which engine can you best afford? I've always liked the D9 myself.
The cheaper and more realistic it looks, the better the sales potential... Hurry up so I can build oneAllison powered Spitfire...there's something blasphemous about that phrase :roll:
No pictures as of yet, mostly graphs and numbers on stability for the last 3 months.
The cheapest engine out of the mix is actually the M14P. Engine/Prop combo is about $40K, which is quite a bargain for 360-400HP.
As much as I like the D9, mostly because of the potentially blistering performance, given my piloting experience, insurance, upkeep, and safety, I don't think its a good configuration for a first prototype. Plus, V12 Falconers are not cheap...
The reason for the large engine selection, along with a modular construction style, is mostly because I'm toying around with the idea of offering this replica as a kit or as plans. Nothing set until the prototype flies, though.
Honestly, haven't done much and didn't really pick things back up until last week. I'm still working on the stability of the airplane by creating a spreadsheet that will spit out the numbers I need to analyze the airplane in different conditions (like clean stall, flapped stall, accelerated stalls, at do not exceed speed, etc...). Once that's complete, I can quickly run the studies, but currently my calculations aren't matching with simulated CFD results and I want to know why.Hey Radicaldude1234 Just wondering how the plans are coming along? Made any big headway? Love to see what you've been working on since last summer.
Yeah, I was curious about the bulge there too and I checked and rechecked the numbers with the same results. The engine data actually only goes up to 15000 ft, so the 20,000 ft figure was actually linearly interpolated...which is a fancy way of saying I made a guess.very nice, what makes 15,000ft such a bad altitude to fly at ? Is it engine related ?
Or you could save a ton of money and use a 450HP LS3 with an airboat drive ala Jeff Ackland’s P85. Stick the liquid cooled setup in the smallest round cowl version (A4 I think) and you’d end up with a cheaper, smaller, lighter, and probably faster plane than a D9 replica. You could use a stock-looking fan bolted directly to the prop hub for ground cooling and to hide the liquid cooled installation. There would be plenty of room for an annular radiator or even a couple cheap square radiators fitted near the firewall and ducted to the stock-looking cowl flaps to adjust temps. The ejector stacks would help with cooling too. Just like the real thing.I'm intending the airframe to weigh ~1400lbs, leaving 3 options in terms of engines: