Posted by Matty on January 30, 2010, 23:21:24 Edited by board administrator June 4, 2013, 23:48:40
--Originally Posted 1/30/10--
A (shamefully long) while ago, I touted the impending release of an aircraft casting designed for easy conversion between any of three different planes (F6F, F2A and F3F).
However another such "three-fer", a casting convertible among three other aircraft, has long been lurking - undiscovered until now - in the Matt Stein Models original 1/500 HellDiver. Designed from the outset to be convertible between the monoplane SB2C HellDiver or biplane SBC HellDiver dive-bombers, a third Curtis aircraft has been cleverly hiding within this casting: the SOC SeaGull floatplane:
Although seeming at first glance rather a far cry from an SB2C HellDiver, this renowned, workhorse floatplane of WWII nevertheless shares common design ancestry with the later, famous WWII divebomber.
The family resemblance can be easier seen by way of comparison with the SB2C's immediate predecessor - also called "HellDiver" - the biplane SBC:
Click on Image to Enlarge
In these gorgeous color LIFE Magazine pics from immediately before WWII, the two beefy silver biplanes - SBC HellDiver, at left, and SOC SeaGull, at center - looked similar enough that in fact the caption for the latter even called it an "SBC" floatplane (incorrect for any period, AFAIK). As shown at right, the SOC - just as the SBC - had a more downward-tapering rear fuselage than the SB2C - and both were likewise deeper in the belly overall - than the SB2C HellDiver.
However for precisely that reason, extra girth had already been designed into the Matty's Models casting:
Click on Image to Enlarge
Thus, the "two-fer" casting (left), facilitating conversion to an SBC, turns out also to be ideal for conversion to an SOC SeaGull (right) - simply by removing the mass (black) indicated, perhaps scraping off a little excess canopy framing and adding separately-provided top wing, struts and floats (not shown).
The resultant SeaGull (a significantly smaller plane than the SB2C Helldiver) scales out to approximately 1/370, which is entirely suitable on builds ranging from about 1/350 to 1/400 - and also happens to be virtually identical in scale to the Matty's Models 370-scale KingFisher floatplane!
I'll build up one (or more) of these, to let you see exactly what could be made - and to expose the SeaGull - sneaky bird - "hiding in plain sight" within this casting, the entire time...
Cheers,
-Matty
Workup / Demos
Posted by Matty on June 29, 2013, 19:11:49, in reply to "Sneaky SEAGULL!"
A Matty's Models customer (I'll protect his name until getting permission) recently ordered some "Production Seconds" (which are all that remains in stock) of my 500-scale HellDivers, explicitly for conversion to 350-ish scale Curtiss SOC SeaGulls - giving me with an ideal opportunity to work up a few extras, as demonstrators:
Conversion of the original-casting fuselage is pretty simple: mainly grinding off the entire belly, right up to the (lower) wing. The canopy gets chopped back with a new windshield formed about 3/4 of the way back over the wing, and the turtleback shaved down a little - not even as much as (mistakenly over-) done here. Finally, the rudder trailing edge gets straightened to be a bit more vertical, and the wing (to become the SeaGull's bottom wing) narrowed by about 1/3 and given just a little sweep-back. I plan to eventually post a conversion/construction-tips page describing all the above, simply and very clearly, with the help of explicit graphics.
Top wings and pontoons (top-left) hadn't yet been mastered for this conversion - so the needed upper wings were hacked from additional HellDiver seconds, and pontoons - both large, main ones and the tiny wingtip floats - were pirated from my OS2U KingFisher, in the same scale.
Note these pics show PE struts for the wing floats in the process of going on (completed at bottom-right). The trick - again, since no struts had (yet) been mastered - was to chop off all but one (the rearmost, vertical) of the molded-in (KingFisher) struts, and use it temporarily for attachment. The angled/inboard struts - "scratch-bashed" segments of of "1-bar" railing, in 540-scale (in truth, a bit on the long side) - wer then fitted. Once this PE was securely hardened in place, the resin strut was then gently, GENTLY whittled away - using an absolutely brand-new/unimagineably sharp X-acto-type Number 11 blade - scraping away gradually, RIGHT AT THE FLOAT - so that, once separated the stick could then be chopped away cleanly and easily, against the wing. Following which, a pair of vertical PE struts (these rectangles cut from some 700-scale float-net baskets) were then glued-in - all of the above using CA, of course - to make for a pretty strong attachment for the wingtip floats.
Note at top-left, on each large, main pontoon all but one of the (three) Kingfisher struts have likewise been removed, in anticipation of exactly the same technique to fit/scratch-bash their PE struts, as (more) accurate for a SeaGull.
This is the point at which I normally would- and so will now take a crack at beginning the final painting - hopefully to stand up well through the subsequent fitting of PE struts to both main pontoons and top wings. Stay tuned…
Cheers,
-Matty
Specific PE "Scratch-Bashing"
Posted by Matty on July 14, 2013, 11:48:35, in reply to "Workup / Demos"
--Originally Posted 7/14/13--
To explicitly lay out the "scratch-bashing" procedure used to provide PE (mostly strut-) details - so that these can be identically reproduced - is almost as difficult as figuring out and doing it in the first place. Detailed pictures are key - both for saving thousands of words and a clearer description, anyway - and so here, below, are exactly the PE snippets I found to work:
Wing "N"-Struts:
These shapes - two of which are indicated at top, in lavender - were cut from bottom rungs of the "Forrestal Deck Edge Antenna", as found - likewise outlined in lavender, at bottom - on the Gold Medal Models 1/540 scale "Midway/Forrestal/Essex" fret. Note it supplies up to 8 such identical "N"s - enough for four SOCs (or also Matt Stein Models F3Fs).
With a ruler, I attempted to measure the height of these parts, to be approximately 0.12" - bearing in mind that the only hand-tool really capable of measuring such tiny parts would be a micrometer. So my numbers could easily be off by 20-30% - which can be enough to throw off the fit (particularly of the upper wing). However these "N"s - whatever their true dimensions - are just the right size.
Also in this vein, note all these pictures (both above and below) are not orthographic, but instead shot at slight angles (to avoid overhead glare/reflections) - meaning that you can't measure absolutely accurate proportions from them. I did rectify them somewhat, digitally - so they are certainly in the ballpark, and clearly recognizeable - however you can't reliably get precise measurements by counting (these) pixels.
The above fret has two sections, of which that shown is the lower/bigger one. The other, smaller section also contained PE which was used, for:
Wingtip-Float Diagonal (inboard) Struts:
Click on Image to Enlarge
These were rectangles (top, again in lavender) cut from "One-Bar" railing, of which there is a single, full-width segment (bottom) included in the GMM 1/540 Midway/Forrestal/Essex fret. The long dimension of each chopped-out rectangle is approximately 0.11". This is a good 20-25% longer than it should be - however when installed the over-long struts don't detract, IMHO, from the appearance of the SOC.
As I worked up these examples, the above diagonal struts went on first - so that resin mounting pegs could then be removed. However now that these specific parts - and especially their (at least, approximate) key dimensions - are known, you can now start with bare wingtip floats - leaving off the resin peg(s) entirely - instead simply gluing on:
Wingtip-Float Vertical (outboard) Struts:
Click on Image to Enlarge
These tiny rectangles - approaching the limit of what my foreceps can even grip, while leaving one edge clear to dip in superglue - were chopped from (what I think are) float-net baskets (top), which are included abundantly on White Ensign Models' 1/600 Moskva fret (bottom). The height - that is, now, the short dimension - of each detached rectangle is approximately 0.03" - and the long dimension (whatever it measures, exactly) is a comfortable 70% or so of the chord of the SOC lower wing, to which it gets attached.
The most (surprisingly) difficult-to-find PE shapes were finally located on another GMM fret, providing:
Main Pontoon Struts and Bracing:
Click on Image to Enlarge
These "open hour-glass"-shaped pieces (top, in lavender) were cut from X-bracing labeled "Taiho" (for the IJN CV) on the GMM 1/500 IJN Carriers fret (bottom). I cut each leaving one end open (aft, on the SOC) to preserve access to a resin mounting-peg, still needing to be removed. But now that you know the part - and I'll tell you its height (short dimension) measures somewhere around 0.09" - your need for any mounting peg, and thus to leave an open aft end, is eliminated - and you can use the full hour-glass shape to provide both front- and back main pontoon struts, in one go.
Note, however, that the above Taiho bracing will provide only 4 such complete hour-glass pieces - enough for only two planes. However also note that immediately adjacent on the fret are X-braces (apparently for Ryujo, or possibly additional parts for Taiho) appearing extremely similar - probably enough so to use for (in toto, at bottom) 8 more, on a full quartet of aircraft.
All the above are workable solutions - as good or better than any others I think one is likely to find. However I am not yet satisfied (at least, not enough to devote time to making a graphic presentation here) with the one type of strut remaining:
Fuselage (-to-top-wing) Struts: A solution for these is simply not yet "ready for Prime-Time" - but I will keep you posted.
Likewise, I am also missing a graphic - though one is not really needed - for:
Two-Bladed Propellers: These I chopped from 4-bladed aircraft propellers of the Gold Medal Models 1/500 USN Naval Ships fret - which contains exactly four of them - so now there are none left on the fret, to show you. However the bashing couldn't be simpler: just chop off opposing blades - while of course protecting the central mounting ring - to leave a two-bladed prop. Note another source stock of 4-bladed props - lots of them - is presented by the smaller section of the GMM Midway-Forrestal-Essex fret, mentioned earlier. Their blades are longer than those on the above GMM 500-scale Naval Ships fret - so you will need to (at least) be careful the final pieces look like they will clear the SOC's main pontoon - however chopping back the tips a bit, as needed, shouldn't present any particular difficulty.
I hope the above is helpful. Again, I will definitely keep updating/posting, as any more/better options come to light.
Cheers,
-Matty
Taking WINGS
Posted by Matty on July 2, 2013, 14:31:14, in reply to "Workup / Demos" Edited by board administrator July 4, 2013, 20:14:09
--Originally Posted 7/2/13--
OK so, learning the lessons from last time: all top-wing installations were re- (and some re-re-) done:
This time after painting the canopy-frames, which are OK (not really accurate for the SOC, but at least with similar "look-and-feel"), and whose very nice (IMHO) custom-chopped windshields, unfortunately, will in the end wind up all but completely hidden by the upper wings.
The top-wing installations, though finally successful, remained difficult right to the end. The problem is that the outboard "N"-struts simply MUST be absolutely perfect in length. Absolutely. PERFECT. Because once their installation has begun, there is just no way (at least, not with any of the skills/tools I possess) to adjust/tweak them.
The tiny fuselage struts - so miniscule they are at the limit of what my tweezers can even grip - proved (the hard way) to require attachment first to the fuselage, as seen at lower-left. Their tips are then free to spread outward as needed, when pressed-down upon by the top wing - until its pre-positioned outboard struts just contact the lower wing. Do yourself a favor and use brass PE - as opposed to the stiffer/harder stainless steel - and don't worry if (just as seen here) the fuselage strut-pattern is not quite accurate: their (more or less correct) height is far more critical. And in any case, they will also end up next-to-invisible, under the top wing.
In person (way more forgiving than these camera-closeups) their appearance has already "popped", to look like little gems. Soon to be yet further enhanced by touchup-painting, and the addition of (at least some) tiny decals.
However first I have to correct a major flaw, just noticed: the main pontoons are too long, and should terminate just before the tail - not all the way back under the rudder. Fortunately, their extra-strength PE attachments should allow for chopping/grinding of their back ends, in-place. Anyway, you know I am going to give it a try...
Cheers,
-Matty
STRUTS Everywhere
Posted by Matty on July 1, 2013, 11:37:39, in reply to "Workup / Demos" Edited by board administrator July 1, 2013, 15:09:26
--Originally Posted 7/1/13--
Custom-fitting both the main pontoons and top wings turned out to be all about finding/bashing the best-fitting PE struts:
Installing main pontoon struts, so far only on the pair of silver-painted demos, the trick of leaving a single peg from the original casting (clearly visible on the blue-gray one, at lower-right), for use as a temporary anchor, did again work just beautifully. While difficult to see here, 500-scale "X"-braces were used (though I realize the cross-members are a bit overscale), as these essentially doubled the strength of the attachment. This method - not yet completed on the silver pair, and barely started on the blue-gray duo - can already be expected to be highly successful.
The same could not be said of the first run at top-wing attachment, as started before pontoon-attachment on the blue-gray pair - the first mistake in itself, right there. Far better to attach the pontoons first - not to mention also to paint the canopy framing (before the top wing gets in the way...Duh!). Besides which, I had quite a bit of trouble fitting the main "N"-struts - as can be seen both in the purple, scraped-clean spots as well as large CA-glue blobs - before adding any fuselage-to-wing struts, also tiny "N"s (not shown). So I will pop all these off and (clean/resurface and then) redo the top wings the right way - although this trial attempt has been invaluable in precisely identifying/fitting the optimal parts.
All the SOC's struts can be glimpsed on one or another of The Real Things - a full quartet of them - photographed astride USS Pennsylvania on July 2, 1939:
Click on Image to Enlarge
Pretty cool, huh? This shot is particularly relevant to the above conversions, as it demonstrates SOCs embarked on Pennsy - and no doubt (especially) her sister, Arizona - in close to- if not exactly the fit depicted by the Revell 400-ish scale mold - for which these (370-scale) conversions will provide the closest (only 15% oversized) SeaGulls available anywhere, AFAIK, and on which they will (IMHO) look just fantastic.