Mitsubishi A5M4 "Claude" [1:32 Special Hobby] - RFI

[Alex]

Overdue for an update here.  The cockpit is about finished.  I didn't take a lot of in process photos because it was pretty standard stuff.  The only AM item used was a set of IJN seatbelts from RB Productions.

 

Here's how it looks set against the sidewall of the fuselage.

 

I'm going to need to shave down the sides just a bit to get the fuselage to close nicely around it, but only a bit, which is nice.  I'll add some pastel to fade/dirty the paint a bit before closing it up (at which point it will be 90% invisible...).

 

I put the engine together quickly, using the supplied PE wiring harness, which is less work that drilling out the distribution ring and putting in individual plug wires, but sadly does not look as good.

 

I'm less worried about the plug wires because they will be somewhat obscured by the cowl bracing that I'm going to have to scratch build.  You can see what it looks like here:

 

I'm kind of surprised that they are not supplied, since they would be an obvious thing to make from PE, and Special Hobby did go ahead and mold the mounting bosses for them into the front of the crankcase.

 

Speaking of the cowl, I'm seriously thinking about cutting off the molded in cowl flaps and making new ones out of metal.  I want to show them slightly opened, and they are of course molded fully closed.

 

The other possibility I considered is grinding away plastic from the inside until they are very thin, cutting through the scribed lines separating them, and then gently bending them outward at the scribed line that delineates their base.  That seems like a bit of a balancing act though.  We'll see.  Special Hobby also missed the two notches in the lip of the cowl that are their to clear the line of fire from the MGs, so I'll have to make those.

[dennismcc]

Coming along nicely, that cowl bracing is rather prominent as you say it is surprising that it was not included in the kit.

 

Cheers

 

Dennis

[mgbooyv8]

Nice progress!

Indeed surprising that the cowl bracing is not present in the kit.

 

Cheers,

 

Peter

[Alex]

I decided to make another attempt at adding rivet detail to one of these.  I tried this on the ill-fated P-36 a while back, but will try to apply some learnings and advice here to do a better job.  Unlike the P-36 kit, on this kit Special Hobby has managed to produce fairly restrained recessed panel lines, and all of them are properly molded, not full of flash the way the P-36 was.  So a better starting place for sure.  I could not find any drawings that show the actual rivet placement on the A5M, so I'm going to make my best guess based on this cutaway drawing:

 

And by analogy to the rivet placement on the A6M, which is very well-documented (and which I can review just by looking at my Tamiya Zero).   I'm not going to try and invent every last rivet, just follow what seem likely to be the major structural members.  I'm doing this on the wing and fuselage parts pre-assembly, as Kev suggested during my P-36 project.  I laid strips of yellow tape to serve as visual guides for the path of the rivet wheel.

 

Here's the first pass - the rivet runs that go fore and aft.

 

They're subtle, and that photo is not ideally focused...

 

And after the second pass running the length of the wing.

 

Still not perfect, but definitely better than my first try.  I am probably going to skip doing the bottom of the wings, in the spirit of saving my neck, wrists, and eyeballs and focusing on the parts of the model that you see on the shelf.  I am going to do the fuselage, obviously, and that will present its own challenge in that the curves of the dorsal spine are tight enough that the rivet wheel will not fully follow them.  So at least some of the circumferential runs of rivets will have to be added by hand with a needle tool, which (based on historical evidence) I am terrible at doing.  I plan to use the tape guides and make some additional bits that are marked off at 1 mm intervals to try and get them more uniform, but it's going to be a challenge to make it look as good as the wings do...

[Alex]

Started on the circumferential rivet lines

[Alex]

It's difficult to get a clear photo of the rivet pattern on the curved fuselage side, but this is after both rounds, circumferential and longitudinal, were done.  

 

It only took two phases of glue-and-clamp, and surprisingly little filler, to get the fuselage closed up and smooth.

That big divot on the nose has to do with a locating pin for the cowl - it won't show later.  But it does foreshadow some engineering I will have to sort out if I'm going to show the cowl flaps open.

 

So on to trying to get the wings to attach cleanly.  It only took paring away about 0.4 mm (I measured ahead with my digital caliper, which you can see in the above photo and which is indispensable) of plastic to get the forward part of the lower wing section to fit cleanly without any force/friction onto the fuselage:

Of course there are still gaps that will have to be filled, but everything lines up without steps or other discontinuities, so minimal (fingers crossed) reshaping should be needed.  Of course you can see at the bottom of the picture that the back end of the wing section most definitely *doesn't* fit flush just now...

 

The scribed line here shows the material that will have to be removed to allow the wing to sit down flush...

 

I sawed along the line a bit with the CMK razor saw (about 0.6 mm deep, bit deeper in the middle), then finished the rabbet with a paring chisel.  I kid you not.  Special Hobby kits are the only ones that ever cause me to dig out woodworking tools.

 

That rabbet allows the back side of the wing to drop in nice and flush.

 

So that's enough for tonight - especially since we're losing an hour of it to Daylight Savings Time here in the states.  Tomorrow I'll tape it up snugly and investigate what will have to be done about the tops of the wings.

 

[dennismcc]

You're doing a great job on that, you just have to get a bit inventive with these type of kits, but it's worth it in the end as no one else will bring out another 1/32 scale Claude.

 

Cheers

 

Dennis

[Alex]

18 minutes ago, dennismcc said:

You're doing a great job on that, you just have to get a bit inventive with these type of kits, but it's worth it in the end as no one else will bring out another 1/32 scale Claude.

 

Cheers

 

Dennis

Very true.  And to be honest the more recent SH kits are getting better.  Half of the 1/32 kits on my “to build” shelf are SH, because they will do subjects that no one else would bother with.

[Alex]

The fundamental issue with the upper wing sections is that they are too long relative to the lower wing.  This is looking from below, so you can see the upper part protruding past the lower.

 

Even after judiciously trimming the upper part at the wing root to minimize gaps and get the major wing strengthening rib to align top to bottom (which thankfully it does), the outer part of the wing is too long, with the result that the leading edge panel lines don't align top to bottom.

 

While "ignore this" is certainly an option, I think I will fill the ones on the bottom and re-scribe in line with the top once I've glued and de-seamed them.

 

On the port side there's a significant gap at the wing root leading edge that will need to be filled with some plastic strip.

 

But the good news (he says, now fully into "proper modeling" mode) is that the rest of the top-to-bottom join is pretty tight.  I was able to scrape away a bunch of material from the inside faces so that the big trailing edge gaps are gone.  And the overhang at the tip is now only ~0.5mm, so just a bit of sanding and it'll be fine.  Plus now the wing root alignments, while not perfect, are vastly better than they were with the parts dry fit out of the box.

 

Port side:

 

Starboard:

 

Once I've got the wing parts glued up I'll dry fit them and scribe a line to guide removal of just a bit of material from the fuselage wing root, and presto - should come together OK.  Which is good, given the work I'm going to have to do on the (underside of, fortunately) tailplanes...   But that's for next update.

 

[LSP_Kevin]

Tough work, Alex, but you're doing a great job!

 

Kev

[Out2gtcha]

Yep, leading edge wing panel alignment is a real PITA when its misaligned from top to bottom.

Great work so far!

[MikeMaben]

Thanx for the pix Al , it's good to know what to expect. 

[Alex]

One nice thing about these early fixed-gear Japanese planes is that they eliminate all potential angst or conflict over how much effort to apply to detailing the landing gear bays that no one will ever look at ;-)

 

Special hobby provides a couple small dimples on the wing that show you where to drill out to receive the small stubs molded into the landing gear spats.

 

I decided that this looked like something that was primed to break off when looked at wrong, and resolved to reinforce the join (hence the third hole in the middle).

 

I glued a styrene block inside the wing section and drilled through it

 

Then, carefully holding the wheel spat up to the wing in alignment, drilled though that down into the spat part.  This allowed me to glue in a piece of brass rod.

 

Having that rod CA glued into both sides will hopefully make the final assembly much stronger.

 

I approached these pieces a little differently, based on experience with the Ki-27 kit.  I taped them up, as you see above, and glued only the upper parts of the legs together before doing this drilling - the wheel cover parts are not yet glued.  That let me get this brass rod bit done (and the two halves fixed in proper alignment) before inserting the wheels.  They will look like this eventually:

 

But before putting them in permanently and gluing up the rest of the seam, I covered just the part that's exposed with tape:

 

This tape won't be hard to pull out once the spat is painted.  Worst case scenario I might need to soak it in a little water for a while to soften the adhesive.

 

Then glued and clamped the rest of the spat.

 

To do that I used (as I think most of us do, most of the time) Tamiya Extra-Thin cement, so it would wick in and fill the space between the halves.  It's great for that purpose.

 

Turning to the wing glue-up, however, I've recently come to appreciate this product:

 

Which I guess is just Tamiya Not-as-Thin cement.  It is good when you need to apply glue to a significant area and have it not flash off of the first part you covered before you get to the last part.  In woodworking parlance, it seems to have a much longer "open time".  Useful in specific applications.

Edited March 16, 2021 by Alex

[LSP_Kevin]

Nice work as always, Alex. An alternative approach for dealing with your already-painted wheels is to just leave them exposed as is, and when you're finished painting the rest of the model, simply rotate the tyres so that the section covered with camouflage paint is now up inside the spat, and a new properly painted section becomes the visible part. Of course, this relies on the wheels themselves being able to rotate comfortably within the spat, and also for the act of rotating the wheels to not scrape any paint off the tyres.

 

Kev

[Alex]

5 hours ago, LSP_Kevin said:

Nice work as always, Alex. An alternative approach for dealing with your already-painted wheels is to just leave them exposed as is, and when you're finished painting the rest of the model, simply rotate the tyres so that the section covered with camouflage paint is now up inside the spat, and a new properly painted section becomes the visible part. Of course, this relies on the wheels themselves being able to rotate comfortably within the spat, and also for the act of rotating the wheels to not scrape any paint off the tyres.

 

Kev

Ah, the voice of experience!  That is indeed an elegant and (now that you’ve said it) obvious solution.  Fortunately the *next* Japanese plane in the queue is also a fixed-gear type, so I’ll have a chance to try that out...