A7M2 Reppu SAM 1/72 Finemolds

[Cuppa_joe]

Hey all getting started on my second build.

As the title suggests, it's a 1/72 scale of the slated successor to be of the in/famous Zero, albeit too late for the IJN and in too few numbers to have effect as only 9(?) A7M2's were built.

After the short comings of the underpowered Nakajima Homare NK9 driven A7M1 were addressed, with a new engine sourced, that being the Mitsubishi MK93(HA-43), it was pressed into prototype and later testing as late as June 1945. 

 

So come forward 75 years and here is little old me painfully cleaning flash and surface details to do the elusive kit some justice... justice Finemolds clearly forgot it's kits needed in the 2000's.

Slow start, found the need to rub back everything. 

Sourced some reference pictures of blueprints, others finished kits and old photos i happened to come by, all with slight degrees of differences between them. Really need to get my hands on a "Maru Mechanic #5" for all the details. I'm saying this as i later found that this prototype had folding wings, shown on some blueprints, and having the correct reference material, it would give me a start at what would be the first kit with modifications for me. More on that later as well as colour scheme... orange sings to me but that also says it's still a prototype and not a fully inducted frame as the green does.

 

Lads your opinions?

 

Back to the kit, it is rather large for a 1/72 but then again compared to a Bf 109, everything is. The consistency if funny on this vintage of kit, all the details are there, but crudely finished where one needs to rub it all back to make it presentable. Case in point...

 

 

 

The panel lines aren't the best either, and i might need to take our some locating pins.

 

I got the chisel out to clean out the gallery between the engine bay and cockpit to give it some depth and consistency against the reference material

Before

After

 

The recessed panelling at the forward end is for the exhaust pipes to exit.

They got marked to be chiseled out themselves for more definition as i will be using actual tube or rod to simulate the stacks, the kit simply has flatish sections that doesn't do it justice. More on that next time.

Until then, the fuselage ports and other areas will be reenforced with sheet and chiseled out the same to give the depth i feel it needs.

Cheers

 

 

 

 

 

[2996 Victor]

I'll be following along, if that's okay, as I have one of these in my stash. I was going to finish it as one of the service trials aircraft.

 

Kind regards,

 

Mark

[Cuppa_joe]

No worries! I'd really like to see how you paint yours up! Cheers Mark!

[2996 Victor]

3 hours ago, Cuppa_joe said:

No worries! I'd really like to see how you paint yours up! Cheers Mark!

 

To be fair, mine's not up for build for a while, but AFAIK the service trials aircraft would have been  finished in standard IJN green over grey with blue-black cowling.....

 

Cheers,

 

Mark

[HOUSTON]

Joe,

 

 

This is one I will enjoy .

I will tag along as they say. 

 

Good start.

 

 

[srkirad]

I've had some trouble during assemblying lower fuselage/wings with upper ones - panel lines on nose part didn't match, so had to glue whole winga a bit to the front, leaving huge gap on the rear joint of wings and fuselage.

Cowling also needed some styrene inserts to properly match its halves.

 

You can see what it looked like here:

 

https://srkirad.wordpress.com/2014/05/29/fine-molds-mitsubishi-a7m2-reppu-06/

 

I'm curious whether this was just my example erroneous or it's mould error generally.

 

Overall nice kit, and pretty big when finished - P-47 level

 

Cheers,

S.

[Cuppa_joe]

1 hour ago, srkirad said:

I've had some trouble during assemblying lower fuselage/wings with upper ones - panel lines on nose part didn't match, so had to glue whole winga a bit to the front, leaving huge gap on the rear joint of wings and fuselage.

Cowling also needed some styrene inserts to properly match its halves.

 

You can see what it looked like here:

 

https://srkirad.wordpress.com/2014/05/29/fine-molds-mitsubishi-a7m2-reppu-06/

 

I'm curious whether this was just my example erroneous or it's mould error generally.

 

Overall nice kit, and pretty big when finished - P-47 level

 

Cheers,

S.

Hi mate, yes pretty much the same fit issues, although you made me realise what i did wrong with the front cowl...now i have seen it, i cant unsee it!! you did well to pack it out to suit the nose cone. time to cut it out and do over.. not up that point of attaching the wings at the moment, doing some modifications internal to the fuselage to allow for better features, and may still go with folded wings, open canopy and exhaust details. 
Forgot to add, the kit looks very nice indeed overlooking its flaws none the less, and with better surface finish it should come up pretty beatifully but damn it needs some work. regardless im keen to see the newer releases it does as i have still some hope

Darius
 

Edited December 31, 2020 by Cuppa_joe

[Cuppa_joe]

Some extra work done 

Marking out for the exhaust path 

 The kit itself 

 

Drilling out exhaust of 1mm with .5mm drill.

 

 

Stacks done and glued together

nose cone before

 

After opening it up 

during 

 

After

 

Trying to modify without too much problem, just turned out to be without too much progress

 

 

Material added to support the fuselage once chiseling out details

 

After researching images available on Zero's to get a better idea of what is seen in and around the engine bay i went and decided to open up the exhaust vents/cowls. Understandably it creates vacuum and would aid cooling from the front of the engine. Hence the installation of a cooling fan on the HA-43 infront of the starter pack but behind the propeller, might have run hotter? Anyway this needed making a jig to lay the open cowls to an eyeballed 30 deg opening, and this will also help to act as a solid stop for the exhaust tubes to be parallel and symmetrical. See how it goes, this is the first time I'm doing mods and have now gone too far with the front cowl to go back.

 

30 & 60 degree templates

 

 

Fixture jig with locating tabs for flaps 

 

Till next time, and happy new year to you all!!!

 

 

 

 

 

 

 

 

 

 

[srkirad]

Yes, although older kit, it has very nice details and panels surface that "overlap" - didn't see this so far on many newer kits.

 

You're doing good work so far, keep going!

 

 

Cheers,

S.

[Cuppa_joe]

Agreed, noticed that now I'm looking to fold the wings and amazingly the seams all work. I'm assuming that is why any kits from Finemolds don't last on the shelf long as the price and quality seem to be in balance.

[Cuppa_joe]

So by sheer luck when I bought this kit, it came with a PE set included in the sale.

Very lucky, but this is also another first for me using PE.

Below are snaps of the instructions and what was included as I'm sure many would not have seen it before.

The instructions though aren't in English, nor very informative at all so need to do some research, especially on the engine fan which i will get to doing eventually.

 

 

Very interesting diagram

 

I think this might be Finemolds paint conversion for Mr colour enamel/ acrylic and Tamiya  acrylic.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Cuppa_joe]

Nail biting start to the PE stuff, snapped some, bent some folded some, need to roll others...a labour of love for sure.

 

 

 

Added some ommitted details, and this will also act as support for a lever in PE 

 

 

 

Finally starting to look like a plane. Very nice to see it take shape as hours have passed with the feeling nothing is done. (Mind the reference pictures in the back haha)

Made a ring for the nose section to help with alignment out of styrene sheet. This has come in handy already.

Just dry fitting to test gaps and seams.

 

 

 

 

@srkirad this is what gaps came to be. About 1mm in the fuselage longitudinally and transversely. 

 

 

this has got me in a pickle as the alignment of the engine cowl is make or break, and to fit the exhaust, the locating dowls need removing, so need to figure out how to maintain this alignment. Looks like many hours ahead staring at it. If you notice, the petals for the exhaust flaps are now being removed and kept safe until they go back on the jig with the exhaust pipes in location.

 

 

 

 

[srkirad]

Yup, pretty nasty gaps on fuselage/wings joints, and that has effect on the nose area too, but as I see you're doing some pretty good salvation steps, so keep following your work till the end  

[Cuppa_joe]

Bit more done, first describing the original tanks and ports, then opening up the different stabilisers and flaps to give more depth as well as a small little modification that took far far longer than I expected! Watch below..

 

 

 

 

 

My goal was to modify the vertical plane/rudder/stabiliser to be mobile, therefore it needed cutting apart from the fuselage, and a hole drilled in from the top by hand with a .4mm drill bit to allow for a .38mm wire to act as a internal hinge.

 

 

 

 

 

 

 

 

Although not entirely perfect, I'm rather smitten with the result and it allows me to flex the rear as well as being another great learning experiment.

 

 

 

[Cuppa_joe]

Found some very hard to find (read search) images and references i found to help with the model. This model of plane is rather interesting and might have a go at the 1/48 in the same FineMolds stable...actually they are the only ones that make it now.
Im really debating whether to have folding wings or not, and leave it for a later build on a larger scale as there are holes in my skills that need, erm, well, learning and experiencing.
Ill try and fail off the model and see how i go!
Anyway found these of interest alonng with a bigger and less relevant horde.
 

 

This one is very interesting as is shows accurate measurements of different fuselage components.
 

Might be just worth getting the print if at all possible.
This all helps to understand how and what works, and have already noticed differances to how the scribes panel lines might be incorrect on my model which made me query exactly how the wings folded. these are located at the butt join of the wings roughly where the Hinomaru is placed. Might have to make a trial hinge and test it.

 

[Cuppa_joe]

and there is this, im leaving this here more for my own reference but also your entertainment. i feel this is a prop but none the less close to that a A7M3 last and final version of my model looks like with very similar features in the video. a lot of work in this model!

 

[Cuppa_joe]

The idea for the foldable wings has been abandoned for a larger scale, still did the work to male the hinges and draw up some ideas before it got canned due to size restrictions. This was slowly becoming my Moby Dick 🐋 and it needed to be cut off before i got carried away

 

 

 

 

Above, drilling templates

Below drilled with hinge pin.

 

 

So wiping a tear away, i moved on to more pressing items that made me displeased with the look of the planes proportions was the Pitot tube. Chasing up some brass tubes in 1mm, 0.8mm and 0.6mm from the local train store was this material supplied by Albion alloys precision metals. I'm very impressed.

Here they are one inside another for effect, as well as layed out on paper to measure out their spacing and length relative to the plane.

 

 

reference pictures shows it to be in line with the front leading edge of the exhaust cowl seams, and whilst the original tubes looked to be of similar dimensions both inner and out, i decided to go with a smaller tube to accent the difference as the 1mm to 0.8mm is hardly noticed.

 

 

 

Edited January 7, 2021 by Cuppa_joe

[Cuppa_joe]

Next up on the agenda is some more scratch.

Looking at reference material, the engine really sucks in detail, but with good reason once covered one cannot see squat.

Regardless i felt compelled to do something... anything about the lack of depth

So here goes 

Engine with part looking to replace the starter/supercharger/oil pump/ water pump/ whatever pump 

 

 

Fitted and compared to cut off part 

 

 

At home in the sloppy cowl. Need to pay attention to center placement 

 

 

 

 And finally a taste of what to expect.

Don't forget that the PE set has a fan in behind the propeller and will almost block off it all from view. 

Oh and the moulding for the bore of the propeller is not center, meaning once spinning it wobbles eccentrically.

😔

That does it for now.

Anyone else notice the district lack of tamiya paint supplies around town? I have been looking for xf10, xf11 amongst others including flat black as spare and my God, if you don't get it from ebay overseas...you ain't getting it

 

 

[Cuppa_joe]

Just a quick one today, needed more material and got other things done instead, like....this! 

I converted the ball/ 360 deg swivel vice to a normal flat bed vice without a clamp. The only other options available are the clamp type cast into the body as many would have seen. As not wanting to buy a clamp to simply destroy it even if it is $20, i opted to get this as it's modular.

 

 

 

 

Several problems with this(and all sub $150 vices) is build quality and tolerance.

To fix this, i installed a multilayered shim on the handle drilled to 11.9mm to stop friction directly on the vice from the threaded clamping pin.

This of course meant the cast surface had to be filed flat to actually make a difference, as well as all holes chamfered to not bind.

 

Next was fabrication of a compensation shim to follow the rear to clamp flat as all the surfaces are sloped, and cast poorly with seams and gaps!!! The filing! 

This was made of a m12 x 1.75mm nut filed down and a plate made 23mm x 19mm in 1.6mm to slide and act as the shim to compensate for the gap underneath and on the guides.

 

 

 

To make this work, the base where the clamp slides needs...you guessed it...filing! 

 

Only once that was done could the unit be clamped together and filed /sanded inside the jaws for squareness as well as on top afterwards, then close to a light polish.

Happy with how it turned out as the casting has an incredible amount of bubbles.

It's crap, but for what we do, more than sufficient. 

 

Mounting to the plate was interesting, as it wasn't just a drill and tap affair but rather a notch needed to be made to compensate for the small embossed square used to locate it the the ball and stop rotation. Simple and effective.

I will need the clamp in the future and figured some might need a similar modification so there was that small spiel.

[Cuppa_joe]

Last time I mentioned that the prop was out of center.

Well added some rod to fill in the hole, then will simply cut off and re-drill correctly.

 

 

Needed to go about opening up the engine cowl exhaust flaps (finally)

As it turns out I bit off more than I could chew.

Reasons for that was as simple a modification it seems, it has some profound implications to the aspect and fit of the cowl to fuselage.

There are internal tabs that are smack on the exhaust tubes on both Port and Stbd which guide the nose on to said fuselage.

To fit these flaps in the open position, the existing exhaust needs to be removed and another installed in it's place supported elsewhere as the flaps no longer provide support as they were cast together.

BEFORE removing the flaps, the jig i made needed modification as i found out to allow for correct alignment as well as center including support whilst installing as all the flap are open at the same degree relative to the cowl.

To do this i installed a central support, a tube, and did the same on the fuselage in the same relative location. Where; it doesn't matter as long as they correspond.

 

 

Here is the bar that goes inside.

I Suspect this can help later with the exhaust, but yet to be seen.

 

 

Mounted in position, and the final outcome with the tube installed on the fuselage

 

 

What it looks like on the jig without the cowl.

 

 

 

 

Note that as the tabs are now gone and this is mounted central to the prop centerline, this, and the seams of the kit are now what is the reference.

A drill being used to keep the parts in alignment when glueing.

final outcome without cowl. 

Looks not bad, and is consistent in final assembly.

 

 

 

Edited January 13, 2021 by Cuppa_joe
Bad post skills

[opus999]

I'm late to the party.  Outstanding work with the jigs and the rudder! I also really like the scratchbuilding that is going on.  I think this is going to be a lot  of fun to follow.