A6M3 model 32 - better base kit for conversion?

[Juggernut]

You’re most welcome.  Sheesh, this is getting to be a bad habit with me but I transposed the versions that were shorter in my original post….  I had initially said the distance was greater on the A6M3 than on the A6M2.   That’s twice I’ve screwed up so far.  I guess you’ll have to seek outside verification/corroboration for my comments.

[seiran01]

It’s ok, I deciphered what you meant!

 

The wings are a perfect fit as well between the -2 and -5, ignoring the different forward center part that forms the lower fuselage with the carb intake. 
 

So what I’m thinking right now is to make a new forward fuselage in CAD along with the cowling, and of course the aileron inserts and wingtips, so that the Tamiya A6M2 can be used without the need for kitbashing. The cowling itself is pretty easy,  so the initial focus will be on designing a good forward fuselage part to copy the Sakae 21-powered airframe. If I can get that to work, the rest should be childs play .
 

*IF* I can get that to work, I will explore options to make this available as a set for others who may be interested. If I can’t get it to work, I’ll just do my own kitbash and be happy with that

 

 

[Troy Molitor]

Oh I love where this is heading.....Mike, Im down for this one for sure.    100%.  Here's to your talents going forward.  

[coogrfan]

On 12/2/2021 at 7:53 PM, amurray said:

 

• The cowling gun ports on the A6M3 are a different shape from both the A6M2 and the A6M5.  Dave Thompson of UMI Resins made an A6M3 cowling before he passed away.  IIRC the 21st Century A6M2 cowling is actually an A6M3 cowling.  The air intake on the A6M3 cowling is a different shape than that on the A6M5 cowling.  Don't use the A6M2 cowling as it has open gun troughs and the air intake is on the bottom.

 A quick fyi on this: the initial release of the 21C A6M2 (yellow plastic) included the A6M3 cowling. There was a second version (same box) molded in grey plastic that included the correct A6M2 cowling.

Edited December 7, 2021 by coogrfan

[amurray]

On 12/3/2021 at 10:21 AM, Juggernut said:

 

Where did you get your information from if I may ask because some of what you've written just isn't fact:

• This has already been established by me in an earlier post.
• The A6M3 used a larger magazine drum than did the A6M2 and therefore the "blister" on the wing underside of the A6M3 was larger than that of the A6M2.  The larger 100 round blister is included in the A6M2 kit and marked not for use; there's no need to cut anything from the A6M5 wing.  I have no idea what you mean by "shell collection blister", please elaborate if you wouldn't mind.
•   The cowl gun ports on the A6M5 are  different than the A6M3....  They are exactly the same between the A6M3 and the A6M5.  They only changed when the Japanese added a 13mm machine gun to the A6M5 Model 52b. The unique shape of the A6M3 intake has already been mentioned in an earlier post.
• The A6M2 spinner (part Q21) is incorrect for the A6M3 but the correct spinner (part Q22) is included in the A6M2 kit but marked not for use.  NOTE:  Part Q22 may be the larger spinner for Nakajima built A6M2's but may work for the A6M3, check your references.  You are correct that the A6M5 spinner is wrong for an A6M3.
• Cockpits differed in various details between A6M2, A6M3, and A6M5; consult your references. 

 

Sprue Layout from the 1/32 Tamiya A6M2 kit:

 

Shorter ailerons for the model 32 (I believe)

 

100 round drum blisters for the A6M3

 

 

Larger A6M3 spinner (also reputed to be the larger A6M2 spinner from the Nakajima built A6M2 so consult references and see if this is correct)

 

 

 

 

I think we are saying the same thing but in a different manner with the exception of the gun ports on the cowl.  The gun ports are in fact different between the A6M3 and the A6M5 - not much, but different shapes nonetheless.  The air intake on the A6M3 is also is a different shape than the A6M5 air intake at the top of the cowl lip.

 

I was unaware of the fact Tamiya had additional parts (to be unused)that would address the A6M3 conversion.  Thanks for pointing that out as such a conversion is one of my planned (fingers crossed!) projects for 2022.  You just saved me some aggravation!

[amurray]

On 12/2/2021 at 10:36 PM, seiran01 said:

Thanks for all that. What’s different between the two kit fuselages? I noticed the A6M2 has a separate spine but otherwise I don’t know the difference.

 

From the photos I was looking at, looks like the long spinner in the -2 box is correct, I was guessing the longer diameter prop from the -5 is better to use with that. 
 

Can you recommend any references that show the difference in cowl gun ports and  other details clearly? The unused shell blisters in the Tamiya -2 kit look to be about right for a model 32 or 22, but I’m only going off of some photos I found online and could be way off.

 

 

 

 

Correct on the spinner/prop:  A6M2 spinner but A6M5 prop.  I'll post some pix of the cowl gun ports and the cowl upper air intake, shortly I hope.  Sorry for the late response but my wife had a medical emergency and has been in the hospital.  All is well now.

[amurray]

21 hours ago, coogrfan said:

 A quick fyi on this: the initial release of the 21C A6M2 (yellow plastic) included the A6M3 cowling. There was a second version (same box) molded in grey plastic that included the correct A6M2 cowling.

 

 

EDITED BECAUSE THE MIND SEES WHAT IT WANTS TO SEE!  SORRY!

 

My gray yellow plastic 21st Century A6M2 kit has the A6M3 cowling.  I had heard (and you have confirmed) that 21st did a correction but one cannot go by the color of the plastic to ascertain that difference.

Edited December 8, 2021 by amurray

[Dennis7423]

On 12/6/2021 at 1:26 PM, seiran01 said:

*IF* I can get that to work, I will explore options to make this available as a set for others who may be interested. 

 

I'll just be over here hoping and praying that you get *that* to work.

 

- Dennis S.

   Thornton, CO USA

[amurray]

On 12/4/2021 at 4:24 AM, thierry laurent said:

The Doyusha kit has some dimension issues. I know it as I used the kit to make a model 22 with the help of leftover Tamiya parts and a 21st century kit. This applies at least to the aileron shapes and the upper cross section of the fuselage behind the cockpit. Nonetheless the panel and rivet scribing was incredible for this era.

 

 

The Tomy/Swallow/Doyushu kit has issues but is fun to build.  It is the kit that got me back into the hobby almost 30 years ago.  Through luck, attention to detail or warpage, it is the only kit of the Zero that has the downturned wingtips that reduced the stall speed, a brilliant design change made by Jiro Hirikoshi to reduce stall speed.

[amurray]

On 12/2/2021 at 10:36 PM, seiran01 said:

Thanks for all that. What’s different between the two kit fuselages? I noticed the A6M2 has a separate spine but otherwise I don’t know the difference.

 

From the photos I was looking at, looks like the long spinner in the -2 box is correct, I was guessing the longer diameter prop from the -5 is better to use with that. 
 

Can you recommend any references that show the difference in cowl gun ports and  other details clearly? The unused shell blisters in the Tamiya -2 kit look to be about right for a model 32 or 22, but I’m only going off of some photos I found online and could be way off.

 

 

 

 

From Mitsubishi A6M Zero by Artur Juszczak (and there are other references)

 

A6M2 Cowling:

 

 

A6M3 Model 32 Cowing:

 

 

A6M5 Cowl.  He screwed up his numbering but you can figure it out.  He got his spinner shapes reversed vis-a-vis the A6M3 32.  In particular note the carburetor air intakes, the gun troughs (longer and narrower on the A6M3 and different at the fuselage) and the exhaust systems of the A6M3 vs. the A6M5:

 

 

[amurray]

2 hours ago, amurray said:

 

 

I think we are saying the same thing but in a different manner with the exception of the gun ports on the cowl.  The gun ports are in fact different between the A6M3 and the A6M5 - not much, but different shapes nonetheless.  The air intake on the A6M3 is also is a different shape than the A6M5 air intake at the top of the cowl lip.

 

I was unaware of the fact Tamiya had additional parts (to be unused)that would address the A6M3 conversion.  Thanks for pointing that out as such a conversion is one of my planned (fingers crossed!) projects for 2022.  You just saved me some aggravation!

 

Okay, here we go DEEP, DEEP into the rabbit hole:

 

Juggernaut properly corrected my bad terminology about wing gun blisters.  BUT in reviewing one of my references I find mention that the A6M3 Type 32 used both the Type 99 Model 1 Mk 3 wing cannon (in which case the blisters on the A6M2 wing are correct) AND ON OTHER A6M3 Type 32  AIRCRAFT the Type 99 Model 1 Mk 4 wing cannon (in which the blisters for the A6M5 or the additional Tamiya parts referenced by Juggernaut are correct).  I have not descended deeper into the rabbit hole to ascertain which aircraft (i.e. unit markings) used which cannon.

[seiran01]

4 hours ago, Dennis7423 said:

 

I'll just be over here hoping and praying that you get *that* to work.

 

- Dennis S.

   Thornton, CO USA

I’ve lost track of other projects… was it you who asked me to design SBCs for the HK Lancaster? I’m planning to print one when I get my new ultra high resolution resin printer in a few weeks time

 

I appreciate all the info on the cowling, guys! With the gun troughs being longer on the 3, it leads me to suspect there may be a slightly different curve to the cowling. Doesn’t make sense to me why they’d appear different for another reason. I’ll examine photos and eventually some books…

[amurray]

Not sure they are longer, but definitely narrower.  Why that would be I have no idea unless the gases were not vented properly in the narrower version or maybe for barrel cooling purposes?  I haven't a clue.  I'm checking my references to see if the nose mounted 7.7 millimeter machine guns were different models as were the 20mm cannons in the wings thus making a gun trough design change necessary.

 

As an aside, I have about 30 references on the Zero.  Although I read all of them over 20 years ago this thread has caused me to re-read most of them.  If one spends enough time looking at the references, one can find conflicting drawings and specs (e.g. the A6M3 spinner vs. the A6M5 spinner) on several fronts.   Bottom line:  I have zero (pun intended) hands on knowledge of the A6M3 Hamp.

[Dennis7423]

7 hours ago, seiran01 said:

I’ve lost track of other projects… was it you who asked me to design SBCs for the HK Lancaster? I’m planning to print one when I get my new ultra high resolution resin printer in a few weeks time

 

Guilty! That was indeed me. As for this project, I've got several kits worth of pieces I can send you to study. I'll shoot you a PM.

 

- Dennis S.

   Thornton, CO USA

[A6M]

Hello Gentlemen,

 

Juggernaut gave me a heads up on this thread and i got diverted from what I am supposed to be doing (LOL) to do a quick write-up of my notes on doing a Tamiya A6M2/M5 conversion to an A6M3 32. I'll try tp post some pics later on.

 

Converting the 1/32 Tamiya A6M2 to an A6M3

 

Fuselage

 

The needed spinner and prop are included as “not used parts”. Use parts E1, E2,  E7, E10, E11 and E14.

 

The A6M2 kit also has most of the needed engine parts for the Sakae 21. Substitute the following parts:

- D20 for Q44; D12 for Q40; D13 for Q39;

- the exhaust components for the Sakae 12 should fit onto the new Sakae 21 engine but may need some adjustment

- build the rear section of the engine with parts D15, D19, D26 (x2), D28, D29

- for the front of the engine use D4, D14, and D27 instead of Q17 and Q46.

- use engine mounts D30 and 31.

 

The A6M2 fuselage must have the firewall moved back a scale 185 mm. It should be possible to use firewall part D22 and the oil tank D21 instead of parts K23 and K25. However, the heat shield K12 may not fit on the new configuration.

 

The big problem is the cowling, cowl flaps, and accessory section. The easiest solution is to use the fuselage and cowling from the A6M5 kit. If it is possible to order spare parts put in a request for Sprues A and C (Sprue C also includes the proper heat shield mentioned above).

 

If the A6M5 cowling is used the cowl gun ports do not need to be changed, but the air intake at the top of the cowl must be reworked. The cowl flaps will also have to be revised. The A6M5 accessory section panels will also have to have the small heat shield panels removed.

 

Using the A6M5 fuselage also takes care of the change to the upper panel of the accessory section as well as the revised fuselage gas tank access panel.

 

If the A6M5 fuselage is being used the small oval access panel on the left side of the base of the tail fin will have to be removed - unless the A6M3 being built has a m/n of 3304 or higher. Beginning with the 304^th A6M3 the rudder had an adjustable trim tab (as is found on the A6M5 Sprue A. For the fin itself use Parts L20 and L14 from the A6M2 kit.

 

Cockpit

 

Use the cockpit floor Part E39 (or shorten the front of Q45 from the A6M2) and cockpit walls EE21 and N5. However, Tamiya muddled the A6M2 fittings on the A6M2 kit. Part Q14 is a morse code key that was not always put in use. Either install it as is indicated or leave the mounting platform empty, file off the raised square on the top of the platform, and drill a lightening hole in the centre of the platform. Part E30 is actually the controller for the Type 3 Model 1 Transceiver which was only introduced with the A6M5. Fortunately, Part E30, the RDF controller, is included in the A6M2 kit and should be put into the location indicated for E30. The radio components Q47 and Q28 are correct for the A6M3.

 

Except for early production A6M3s Part E37 should have the extension for the hydraulic pressure gauge cut off.

 

The instrument panel may need some modification. The A6M2 kit panel is correct for very early production Type 32s but the components below the panel were soon modified. A6M2 Part Q48 consists of an inclinometer on the left and an oxygen supply regulator on the right. Looking at the lower section of Part E42 there can be seen, from left to right, a combination hydraulic gauge and oxygen supply regulator, a electrical firing system controller, and wing tank booster pump switches. The changes occurred as follows:

- the inclinometer remained on the left side throughout Type 32 production.

- the electrical firing controller never was in use on the Type 32 but very early in its production the combination hydraulic gauge and oxygen supply regulator was located in this position. Note that when this was done the hydraulic gauge mentioned above was moved from the location on part E37.

- the wing tank booster pump switches box was added at some point in the later production of the Type 32.

 

Wings

 

The Type 32 initially used Type 99 Mark 1 20mm wing guns with a 100 round ammunition drum. This larger drum made it necessary for the underwing gun bay covers to have large blisters to accommodate the drums. Thus use Parts L16 and L17.

Half of the last 40 Type 32s (beginning with m/n 3304) were equipped with long barreled Type 99 Mark 2 20mm wing guns. The ammunition bay cover may have been simplified; thus Parts L16 and 17 should have some of the scribed panel lines filled in. As well, the cannon barrels will have to be replaced.

 

The small round indentation on each of the A6M2 upper wings just inboard of the gun bay should be changed to a U-shaped hinged panel.

 

The early production Type 32s retained some of the fittings for the A6M2 folding wing-tips. This included the flare in the end of both spars and the underwing access panel for the wingtip latch to the rear of the front spar. In about the mid-production period of the Type 32 the flare in the end of the spars was eliminated as were the remains of the wing fold latch mechanism.

 

The early squared wingtip fairing had a panel line in the middle of the fairing. This was done away with in the later production aircraft.

 

The ailerons, Parts 2, 4, 9, and 11 should be shortened one rib width at either end. The space on the wing between the inner end of the aileron and the flap line will have to be filled in.

 

Hope this helps,

 

Ryan