Would it be possible to convert Tamiya's Betty to a G4M2 or 3???

[Ohm-men]

I'm just wondering? Could this be done. Fuselage would need some serious surgery and it would need different shaped engine nacellers and a larger tailfin.
But the G4M2/3 also had a redesigned wing with a thicker profile and different airflow.
I have no idea how different the wing is of a G4M2 or 3 when compared to a G4M1 (like the tamiya kit)

So, what would be a good publication to check the differences of the various G4M models.

It's just a random idea. It would be interesting to build a Okha carrier aircraft from the Tamiya kit.
Though I guess it will be not an easy task. I just hope to find out just how much of the Tamiya wing I could use for such a conversion.

 

[Wurger]

All is possible. Here in an example. A Mercury jet liner into Il-14 ... the rest of images of the work here.... Modelarstwo z pasj? ? Zobacz w?tek - I?-14 1:72

 

[Lucky13]

 

[Ohm-men]

Wow, that's one crazy conversion!!

As for the Betty, I think it can be done. I just enlarged some scale plans of the Osprey Publication on the G4M to 1/48th scale.
The main differences are ofcourse the nose (more glass) and nose cone (different shape)
The adition of the upper turret and the repositioned side guns.
The tailplaines are also larger. All of this seams doable.

The wings looks pretty much the same on both model 11 (Tamiya Kit) and model 22.
the latter had a redisgned wing with was is described as a "laminar flow airfoil" wing.
Thickness and shape look simelar to the wing of a typ 11, the typ 22 has different pannel lines and rounded (larger) wingtips. Ofcourse the typ 22 had different engines and exhaust. Though also this seams doable....

So, there is an itch to scratch here...I have a Tamiya betty in the stash and hopefully I'll be able to find a MXY-7 model 11 Okha (either the trainer of full flying bomd) from Fine Molds.
This would produce quiet a interesting model I think...

Even though the different wing still isn't clear to me yet, but since info on the latter Betty's is pretty scarse, I think I'll go with it. I can always copy the pannel lines of the Hasegawa 1/72 G4M2 (simelar as I did for my Ki-67)

Once I decided which route I'll go, you'll most likely see a new topic in the start to finish build section here

 

[Wurger]

 

[Ohm-men]

So, I laid the Tamiya G4M1 model 11 parts on the G4M2 model 22/24 drawings and it seams doable...

Fuselage is spot on.

Wings are also close..

Tailplanes, idem dito...

Cocpit transparancy fits too!

As does the nose transparency (model 11, that is. Pic taken for reference)

The real problems are the engines and their housing. The diameter of the G4M2 Model 22/24 are slightly bigger
then tose of the G4M1 model 11...

Perhaps not that fisible in this picture, but the difference is some 1.5 to 2mm in diameter.
But I think even this can be dealth with. Since the tamiya kit includes closed engine flaps as well, I could cut these in 4 pieces and ad strips of plastic card, the same will have to be done with the engine covers and nacelles.

But if well planned, I "think" I might get away with this. Since there is little to be seen ob the actual engine, the model 11 engines can be used. The G4M2 used VDM props and I think some early Ju 88 A1 props are very close to their Japanese counterparts...

So, something to think about. And I just found a used Tamiya Betty kit in mint condition for the equivallent of 30 bucks...
Oh, oh...decissions, decissions....

 

[Shinpachi]

Looks like a great project, Ohm-men!

 

[Wurger]

Great. It looks like the chord of the elevators has to be resized a little bit up.

 

[Airframes]

Good stuff, and I agree, it should be very 'do-able'. Even without alterations to the engine cowlings and elevators, once the main changes are made, and it's all built and painted, I think it would easily pass inspection - it would need to be physically measured to spot a difference of 1.5 to 2mm overall.

 

[Ohm-men]

I'm gonna try and get plano copies at 1/48th scale from the Osprey book so I can measure and compare everything.
But like you said, it seams very doable.

As for the engines, you got a very good point there. If the exhausts are changed, the 4 bladed props installed, the top and lower intake on the engine nacelle made, you'd have to be an expert to notice the the smaller diameter...

The tail surface elevators do need indeed some sizing up, but not much. So do all the wing tips and tail tip. (rounded profile instead of the squared off ones on the G4M1)

I measured the nose as well, as the glass panes will have to be installed. Though at first look and measurement, it seams I can simply enlarge the existing windows on the nose withouth too much surgery.

Side blisters and top gun position are easy to fill with plastic card and sanded flush, new sqaure gun side windows don't seam to difficult.
As for the guns, German Mg 131's and MG FF's can be altered to look more like their Japanese counterparts.

I think I might take a stab at it.

Though to tip the cherry to this pie, I have to find a Fine Molds Okha...I think this will be the most difficult tast afer all...
To get a 1/48th scale Okha kit for a decent price. Oh, well...There's the Ki-67 to finish first!

 

[Airframes]

Looking forward to seeing it develop. As for the Okha, if all else fails, that could be scratch-built, even if it means a 'solid' fuselage carved from balsa, and profiled with something like 'Milliput', and possibly a balas or foam core for the wings. Or even make balsa patterns, and mould the basic components.

 

[Ohm-men]

I really like your line of thinking Airframes!

Hmmm, I would be possible to scratch build the Okha flying bomb.
Since it will hang under the fuselage, there won't be that much visible.
I think I can find scale plans of the Okha piloted bomb online and start from there.

Or, I could try to find an old Hawk/Testors kit of this bomb. I know it isn't as deatailed, but I could be a good starting point (especially, since details aren't that important here).
I think Italeri re-issued it once together with a V-1.
Since in a few months the swap meets and modelling show season starts again, I could go on the hunt!

 

[Wurger]

Sounds good.

 

[Ohm-men]

Ah, my nice co-workers printed me some 1/48th scale plans for the Betty.
So now I was able to compare the Tamiya parts to both the G4M1 and G4M2 scale plans.
The engine nacalles are either oversized on both the G4M1 and M2 drawings are Tamiya's are undersized.
(Though I think it might be the scale plans as the wings are a tad longer and wider as well)
But they are the same. Tamiya's props are spot on on the Model 11 drawings. Engine openings are also the same on both models as are the nacelles.

Wings on both models have the same width. G4M2's wings are a bit longer, but not much. Flaps have the same size on both models.
When the two types scale plans are compared, only some pannel lines are different and the wing tips differ as well.
The flaps apear to be unslotted on the G4M2. And the G4M2 has a few extra fuell caps on it's wings.

The overall thickness also apears the same, only has the G4M2 extra "armour" under the wings to protect the fuell cells (from what I read, these were just rubber mats glued to the underside of the wings to act as some sort of self sealant in case of a bullet puncture)

So, if the drawings are somewhat correct, the main surgery has to be done on the fuselage in order to convert the G4M1 to a G4M2.

It will still be a rather big conversion, but it seams doable... I think...or hope

 

[Wurger]

How did your co-workers resize these scale plans for the 1/48 scale? Did they use any measurement?

 

[Ohm-men]

How did your co-workers resize these scale plans for the 1/48 scale? Did they use any measurement?

The original 1/144 from the Osprey book scale plans were scanned in high resolution and enlarged by 300% to reach the 1/48th scale. Since I work at a rather large print factory specializing in both Offset and Digital large prints, we are used to scaling up and down various files and making sure they are correct, as our clients demand this.

Again, the Tamiya Fuselage lined up perfectly with the enlarged Osprey plans, just the wings seam a few % to large, compared to the Tamiya kit.
Though, I also discovered that the Tamiya kit' representing an early to mid model 11 G4M1, lacks a few details that are visible in pictures and are on th eOsprey plans. There is a row of strengtheners on the aft fuselage (just aft of the side blisters) that is pretty prominent, but is not on the Tamiya fuselage.
These strenghteners were dismissed on the late model 11 and models 22 and 24.
Aside from that, model parts and Osprey plans do no show dicrepancies.

 

[Wurger]

I see. Well done then.

Perhaps this can come in handy too.

View attachment g4m.zip

 

[Ohm-men]

Thanks a lot wurger! These are great.
I"ll check these against the Osprey scale plans and start from there.

There seam to be a few details that are missing on the Osprey scale plans, so I guess I'll see where both sets of plans get me.

I have to get my hands on that book G4M book a looked at a while back. Should of bought it, though I'm sure that vendor will be on one of the swap meets in a few months.

Next I will have to go on a search for some decent G4M2 model 24 pictures. There are some on the web, but most are of low quality.
Though the front of the fuselage preserved at the Garber facility seams wel documented. The interious of both the nose compartment and cockpit seam well preserved to give a general idea of the interior.

 

[Wurger]

My pleasure. Also here you are a shot I have found via the Internet. Maybe it can be useful for you too.

View attachment G4M Betty.zip

 

[Ohm-men]

Thanks again! Indeed very useful
Quiet detailed on the attachment hardpoints for the Okha.
And also very slear between the trainer and warhead loaded Okha.
(there are slightly more differences then I thought.)