Monogram 1/48 Boeing B-29 Superfortress

[DMC]

This build, Jamie, should be a learning experience of the first magnitude and well worth following.

 

And as an aside: I am currently reading the book Atomic, a very readable account of the development of nuclear weapons.  I’m at the point in the book where General Groves and Robert Oppenheimer have decided on Los Alamos as the location for the Manhattan Project.  Can’t help but wonder what either would have thought about being able to buy a kit with scale models of Fat Man and Little Boy.  Beggars belief.  

 

Dennis

 

[Johnny_K]

Jamie,

 

I built one of those last year. It is a really big model when finished. But boy is it impressive. That kit has some big, big problems. If you like, I can offer some suggested solutions. Let me know.

 

 

 

 

 

 

Edited February 17, 2019 by Johnny_K

[busnproplinerfan]

I forgot how much weight I added to the nose, took quite a bit. I know I put wheel weights in the rear of the cockpit to. Not sure if I needed all that. 

[Jamie @ Sovereign Hobbies]

I may try lightening the tail end a bit. That could be a more natural solution particularly given the long model the tail has and the short moment the nose weight would have. The result would be lighter and less likely to squash the main undercarriage. The Dremel could come in handy!

 

This morning though I have made up another piece of photo etched detailing. I'm going to take a break from this and make up that sanding board I mentioned. Too much PE can result in burn-out.

 

[Jamie @ Sovereign Hobbies]

I got distracted and started making bottles to go on those mounts... there is supposed to be a similar set on the other side. The parts are included on the PE set but they aren't mentioned on the instructions.

 

I found some scrap sprue (sorry injection moulding professionals) that was slightly too big to fit inside the PE retaining band clamps and attacked it with Infini Model's excellent sanding stuff - firstly reducing the diameter and correcting out-of-roundness by spinning it in an electric drill chuck using the 220 grit soft stick, then putting a domed end on it once it was a snug fit inside band clamps. It was then finished up with the 800 grit sanding sponge. Whilst these make rapid work of sanding tasks, it's difficult to accidently sand a flat on to something using the sponges which is ideal for this sort of thing.

 

 

 

I added the nozzle for the tubing from brass tube after drilling the end of it once it was to final shape.

 

 

Now to simply do exactly the same again - not my strong suit!

[Jamie @ Sovereign Hobbies]

Done.

 

 

Right - I want that big sanding board now...

[Jamie @ Sovereign Hobbies]

One of the nose wheel bay side walls is done (and so is the sanding board that you are all no doubt wondering about)

 

[Jamie @ Sovereign Hobbies]

Building up the other side reveals that the Eduard details clash with the Eduard details - note that the folded box when correctly positioned on its marked space on the main etching clashes with the nose-gear bay roof structure, and as a result daylight is visible along the joint where it shouldn't be. I will try relocating these, and if that doesn't work one of the boxes will be omitted. I find this a lot with Eduard PE so it's not really a surprise.

 

[Brandy]

Holy whatsits, that's a lot of brass. Will you need those weights with all that in there? 

One thing is for sure, the extra detail will make this very special. I noticed when I checked your link for the resin bits that there is a note saying the moulds gave out! That is one heck of a nice set, but it looks as though it may be no more!

 

Ian

[Jamie @ Sovereign Hobbies]

7 minutes ago, limeypilot said:

Holy whatsits, that's a lot of brass. Will you need those weights with all that in there? 

One thing is for sure, the extra detail will make this very special. I noticed when I checked your link for the resin bits that there is a note saying the moulds gave out! That is one heck of a nice set, but it looks as though it may be no more!

 

Ian

 

Hi Ian,

 

I reckon more weight yet will be needed but I plan to use the space behind the engines and maybe the leading edges of the wings too inboard of the engines. Obviously that's less effective though. Really the back end needs lightened.

 

I saw the same when I went to get the link for the Flightline Engineering set. I expect he still has the masters so could make another set of casting moulds. I imagine these will reappear in due course when he's got time and when there is a sufficient list of people asking for a set

[Johnny_K]

 A lot of weight is needed to keep the nose down. First I glued solid weights to the underside of the flight deck. Then  I put lead balls into a plastic bag which I located in the area of the flight engineer. 

 

[allyby]

Hi Jamie, long time no speak, hope you and yours are well, looking forward to watching the progress on this one..😊

[fubar57]

Very nice. Any thoughts of making resin copies of those bottles? I've seen many builds where those were also scratch built after the builder had asked if anyone knew of after market bottles

[Johnny_K]

The PE stuff is looking really nice.

 

That kit has a lot of problems: warped main wings, warped greenhouse, nasty seams at engine nacelles, incorrect engine exhaust pipes, nothing to glue the engine cowlings to. You can go here for my solutions. http://cs.finescale.com/fsm/modeling_subjects/f/2/t/179912.aspx You can see my finished model here: http://cs.finescale.com/fsm/modeling_subjects/f/2/t/177401.aspx

[Jamie @ Sovereign Hobbies]

14 minutes ago, Johnny_K said:

 A lot of weight is needed to keep the nose down. First I glued solid weights to the underside of the flight deck. Then  I put lead balls into a plastic bag which I located in the area of the flight engineer. 

 

Hi, that's a practical solution and one I might have to accept if tail-end lightening fails, but I really hope I can avoid it. I can't rationally explain why, but I think that would really grate on me 😕

 

9 minutes ago, allyby said:

Hi Jamie, long time no speak, hope you and yours are well, looking forward to watching the progress on this one..😊

Hi, you've been fairly quiet for a while unless I've been living under a rock (which probably is the case). How are you?

 

8 minutes ago, fubar57 said:

Very nice. Any thoughts of making resin copies of those bottles? I've seen many builds where those were also scratch built after the builder had asked if anyone knew of after market bottles

I suppose I could, but I'm not sure they're good enough really. It could save myself some hassle in the long run I suppose. I haven't scaled these from anything real - they were just made to fit the PE parts. Maybe correctly sized bottles would be something marketable though? I'd have to measure some up next time I get to Duxford.

 

Speaking of which - does anyone have any photographs of the inside of the nose wheel bay of Duxford's "Hawg Wild"? I had, but lost them with my hard drive failure at Christmas. I'm interested in Hawg Wild because it's unrestored, but any other unrestored airframe in the USA or elsewhere would also be of use. I've spent some time searching the internet for photographs and have only found Enola Gay which is painted silver, an unnamed aircraft in Interior Green and there is the Monogram instructions which call for Interior Green, but I trust none of these modern preservations or kit instructions as reference material for colours.

 

[Johnny_K]

I understand your concern regarding putting weights in the flight engineer's area. But I would rather put weight in the flight engineer's deck than end up with a tail sitter. I also recommend that you make sure that you have enough weights before you glue the fuselage together.  I taped my entire model together with blue tape, including the main landing gear. Then I started adding lead balls to the bag until the nose dropped down. Then I added more for good luck. I was surprised how much weigh was needed.

 

 

 

 

[allyby]

13 minutes ago, Jamie @ Sovereign Hobbies said:

 

 

Hi, you've been fairly quiet for a while unless I've been living under a rock (which probably is the case). How are you?

 

 

 

I'll post a Re Into thread later mate, don't want to hijack you thread but I'm well though!

Edited February 17, 2019 by allyby

[Johnny_K]

I just weighted my B-29. The complete model weighs almost 2 1/2 pounds. There is a lot of weight up front.

[busnproplinerfan]

14 minutes ago, Johnny_K said:

I understand your concern regarding putting weights in the flight engineer's area. But I would rather put weight in the flight engineer's deck than end up with a tail sitter. I also recommend that you make sure that you have enough weights before you glue the fuselage together.  I taped my entire model together with blue tape, including the main landing gear. Then I started adding lead balls to the bag until the nose dropped down. Then I added more for good luck. I was surprised how much weigh was needed.

 

 

 

 

I was going to suggest this but your picture explains it better than I could. Also if you park it on a diorama, you could put a bolt in the nose wheel and nut underneath. Or just wire it down around the axle.

Edited February 17, 2019 by busnproplinerfan

[Nikolay Polyakov]

1 hour ago, busnproplinerfan said:

Also if you park it on a diorama, you could put a bolt in the nose wheel and nut underneath.

Yes, it’s a really good solution, also a diorama base can prevent the issues with the wings-to-the-fuselage joints. This solution has a very detailed explanation in an original instruction sheet.

 

Cheers! 🙂

Edited February 17, 2019 by Nikolay Polyakov

[pacificmustang]

40 minutes ago, Nikolay Polyakov said:

Yes, it’s a really good solution, also a diorama base can prevent the issues with the wings-to-the-fuselage joints. This solution has a very detailed explanation in an original instruction sheet.

 

Cheers! 🙂

right here, in fact

http://sheperdpaine.atspace.com/b29.htm

[bigbadbadge]

Hi

Great start, wow that'll be a lot of PE.  I am very interested in your solution to the raised panel lines. I have a C47 and  B17 to build and am wondering what is the best thing to do with them.

Great work so far.

All the best

Chris

 

[Ex-FAAWAFU]

This promises to be fascinating.  I’ve alredy learned lots (I’d never heard of Silverplate, for instance), and no doubt will learn a lot more.  @Johnny_K - superb result from all your hard work.

[Jamie @ Sovereign Hobbies]

Some more thoughts on weights...

 

Unlike most I have straddled many camps within a wide world of model making and there are things that the well-seasoned modeller of one camp takes for granted as common sense that seldom occur to well-seasoned modellers in other camps.

 

One of the things I've done before is design, build and fly radio controlled aeroplanes. Like real ones, they have to balance or they don't fly. Every pilot/builder of flying models knows that the correct way to balance a model is to lighten the tail, not fill the front end with lead. Doing the latter results in the total weight going through the roof, the power to weight ratio dropping and the wing loading increasing. The somewhat dimmer aeromodeller tried to offset bad building by fitting bigger engines, but that does nothing to help the high wing loading and high stall (and therefore takeoff and landing) speeds.

 

To arm myself with some data (me coming back to my Engineering roots here) I have inspected the rear fuselage and tail parts from the kit. These are very substantial mouldings and must be close to 2mm thick everywhere. Ignoring the wings for now, I taped the fuselage halves and tailplanes & elevators together and balanced the fuselage on the point where the main wheels coincide. The tailplanes have relatively massive locating tongues which overlap inside the fuselage.

 

 

 

Even like this with interior parts missing and no wings, the tail is weighing over 90 grams on the scales:

 

So why am I making such a fuss about the thickness of plastic back there? Because Engineering, that's why...

 

 

Here are the moments about the Centre of Gravity (which needs to be at or ahead of the main wheels for this thing not to sit on its tail striker)

 

The scale of the drawing is irrelevant because the moment arms only need to be in proportion with each other, not true to life - the results are the same regardless of the scale.

 

The moment about the CoG at the tail (which I have labelled T and which is where most of the excess beef in the tail planes, elevators, fin and rudder are - there is more redundant weight ahead and behind) is the the mass on the scales times the distance from the CoG.

 

The mass needed either immediately behind the cockpit (which I really don't want to do) to balance this out with only half the leverage (48mm ahead of the wheels) is as near-as-damn-it double, or 179g which needs to be considered an underestimate because paint, guns, some PE in the aft compartment etc is going to tip this a little further aft.

 

Point B above the front lower turret is worse still needing 210g placed there to offset the tail's moment.

 

The moral of the story is that for every 1 gram of redundant mass I can Dremel out of the back end of this thing, I save the need for an absolute minimum of 2 grams of counter balance up front which means the finished model is 3 grams lighter than it would have been had I left the tail as-is. If I am to have any chance of getting this thing to sit on its nose wheel without spoiling the interior I have to do this, and the main undercarriage will thank me later when I do.

 

With the nose weight already stuck to the cockpit floor inserted into the fuselage, the same experiment on the scales still shows a residual weight of 60 grams on the tail. That means that if I don't try to lighten this thing's fat backside then I need at least another 120g up front immediately behind the cockpit.

[Nikolay Polyakov]

42 minutes ago, Jamie @ Sovereign Hobbies said:

The tailplanes have relatively massive locating tongues which overlap inside the fuselage.

But not so much loss of the weight when you cut it a half, right?

 

You have done a very interesting calculations here, bravo! What about to put a some weight into the forward tunnel part (I think it’s not be visible there)?

 

Cheers! 🙂

Edited February 17, 2019 by Nikolay Polyakov