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Old Dec 19, 2013, 02:29 AM
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So here we are again finally with an update on the B-29

After successfully seperating the two fuselage halves, with no twisting of either thankfully, I was able to divide the front and rear sections also without issue, I was able to drill and add the aluminium tubes and dowels for joining the two sections after transporting. The alloy tubes were located in the forward section with ply reinforcing and the two front fuselage halves glued thoroughly back together and then the upper decking was added where the electrics will be placed once all was dry. The dowls were then added and again reinforced to the rear section and again the rear fuselage sections glued back together. Once dry I test fitted the front and rear sections to make sure all lined up perfectly and they did













Next a horizontal plywood bracket was made for each side of the two halves with spacers fitted and these were drilled with a 6mm dia hole for the wing bolt being used to pull the two sections together. The steel bolt you see is just temporary until I can get hold of a proper plastic bolt. As you can see from the following shot all goes toether well.

Next it was time to fit the bomb bays, so I seperated the two sections and turned the fuselage over. A very basic box was added to the front bay more to keep it strong in that area really although it will still look good once finished and still have operating doors. Likewise for the rear bay, however this was slightly modified as it is going to be the area I use to allow access to the rear fuselage joining bolts. Constuction was the same apart from the large section cut away for the access. Another floor panel was then made and added over the top held in place by four small self tappers in each corner. The tiny holes were drilled for these screws and then I added CA glue to each to harden the wood and stop it splitting. Again as you can see from the picture it looks fine.

Then it was time to add the front wheel bay. Now, you may recall I was having issues regarding the front wheel alignment because the oleo on a 29's front leg is forward of 90 degrees. Keeping it scale, I was having issues with the wheel retracting in the full size tacky mock up I made. Positioning the retract unit at an angle to compensate for this meant when the wheels retracted, they hung low out the fuselage so this meant the bay doors would not shut. You will see what I mean in the last two images here.............after studying closer at image of the full size bomber, an 'Oh my god'!! moment errupted













Following on, I noticed that the front oleo strut just above the top of the wheels, was kinked rearward where the suspension knuckle is! Well this changed everything! I modified my excellent mock up wheel strut, basically snapped it where the knuckle was and bent it back to the required angle and look what happened..... it retracted fully into the bay! Happy Rob was an understatement

Anyway with that all sorted, the front retract bay was contructed, firstly from 1/16 balsa to make the templates, then when happy it all went together properly, these were duplicated in 1/8 ply to make a box section. The very front was cut away to allow fitting the box but slots were cut into the first to third formers mid way down and a 1/8 ply base was epoxied into place for the retract bay to be glued too, A ply front wall for former number one was also added to give strength to this area and once glued and postioned and lined up, it was heavily epoxied in place.

I have now been thoroughly sanding the whole fuselage and I am about ready to start skinning her.

And thats it for now guys. Hope you are all enjoying this build as much as I am. I fear it is ripping along rather rapidly. At this rate I will soon be thinking about what other large model aircraft I can build.......Tiny hint.....in the pipeline an Avro Shackleton

Again for the weight watchers in us, total all up weight so far 868grams (31.0ozs)











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Old Dec 27, 2013, 09:56 PM
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Hey Rob, with Christmas over, the rest of us are back to work >hint< >hint<

Seriously though, hope yours was a good one!
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Old Dec 27, 2013, 11:04 PM
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Originally Posted by greenseaships View Post
Hey Rob, with Christmas over, the rest of us are back to work >hint< >hint<

Seriously though, hope yours was a good one!
Funny you should say that. Stick around for 10 minutes, I'm about too update
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Old Dec 27, 2013, 11:15 PM
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Festivities Gone!!!! Hurrahhh

Finally with the festive period well and truly scrapped, the more serious subject of updating the progress of the B-29 Superfortress can now continue. I hope you all had a great Christmas all the same

Now then since my last update, a rather large chunk of the bomber has been done, in my standards anyway. You will recall on my final chapter before the festiities arrived I was about to sand the front section of the fuselage ready for skinning. This has now been done and I decided to plank the structure diagonally using 1/16 sheet balsa strips 1/2 inch wide. This has proven to be successful, albeit a rather long process.

The six images below show the process from start to finish before trimming. The more difficult areas were around the wing root section of the fuselage. For this area I planked upto the root and cut the strip at 90 degrees where it met the root, leaving me small elongated triangular sections to fill after. Because the surrounding areas of he root between stringers was filled with 1/8 sheet, this gave me a solid surface to CA the triangular sections too once cut to size.













This set of six images show the fuselage sections bolted back together. Some of the triangular sections still need to be added and the planking trimmed. This bolting back together process was merely a test to check planking the front section had not bent or twisted the framework and as you can see it is all still good. One slight alteration or modification I did however make was were the two sections join, I noticed a small amount of movement vertically was present. So I decided to drill two 4mm holes opposite one another at the top and the bottom of the formers that butt up together. I then cut out four 1 inch square 1/8 ply sections and also drilled these with a 4mm hole through the middle. I then Epoxied a 3M nut over the hole on two of the ply squares and again epoxied these to the inner areas over the holes on the rear sections former passing a 3M bolt through the hole to keep it all lined up. I then repeated the process on the other two 1 inch ply squares, this time with a 3M 1 inch diameter washer. These were then epoxied to the inner sections over the holes on the former on the front section of the fueslage, again using a 3M bolt to keep it all lined up. Once the epoxy set, I slid the two sections back together and bolted it all up. As well as the 6mm bolt in the middle, the two new 3mm bolts now made everything strong and movement free. Slight cutting away of the inner sections of two of the formers in the front fuselage section was needed to allow me access to the new bolts but has not altered the strength of the model so all is good.

Once again I added the tailplane and fin to the rear section dry, just to stand back and look at the progress of this monster model. The last image you can just see the 1 inch diameter washer and 3mm screw bolt head, just below and left of the main centre 6mm bolt.













The first image you can see the ply plate that travels from the front former back through the second and third formers that the front retract bay is epoxied too underneath. This ply floor will also make for good Lipo battery positioning incase I need to shift the CG forward more after set up.

The following images are of the building of the rear bomb bay doors. These were made by using the inner walls of the bay area to get the correct curve for the doors. Four curved sections were made and a sheet of 1/16 x 4 was cut too length and scored all the way down 1/4 inch apart. This allowed me to acheive a curve in the sheet. I then glued the four sections to the sheet and allowed it to dry. I then marked the centre point of the hatch and carefully cut it down the middle seperating the two doors. This was then followed by trimming back the curved sections to give me a better looking less drag free door when open in flight. Test fitting to the bomber was then carried out and at was great, although one door did need a little steam and a twist to remove a peskie warp but it all lined up good. Don't be, like I was, put off by the seemingly totally out of line bomb bay doors in the image where they are shut. It is what I think they call an optical illusion because the direction I have planked the fuselage. Trust me, I measured, lined up, angle checked, god knows how many times before I was convinced haha

Anyway thats it for now guys. For all you weight watchers out there, total all up weight of everything constructed so far......... 455grams (16.0ozs/1lb)











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Old Dec 27, 2013, 11:30 PM
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Holy Cow, Rob! For a balsa builder, you sure work fast! My favorite kind of builder

Can't wait to see it all sanded. Are you planning to cover/coat it with anything? I worry about the wood splitting over time in really non-scale (diagonal) directions.
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Old Dec 28, 2013, 12:04 AM
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Originally Posted by greenseaships View Post
Holy Cow, Rob! For a balsa builder, you sure work fast! My favorite kind of builder

Can't wait to see it all sanded. Are you planning to cover/coat it with anything? I worry about the wood splitting over time in really non-scale (diagonal) directions.
The joys of contact adhesive

I'm not really sure yet what to cover her with. I have four options, sanding sealer, filler no doubt with primer and a few coats of silver spray paint, dope and tissue again followed by sanding and spraying, again sanding primer and aluminium foil tape that polishes up real shiny or good old tight wrapping iron on film.

I like the idea of the polished alloy look but the fear factor is weight and a huge amount of rolls to do it. If the all up weight of the model is really low and can afford to add the extra weight of alloy tape then I may do that but I think for added strength the iron on film is the best option really. I can alway airbrush weathering and detail on top of this covering plus I'm also thinkin of doing a bomber with the black lower half.

It's a real head scratcher to be fair but I don't really want to be spending weeks covering it. Something quick and strong is what I want.
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Old Dec 28, 2013, 12:34 AM
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Ilkley, West Yorkshire, UK
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Good work, fella! My only attempt at planking years ago went terribly, terribly wrong.....

What's the logic behind the diagonal planking? 'Unthoughtout' logic would have me worried that the spiral being held all the way round (ie like the stripe on a barber's pole) would impart a twist to the fus?

Loving the build!

PS Rob, can I ask why you're embedding the photos rather than using the 'Manage Attachments' button? For those of us on a slow connection (especially when Young Pippa Blinkette is playing some odd teenage game online) it's a bit of a pain as the text leaps out of view as each photo gets loaded!!
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Old Dec 28, 2013, 01:12 AM
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This is not the official B-29 build thread. It is actually one of three sites I have this build on. When I update the official site I merely copy and paste what I put on the other sites. Its far quicker and easier for me.

As for the diagonal planking I got the idea off zee Germans with theyre WW1 Albatross and DeHavilland with the Mosquito. This was how they skinned the fuselage on these designs and it proved very strong as is the case here with the B-29. What I haven't explained on here, before I apply a plank strip I twist and pull on the strip to warp and bend it to the shape of the fuselage making it less hassle and easier to apply
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Old Dec 28, 2013, 05:08 PM
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Excellent

Very nice work.
Good job
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Old Dec 29, 2013, 12:51 PM
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Love the diaqoanl planking, be almost a shame to cover it up once its all finish sanded, great idea for awkward shapes and I can imagine it does add strength

Keep the updates coming!
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Old Dec 29, 2013, 06:59 PM
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Love the diaqoanl planking, be almost a shame to cover it up once its all finish sanded, great idea for awkward shapes and I can imagine it does add strength

Keep the updates coming!
Thanks Ken I will be and it does add a fair amount of strength trust me.

On a different note, be ready for my announcement of my new project to follow on from the B-29........It's big......very big
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Old Dec 29, 2013, 10:22 PM
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Originally Posted by RobTheBomb View Post
Thanks Ken I will be and it does add a fair amount of strength trust me.

On a different note, be ready for my announcement of my new project to follow on from the B-29........It's big......very big
Uh-oh. Announcements are fine, but don't start anything new until this one is at least ready for electronics installation. Wouldn't want the build to die after all this.
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Old Dec 30, 2013, 05:45 AM
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Uh-oh. Announcements are fine, but don't start anything new until this one is at least ready for electronics installation. Wouldn't want the build to die after all this.
Oh dont worry the B-29 will not be suffering this fate. I'm not a start and build and stop to start a new better project person. I do however like to choose my next subject while building my on going one at theme. It gives me an insentive to complete what I'm on besides I won't have the room to start the new project while the B-29 is being built because this new models wingspan in 6ft bigger than the B-29
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Old Jan 01, 2014, 11:58 AM
UMs & parkflyers... for now.
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Not going to build a B-36 to the same scale, are you?
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Old Jan 03, 2014, 01:35 AM
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A lot of common threads among big bomber builders I guess.

I'm getting ready to start a 12-foot B-36 within the next couple of weeks.
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