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May 07, 2011, 08:42 AM
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Where We Started & Where We Arrive At The End





My project's creative process started with determining which edf would be appropriate (thrust across time) for a B-47E of a given size to sustain its operation. Our maximum weight sans batteries is set by FAI F4C guidelines so we were left with how small/large a B-47E could be designed to provide the greatest power to weight ratio.




Above you see the bifurcated Dynamax mounted to the removable pylon blade. The blade has cutouts for batteries, Eagle Tree, and of course it holds the edf along with the esc, outrigger retract and all the nacelle shapes and exhaust ducting.
Last edited by FliteMetal; Sep 27, 2012 at 02:04 PM.
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May 07, 2011, 08:59 AM
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Flaperoni


The entire flap was redesigned resulting in a 98%...yes...98% reduction in weight. Obviously carbon
fiber replaced all the brass with the exception of retention pins.

Sam is currently creating the "removable" flap bays which more convenient access for servicing what
is assumed to be a high maintenance item given everything is suspended overhead from the flap bay.
I should be able to post images of this reop in a couple of weeks.
Last edited by FliteMetal; May 30, 2012 at 10:35 AM.
May 07, 2011, 09:10 AM
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Down & Locked Robart Tailwheel Retracts



From the beginning I realized I didn't need to worry too much about retracts for this project because Robart's off the shelf
tailwheel retract is the perfect solutiuon...well, almost off the shelf.... :^)

First it had to be converted to electric to reduce the garbage count. That in the end was simpler than you might imagine.
Down & locked took care of the conversion process with no issue. The same for the outrigger retracts.
Last edited by FliteMetal; Mar 20, 2012 at 10:43 AM.
May 07, 2011, 09:22 AM
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Dim Darn Dims


Here are the latest and last dims for this 1:8.7669 /1:8693 project. Yes, I know its been too long in posting here...I'm editing to bring it up to speed. We're amidst final CAD editing.
Last edited by FliteMetal; Sep 27, 2012 at 02:09 PM. Reason: Include Dims Document
May 07, 2011, 09:57 AM
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Root N Tip


Before I close this update I will leave the root and tip images of the BAC airfoil with you.




More when it happens...
May 09, 2011, 11:19 AM
Scale Modeler
Concordefan's Avatar
Hey Ed,

Enough of Solidworks images, i was hoping to see this 47 being materialized by now, anyhow3D solid model images and your highly detailed and accurate drawing are just jaw droopingly stunning!!!. When can we see this 47's construction?
May 09, 2011, 12:11 PM
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Impatience


Quote:
Originally Posted by Concordefan
Hey Ed, Enough of Solidworks images, i was hoping to see this 47 being materialized by now, anyhow 3D solid model images and your highly detailed and accurate drawing are just jaw droopingly stunning!!!. When can we see this 47's construction?
Sam,

This project is building a pair of 1:8.7669 B-47's. This requires patience and step by step planning...aka design. I realize you may subscribe to
a different method and process in your modeling. That's fine, for you... However at the $ commitment these require, I can not afford to kinda
sorta work through the project.

We prefer not throwing unnecessary $ at this trying to kinda sorta gett'r done. Doesn't work like that. The typical planning & design phase of a scratch built project is 24 months, with minimum component building along the way to prove out some mechancial issues like we did on our flaps. The drawings you see above were all drawn months ago...some a year ago.

With the evolving tools we are working with to create a rapid development system we are cutting out no less than twelve months from the traditional timeline. If we continue on our current path, we anticipate doing an entire scratch project from start to finish in one year or less. That doesn't just kinda-sorta happen.



For example you mentioned the Solid Works fuselage front shown. Traditionally that would have required a week to ten days to arrive at the image you see... however what you see was created in less than one day. This image is not correct, it is an initial loft of the cross sections I created, gave to Bob who lofted the Solid Works rendering you see.

The loft provides evidence of deficit in the shape. These are seen in irregular light reflection from the surface. This is worked through until the shape is correct, sliced, and milled. This is obviously the better choice over using filler to correct an error after milling.

Someone asked some time back if I was out-sourcing portions of these. At this point, as has been stated in the build thread, the plan is to acquire a mill to mill the shown parts when their design is completed. The two surffoam© CNC hot wired fuselage center sections are being out-sourced because of the density of the foam and the experience that person has with Dow Surfboard foam©. The same for the wing with the spar matrix cut-outs. Yes, the wing "was" Dow Surfboard Foam©.

Unless this model is designed and built this way, there is no way I can hope to meet the AUW target. That is the number one requirement because if it does not do so, I have failed!
Last edited by FliteMetal; May 08, 2018 at 08:18 PM.
Jul 20, 2011, 08:15 PM
Brooklynite In Texas
I have been considering this bird for quite some time now.

Being lazy I simply scaled up the drawings of the controline plans. I have seen a r/c version in m.a.n. mag.

I don't think I will do as much design work as you, but I will be watching, Good luck to ya!

DONNY
Mar 20, 2012, 11:12 AM
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1:8.6 Grew Into 1:8.7669 Over 24 Months


I saw no reason to double post between WattFlyer and here during a long design audit process that took 24 months.
I have finally arrived at the final config and we are making components for the two B-47's after purchasing an Up3D
printer for our small parts and will shortly acquire a ShopBot DeskTop CNC mill. More, with photos next time.

Mar 20, 2012, 12:13 PM
Official Boat Bum
Eddie P's Avatar
This is an amazing project, thank you for posting so much of your work. I believe a lot of "raising the bar" work is being done here for model aviation that will be tough to beat! I have been watching this project for a while on other forums, looking forward to the progress.
Sep 27, 2012, 02:16 PM
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Eddie P,

Thanks, we took a break working on a pair of A-10's. Getting back to final edits for nacelles. Thought we were
going to have to go in a slightly different direction on the inboard EDF but that appears to be back on track. I
added a pair of 90mm in the outboard nacelles for another 10# of push.
Sep 27, 2012, 02:51 PM
was geht , müssen unten kommen
Keenan smith's Avatar
Crazy Awesome Subscribed

K
Dec 30, 2012, 09:12 PM
Banzai Institute
buckaroo's Avatar
Hello Ed, I think we just met in the Lander metal retract discussion area of HK here:

https://www.hobbyking.com/hobbyking/s...uct=21166&pb=1

Howdy. I like your style. You are doing it right with the attention a big scale project like this needs. If you checked my last post in the HK thread I think I have solved my problems with the Lander 120 size full metal retracts. I contacted Tim Wan via PM and he was very helpful. I will be getting new PCB boards for my retracts. The side frames and micro switch assemblies have been improved. I am confident these retracts will preform well enough for their stated ratings. Have you settled on what retract you will use for the outriggers? I think your thoughts on modifying the Lander nose units to freewheeling would work. Nice work on the build. I am subscribed.

Dean
Dec 31, 2012, 01:26 PM
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FliteMetal's Avatar
Thread OP
Dean,

The actual thread(s) are at Wattflyer.com under what else... or you can Google Boeing B-47 and the threads from the beginning, and in the middle will pop up. This, like all scratch projects, is three years long.
Apr 09, 2014, 10:39 AM
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Thread OP

What's Going On Today?


Sorry to have been so tardy in bringing this thread up to speed. Have had to deal with a lot of errant
CAD issues correcting some not so solid geometry which was not water tight.

Should have inboard nacelle test milling in hand within the next ten days or so. I'm fortunate to have
benevolent customers using Flite-Metal. They had to correct the lack of water tight drawings...



Upon receipt of test mill will do internal hot wiring for bifurcation, pylon blade, inlet, and Dynamax.
Because I designed it with minimum thickness of vested foam we save a lot of overall weight while
unitizing components for greater strength. There is a lot of C/F vail in this design technique.

I purchased unassembled 8th baseball capped crew figures from Lyle @ Best Pilots and helmets
from an online source. Helmets are proper version for mid-fifties SAC with soft face mask, tinted
elasticed goggles, and a cast aluminum helmet. Yes, cast aluminum...2.45 ounces each. I am taking
care of that by making RTV molds for heads wearing helmet.

Dremeling earphones and cap from head makes for a good fit. Using sulphur free modeling clay I am
filling gap between head and inside of helmet. I show an upside down mold positioning for pouring
resin into RTV mold for best results of molding new pilot heads.

Face oxy mask is molded from soft compound. Goggle is molded from tinted crystal clear resin. Both
are not molded with the helmet and head.





Last edited by FliteMetal; Apr 09, 2014 at 11:54 AM.


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