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        Build Log 747-8i Build

#1 rlebaron Jul 29, 2012 10:58 AM

747-8i Build
 
3 Attachment(s)
Ok everyone. I am newish here but have finally decided to stop being a reader only and build an airliner. I think I might as well go for the gusto and start with a 747-8i. Basic plans are as such: I will be using the 3 view schematic found online since there are not a whole lot of in depth drawings. The plan is to make this out of solid home depot 2" foam cut with a hotwire. I have already done a mock up 10" model that seemed to turn out well with that technique (pictures below). I just think doing a depron fuselage is going to be tough with contours the way they are ( not that all of that sanding will be a cake walk). The plan is to start with the fuselage in the next week or so.

Dimensions:
Length:83" (6.9')
Width: 74" (6.2')
Estimated weight:?-5-6 lbs.

Power: 4 70mm edf's from hobby king (http://www.hobbyking.com/hobbyking/s...ssembled_.html ). I've used this one on a parkjet I built and it seems to hold up well for the money.
Batteries: Need some help. Planning on 3S, 25-30C- Should I go for 4 smaller guys (2200 mAh range) or drop two large ~4000-5000 mAh in?
Servos: Have not built a plane this large so I am open to suggestions. Not sure how big I'll need given the relatively light weight.
Retracts: 5 servoless. Does HK sell a steerable nose retract?
Gear: Homemade using DD's method. I'm a little unclear how the strut attaches to the gear truck.
Nacelles/cowling: Plan to use Woolfson's method. Seems the most strait forward.
Flaps: Probably just simple fowler type flaps- both inboard and outboard.
Spoilers will be on there for scale appearance but I'm not sure if I will make them functional.
Not planning on other goodies such as leading slats, gear doors, thrust reversers, etc. We'll see. If this one goes well maybe I do another in 90mm and get a little more fancy.
Livery: Not a whole lot of choices yet. Maybe Lufthansa or even the new Boeing red/orange.
Airfoil: Clark Y.
As this is my first airliner I am anticipating that attaching the wings to the box and horizontal stabs will be technically difficult. Any input, ideas, thoughts, jokes, etc would be greatly appreciated. Stay tuned for more.

#2 demondriver Jul 29, 2012 11:05 AM

OH-yeah!:D You know I'm Subbing up for this Build Baron!:D

This is gonna be great!:D

#3 Keenan smith Jul 29, 2012 11:31 AM

747 build!!! i likeeeeeeee!

#4 WAGliderGuy Jul 29, 2012 01:47 PM

Subscribed! :popcorn:

Ethan

#5 NAKIAM949 Jul 29, 2012 04:08 PM

VERY interesting...subbed!:popcorn::popcorn:

#6 clsink1128 Jul 29, 2012 08:24 PM

Can't wait to see this one maiden. I'm tuned in.

#7 Doushiyou12 Jul 31, 2012 07:22 PM

subbed

#8 rlebaron Sep 09, 2012 08:51 PM

Update
 
4 Attachment(s)
So progress is slow- mostly due to hectic work hours and limited time at home but it's coming along. I just finished the rough fuselage- made with 4 stacked blocks of 2" home depot foam. I outlined the template then used a foam cutter to make the basic design. Now lots-o-sanding on the horizon. I have also cut out wings and stabilizers but need to now cut airfoils. I am sure I will need to do some hollow work to the fuse to cut some weight.

#9 Concordefan Sep 09, 2012 08:55 PM

Look good, nice outline profile there of the fuselage mate....:)

What are specs of your model?

#10 demondriver Sep 09, 2012 09:06 PM

Rlebaron that's outstanding work so far:D . . .. nice technique! Just be shure to hollow her out or she'll be VERY heavy.

#11 rlebaron Sep 09, 2012 09:10 PM

Thanks.

So the fuselage is 69" long (5.75 ft, 175 cm) and the wing span is 62" which is a little shorter than originally planned. I used a tile program and set the scale off of the nacelle.

Yeah- not sure what the weight is now but it's gonna need some slimming down.

#12 rlebaron Sep 09, 2012 09:14 PM

Quote:

Originally Posted by demondriver (Post 22688320)
Rlebaron that's outstanding work so far:D . . .. nice technique! Just be shure to hollow her out or she'll be VERY heavy.

How do you hollow out your nose and tail sections DD? I was thinking a long knife- not sure if it's too crude though.

#13 Concordefan Sep 09, 2012 09:29 PM

I can help with hollowing your fuselage but it will require sectioning it in 5-6 sections and then use templates to do so. Do you have cross sections or station drawings for the fuselage?

#14 rlebaron Sep 09, 2012 09:45 PM

I don't have cross sectional templates for the 8i. I was essentially shooting from the hip on some from the 400 + google images. So you're saying sand it, then cut it into 5-6 sections then hollow correct? Sounds like a good idea. Would you reassemble with epoxy + some type of rod (CF) as support?

#15 Concordefan Sep 09, 2012 10:07 PM

If you have any 747 variants cross sections except for 747SP then those will work, B748 was not widened but it was stretched 18.5' the other previous models, it's wingspan has been also increased to 250' vs 211' for 744.

You really need cross section drawings to make accurate templates through out the length of the aircraft. Now if you can find for earlier variants, thats good coz we can place them further apart at strategic locations before cutting the fuselage in sections. See what you can find and then enlarge those drawings to scale of you fuselage to match them exactly....


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