Size 36: The build of an 18' B-36

[b-29er]

Don't worry, you're excused if you thought this project was dead in the water!
-Formers in the fuselage have been glued in place
-bomb bay walls are in place in the empennage, gluing the fuselage ones in tomorrow
-reinforcements are in place to help the wing stay attached to the fuselage
-Empennage formers are in place and ready for Dollar Tree foamboard covering and tailfeathers
-Wing spars are completed, the trailing edge ribs have been glued in place, leading edge ribs get glued tomorrow, followed by mating with the trailing edge
-The first ESC/m60k motor has been tested and working

To do:
-order propellers (15x7 tri-blade Master Airscrews)
-Landing Gear (fixed, no time for retract sorcery)
-Bomb bay
-Cut nosecone (Friend of mine designed it, just need to cut it on XCARVE)
-Secure wing attachment points
-wiring
-WIRING
-figure out how to attach this to the top of my van (trust me, i'm an engineer)
-Invent time machine and get my butt in gear a month earlier

 

[DamoRC]

Pics?

DamoRC

 

[b-29er]

Pics?

DamoRC

I'll have more than what i edited in above tomorrow. the fuselage (currently 12' long) is dominating the 1-car garage it is being built in so i can't really get a camera around to get a decent picture.

 

[rockyboy]

Awesome!!

 

[kilroy07]

-Cut nosecone (Friend of mine designed it, just need to cut it on XCARVE)

I thought you were 3D printing the details?
I was hoping you might be willing to share the STLs, I have plans to do a mini B-36 for FF.

 

[Mid7night]

That’s looking AWESOME!

Sorry I dropped the ball on helping you with the landing gear and flaps....I’m getting swamped with my own FF prep-building. 😬

Only 2 more weeks!!

 

[b-29er]

I thought you were 3D printing the details?
I was hoping you might be willing to share the STLs, I have plans to do a mini B-36 for FF.

I was going to 3d print but i am still concerned with weight. I am going to release stls. In fact if you feel like scaling merry christmas, here is a nose. There will be a v2 with more details and stls will be available, i just want flying at this point

That’s looking AWESOME!

Sorry I dropped the ball on helping you with the landing gear and flaps....I’m getting swamped with my own FF prep-building. 😬

Only 2 more weeks!!

Dont remind me lol and no worries

 

[kilroy07]

In fact if you feel like scaling merry christmas, here is a nose.

Message from the slicer "Cannot auto arrange. Largest part exceeds build dimensions."
Thanks, the diameter of my fuselage scales be a paltry 3.5"... so... yea, "might" have to scale that a tad.

I just saw, we have what 2 weeks to get these wrapped up for FF... Jeese, what has I gotten myself into?! I won't even get to start on this in any depth until next week... My goal is for us to fly in formation (although, I'm going to have to fly a LOT closer to the crowd!)

This first run will be a A model, I'm pretty sure I won't have time to model the Turbines (although, where they attach to the wing is just about where I was going to add extensions, so I might have to do something.)

Is there anything I can help YOU with? (Have you modeled the birdcage, I could do that if it would help?)

 

[b-29er]

Message from the slicer "Cannot auto arrange. Largest part exceeds build dimensions."
Thanks, the diameter of my fuselage scales be a paltry 3.5"... so... yea, "might" have to scale that a tad.

I just saw, we have what 2 weeks to get these wrapped up for FF... Jeese, what has I gotten myself into?! I won't even get to start on this in any depth until next week... My goal is for us to fly in formation (although, I'm going to have to fly a LOT closer to the crowd!)

This first run will be a A model, I'm pretty sure I won't have time to model the Turbines (although, where they attach to the wing is just about where I was going to add extensions, so I might have to do something.)

Is there anything I can help YOU with? (Have you modeled the birdcage, I could do that if it would help?)

Birdcage is modeled, i actually have it modeled for vacuum forming but doubt i'm going to mess with that so i'll probably just 3d print and dremel. If you're starting on this two weeks out from FFE, i'm just gonna let you do your thing. If you feel like building an 18' like mine for next year, let me know. I'm going to be making a V2 with all the goodies i omitted this year (jet pods, retracts, detailing), making plans and parts public and doing a vlog as i build v2.

 

[b-29er]

@DamoRC heres the build so far, rear wing spars, ribs and fuse. No bananas on hand so minivan for scale

and since i have the plane out of the way, heres a weigh-in on the powerplant. 4 multistar 6s5000s, 6 m60k motors (5065 540kv), 6 mystery cloud 80a escs. I expect to add a good bit more with wiring and props but should stay under 55lbs. Hopefully

 

[FOGeologist]

Have you considered laminating in kraft paper and thinned PVA? Loads of strength, and not much weight. You will be fighting torsional rigidity issues with everything being at the scale of this huge-mongous build.

 

[b-29er]

Have you considered laminating in kraft paper and thinned PVA? Loads of strength, and not much weight. You will be fighting torsional rigidity issues with everything being at the scale of this huge-mongous build.

I have considered it, but have opted towards using packing and fiber tape instead. Fuselage currently has a layer of packing tape around it, wings will probably have fiber tape along the lengths. Rigidity is actually why I am sticking with the stock airfoil. The wing spars are up to 6" tall x 1/4"thick in places, makes for a good bit of support. Add in 1/2" foam on top and bottom and im not nearly as worried as i should be.

 

[FOGeologist]

I have considered it, but have opted towards using packing and fiber tape instead. Fuselage currently has a layer of packing tape around it, wings will probably have fiber tape along the lengths. Rigidity is actually why I am sticking with the stock airfoil. The wing spars are up to 6" tall x 1/4"thick in places, makes for a good bit of support. Add in 1/2" foam on top and bottom and im not nearly as worried as i should be.

I found a foam board at Hobby Lobby that is about 1/2 the thickness of DTFB, and the paper covering seems to be a bit more tough. Seems like pretty good building material.

 

[b-29er]

I found a foam board at Hobby Lobby that is about 1/2 the thickness of DTFB, and the paper covering seems to be a bit more tough. Seems like pretty good building material.

This guy is a bit beyond just dtfb. 80% of the construction is 1/2" pink foam sheet, dtfb is only being used in areas that require a high degree of flex (leading edge).

 

[FOGeologist]

This guy is a bit beyond just dtfb. 80% of the construction is 1/2" pink foam sheet, dtfb is only being used in areas that require a high degree of flex (leading edge).

Making sense. That pink foam stuff, is this the same as the pink foam you can buy at Home Depot in thick boards for construction of smaller models? And I guess you're using thin stuff so you can cut and roll it into tube shapes, right? Do you need to throw in some balsa or basswood formers to preserve the shape? I see you're doing some forming with HD rulers, which is hilarious. Do these things actually provide strength at their weight?

 

[b-29er]

Making sense. That pink foam stuff, is this the same as the pink foam you can buy at Home Depot in thick boards for construction of smaller models? And I guess you're using thin stuff so you can cut and roll it into tube shapes, right? Do you need to throw in some balsa or basswood formers to preserve the shape? I see you're doing some forming with HD rulers, which is hilarious. Do these things actually provide strength at their weight?

Yes, the pink foam is the same foamular you can get at home depot, and in fact was purchased there. I'm not using fanfold, i'm using the 1/2" boards. The fuselage is made from a 1/2" board with cuts every 3/4" to provide a place for the foam to bend from. The foam is wrapped with strips of tape oriented with the circumference of the fuselage. Foam formers are used to shape the fuselage, with two 7" strips of foam in the bomb bay to act as reinforcement and a transition to the empennage. The sharpest portion of the leading edge is going to be made from DTFB, the 1/2" foam is top and bottom where it can provide the most support.

The HD rulers are actually quite strong and the weight is very good. Each of the 4 spars weighs a smidge over a pound, like 1lb .7oz. The spars are composite, HD rulers form the outside and balsa is used on the inside to form the basic shape. Looking at other builds like the JU-88 from last year

or Peter's big guinea build

The material quality on the b-36 may be a bit jank, but with the thicker foam on the airfoil and thicker wing spars, i'm not overly concerned with a wing fold. But we'll see in a few weeks.

 

[FOGeologist]

WWWWOOOOOWWW!!

 

[DamoRC]

No bananas on hand .....

What? I am beginning to think you are not taking this seriously. Here's 3 minutes and 20 seconds of you life you are never getting back.

DamoRC

 

[kilroy07]

4 multistar 6s5000s, 6 m60k motors (5065 540kv), 6 mystery cloud 80a escs.

NOW I remember why I'm sticking to a smaller version!! $$$$

 

[b-29er]

What? I am beginning to think you are not taking this seriously. Here's 3 minutes and 20 seconds of you life you are never getting back.

DamoRC

There are parts of this i take seriously and parts i dont. Design? Dozens of hours of research, documentation hunting, referencing other large scale designs for ideas, dozens more hours in autocad. 100% serious. Construction? Overkill. Plane's not going to be looped or anything but the wingspars are already beefier at scale than the 12' JU-88s that flew in texas. Learned to use a CNC mill for this project to add precision parts where needed or lazy. Documentation? No one dies if i'm a little silly in the documentation.

NOW I remember why I'm sticking to a smaller version!! $$$$

I got lucky on the electronics. All that was around $280. The m60ks were on a flat spin sale from RMRC for $15ea, the ESCs were cheap chinesium for like $15ea and the batteries were on sale for $25ea. Then again i've been sitting on this project for over a year so i've had time to source materials. And to be honest the m60ks are overkill by like...a lot. Like minimum of 1.25/1 thrust to weight if the motor specs are accurate overkill. I just wanted something that will spin a 15" triblade, which wound up being more expensive than the bloody motors!