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Old Aug 12, 2011, 10:41 PM
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Rich,
I've seen some of those threads on using depron for stuff. If i do the DC-10, the time expended in CAD work alone would make it to where i would have to make it available for purchase to make it worth-while. By doing that, I would do a fiberglass fuse (or portions of it) and foam wings/tail.

What I am thinking is:
Fiberglass fuselage. Split into 2, possibly 3 pieces.
Foam Core horizontal stab (vertical stab would be molded w/ the rear fuselage section and nacelle).
Wings would either be foam core, or composite and broken into 3 pieces (Center section and tips w/ the tips separated from the center section just outboard of the wing nacelles).

Power would probably be either twin 5" fans (or close to it) or a single turbine (in the tail). Since the fuselage would be essentially so open, their would be TONS of room for fuel tanks and batteries so it would make an excellent candidate for either.

The big question is.. how big to make it. I like stuff "BIG" but my trailer is quickly becoming full (ok, who am I kidding, it IS full if you include the F-14 in their).
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Old Aug 12, 2011, 10:44 PM
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check out the hotwire method before you go with Depron. it's much easier and the material doesn't sag like Depron. I love building with Depron, but since this method has been introduced into my life, I'll be building this way from now on.
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Old Aug 12, 2011, 10:46 PM
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depends how big you like big to be. LOL. 1:10 scale is a HUGE airliner, especially the DC-10. if you want flap sections and stuff like that, I have everything you need, including proper CG location and nacelle angles, etc.. kind of everything you need. my 757 is either 14 or 15 scale. I'de have to look at my drawings to make sure. I can tell you that it's about 7 feet long at that scale, to give you an idea.
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Old Aug 12, 2011, 10:47 PM
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To put sizes into thought:

1/7 = 283.5" wingspan (almost 3 times the F-14) LOL

1/10 = 198.45" wingspan, 218" long, 70" tall

1/15 = 132" wingspan, 145" long, 47" tall

1/18 = 110" wingspan, 121" long, 38" tall

1/20 = 99" wingspan, 109" long, 35" tall
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Old Aug 12, 2011, 10:49 PM
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yup. like I said, the 757 is about 7 feet long and it's a smaller plane than the DC-10. you are looking at a HUGE model. how cool would it be to have your F-14 air to air refueling with a KC-10 though? LOL.
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Old Aug 12, 2011, 10:50 PM
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I definitely wont be doing depron. The main fuselage section (that is fairly constant in shape) would be hot-wired from foam and them sheeted with balsa. The Nose section would probably be all built up from wood, since their are so many curves and what not to get right, and the Rear tail section would probably be balsa sheeted foam as well.

I've got some really nice engineering drawings of the 10 showing fuselage cross-sections, nacelle cross sections (both of them), Horiz and Vertical stab airfoils, along with all of the airfoils along the wing. The only thing it doesn't show in any detail are flaps, ailerons, spoilers, slats, etc etc etc
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Old Aug 12, 2011, 10:51 PM
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Quote:
Originally Posted by LuvEvolution7 View Post
yup. like I said, the 757 is about 7 feet long and it's a smaller plane than the DC-10. you are looking at a HUGE model. how cool would it be to have your F-14 air to air refueling with a KC-10 though? LOL.
Thats the first thing that popped into my mind when i thought about it.. but at 240" long, that would be a one-off model as i really doubt their would be ANY sort of sales market for one.. then again, those guys on the other side of the pond are nuts for BIG, but shipping would be
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Old Aug 12, 2011, 10:54 PM
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shipping!!!!!????? you could just fly it across as a UAV. LOLOLOLOLOL.

I have all the cross sections of flaps, slats, spoilers, flap canoes, etc.
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Old Aug 12, 2011, 10:56 PM
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Quote:
Originally Posted by LuvEvolution7 View Post
check out the hotwire method before you go with Depron. it's much easier and the material doesn't sag like Depron. I love building with Depron, but since this method has been introduced into my life, I'll be building this way from now on.
I used hotwire method for me DC-10 fuse, took me a whoooooooole 3hr week night and some other night...similar to this



but using EPP foam and hollow inside....will post pics of plane in scratch forum once I get the nacelles hogged out for 2 70mm fans...yeap, > 6 ft long and only need 5 pds of push to get it up in the air and then it glides down

It's a fast method of getting fuse built and with EPP it's tough as nails... a lot lighter than what I thought it would be too.

DC-10 crosscountry

DC-10 crosscountry (6 min 16 sec)
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Old Aug 12, 2011, 10:59 PM
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And just to put the size difference into perspective:

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Old Aug 12, 2011, 11:07 PM
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yup, it would be huge at 7th scale.

like I said, we make templates, then cut inside and out, so you essentially end up with a hollow tube. you join all the sections together and fiberglass the inside and outside. you end up with a strong fuse that way and light.
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Old Aug 12, 2011, 11:11 PM
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ahh ok.. now i got you. Yea that would work well. Maybe a one-off would be good, but I think if the size is right, their would be people interested in this sort of model. After-all, you never see them as kits, and if it was offered as a fiberglass/foam short kit, i think their would be a market for it, or even if it was all composite.
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Old Aug 13, 2011, 12:42 AM
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like I said, we use pink foam or equivalent and we make the template about 6mm thick, so you have a 6mm thick tube once it's cut. for a plane that big, I might be tempted to go a little thicker.......10 or 15mm perhaps.
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Old Aug 13, 2011, 07:23 PM
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Back home.. so guess what that means.. MORE F-14 time baby!

Alright, so in order to make some room, i need to get rid of some materials. well, in order to get rid of some materials, i need to make some molds. So in order to make some molds, what does that mean.. PARTING PLANES BABY!!!!!!!!!!! [] (Man its nice to be home!).

Alright, so first off.

Take your part, lay it on some white-plastic covered shelving boards, and trace the outline of your part onto the shelving board.




Then drill some holes in the corners. Use a REALLY (IE brand new) sharp bit so as to eliminate as much chipping of the plastic covering as possible. (Those are 1/2" holes)


Then cut out the inside of the lines you drew where your part will set into the parting plane. If you were really accurate with your line placement, you can cut On the line, if not, cut inside slight and adjust it to fit. You don't need a perfect fit, just a fit good enough for the part to fit into. For the stab, I made a 1/4" deep (1/2 the diameter of the pivot shaft) and 1/2" wide channel for the shaft to ride in. *TIP* on thin surfaces (like trailing edges) if you cut the line at an angle (so it angles towards the center of the part) this will help support the plug.


Now place your parts in the partings planes. Adjust the hole in the parting plane to get the parts to fit. If the part fits tight to the parting plane edge, good, if not don't worry, we will fix that later:


Adjust the position of the part so the trailing edge is split down its center, along w/ the leading edge. If your doing something like a fuselage, you want the parting to planes to be near centerline of the widest portion, so their is no "negative draft" that will look the plugs in the soon to be laid up molds.


Now using some Hot-glue, go on the back-side of the parting planes (the side that is not going to have the mold laid up on) and glue the plug to the inner surface of the parting plane "hole". What you are doing, is essentially creating a "shelf" for the part to fit on, so it goes back to the exact same position each time you install/remove it. If you are doing this to a painted part, put a piece of masking tape where you intend to put the hot glue.
Then once the glue has cooled off and hardened, remove your plug from the parting plane board (you may need to take a straight razor blade to cut the part free, Cut between the surface and the glue paralllel to the part surface). What you should get is shown below:



Now wax your plug with your mold release wax of choice per the directions for that wax.
Place your plug back on the hot-glue blob "shelf".

Now mix up some body filler (you can also use non drying modelers clay) and spread it down into the gaps between the plug and the parting plane board. When it is almost completely cured (it should barely feel sticky) remove your part from the parting planes. take a straight edge razor and clean off the excess clay/body filler from the top of the parting planes. Make it nice and parallel with the top. Then when it is fully cured, sand the entire area around the parting plane hole with some 220 grit paper to get a nice smooth texture free surface.
Then Re-position the part back in the parting planes, put a few more blobs of hot-glue in position to hold it in place. (It should be a really snug fit, my parts actually "snap" into position). When done correctly, you'll get a really tight fit of the part to the parting planes. If your using clay, you need to do the 220grit sanding first, and skip most everything else.

Here is what the lack of gap looks like on my parts:


Once done, you can put your alignment pegs (in my case, vinyl floor "bumpers) on the parting planes and everything is now ready for wax, PVA and molding

I'll have a video posted up on the entire process when it finish's uploading.
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Old Aug 13, 2011, 09:21 PM
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video's:

How to Build an F-14D Tomcat #24 (8 min 53 sec)


How to Build an F-14D Tomcat #25 (16 min 31 sec)


How to build an F-14D #26 (3 min 32 sec)
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