Mc Clain Wing Cores 48" virgin foam and EPP flying wing - RC Groups
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Jun 26, 2008, 10:28 PM
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Build Log

Mc Clain Wing Cores 48" virgin foam and EPP flying wing

Hey folks,

We are back with another building thread of the McClain MCW 48" flying wing!

This wing can be purchased from

Jeff has been cutting cores for a long time. I first became aware of his stuff a few years ago when a friend purchased a set of cores for a Mosquito bomber from his ebay store. The cores were right on the money and the plane was just phenomenal.

The wings from MCW are no different. I have built the 24" and the 36" wings and I can say that they were dead on the first time, no funky twists, no funky CG issues wich are very common with flying wings from other mfgs!

The planes all worked with the stated CG from MC Wings and the design flew so well that they are now both my favorites and fly in all kinds of wind!

I am referencing the other threads for your edification.
[INDENT]24" building thread

36" wing building thread

Starfire Building thread:

The plan is to start this build next week when I have some time off again, I just got them today and was impressed by the quality of the cutting as well as the quality of the foam.

I get PMs and email constantly about the build threads, esp. in so far as powering these planes.
Please post your question in the thread so that everyone can benefit from the response. Nothing is better than having everything in one place for future reference.

Last edited by pval3; Oct 12, 2008 at 11:16 PM. Reason: video link
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Jun 28, 2008, 12:32 AM
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Basics of the plane and updates

Hey guys

These are the basic specs from McClain:

MWC 48" Flying Wing


48" Wing

Wing area is 216

CG is 6-15/16 to 7-3/8 from the L.E.

The cores are ready cut of elevons

The cores are made of virgin white bead foam with a EPP L.E.
Here is how I plan on equipping this model: Wicked 2700KV 450 outrunner
New version of the "Wicked" Brushless motor with a true 2700 KV. This is a great motor at a great price and offers more prop selection than the original 3000 KV version. For the original "Don's Wicked motor" see the specs here.

This true 2700 KV verison of the motor allows a wider prop selection on 3S and on 4S.

KV: 2700 rpm/volt
Weight: 69 grams
Battery: 3--4 cell lipo
Shaft size: 1/8" (3.17mm)

Now includes 'X' mount and mounting screws!
Requires a 1/8" collet adapter which can be bought here.

Here are test results from the new batch , all data with APC props:
3S lipo:

Prop RPM Amps Watts Pitch Speed
4.7 x 4.2 24500 rpm 23 amps 240 watts 97 mph
4.7 x 4.7 23000 rpm 27 amps 280 watts 102 mph
5 x 5 22000 rpm 30 amps 310 watts 104 mph
5.2 x 4.7 22000 rpm 29 amps 290 watts 98 mph
5.2 x 6.2 20500 rpm 34 amps 350 watts 120 mph
5.5 x 4.5 21500 rpm 32 amps 320 watts 92 mph
6 x 4 21000 rpm 33amps 340 watts 80 mph

4S2250 Long Max lipo
Prop RPM Amps Watts Pitch Speed
4.1 x 4.1 34000 rpm 28 amps 402 watts 132 mph
4.5 x 4.1 33000 rpm 34 amps 500 watts 128 mph

tower pro 9g servos from
8.5g Micro Servo
Compact 22x12x29mm, 0.87 x 0.47 x 1.14"
.11 sec 60deg @ 4.8V
Torque @ 4.8V = 1.6kg/cm, 22.2oz/in

SP 30 Amp ESC from
Compact 30 amp Brushless ESC
3 amp B

Battery will be a 3s 2200 from loongmax but I will be cutting the hole to accommodate up to a 3000mah 4s pack.

elevons will be from 1" balsa

Elevon control horns 1/2a control horns (small) from Dubro

Pushrods will be 1/16" wire with z bends

hatch covers will be cloroplast sheet 1/8" thick

winglets will be 1/8" lite ply

Covering has not been decided yet....currently looking at econo-coat black on the bottom and yellow or red on the top...
After much deliberation regarding options and the absolute incredible versitility that I see in this design in so far as a cross platform model. I contacted eff at McClain and asked him what he thought of building it real light and set it up for slermaling or cross platform plane or transitional model between someone who has built and flown a wild wing or stryker and is just not ready for the likes of a Rite wing yet. A versatile transition plane that will handle the same flight pack from your wild wing or stryker yet offers the ability to throw it off a cliff or hill and slope it all day with the same set up . . . . or climb it up high and thermal the crud out of it.

One of the most basic and inexpensive power options available is the power combo offered by Hobby city ( ) or ( )

These power systems offer low draw and high output on a budget.....most of all, they are light and can be mixed with a folding prop easily to reduce drag once the motor run is finished.

* Weight:1.77oz (Including the Aluminum mount)
* Size:30(Dia)X27(L) mm
* Output Axis:M3
* Max Current:14A
* BATTERY: 2-3LIPO (7.2V-12.6V)
* KV:1750

Direct Drive
600 grams/ 21.0 oz

This motor is available under a whole bunch of names and outlets and varies in price from as low as 9.00 to 21.00. A simple 18A to 25A esc will do fine but I have a spare 30a I will be using on this project as I already picked it up for the build.
Last edited by pval3; Aug 06, 2008 at 04:03 PM. Reason: CHANGE IN BUILD
Jun 28, 2008, 12:33 AM
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Flight video is up

first flight synopsis with settings is in place on page 5 of this tread
Last edited by pval3; Oct 16, 2008 at 10:52 AM.
Jun 28, 2008, 12:36 AM
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out of the box

here are some pics of the cores and leading edges out if the box

notice the marking that MCW places on the leading edges to make sure you set them up with the proper halves AND with the proper ends together!

Great quality materials and cutting. .
Jun 28, 2008, 12:55 AM
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why the two piece cores and why the different foam??

Well, it is a legitimate question, why would you add so much work to cutting the kit or building when there is epp only???

what the heck does all this added work do for me??

In general, virgin white foam is far more rigid than EPP, it keeps it's airfoil better, keeps the model truer and is a heck of a lot easier to cut than EPP.

It is also very easy to cut, melt, shape . . . . .far more so than epp.....

It is a better material in general for building, however, it does not do well when you bang into something - like a tree or a post or a rock on the ground.

It does not do well with impact as it tends to shatter with the application of blunt force.

EPP on the other hand is much spongier than Virgin foam and takes a hit incredibly well seemingly without any damage . . .it is the ultimate "bumper" but waves like a wet noodle unless it is reinforced with resin, cloth and lots of carbon!

For airplanes that are clothed and glassed and carboned up the wazoo, the epp only makes a lot of sense. like a surf board, they take a likkin and keep on tickin!

For a sport type model, that level of bullet proofing just doesnt make sense . . . so you take the best of both worlds, the rigidness of the Virgin Foam for the main part of the core and the impact resistance of the EPP for the leading edge to get the best compromise of durability and rigidity to provide a fantastic model!

At first I was skeptical, but I have put a 36" and the 24" MCW through hell and can say from experience that Jeff has managed to get the compromise between ruggedness and durability right on the money.

I flew the 24" into a tree at full bore and it bounced like a pin ball through the trees around the one I hit and came out the bottom unscathed . . . .I broke a prop . .. ..

I believe that the 48" wing will offer all the upside of the 36" but with a little more wingloading to allow it to slow down even more for landing and make it easier to see at altitude!
Jul 16, 2008, 10:59 PM
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hey folks

Been working working working at work and no time at home to do any hobby stuff!

I wanted to at least give a little update and some observations.

I layed out the cores tonight to get an idea of span and config. Also trying to figure out if I can fit my 3000 mah lipo in the nose without it poking though the top!

From what I can see, the lipo issue will work as long as I use CKs gorilla glue and henry's on the floor to keep it as thin as possible. I should just be able to get that 4s in there as long as I use a thin battery box cover!

In so far as the overall layout, the wing appears to have a little more epp than the 36" proportionally. It seems to also have a little more wash out in the tips than the 24 and the 36 also. This should make it very stable in slow flight mode.

I wanted to try to see how much meat there was for larger servos, with a 4s I will need more torque and a little stronger gear set than what the std. micro servos will afford.

Cutting was great and clean. Jeff does a phenomenal job with these cores
Jul 16, 2008, 11:00 PM
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pics from above

I pulled the cores from the beds and laid them out so you can see what ya get

here you go
Jul 16, 2008, 11:02 PM
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compare and contrast

I am doing two builds at once, the std 48" wing and the new Starfire!

Here are they are one over the other for comparison!
Jul 27, 2008, 09:49 PM
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fast n furious@!

Well guys,

I beat the reaper again yesterday, passed my big tests at work and am back in the saddle again!

My wife was kind enough to let me get a few minutes in the garage this evening . . . first night back from stress central . . .so this is usually her time

Either way . . . . we got a few minutes to do a little set up and start.

From this point on, the posts are going to come fast and furious as I intend on whipping though the build and onto the starfire.

I have been lamenting the "speed" angle and thinking more along the line of a lighter build and strong.

After looking at the cores and the airfoil, I think this one would actually be better at the slermaling than the 36" as it seems to have a little more meat to than the 36 did.

I think the CG should be able to be maintained with several power options while keeping the same set up by simply adjusting the size of the battery to counteract the weight of the larger and hotter wind motors. . . . with a lighter pack, a lighter motor can be used and the bird should be able to thermal without much trouble. . . . . it is only two months away to slope time in Raleigh as the winter months are the only time we have the direction and speed to get the few slopes workable . . . . just something to keep on the back of my mind
Jul 27, 2008, 09:53 PM
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basic sizing

take the core out of the taped beds and check the cores for any damage or dings. check the leading edges for any dings or dents, now would be the time to put a little spackle in the dent to even out the surface to ensure a good solid glue joint.

lay the cores in the beds and make sure the inner surface of the joint fit without any openings.
Jul 27, 2008, 09:58 PM
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biggun s

My building area is 72" long. You can get an idea of the size of the area needed to work on this airplane.

Although the belt sander does take up some area at the end, the wing takes up a good section of that table!

It is a big bird with a nice high aspect ratio appeal!

I laid the cores out and laid the leading edges into the front of the beds to get an idea of how they fit.

the fit was dead on and the cutting matched dead on too top and bottom.

Jeff does such a nice job on the cutting. . . .makes this so easy to work.
Jul 27, 2008, 10:00 PM
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"hair" remover

you might find a small amount of "hair" on the top and bottom of the EPP leading edges. If you do, take a sanding block of 400 grit paper and gently rub the top and bottom of the trailing edge of the piece to remove this before you try to join the front of the wing to the back of the wing!
Jul 27, 2008, 10:04 PM
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preping the halves

check to make sure you have the left leading edge with the left rear and the right leading edge with the right rear.

check the fit again and make sure you will be able to get a clean join on the halves before you apply glue

take the left lower bed and the right lower bed and place the cores in the respective beds. The middle is not to be disposed of . . save this, you will need it again .. and again . . . and again!
Jul 27, 2008, 10:20 PM
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test fitting and jigging

well, nothing makes a job easier than a jig to help you align things.

take the core bed and push the wing core back 1/8". take a straight edge and place it up against the root. This is critical to ensuring that there is no gap or lip between the front and back of the cores as it will cause the wings to push apart when we try to join them together later on!

you must also make sure that you have no ridge or bump between the leading edge and the trailing edge of the wing . . . . make sure the joint is going to work.
Jul 27, 2008, 10:30 PM
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I know . . . I know . . everyone has got a favorite glue for their favorite type of application . . more than I care to admit to trying and have sitting in my glue box!

The one I have found to join these disparate foams giving maximum gluing capacity but the flexibility to provide the maximum performance of these two products in your airplane!

Shoe goo works . . . but for some reason it is thicker than the UHU foam.

They both join the same in normal applications, but the uhu soaks into the epp better in my opinion. It also seems to allow a little more movement and replacement before it sets than the shoe goo.

that is my opinion . . . take it or leave it . here is a picture of the tube for easy id! It is available at Michaels and AC Moore and you can score a 40% off coupon every weekend in the sunday paper . . . . . 2.40 a tube!

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