Kit Build - Mountain Models J-3 Cub - White

[texasclouds]

Ok, I'm going to order the Mountain Models J-3 Cub kit soon. I've looked at many pictures online, and have decided to go with white. Then I got to looking at the Super Cubs. I think I can make a faux Super Cub with this kit. From what I gather, the physical dimensions are the same. The Super lacks the engine heads showing on cowl, has an oil cooler port under the cowl, has a more potent engine, and had a slightly different tail curvature (along with some internal differences like electronics package and wing fuel tanks).

I'm on the fence as to white or blue for the striping. Here are some inspirational pictures I found:

[texasclouds]

[Sky Sharkster]

Hi T.C.,
I like the red and white personally. It might be a good idea to make the side (color) flashes bigger, for better visibility. For the same reason I'd suggest putting big red (or blue) patches on the wing bottoms, say the last three rib bays or so. Remember, you're going to be looking UP at the model, trying to determine the attitude, angle, direction. Solid-color models make this very difficult.
Good luck with the M.M. kit, they're great!
Ron

[gramps2161]

Ah texas the build bug has bitten I like the red to, yellow shows up great in the sky too. Glad you like building with balsa what ever you do have fun doing it.

[park]

Great idea going with the white! Looking forward to watching your build.

[texasclouds]

bottom view:

[texasclouds]

this is a similar look to the blue on in the 1st picture posted. i'm thinking solarfilm will be more opaque than solite. extra weight of the film should be offset by the lighter battery. i'm going lipo on this one. i want to get some bush/tundra tires though. stock tires are too small for me.

[texasclouds]

MM J-3 1/9 Specs:
Wingspan: 48 in Length: 30 in.
Weight: 13.4 - 17 oz
Kit comes with 2 in. DuBro main wheels, 1" DuBro tail wheel


May consider the Trexler Ballon Tires in 2 5/8".

Numbers on top right of wing and left of fuselage only. Lightning bolt on both sides of fuselage.

[texasclouds]

i added a poll in regards to which covering to use. this is my second plane to build...i don't want to pick the more opaque solarfilm and warp the plane too much. flyability is a notch higher in importance to looks. i am a bit worried the solite will be too transparent. let me know what you think.

mark ii

[Stevephoon]

texas,

I used the SoLite white on my EVA. It is still slightly transparent, but just slightly. If white is your base color and the red is on top, then I think it will look good and still be light weight. On my EVA, the black solite easily covers the white, but the white would not look good over the black.

I like your last color scheme a lot. It will look great!

Just my 2 cents. I don't think you could go wrong with either covering.

Steve

[BradT]

Solarfilm is one of the heaviest coverings on the market, definitely not appropriate for this model. Oracover, Monokote,Econokote are all much lighter than Solarfilm, and very opaque. They are heavier than Solite and its clones, though.

That will be a very nice model, in your red/white colour scheme and trexler wheels/tires.

Brad.

Brad.

[mararra]

Hello Texas
You might want to check out this thread: http://www.wattflyer.com/forums/show...light=covering Good info regarding weights of a whole host of materials.

I like Solite; easy to apply and shrink, great for light weight structures. It is translucent however. Close up you'll see the bones.

Solarfilm and it's clone Coverlite are heavier, take more heat to shrink, but they are opaque. Can't see thru them unless you hold it up to a light. I have had some problems with some colors not adhering properly on overlaps. I recently purchased a chemical etching fluid that is supposed to cure the lap joint problem. Havn't had a chance to try it yet; I'll post my observations when I do.

I used Solite on my J-3. I was disappointed with the see thru look at first, but you don't really notice it in flight. You picked a great kit, keep it light and make sure you have enough power. My first flights were a bit hairy because it was minimally powered. Dropped in a 120 watt motor on 3S, and it was much better.

fly well,
M

[Sky Sharkster]

Hi Mark,
I'll put in my vote and recommendation for SoLite/MicroLite/Nelson LiteFilm, and not just because Mountain Models does, although that's a pretty good reason. The mid-weight or heavier films not only add unnecessary weight, they have a much stronger "shrink" factor and will easily warp (or even crush) a light structure.
The "Micros" are made for this purpose, lightweight electrics. To have such a thin material, some of the structure will show through. This is more apparent on lighter colors and white most of all. But it's not transparent, not even close. Here's a close-up of the horizontal tail of my 1/2 scale Astro Hog. You can see the ribs and cut-outs, but not clearly. This is covered with SoLite, as are the other models shown, the Cessna 180 + Corben Super Ace. With yellow, the "Show-through" factor is nearly gone. So, if the framework showing is a real concern, I'd say go with any other color but white. But I wouldn't use a heaver film in any case.
JMO,
Ron

[texasclouds]

Thanks for the advice on the covering. I'm now leaning towards the solite. I ordered some to try on a Dandy GT wing.

Callie is hooking me up with a graphics package:
http://www.callie-graphics.com/

[texasclouds]

i'll put the white down first then red, seams over structure. 1/4" overlap




where the trim color seam is, should i add balsa pieces to horizontal stabilizer? it is a small area.




do you think this rear wheel attachment method is robust enough?

[buzzltyr]

texasclouds, if you are going to cover the flight surfaces with red, and just put the red over the white, you won't need any additional surface area. Are you going to use Solite or Solartrim for the red? Solartrim over the white would be my suggestion, if you haven't already purchased the Solite. If you have, I'd put the white down first, and then the red over it. I'd have at least 1/8 to 1/4" of overlap, red over white.

I think the tailwheel should be fine. It's a lightweight model. If you wanted a little extra support for your piece of mind, you could CA a small piece of Tyvek or the stuff used for CA hinges over the tailwheel at the bottom of the rudder. You'll get a little bump there when you cover it, but it will be plenty strong enough.

Mark

[texasclouds]

buzzltyr,

originally, i was going to do all white solite, then add the red solar trim over it.

then i got to reading some info on covoring with multiple colors, and I thought the proper thing (and possibly easier on complex corners) would be do put the white down (stopping at wood points) then red with a 1/4" overlap.

what would you do?

the numbers, lightning bolt, and cubbie will be coming in the mail from Callie pre-cut.

for the strip above the lightning bolt, i was going to cut it out of solar trim.

mark ii

[buzzltyr]

As long as you've already got the red Solartrim, I'd cover all the pieces with white, and then use the red Solartrim over the white. The Solartrim will not shrink as well as the Solite, so it may take a bit more fiddling around the compound curves, but it will work.

Mark

[texasclouds]

Originally Posted by buzzltyr

As long as you've already got the red Solartrim, I'd cover all the pieces with white, and then use the red Solartrim over the white. The Solartrim will not shrink as well as the Solite, so it may take a bit more fiddling around the compound curves, but it will work.

Mark

i haven't bought the covering or trim yet. i did buy the power system, lipo battery and charger. i'm going order the wood, covering, and servos in December.

fyi, the assembled wood pictures above were found in build threads.

[Sky Sharkster]

Hi Mark,
Here's my $.02, and worth every penny!
I don't double-cover anything, except the lettering/numbers.
Several reasons; Weight, even though it's not a lot, you're using the lightest covering available, why double the weight in these areas?
Air Bubbles. Even with the best technique, double-covering any section results in some bubbles. The heat is trapped and bubbles are the result. Using a spray under the second layer helps some, pin-holes help also. But you will still have some bubbles and with single covering, none.
It you plan out your scheme (as you've done) double-covering can be virtually eliminated. Make the seams over a rib, spar or fuselage component. I've added extra ribs in places where I planned to change color; no big deal. There are no double-covered sections on the Cessna except the lettering and seams. Overlaps on seams are 1/8" at most.
Microlite has one bad habit; It sticks to itself, even without heat, and is very difficult to separate. Say you have a stab made from 1/8" sticks. You cover the bottom, then the top. Before you can shrink it, a small section of the bottom (on an open area, between ribs) will adhere to the same spot on the top covering. It will form a "pucker" or wrinkle and nothing will pull them apart. Result, you have to re-cover the section. Paul (PD1) has written about this and I did too, previously.
With double-covering and additional layers, heat, etc., you almost guarantee this will happen. Use ribs and spars to join different colors and use only one layer of film.
Hope this helps!
Ron

[mararra]

Hey Texas

I'm gonna stay outa the covering techniques... yur gettin much better advice than I could give.
As far as the strength of the tail wheel however, I do have some first hand experience. I installed mine per instructions, and it lasted one flight. Epoxied it in the second time, lasted a couple more. There just is not enough wood structure there to absorb the abuse of a bonehead pilot like me.

fly well,
M

[texasclouds]

Originally Posted by Sky Sharkster

...Microlite has one bad habit; It sticks to itself, even without heat, and is very difficult to separate. Say you have a stab made from 1/8" sticks. You cover the bottom, then the top. Before you can shrink it, a small section of the bottom (on an open area, between ribs) will adhere to the same spot on the top covering. It will form a "pucker" or wrinkle and nothing will pull them apart. Result, you have to re-cover the section. Paul (PD1) has written about this and I did too, previously.
With double-covering and additional layers, heat, etc., you almost guarantee this will happen. Use ribs and spars to join different colors and use only one layer of film.
Hope this helps!
Ron

Thanks for the advise.

When I build my Dandy Sport, I pinched two 'window' areas on each aileron. I had to cut it out and patch.

So, for the color joint on the horizontal stab section, you think i should add a couple support pieces at the covering joint?

[texasclouds]

Originally Posted by mararra

Hey Texas

I'm gonna stay outa the covering techniques... yur gettin much better advice than I could give.
As far as the strength of the tail wheel however, I do have some first hand experience. I installed mine per instructions, and it lasted one flight. Epoxied it in the second time, lasted a couple more. There just is not enough wood structure there to absorb the abuse of a bonehead pilot like me.

fly well,
M

I ordered one of these to try. Says it is ultralight. Plastic part goes on your fuselage. I'd like to add a little collar with set screw under the plastic to help absorb the weight there and not transmit it up to the rudder. I'm on the fence as to how to connect to rudder for steering control. Either plug into the wood like the manual states, or I may bend it the same angle as rudder bottom and tape it underneith. This may give more cushion if abused.

[Sky Sharkster]

Hi Mark,

So, for the color joint on the horizontal stab section, you think i should add a couple support pieces at the covering joint?

Absolutely; Otherwise you'll be making a color change (or seam) over open space, and when you touch it with the iron, the unsupported film will stick to the inside of the film below it, the bottom covering.
Seams, overlaps and color changes should all be over a structural piece. The only other option I know of is to stick two pieces (colors) of film together on a sheet of glass, then iron the combined piece to the structure. This is a lot of extra work and sometimes still will separate when you shrink the film.
I've seen articles where the adhesive on the bottom (inner) layer was removed with acetone or other solvent so it wouldn't stick to the glass, but never have tried it.
Using the ribs or structure is the simplest solution, but there may be others!
Ron

[texasclouds]

ok, tires came in, but it looks like they are for a 3/32" axle. Mine is going to be 1/16". i may try to fashion a bushing of some sort. picture doesn't show it well, but they are nice and chunky looking. any advice on how much play you want between the axle and wheel?



my graphics came in too: