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Old Jun 09, 2012, 01:06 PM
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Quote:
Originally Posted by jayb1rdz View Post
... The wing surface area looks as though it could handle the loading.

Herb, is the problem the engineering or the surface area? I was planning 7s 3800s Mega 1400 kv in the Mach all alloy.
The wing area is fine for these kind of edf models (the wing is in fact slightly oversized, if you look at the scale proportions I listed on the first post) - but the retract mounts are just flimsy. This is imo a design flaw of the model.
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Old Jun 09, 2012, 08:16 PM
chillax! It's only a Hobby
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United States, CA, Millbrae
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can't belive it
got the lens for the tip tank, but no tip tanks
i don't get it
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Old Jun 10, 2012, 12:38 PM
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... probably just a misunderstanding.

Maybe next time they will send you a complete Hawk by mistake
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Old Jun 10, 2012, 05:57 PM
Never fly an A model anything!
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I went back through the entire thread here and it appears that the only major issue is the strength of the wings. I'm inclined to press the button on the HK version and see if a quick and dirty fix on the wings will work. happy for opinions.

I have had success with wetting Gorilla glue to fill and strengthen structural failures in other models. The Gorilla glue expands and bonds extremely well.

I was thinking about removing a fillet of the skin around the retract rails. Tape off some of the lightening holes and ribs to restrict the spread of the glue. Wetting and pour in and replace the fillet. If I get the mix right. It should survive a nuclear attack without adding too much weight or doing too much to disturb the cosmetics of the outside.

Worth a try??
J
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Old Jun 10, 2012, 07:36 PM
chillax! It's only a Hobby
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ya, maybe they will get it right someday
My jet buddy just give me a nice used A4 skyhawk by Tamjets
i'll be stuffing the TJ 100 in it this summer
IMO this L 39 fly better then most jets i have owned
So just do it and buy the HK one and take care of the retract area and you will have a great flyer
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Old Jun 11, 2012, 04:55 AM
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I've had them make a mistake before. I ordered just an L-39 body from Scaleflying and they sent me the body with retracts, servos, motor and ESC installed.

Anyway I am really tempted to get one of these:
http://www.highendrc.com/index_eprod...roducts_id=267
I know they are more expensive but I love the paint.

I'm flying my camo L-39 sometimes as much as 6 days a week.






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Last edited by urrl; Jun 11, 2012 at 08:35 AM.
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Old Jun 11, 2012, 10:48 AM
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Quote:
Originally Posted by jayb1rdz View Post
I went back through the entire thread here and it appears that the only major issue is the strength of the wings. I'm inclined to press the button on the HK version and see if a quick and dirty fix on the wings will work. ...
Jay, In my opinion it is certainly worth it, and looks a lot better imo than the HET (but not the Savex or JTM, which have a fully molded wing).

I've seen all of those in person

It is also a great flier as you can see from the video I posted. But of course not a lightweight (but then most people know how to read a weight table nowadays ).

Having said that, it cannot be flown out of the box as is - due to the wing design / mains retract mount problem (again, imo) !

So if some wing work is not an issue for you, then go for it.

Again, imo the problem is not so much the work per se, as the fact that there's such beautiful covering that you want to preserve, at least on the top.

So all the wing work has to be done from the bottom ...
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Old Jun 11, 2012, 10:54 AM
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Quote:
Originally Posted by jayb1rdz View Post
... I have had success with wetting Gorilla glue to fill and strengthen structural failures in other models. The Gorilla glue expands and bonds extremely well.

I was thinking about removing a fillet of the skin around the retract rails. Tape off some of the lightening holes and ribs to restrict the spread of the glue. Wetting and pour in and replace the fillet. ..
Well imo Gorilla glue (PU) is not very rigid. I prefer epoxy + FG or carbon cloth.

PU is good for lightweight joints of ply on ply or balsa on balsa (ie laminating), and excellent for filling gaps.

But those retract mounts just need more ply and more epoxy

And the worst part is that the mains load cannot be absorbed just by the wing top skin

I will post some pics when I get to the new wing. Right now the old modded wing is still fine.
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Old Jun 11, 2012, 06:09 PM
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Just installed my new 12 blade ChangeSun fan/Warhead 1350kv motor/Castle Icelite 100A into the L-39. Will see how it goes with the 6S but I predict it will be underpowered. Looking at the specs just now I am hoping it will take an 8S battery now, although I have none on hand.
EDIT: I see my Castle Icelite is only good for 6S so I will need the Pheonix Ice 100A rated for 8S
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Old Jun 12, 2012, 10:57 AM
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Flew this morning 6S 12 blade and although the speed was perhaps a little quicker the jet was a LOT quieter as it flew by and it was more of a hum than the jet engine sound of the 5 blade fan with 1900kv motor. I stopped in at the hobby shop and bought a Phoenix Ice 100A ESC along with two 3800 mAh batteries I plan to put in series, bringing it to 8S. I plan a test flight tomorrow.

12 blade ChangeSun
8S level

I can use the five 5000mAh 6S batteries I already have for cruising around and if the 8S level performance is considerably better I plan to buy more 8S batteries.
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Old Jun 14, 2012, 10:03 PM
chillax! It's only a Hobby
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United States, CA, Millbrae
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Quote:
Originally Posted by urrl View Post
Flew this morning 6S 12 blade and although the speed was perhaps a little quicker the jet was a LOT quieter as it flew by and it was more of a hum than the jet engine sound of the 5 blade fan with 1900kv motor. I stopped in at the hobby shop and bought a Phoenix Ice 100A ESC along with two 3800 mAh batteries I plan to put in series, bringing it to 8S. I plan a test flight tomorrow.

12 blade ChangeSun
8S level

I can use the five 5000mAh 6S batteries I already have for cruising around and if the 8S level performance is considerably better I plan to buy more 8S batteries.
CMP L 39 fan test (0 min 47 sec)

Here is my fan on 8s CS fan, you will love the way it sounds!
Watch for high amp!
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Old Jun 14, 2012, 10:11 PM
Chillaxin dude!
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Mine didn't survive the postal system It's with HK support at the moment... hope I get a new fuse & inlets for it...
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Old Jun 15, 2012, 10:41 AM
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Sorry to see that ... it's a beautiful model and it's hard to see it trashed like that.

I am not sure what happened, but let me guess : HK / HK customers save on shipping costs by not having the L-39 kit double boxed ?

Expecting such a large flimsy box to travel half around the world unscathed is imo a pious illusion.

RC Aerodyne / Scaleflying .com sent his DOUBLE BOXED ... That is how it should be. You get what you pay for

.
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Old Jun 15, 2012, 12:46 PM
Never fly an A model anything!
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Hey Bullet, I suppose the freight was the best part of $100 to Aus?
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Old Jun 15, 2012, 02:40 PM
Chillaxin dude!
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Jayb1rdz... shipping was around $70 I think...

Herb, it was double boxed, but the quality of both boxes was thin and not that strong I think....

Wood reinforcement is definitely the better option. But having said that, both the Hawk and the Viper I got from HK boxed in a similar manner arrived unscathed..
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