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Old Aug 24, 2012, 10:59 AM
Some Girls r Bigger thn Others
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I'd actually like a fiberglas J-10.....after a JA-37 and F-20 of course. I've owned 2 in the past both 70mm, the GWS foam J-10 flew fine for me but the wing was too thin and didn't last...I had one rough landing it it was done. The Wings Maker J-10 is so far from scale it was almost sad, but it was nice flying, but with terrible space for batteries so a 2min flight max. Both suffered from no retractable gear.

On another note Kin,

Something I was thinking about with E-flite putting out a couple models in the 80mm category; they have created a whole market of guys that have invested in a fan size that doesn't yet have any competition. Why not make an 80mm plane or two for the guys with Habu 32's that want something scale or the guys who just crashed their F-4 and have electronics without a home now? 2013 maybe?

I think the A-4 would be a good candidate, or even an F-35, F-16 or F-18. On the twin side an F-15 or T-50 in 80mm would be awesome! Just a thought.
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Old Aug 24, 2012, 11:46 AM
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United States, TX, Grand Prairie
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...I'm going to be broke !!

Jus sayin....keep em at nice price if you can

Regards
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Old Aug 24, 2012, 12:13 PM
kin
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The size for the fan is not a big problem . just conside the total flying weight and the main point is the (start) fuselage weight , it effect all the combination of your power system (weight) . for a exsample . if i can make a 1.6m fuselage but just the weight in 3.5-4kg , so you only need a normal 90mm fan and a 6s battery is flying ok right , but if the weight is heavy about 5-6 kg , so i need a very powerful fan or maybe a 8s or 10s battery in the power set ! i think not wrong right ! but if the flying weight is very light , the power set is down grade and wing load ratio is small . the plane is good preformance and possible upgrade the fan be very fast . So the first conside is weight ! Weight can let your models base design in 90mm fan if the size is not too over size , you can let the 80mm fan to fly a (light weight 90mm ) modelright ? so the fan size in market is not a factor effect the models size . the ducting for 90mm size still possible ise to 80mm fan , it is no problem . factory also can do a different size for the ducting size , so no need worry the fan size , in fact , more size to the market is more funny.Maybe i can make a twin 80mm F-14 ! but i have no need make a new mold for new size F-14 . if i can make the F-14 light it can from 80-100 mm fan still possible use in size models . it depend onj how the fan power .and total flying weight .I have make a oem models 1.85m long very complicate (full composite and hollow mold wing modles) but the weight is 2.0kg . with former is 2.45kg . is it a dream ? but i success it . So my building models concept is light weight first ! I am not first worry for the complicate parts .fuselage ,i just worry can not make the fuselage light . But till now all models is flying good !
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Old Aug 24, 2012, 12:15 PM
kin
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Please ! who know the c/g point calulation of the JA 37 ? i have no idea in this models c/g point !
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Old Aug 24, 2012, 12:25 PM
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Quote:
Originally Posted by swps View Post
...Something I was thinking about with E-flite putting out a couple models in the 80mm category; they have created a whole market of guys that have invested in a fan size that doesn't yet have any competition. Why not make an 80mm plane or two for the guys with Habu 32's that want something scale or the guys who just crashed their F-4 and have electronics without a home now? 2013 maybe?

I think the A-4 would be a good candidate, or even an F-35, F-16 or F-18. On the twin side an F-15 or T-50 in 80mm would be awesome! Just a thought.
On this note I think they can still be 90 "sized" planes and push 11lbs of combined thrust in a twin eflight fan power system and do it with really inexpensive motors for 2500 combined watts.

I really like the eflight fan, I don't know too many other EDF fans out right now doing 5.5lbs of settled static thrust at 1240 watts.....that's 227 watts a lbs

Basically 11lbs of thrust with tons of efflux and can be ran off a single 5 - 6000 mah pack for 110amps for both of them and will push a good number of the twin 90mm sized jets and be fairly light in weight.

I've tested the Eflight with a closed can TACON inrunner and got 5.5lbs of settled thrust at 55 amps on 6s... very low cost and only weight 10 oz without lip...so that's a 11lbs twin system that weighs prolly 1.5lbs in weight with escs.
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Old Aug 24, 2012, 12:40 PM
kin
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can guy offer more different combination of your twin 90mm fan . how many thrust power /Battery cell piece number /battery+fanx 2 weight . i can more easy to calulation the total flying weight and the design the size and the wing loading .i can easy choice the air foil and let to know( forcast )the flying preformance .
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Old Aug 24, 2012, 12:53 PM
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Originally Posted by kin View Post
can guy offer more different combination of your twin 90mm fan . how many thrust power /Battery cell piece number /battery+fanx 2 weight . i can more easy to calulation the total flying weight and the design the size and the wing loading .i can easy choice the air foil and let to know( forcast )the flying preformance .
2x CS90 12 blade fan with L3026 motors and 2 HK 90-100 amp escs all from hobby king = 140usd shipped.

7.5lbs of thrust each maximum or 15lbs of thrust max at 4400 watts with 2 x 6s 5000mah 30c packs...

Weight would be around 5lbs total motors, fans, esc, packs and wires...

If the Fuselage is kept maximum 3.65kg to 4.2kg (about 9lbs) combination of power system would be very very wide open IMHO.

Servos, Radios, retracts, struts can add another 1 -2lbs of weight depending on what a person choose.

There's a LOT of jets 76" or shorter that can be made under that weight...Currently I'm working with a 85" jet that is 5kg empty with formers in it.

Looking forward to the F14

Regards
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Old Aug 24, 2012, 04:59 PM
Never fly an A model anything!
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It's not just the 80mm fan that has been the reason for the Habu success. There is the plug in electric retracts the very good engineering and "generally" good build and quality of components. There are literally thousands of happy owners who go buy second and third models because they can trust in what they get.

if Kin ticks these boxes, any model of any size will be successful.
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Old Aug 24, 2012, 05:12 PM
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Please ! who know the c/g point calulation of the JA 37 ? i have no idea in this models c/g point !
Kin, the CG point of a Viggen is at the 16% mark of the root chord. At least that will give you a good starting point. It'll be a bit nose heavy, but a great place to start.

Rich
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Old Aug 24, 2012, 05:14 PM
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I meant the root chord of the main wing. 16% from where the LE meets the fuselage.
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Old Aug 24, 2012, 08:13 PM
Some Girls r Bigger thn Others
swps's Avatar
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Quote:
Originally Posted by jayb1rdz View Post
It's not just the 80mm fan that has been the reason for the Habu success. There is the plug in electric retracts the very good engineering and "generally" good build and quality of components. There are literally thousands of happy owners who go buy second and third models because they can trust in what they get.

if Kin ticks these boxes, any model of any size will be successful.
I did not mean to imply that the 80mm fan was the reason for the success. It does have some great benefits but I attribute the success of the planes to what you said.

As to Kin's comment above I understand that you can engineer the plane to fit multiple fan types but that does come at a cost in incorrect inlet sizes, exhaust size, having to make either different adapters for the ducting or separate ducts for different sizes, reduced performance, etc. For me I'd rather have the model designed for one size fan and have it optimized for that size rather than have compromises in it to make outfit multiple fan systems. Honestly, if I see a plane that will fit an 80, 90 and 100mm fan I'm not going to stick a 80mm in it. But if I see an 80mm only plane and if can have E-flite quality (which it sounds like Kin is going to achieve) and would let me use my E-flite gear and is priced reasonably.....no brainer for me.

So with that in mind and since E-flite has already got the 80mm market started; I see a good potential for some planes that are designed specifically for an 80mm setup.
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Old Aug 24, 2012, 10:51 PM
Cut the yellow wire
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United States, NJ, Trenton
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Originally Posted by kin View Post
Please ! who know the c/g point calulation of the JA 37 ? i have no idea in this models c/g point !
I don't know if this will help but here is a link to some photos of my SAPAC Gripen's CG. It is very near the leading egde of the wing at the wing root.
http://www.rcgroups.com/forums/showp...postcount=1418
Mike
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Old Aug 24, 2012, 10:54 PM
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Looks to be pretty close Mike. If you measure your root chord AMD the position of your CG from the LE/root junction, I bet you are gonna be pretty close to that 16% mark. Seems about right for.a close coupled canard.
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Old Aug 25, 2012, 08:15 AM
kin
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See the detail photo of is two first painting models and she weight 1.6kg with full former and two ducting tube battery tray .Not bad ! it mean if the full composite wing for mini turbine version is about 1.8kg .So add the flying equipment about 4.0 -4.5 kg total weight is possible . Happy weight !
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Old Aug 25, 2012, 08:29 AM
Watt me worry?
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Florida
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Kin that model looks great...........you are a fast builder and your products are very nice. On the Mustang........I had to buy another (Hyperion P-51)because yours doesn't seem to be ready. I would have preferred the composite model you have althought the Hyperion is a great model.....looking forwad to purchasing both EDF and prop models from you once you have them for sale online. Good to see more 80mm-90mm planes and would love to see more models which are not being offered for sale by other companies(the Hawk is offered by everyone and in fact I fly one myself).
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