Nihjuis Spitfire 62"

[Hugh Coleman]

Hi Snaba,

I like the way you are thinking, but these are HUGE flaps you have built.  They will stop the plane in mid air when deployed as if an anchor has been thown out!

I like that you have th contol horn inside the wing... Hmmm... Thinking, thinking...

 

Cheers,

 

Hugh

[Snaba]

I decided the flap building based on two things: first, if I didn't see wrong in original the flaps are around this size and the pilots were instructed to open the flaps 45 degrees or not at all during landing, and, in my Reflex simulator I have an extremely scale Spitfire where the flaps open only maybe 10-15 degrees, and plane this one is a peach to land! I thought this degree would move the lift point enough to slow down the plane when landing without inducing too much drag assuming I keep a bit idle gas on. Also, if I make the effort to build flaps I let them be big enough for creating a huge effect if so desired/needed, and keep the possibility to use them moderately for smaller effect. I thought it is better to have a choise. Practice will show if this idea (and the Spit) flies at all

 

 

The flap linkagefrom inside the wing didn't work as well as I thought, there was too much flex in the system. I'm thinking of new options but getting prepared to make external links, if the sunny days arrive earlier than a new idea...

[Hugh Coleman]

Hi Macsood,

 

Didi you install the Sheer Webs before you sheeted the top of the Wings?

 

Cheers,

 

Hugh

[Paul Jarvis 1]

Hi Hugh,

 

Thanks, you confirmed what I thought.

 

So I rigged a a couple of wood blocks and broom handle lever and wetted and twisted the port wing overnight, with only a small patch of lower surface sheeting lifting near the wheel due to compression.

 

This morning... AMAZINGLY...  the wing stayed set at the new AOA... in fact one last tweek last night means Ive overdone it slightly.... oops  

 

Still its much better than before and hopefully will fly out at take off now rather than burying itself.

 

The fuse is not warped I just havent shaped the lower section yet. 

 

Cheers

 

Paul

[Mac Duberia]

Hi Hugh,

 

No i didnt install the sheer webbing before sheeting the top(i only followed the instructions, but i dont think i should have now.)

 

Mac

[Hugh Coleman]

Yes, I know.  The isntructions state to fit the sheer webs after sheeting the top... Seems counter intuitive to me... You would thing that installing the sheer webs first would add rigidity to your skeletal frame so that there was less possibility of the whole thing warping when the sheeting is applied...

 

However, the instructions might very well be correct and your application of the sheeting might have been the cause of the waroing diue to some process that you might have done incorrectly... That is always something that I am willing to face up to my self.

 

I will be installing the Sheer Webs first, just to be sure.

 

Cheers,

 

Hugh

[Mac Duberia]

When i sheet the bottom, i'll make sure the wing panel is held flat against the board whilst the glue is drying and hope for the best.

 

[Hugh Coleman]

Hi Macsood,

 

I just sheeted the top of my left wing and the whole thing twisted up at the outer trailing edge just as yours did.  I isntalled the sheer webs before sheeting too.

 

I know why; it is the relieving of the stresses in the sheeting that is doing it.

 

I reckon that if I jig the wing properly before sheeting the bottom, it will come good.

 

It might need some experimenting.

 

Cheers,

 

Hugh

[Bob Stringfellow]

Hi everyone

 

I have just started my build, so far I have cut out the Fuselage Formers F1 to F5. I note that the plan and the Magazine state the left side of the Fuselage is shorter than the right, is this correct ? To give Right Side Thrust I think the opposite should apply.

[Paul Jarvis 1]

Hi Bob,

 

Yes the plan and article descriptions are incorrect, I checked this with Tony N, the opposite is needed to give right thrust.

 

I just covered mine (silver solarfilm) and test flew it last weekend, after a few ground runs and dummy take off's it flew perfectly from initial set up needing only very slight down trim.

 

I used the 4 max recommended electic setup and needed 7 oz of lead at the motor mount to get C of G balanced.

 

This was my first ever build and it was fairly straight forward, the only issues for me were... I would probably have tried to pre bend the wings main spruce spar (is this possible ?) as this introduces some upward bend at the tips, and the wing sheeting distorted the wing because I didnt bolt the wing skeleton down to the bench.  

 

Im gonna try Dulux emulsion test pots to paint it...   

[Bob Stringfellow]

Hi Paul

 

Thanks for confirming that. As for the wing I might try steaming the main spar to introduce a bend. I would be interested to know how the Dulux works out.

 

Bob

 

[Hugh Coleman]

Paul,

I now have my wings fully skinned and I have ended up with a similar twist to you.

Surprisingly, what twist there was before the fitment of the leading edges was greatly reduced after I glued them in place...

 

And one wing has heaps more washout than the other...  SO your broom stick handle trick worked then?

 

Cheers,

 

Hugh

[Mac Duberia]

Hi,

 

Got back to my workbench after a short break, i have now got a stage where i shall be shaping the wing tips and the L E. Incidently my wing wasn't too bad after all, i made sure the wing was held flat whilst the bottom sheet was drying. i guess i probably find out when i fly the thing.

[Mac Duberia]

Has anybody got any ideas as to what the other four components are on the 4mm ply plate which came in the cnc pack, this plate also has the wing mounting former.

 

cheers.

[Trex700e]

Haw did every one do the wings, did you sheet the bottom then join them or the other way around?

 

[Paul Jarvis 1]

Hugh, Did the broom handle trick work on straightening your wings ?

 

Bob, I painted with dulux match pots... a ver y cheap option but difficult to get good spitfire colours and lots of brush marks, so then I sprayed with car paint which added a sheen and showed up the brush marks even more, wish I d used car sprays to start with.

 

The model flies lovely... only one problem.... I bend the legs on each landing

 

 

[Mac Duberia]

Hi Paul,

 

wheres the exhaust stack? Got to have one on it

[Hugh Coleman]

Hi Paul,

yes it did... but I ended up with a section sheeting lifting just as yours did. 

Slowly getting to the covering stage.

 

Cheers,

 

Hugh

[Bob Stringfellow]

Hi Paul,

 

Sorry the Dulux didn't work so well I shall probably go for the car paint option, I have used it before and its ok provided its well sealed with fuel proofer. incidentally which retract option are you using?

I am a long way behind you, Iast did a scratch build from a plan about 45 Years ago, at the moment I have almost completed the Fuselage and I am contemplating ordering the Unitracts.

 

Cheers

 

Bob

[Paul Jarvis 1]

Hi,

 

Exhaust stacks are now fitted, just gotta add some lettering.

 

I used Unitracts, not sure whether oleos would help stop the legs bending, I doubt it as I guess the wire at the top would still bend.

 

Flew a good 10 to 15 mins today on two "parallel wired" 3S 2200 lipo's at halfish throttle, flies beautifully ! 10 to 15 mph wind and a  smooth shallow approach but it still came in rather fast and bent a leg, kinda wish I had fitted flaps now. 

 

Havent dared fit leg covers as I need the clearance a bare leg offers, gotta improve my landings and / or smooth the runway down considerably !       

 

Final all up weight 3.0 kg (7 and a bit lb). Initially I broke a few props on take off as shes nose heavy and  kept tripping up on the suggested elevator throws, now cured this problem with LOTS of up-elevator on high rate for take off and £1.50 props from giantcod.

 

Paul  

[Trex700e]

did you use the metal unitracts mechanism? How many people actually wish they had fitted flaps?

 

do you sheet the underside of the wings then join them or the other way around?

[Paul Jarvis 1]

I used the Unitract standard sport retracts as recomended in the build and 3inch wheels, I believe the build says sheet the wings, top and bottom, and then join the two halves with 3 inch glass tape / epoxy, this is what I did.

PS.. Ensure the wing is held in the correct profile somehow when sheeting as I got warping of one wing when weighing down the wing / sheeting during gluing. 

 

Paul

[Snaba]

I see I need to speed up my work to catch up with you folks

 

Paul,

it does mean some work but you can pretty easily add flaps like mine, also afterwards it should not be a big job. You only need to open up the lower part of sheeting until the t.e. spars and make the flaps from 3 mm ply of right shape. I glued a 3 mm bruce to the t.e. which results in that the flap will close with no gaps (need a picture?)

 

The problem with nosing could come from using 3 '' wheels...can you still try 82 mm? My scale wheels are that size and also thinner: I can eventually fit leg covers AND they should also cloe fully.

 

I sheeted the wings first and then joined them with o/n epoxy and wrapped the wing with glass fiber the day after as instructed. The alignment during joining was made a bit easier by drilling holes for wood IKEA dowels to the first ribs when manufacturing them, like you see in gliders. I had no warping at all.

 

[John Laverick]

Hi Snaba,

I've just finished the Lysander and was so impressed with the build I've moved straight on to the 63" Spit. I intend to fit flaps and will follow your idea, can you tell me if your method of fitting the servo connecting rod inside the wing has worked?

 

Regards

 

John

[Snaba]

John,

it didn't work. In principle it should but as all contruction is made from wood and the lenght of the connector in the flap can not be very long I think there was unacceptable amount of flex in the setup. I could just get a grab from the flap and move it, I think there was enough torque to stress the servo. I decided to give myself a break and use a standard system...