Scratch Built CESSNA 185 Build Log

Started by Bilal, July 09, 2012, 07:08:27 PM

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Bilal

Good evening fellas,
I've been introduced to this wonderful hobby by my brother in 2008 and since then I've been reading about it on various forums on the internet, and tis now that i found myself knowledgeable enough to try my hands on scratch building a high wing trainer.

After deciding this I started eyeballing various threads here and on RCG and finally found this plan of Cessna-185 that i really liked and decided to try it as my first plane

here is thr link to original thread on RCG:-
http://www.rcgroups.com/forums/showthread.php?t=1190685

Following are the specks of the plane:-

Construction Material: high density thermocol from fish box and from refrigerator packing material

Wingspan: 41''

Power system: not yet decided, depends on the weight of the complete airframe

following are a couple of pics of the build so far......the airframe would be completely scratch build
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

rastsaurabh

Hi Bilal,

I have seen your crafting its good ...... rather than the cesna TRY this look alike its good plane easy to understand and build.



Also have a look at what i attempted..... i used the thermacol from packing of TV, fridge. That is equally good high density thermacol.

http://www.rcindia.org/electric-planes/scratch-building-a-look-alike-of-axn-floater-or-fms-800-or-easystar/msg108284/#msg108284

Power system is same as AXN floater.

Bilal

Thanx Saurabh Sir(?) for your sugesstion but i have started working on the plane and in fact the fuselage is almost complete,...i only need to add a rudder and landing gears to it and it would be complete.

Actually my internet connection is darn slow ritenow...else I would've posted a couple of pics of the build.......but will try in the morning.

And I've seen your AXN thread....and i must say, you've got great crafting skills....atleast with thermocol:D......in fact your build log inspired me to try thermocol insted of coro for my first build.....sooo thanx
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

rastsaurabh

Why a question mark after sir......?
I am also a new person in hobby but did my engg. in 1996 !!!!

So with age perspective you can leave sir as it is and remove (?). ;-)


Also you posted your idea after you built the fuse.....!!!! but did you do exactly the same as mentioned in the thread??

Bilal

Ok Sir, as you wish;)
and yeah i followed the exat build procedure as stated in the build log on RCG......infact I kinda liked the techneque of using centre block for fuse construction as it enables building your fuselage nice and square without any wrapping.
I did try using treditional technique using formers and stringers(just replaced balsa with thermocol) but didn't get any success.

And one more thing Sir, how did you build the wings for your AXN....i really liked that polyhedral it had and the raised wingtips.....did you hotwired it or shaped the entiere wing by sanding?
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

rastsaurabh

I got the basic shape through hotwire...... Found hotwire cutter very good once you have the right kind  and right skill...
After getting the aerofoil shape on flat wing i have explained on reply no 58...

http://www.rcindia.org/electric-planes/scratch-building-a-look-alike-of-axn-floater-or-fms-800-or-easystar/msg108426/#msg108426

Bilal

#6
Status of the build so far- fuselage completed with newspaper covering and controll surfaces attached, it just needs a landing gear
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

abhay

Hey bilal!! What are u using for landing gear? can u post the original specification of wings etc which u intend to build? or it is the same as in RCgroups.
I can take off and fly well. Its landing which sucks :banghead::banghead:

Bilal

#8
Yeah Abhay bhaiya......all the specs are same as in RC Groups thread.
I just wany yo know the location of the main landing gear and the distance between the two wheels.
And FYI, i intend to make a tail dagger type landing gear
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

Bilal

I made a sort of latch on fuselage top to fascilitate me while installing pushrods, will glue it back after final adjustments.
I covered the entier fuse with newspaper and 25% diluted solution of fevicol, and i must say it came out very well, smooth and glossy and without any wrinkels
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

Bilal

The original designer on RCG sugessted the rudder and the elivator to be build from 6mm depron, but since I didn't had any, I tried another method.
I build the frame of elivator and rudder from some 3mm balsa I had lying around, filled it with thermocol and sanded flush and finally covered it with 1mm foam and voila, I had some nice and stiff stabelizers
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

Bilal

#11
Since someone said, 'pics are better than a thousand words' :)
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

Bilal

Now one question from the forum members-
the plan suggests a slightly underchambered wing, something like 'naca 1224' and i want to go for a flat bottomed 'clark y' due to the ease of building......soo please suggest which airfoil should i choose?
And one more thing, please suggest a suitable paint scheme, something that is clearly visible in the sky for orientation as I am a newb
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

VC

EXCELLENT work on the Vertical tail and the stab! :hatsoff:

My Cessna has an under cambered wing, but I guess a flat bottom would work just as well.

As far as the paint scheme is concerned, go for dark undersides and some stripes on top of the wing. It will help so that you don't lose the orientation of the model in flight.

Some reading material for you:

http://www.rc-airplane-world.com/rc-airplane-disorientation.html

http://www.rcgroups.com/forums/showthread.php?t=867259&page=655

Picture courtesy www.rcgroups.com. (I hope that they don't mind)
Growing old is mandatory, growing up is optional!

Bilal

Thanx VC Sir......your comments meance a lot to me
Sir, can you throw some light on the position of the main landing gear in tail dagger configuration....i mean it should be directly under the CG or slightly ahed of it?
And also, what diameter wheels should i use?

And as far as paint scheme is concerned, i was eyeing this one ;D
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

Bilal

#15
Good evening everyone,
I know i am being impatient here, but I have just a week a vacations left and want to complete atleast the fuselage.....soo please help me out by giving your precious comments on following issues-

1. What should be the position of main landing gear in taildragger configuration....directly below CG or ahed of it?

2. What should be the distance between the wheels of main landing gear?

3. What diameter wheels should i use?

4. And whai should i use as pushrods and how to install them?

-regards
Bilal
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

Bilal

5. And one more thing, where should i place the control horn?....i know that the holes must align with the hinge line but what should be the position of the horn itself, i mean ai what hight from the base?
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

khan

that's a really nice work i did build few thermocol plain but never this good and at that at time i only had 1ch tx so all never took of from the ground but rode like a car...now im going to make one...i used hot glue few times on thermocol but it made right through it..is there a specific one to use...and instead of using the brown paper u can also toilet paper it makes really hard surface {:)} {:)} (:|~ (:|~    what motor did u use and how much

Bilal

Khan Sir,
I dunno about the hot glue, I just use plain old PVA glue of 'Jivanjor' brand. The key here is to lightly sand the thermocol and apply a really thin coat of glue on both the surfaces and wait for a couple of minutes....and when the glue is still a bit tachy, attach the foam and wait it down for a good bond.

I have found that allowing the glue to dry a bit before actually gluing the parts together, reduces the curing time conciderably
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

VC

I hope you find some answers for the landing gear installation here:

http://www.rcindia.org/electric-planes/avispad-build-log/75/

Am updating the thread so please check after 15 minutes.
Growing old is mandatory, growing up is optional!

Bilal

VC Sir,
am closely following your thread........tis actually been my savior till now, thanx
Cessna - 184
Mr. Moss
Self-Design Glider
550 DIY Quad
Scratch Build TriCopter
VT-Allrounder
Telemaster 400
ZMR 250

bhaveshsangani

Ask questions or you will never get the answers.

VC

#22
Whatever you do, don't follow Hitesh / Maserati's build log. It will freak you out. He has taken perfection to an exalted level. My Avispad is like a novice, first timer build when compared to his construction.

Check this out: http://www.rcindia.org/gas-glow-nitro-planes/my-new-built-coro-cub/msg109567/#msg109567
Growing old is mandatory, growing up is optional!

rcpilotacro

1. What should be the position of main landing gear in taildragger configuration....directly below CG or ahed of it? About an inch ahead of it, else she will topple over, on or near CG will also have the same effect, due to rolling friction

2. What should be the distance between the wheels of main landing gear? that is called the track, should be atleast 1/4 the span, give or take

3. What diameter wheels should i use? nothing hard and fast on that, if you look at multiplex fun cub the wheels are big, in you case keep it light could be about 1.5 to 2 inch wheel

4. And what should i use as pushrods and how to install them? cycle spokes, umbrella rods, or a lighter version is two 'Z' bends using safety pin and a balsa stick/carbon rod in between

5. And one more thing, where should i place the control horn?....i know that the holes must align with the hinge line but what should be the position of the horn itself, i mean at what height from the base?
In line with the servo, so that servo is not loaded, remember it is the horn which transfers servo push pull force to the control surface, so that needs to be reinforced.

Few other thoughts
I have seen many start the hobby with making a model, painting them nicely and crashing in the first flight, then they come here sell off the stuff and quit the hobby. So that it doesn't happen in your case, keep these aspects in minds:-

(a) Ensure you have done enough sim of the same model. should be able to take off do some aeros and land at the same spot with same speed every time.

(b) For a newbie, it is preferable to let some experienced to do the maiden.

(c) Don't worry about beautifying it, just differentiate the top and bottom surface of the wing and fly it stock, fine tune it (if it survives), then go ahead and beautify. with that, even if it crashes you are not too attached.
Gusty's Hangar and Introduction.

A Good pilot will practice until he gets it right,
A Great pilot will practice until he can't get it wrong.

maserati

good going bilal..
your fuse looks beautiful.actually my internet connection was out of order for a long time.saw your post yesterday.
i know its a tough job to cut thermacol with such precision and then to sand it to give it a final look.i had  a tough time when i made my first plane of it..best of luck for your maiden..

regards..
hitesh..
ultra stick(electric),osh kosh,SPADET LC-40,coro piper cub 76".