First Chuck Glider

Started by rajathv8, July 31, 2010, 01:47:08 PM

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rajathv8

It's is just too breezy these days, waiting for a nice calm day when i can test this one properly. I plan to make a balsa glider next. Te simplest one possible as this will be my first build.
The wing just doesnt stay as a dihedral. Iv tried glue and doublesided tape. Any suggestions?

VC

First glue the dihedral parts together with super glue (CA). Once it sets, use a Quickfix  or epoxy and let it set for 6 hrs. Just remember that both the port and starboard (left and right wing) dihedral angles are identical. Build a cardboard template, it will help you.

We used to cover the joint with a glued thin silk ribbon for added strength.

Oh dear! I know that the dihedral template and the silk ribbon won't make any sense to a 2010 newbie! Will try to load some photos or else call me tomorrow after 11am for details.

Cheers!
Growing old is mandatory, growing up is optional!

VC

#27
This is what I mean .

(I haven't used Paintbrush in years and it took me 30 minutes to create this. Rajath, my friend, you owe me a treat - BIG TIME!) ;D ;D ;D
Growing old is mandatory, growing up is optional!

VC

Mistake on my part - read 30 degrees wing dihedral as 150 degrees. The smallest acute angle of the cardboard template is 30 degrees, therefore the wing dihedral angle = 150 degrees.
Growing old is mandatory, growing up is optional!

VC

Growing old is mandatory, growing up is optional!

sushil_anand

Quote from: VC on August 05, 2010, 01:54:03 AM
Mistake on my part - read 30 degrees wing dihedral as 150 degrees. The smallest acute angle of the cardboard template is 30 degrees, therefore the wing dihedral angle = 150 degrees.

Dihedral is ALWAYS with respect to the horizontal plane. So it IS 30 degrees!
Hangar: Zlin 50L -120, CMPro Super Chipmunk, Ultimate Bipe EP, Imagine 50, Christen Eagle 160, Ultra Stick, Super Sports Senior

rajathv8

Thanks a lot VC, Will put it to good use and include a treat if we get to meet :) Just one question. ? The one you showed is a double dihedral right.? I will make changes to suit my single dihdral. Use of silk ribbon makes sense now :)
And the model is of foam so no using quickfix right?

tg

Quote from: rajathv8 on August 04, 2010, 10:52:13 PM
It's is just too breezy these days, waiting for a nice calm day when i can test this one properly. I plan to make a balsa glider next. Te simplest one possible as this will be my first build.
The wing just doesnt stay as a dihedral. Iv tried glue and doublesided tape. Any suggestions?

Waited for the glue to dry??? Can even tie a string between the wingtips to keep them at the di-hedral angle if you are complaining of sag. Long wings can sag at the tips if not reinforced properly at the joints.

rajathv8

I guess the string theory is easier. Will try the string and ribbon combo first.

rajathv8

Used a string to hold the wings and counter sagging. The flight is stable and smoother now compared to earlier. The distance for given number of turns has also increased. Thanks Tg :)
@VC: will use the cardboard template for balsa gliders which i plan to start in a day or two :)

anwar

It would be fun to see a flight video :)
Hangar : Please see my introduction.
RC India forum and me : About this forum.

rajathv8

#36
Yes i will :).  Once the breeze dies that is :(. Love the way it flies (considering it consists of just a few simple parts) after geting the dihedral right.

Got myself a balsa chuck glider kit today (wood and plans actually). Will start with it soon. This is going to be my first build :D Absolutely no experience in sanding and stuff. Mr. Gupta explained for more than an hour as to how and what to do (with a demo) and thats all i have to start with. Exciting :)
Done with sanding a hardwood block to perfection - to be used to paste sandpaper for sanding balsa.

tg

Hi,
     Its actually better if you can get a sheet of depron or EPP and then use that to make as many gliders (and different designs) you want. The balsa can be cut into spars for reinforcement. Can get free glider plans and make those.

Any indoor places in Bangalore (south) where these can be flown. Don't know if the indoor stadiums in Bangalore can be ever used with permission.

rajathv8

I wanted to start with balsa as it will serve as a bse during future scratch builds. It's just to learn and nothing else.

I don't think there is any. Will try it out at my friends appartment indoor badminton court, its pretty big.

rajathv8


rajathv8

Started with balsa. Practiced on a small piece first.
The width was 4cm and the highest point of the airfoil is 1cm from the leading edge. Does it look fine or should any modifications be made?  :help:

The second pic shows what was given as part of the the kit.
NOTE: The ribbon is included as you said VC :)

rajathv8

After a long long time i managed to finish sanding the surfaces and making the profiles/contours. Need to make a template before glueing.
The plan says the wing leading edge sould be 5.5cm from the tip of the nose and the fuse length is given as 25cm.
The actual length is 30cm so iv decided to place the leading edge of the wing at a distance of 6.5cm from the tip.
This is my first attempt so im open to suggestions on any matter.  8-)

I was told to use "lacquer" to fill up the tiny holes. Dont know much about this. Can someone shed some light on this gray area? Will it affect the weight?

Attaching pics showing aerofoil and sanded sections.

flyingboxcar

Nice work on aerofoils there.
Go buy some quickfix, same as NC lacquer and you could buy a tube instead of say half a litre and save. Thin it with NC thinner if required.
You can also mix some talcum powder with the quickfix thin it and brush it on (make sure it is thin coats). After dryiing for atleast 24 hours you can wet sand with wet/dry sandpaper while using slightly soapy water. Two to three coats should give you smooth silky surface (Use progressively finer grade of sandpaper upto 600 if availble else 400 should also be fine) 
If you are really into scale you should be here. www.rcscalebuilder.com

VC

#43
+1 Flyingboxcar - Nostalgia! (only old aeromodellers will understand the meaning of this post.)

Rajath, good work done! Listen to Flyingboxcar very carefully, he is guiding you PERFECTLY. Just do as he tells you. Lad, you are entering a magical world.

Flyingboxcar, you won't believe what I got today. I got an ORIGINAL Aurora Hunter Catapult Glider packed and sealed. This was my first ever model way back in 1974/75. I am probably going to sleep with the kit by my bedside. I have waited many years for this, Dad taught me the basics of aeromodelling with this particular model. As I said before, nostalgia...............
Growing old is mandatory, growing up is optional!

dileepbalan

VC,

I would like to know how the aerofoil made to that shape? is it solid piece of Balsa wood sanded / shaped like that? what is "Lacquer"? is it same like clear varnish? is it available in hardware shops?

Rajath,
post your video

Regards,
Dileep
Spektrum DX6i | AXN Floater-Jet

rajathv8

@ dileepbalan's :

To make aerofoil profile:
1. First mark the highest point or rather highest line of the aerofoil on the top face. Iv taken 25% of the wing width.
2.Then sand the bottom face flat.
3. Mark centre line on the bottom. This line will serve as refference while glueing to the fuselage. Do this now as it will difficult once the aerofoil is done.
4. Then sand from the high line moving towards leading and trailing edge of the to be wing. I usec corse sand paper (80).
5. Use finer sand paper to make the contour along the edges. I used 120. Carefull with the trailing edge of the wing in the final stages. The balsa becomes very thin in this part and may get damaged if force is applied. It happened to me, fixed it with the wood dust and glue :D

Dont know about the lacquer :)

Im dont have a video yet as im busy with coll work. All the work on the glider was done late night and i took my own time without any hurry. :)

@VC & flyingboxcar : Thanks guys :)
Iv got the quick fix, 400 sandpaper and thinner, will take some lacquer from a known person.
Should i glue the wings,fuse etc first and then use lacquer or vice versa? What is wet sanding and why is it done?
Flyingbox can you please explain with detail as i have no experienc whatsoever :)
Thanks.

flyingboxcar

Wet sanding gives you smoother surfaces, keeps dust down and takes away the heat of sanding.
For wet sanding you will need wet/dry sand/emery paper. The ones with black grit.
Take some water in a flat dish, mix a few drops of soap liquid or dissove some solid soap into the water, now when you start sanding, dip the wet/dry paper in this soap mixed water and start sanding, keep wetting and sanding till the desired surface condition is acheieved. BTW you could sand with the wet/dry as dry too but surface finish would be much less smoother. Also rememebr to wet sand only after you have sealed the wood grains with coats of dope/lacquer/quickfix/mixed with talcum else the wood will absorb water and swell and even distort.
You should glue all the parts and then coat and sand, if you do the other way, you you will have to leave the surfaces to be glued uncoated and that will become an issue with wet sanding. 
If you are really into scale you should be here. www.rcscalebuilder.com

akky

i also got two planes from there
1 is stick but can be converted to high winger or a  bi plane
1 is nor malll plane
but much wings got crushed in the parcel :banghead: :banghead: :banghead: :banghead:
Arcarious @ Akky.....
I have never crashed while flying....Its the Landing only that gets me....
Happy Landings....&.....Happy Crashings

flyingboxcar

If you are bent upon lacquer, best is to buy Duco clear lacquer and thin it with NC thinner. The Duco stuff out of the tin would be of jelly consistency and needs to be thinned as per requirment. Nothing like if you could get some aircraft dope
If you are really into scale you should be here. www.rcscalebuilder.com

rajathv8

#49
Thanks a lot flyingbox. Din know anything about wet sanding :)

Well i visited IMM today. He gave me some lacquer and thinner. Not sure if its duco - it was in a baby food container :) but its clear. So now i have everything i need.
Since im new to this i guess its easier if i apply the dope, sand and then glue. Il stick to dry sanding for now and use wet sanding for my next model. Will try wet sanding on a sample to satisfy my curiosity :D

@akky: Is the biplane the yellow one?
You can make the wings using biofoam plates i guess.
I have three of the normal ones now : got two as compliment :D :D