RC India

RC Models => Electric Planes => Topic started by: Bilal on June 08, 2011, 01:23:12 PM



Title: suggestions needed in building my first rc airplane
Post by: Bilal on June 08, 2011, 01:23:12 PM
hello everyone,
i am abbas, and i am building mu first ever rc airplane. it is cessna 185 (here are the plans...http://www.rcgroups.com/forums/showthread.php?t=1190685) and i think it is quit suitable for me as it is a high wing electric airplane and a slow flier too(as said on the RCG thread). i have been following this forum since four months and have gaind enough knowledge to start my build.
But here arte a few problems that i am unable to solve myself and need the help of experienced forum members, especially the foam experts like ashta sir, zonuna sir, rc sir etc
I am using high density thermocol as the construction material which i got from air conditioners packing and from fish/ice box. this is not because i preffer thermocol but because it is the only thing thai i could get and because i have some experience in thermocol modelling (i build thermocol models for architecture students professionally).
 i have build myself a hot wire foam cutter power supply but i am unable to find suitable wire to stari with.
apart from this i am unable to figure out how to reinforce the wings and fuselage as i can not afford carbom fibre
the plan suggests an undercambered wing but i want to use a flat bottomed clark y due to its gentle stall characterstics so i am unable to choose between the two
nd finally would it be better to use coro for the controll surfaces instead of 9mm thermocol?


Title: Re: suggestions needed in building my first rc airplane
Post by: rajathv8 on June 08, 2011, 01:45:56 PM
Hey you dont really need CF. Get yourself wooden beeding. Its easily available and costs nothing - its not too heavy either. CF helps when weight is a constrain but since you are building fresh use these beedings and get an appropriate power setup.


Title: Re: suggestions needed in building my first rc airplane
Post by: Bilal on June 08, 2011, 02:06:36 PM
@rajathv8:. sir i thought of using bamboo sticks/kebab skewers for reinforcing the fuselage but i am afraid it would add weight to it and since the plans suggest blue wonder 1500 kv motor which gives a maximum thrust of 460 gram with 8*3.5 prop and 3s lipo so you can see i don't have much room to experiment
 


Title: Re: suggestions needed in building my first rc airplane
Post by: bokilap on June 08, 2011, 03:10:27 PM
Do you have to use that motor only?
There are a lot of other options available.
I would suggest you complete the model, weigh it and then based on that decide which motor-prop combo to use. Not the other way round.


Title: Re: suggestions needed in building my first rc airplane
Post by: abhay on June 08, 2011, 03:56:28 PM
hello bilal,
First of all a hearty welcome to forum... :)
i have made several wings using thermocol, and have used aluminuum beadings. I have used bamboo as well and they work good for electrics.
On more thing, if you cover the wing finally by a paper, applying glue(i use diluted fevicol), u will get drammatic but a very good strength.


Title: Re: suggestions needed in building my first rc airplane
Post by: harsha on June 08, 2011, 04:19:38 PM
using packing tape(brown color tape) is also0 a good method to get the wing stiff


Title: Re: suggestions needed in building my first rc airplane
Post by: Bilal on June 08, 2011, 06:42:10 PM
thank you abhay sir and harsha sir for your valuable comments. Abhay sir i have tried the method suggested by u but with a slight variation, i have used newsaper soaked in 50:50 solution of fevicol sh and water but i am öt gettin a smooth finish


Title: Re: suggestions needed in building my first rc airplane
Post by: harsha on June 09, 2011, 08:31:23 PM
try to use packing tape,it may help,try on some sample piece so that you can understand


Title: Re: suggestions needed in building my first rc airplane
Post by: abhay on June 11, 2011, 01:36:49 PM
 Im sure you will be having problem, since the newspaper shrinks due to excess moisture.

You can use a bit thicker sheet..But dont dip the sheet in glue. instead apply the glue to one side to be stuck, using some paint brush. I use 1' paint brush for the purpose. The paper may shrink a bit, but you will surely get a good finish when it gets dry..
You can See http://www.rcindia.org/gas-glow-nitro-planes/high-wing-nitro-trainer-using-thermocol-bamboo-and-mirandi-and-waste-paper/msg67075/#msg67075.. Its the outcome of my method. I have used a T-section of aluminium at upper side(which suffers compression), while a bamboo on lower side(which suffers tension)..

Just make a try using A4 sheet on small thermocol.


you can also try Harsha's method.You will get near to the following outcome. The only difference is Cellotape instead of packing tape..
http://www.rcindia.org/beginners-zone/my-first-high-wing-foamie-made-from-thermocol-fish-packaging-box/
Abhay