RC India

RC Equipments => Tools, Materials and Building Techniques => Topic started by: shobhit17 on May 19, 2014, 03:03:59 PM



Title: Building my Second Model from commercially available thermocol.....
Post by: shobhit17 on May 19, 2014, 03:03:59 PM
Dear friends,

I have been here for a while now and have been hurt by what everyone says that.... HD thermocol or Depron or Blah Blah is required to make a working aeromodel.  I have till date never purchased a kit to make a model or brought any ARF model.  All my models have been scratch built from material available to me.  Yes the special part is that my father had got me a few plants of Balsa or Balsa like wood from dehradun which I used to grow at my home and use its wood for making my models.  Making models literally from a three trunk.  Earlier I used to get the wood cut at a Saw Mill near my home but now its courtesy Sharma Models that I get sheets out of it.  They have been very kind to help me with their machines whenever I wanted.  After all we have had very good relations together for over 30 years now.

Lately, there has been a lot of talk about making models at low cost and flying them as one likes.  So here is my second model.  
1.   The model is made up of commercially available thermocol.  The sheets used by false ceiling fabricators.  I got 10 sheets of 2 in thickness locally and have cut them to my requirement.  They cost me Rs 50 each I guess.
2.   The fuselage has been made from half inch sheets collected from local Godrej and Samsung Refrigerator agency.  He gave me some 10 sheets of 1 feet x 5 feet free.  
3.   I have used 1.5 mm Ply to strengthen the front portion of the fuselage.  I prefer my fuselages really strong as it removes all possible vibrations coming from the engine or motor.  With this arrangement I can also use a Glow plug or a diesel engine.
4.   I have used some of my Balsa mainly as spars for the wings and the centre wing connector.  The spars are 4mm x 5mm size.  I have also used 2 mm Balsa sheets (laminated three sheets together - used fevicol for joining them) to make 8 mm balsa tailplane and fin frames.  The same have been covered using computer paper and 50% thinned fevicol.
5.   I have also used Blue foam given to me by Mr Gaurav Agarwal at Allahabad a few days back when I first met him.  This has been used for the leading edges, wing tips and alierons.

The model is still under construction and may get delayed as I am waiting for wheels to be delivered to me from my friends.

Here are a few pictures.

The first picture shows the planform of the wing made by me from a net download.
The second picture is the complete drawing of the model on a sheet of paper.
The their and the fourth picture clearly show the 1.5 mm ply reinforcement used on the front half of the fuselage for additional strength.


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: shobhit17 on May 19, 2014, 03:08:45 PM
Here are some other pictures of the model under construction.... Ohh I forgot it is a 4 feet span model of S 300 and will be powered by a 3530 NTM or a turnigy motor.  For additional thrust I might use a 4 cell lipo instead of a 3 cell lipo.

The pictures are:-
1.   This is one side of the wing.  One can clearly see joints in the thermocol.  There are two of them.  It just does not matter is the thermocol is in one piece or pieces joined together.
2.   This is the wing and one can clearly see the coarse grain of the commercial thermocol.  So guys go ahead and use this Thermocol for your constructions.  This will be lighter as the density of thie kind of thermocol is just about 5 - 10 Kgs per Sq Meter instead of 30 + kgs for the HD one.
3.   One can clearly see the Spar of Balsa.  There are two of them.  one on the upper and the lower surface each.  The LE and tips made of Blue foam.
4.   Not to miss the ailerons made of Blue foam.
5.   Do please see the tail plane and the fin have been been as stated earlier.


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: K K Iyer on May 19, 2014, 04:20:28 PM
@shobit17 sir,
Your model looks like it will be strong without being too heavy.
Best wishes.
Will you use a 0.15/2.5cc or larger?
Aerofoil sanded or hotwire cut?


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: shobhit17 on May 19, 2014, 06:11:08 PM
Well... I used the age old method of using the sanding block.  Tried my hand on hot wire.... but am still not too confident of it.  Being an oldie for aeromodelling do not mind putting sandpaper to the block.  I am going to use either of the two motors i.e. http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18227 (http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18227) OR http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=16234. (http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=16234.)  Initially will be using a 3 cell lipo but plan to use a 4 cell for the added kick.  The next build will cater for a .35 cu Glow (OS Max).  

.15 / 2.5cc are too small to be used for such models as they can neither give the required speed nor the overall performance required for an aerobatic model.  I generally fly my first sortie of 5 minutes for trimming or rechecking my model trims.  The next one is a no holds barred sortie where the engine needs to roar to it max performance at far too many an occasion.  I still do not consider myself a good aerobatic pilot..... but yes am getting to be a better one each day.


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: utkarshg13 on May 19, 2014, 06:21:49 PM
Hello Sir,
I wish I'd been present that day when you visited Gaurav Sir. Got to know from him that you grow Balsa at home. Thats really most amazing part...
Now coming to this model, I'll have to say if its done by hands then  :bow: :bow: :bow: :bow: :bow: :bow:. Because its simply perfect.

 :hatsoff:


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: shobhit17 on June 12, 2014, 07:14:44 PM
Friends the construction of this model is rather slow... mainly because of work schedules and the excessive heat of summers.  Have not been able to go and fly for the last 3 weeks.... Anyway here are a few pictures....

For all of you out there... this is a thermocol model.  Thermocol collected from various places including Fridge Dealers, TV dealers and even the local Computer market where a host of items come packed in thermocol.  ALl that was collected and cut into .5 inch to whatever thicknedd I could manage.  These sheets were joined together to produce this model.  The entire surface was covered with 80 column computer paper using 50% diluted fevicol... the same was rubbed over the paper and allowed to dry to give the strength.  This is now being painted using fevicryl colours.... SO thats it... Cost of the model is just the cost of thermocol (Rs 00/-) + paper (Rs 15/-) + fevicryl (Rs 70 or so) + cost of undercarriage main wheels (Used 3mm aluminum sheet), tail wheel (HK about 5 USD), wheels (HK about 5 USD) hinges etc (Rs 75)... well withing control.... please add up and you will be surprised......

The span of the model is 4 feet and will be using a Turnigy close to 2 kg thrust (750 KV) motor driving a 13 x 8 propeller.

Happy Flying


Title: Re:
Post by: docnayeem on June 12, 2014, 08:38:05 PM
Excellent hats off


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: shobhit17 on June 13, 2014, 03:49:43 PM
The painting is still to be completed and the cockpit, main landing gear and nose section is still being done up....  This the picture of thermocol I used for that model.....


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: shrividhya s on July 11, 2014, 04:54:35 PM
WONDERFULL. .... :hatsoff: {:)}

vidhya
8987578700


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: kiran rc on July 12, 2014, 09:03:09 PM
It a nice build. {:)} {:)}


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: manu on August 19, 2014, 10:26:17 AM
wow.


Title: Re:
Post by: sanjayrai55 on August 19, 2014, 07:04:05 PM
Brilliant stuff!


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: RCNeil21 on August 19, 2014, 10:59:05 PM
There are very few thermocol plane makers i have seen, but all of them are masters in their craft, you certainly are one of them sir :bow:

Amazing!!!


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: K K Iyer on August 19, 2014, 11:04:38 PM
@shobhit17 sir,
Nice build sir.
So far we used to envy your balsa tree.
Now we will envy your thermocole tree. ;D
Regards

@sanjayrai55 sir,
Kindly provide pilot (preferably one who looks like...)


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: shobhit17 on August 23, 2014, 06:50:09 PM
KK Sir,
Ha ha ha.... I have nothing with me which one can envy..... everything is up here for free.... it needs someone to come and take it....  No egos... no hangups..... That Balsa was just because my father was a Botanist and he was given the plants by the Director FRI at Dehradun when we visited the FRI.

Thermocol is everywhere..... one just needs to venture out and grab it....

OK here is the final picture of the completed model.... I took my time as the undercarriage took time to be made...... Wish to fly it tomorrow.  lets see how it goes.

Regards,
Shobhit


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: topalle on August 23, 2014, 08:18:46 PM
can you show how you made the control surfaces???


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: wingmanbunty on August 23, 2014, 08:36:45 PM
@shobhit17



  :goodjob:


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: shobhit17 on August 23, 2014, 08:43:43 PM
The control surfaces on the wing are made out of Blue Foam.  The Tail Fin and the Elevator are made of laminated 2 mm Balsa sheets (3 lamination given for strength and also because I used scrap pieces of 2 mm Blasa and it needed to be laminated). All the surfaces have been fixed using Nylon (black colour) hinges given to me by the Sharma Models..... Well I can say... thanks you Anand Uncle and Vivek and Vishal.


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: ponappa on August 23, 2014, 08:48:14 PM
 {:)} {:)} {:)} :hatsoff:


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: sanjayrai55 on August 24, 2014, 12:05:26 PM
Iyer sir; the only pilot available wears galluses, has a white mustache, is a cranky old gentleman often accompanied by a lady bodyguard (to keep him out of mischief)

Chalega?

 :rofl:

(Sorry to gatecrash your very very excellent build log Shobhit)


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: topalle on August 24, 2014, 05:42:14 PM
have you repainted it sir or is it a different model?
In the initial pics, the model wass yellow coloured ,now its red... so I'm asking...


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: shobhit17 on August 24, 2014, 06:54:09 PM
Yes I did not like too much of yellow so used my paint and brush to make it Red mostly..... It is covered with paper and painted with Fevicryl colours.  But the wings are still the same Red and Yellow.  Its the fuselage which has been painted red now.


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: santhus999 on February 02, 2015, 11:59:41 PM
Ha
Great make me a big fan of yours


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: kamalsahai on February 03, 2015, 11:36:14 PM
first of congrats to for building such aeromodel from scratch

i am also interested in such self build model


can u provide link so i can also download drawing plan (yellow and red yak photo)

second i hope u will provide telephonic assistance for building such rc plane so give ur phone no.

kp chandigarh


Title: Re: Building my Second Model from commercially available thermocol.....
Post by: ShantanuBorate on February 04, 2015, 12:14:20 PM
Nice model... Keep it up