RC India

RC Equipments => Tools, Materials and Building Techniques => Topic started by: amit_delhi on May 17, 2012, 01:31:46 PM

Title: Pls help identify this foam
Post by: amit_delhi on May 17, 2012, 01:31:46 PM
While strolling in market I came across this foam sheet. Couldn't figure out what is this. It was in 1'' thick sheets and weighs 244 grams for 36'' X 24'' sheets. Pls look at the attached pictures. Can it be used to make foam models?

Cost was around rs. 350 for 8 X 3 sheet.
Title: Re: Pls help identify this foam
Post by: Pradeep on May 17, 2012, 01:39:58 PM
this one looks like EPU(POLY URETHANE) foam to me.....
Title: Re: Pls help identify this foam
Post by: amit_delhi on May 17, 2012, 01:42:56 PM
It was available in a cushion / upholstery making shop, just by curiosity I bought a small portion of the sheet. Its very flexible and spongee. Can it be used to make wings etc.?   
Title: Re: Pls help identify this foam
Post by: Pradeep on May 17, 2012, 01:48:17 PM
could be used as a foam wing core but not a hollow wing ...as this is very flexible ...need to give more stiffeners if u r planning to make a wing core out of it... suggest u to get a high density thermo for a wing core and have a hot wire cut done of what so ever template u have. should work out. and works out even more cheaper....: :thumbsup:
Title: Re: Pls help identify this foam
Post by: amit_delhi on May 17, 2012, 01:56:23 PM
Thanks Pradeep, I did exactly as you suggested. I am not sure my thermocol is a low density or high density as I bought it from a stationery shop. Made a hotwire bow and cut it to shape.

Now I am trying to add strength to it. Planning to do diluted fevicol and light cloth covering.

At present the weight of this wing is 40gms and 38" width, 8'' chord.
Title: Re: Pls help identify this foam
Post by: Pradeep on May 17, 2012, 04:02:58 PM
very nice work amit...the difference between high density and low density is that the granual's  are much closer to each other and when u press it its hard.. you can easily make out if its high density or a low density thermo. no what u can do is use a thin layer of fevicol on to it and if u have solartex cloth u can used it on to this one.

note:- u will have to provide the leading edge and the trailing edge with the help of a tip rib and the root rib with top spar and bottom spar to acquire the strength on to the wing....:)

as i can see there is only top spar available on foam ... kindly insert a bottom spar as well to give u more strength.
Title: Re: Pls help identify this foam
Post by: amit_delhi on May 18, 2012, 10:20:55 AM
gr8! going to add bottom spar as well. Please look at this thread

http://www.rcindia.org/electric-planes/first-scratchbuilt-trainer-stick-need-help-fixing-it/msg102174/#new

I have posted pics of the stick.