RC India

DIY hot wire foam cutter with switch and led indicator

Bro mine is also like this one, but this bends due to tension

I think to avoid bending, one can have one more horizontal member..

You may have seen this old thread...
http://www.rcindia.org/self-designed-diy-and-college-projects/5th-sweepstakes-entry-diy-lipo-powered-hot-wire-cutter-k-k-iyer/?all#lastPost

Was intended to be self contained and portable, without long leads to a car battery or transformer.

Mine is using 3 amp 12v adapter

Its 1.4 m and uses 1st string

I have used 32 gauge wire so it does not need high tension ...

As for 32 gauge requires more watts but it cuts very fine...

That's very nicely cut!
How do you avoid getting a curve in the trailing edge?

Hello Tic,
very nice cutting, what wire of 32 gauge you have used ?

for reduce bending you can use shorter length pipes at the end holding wire.

regds
Saurabh

@k k Iyer sir actually I don't know the reason behind for the no curve for trailing edge as it was my 2nd attempt but it may be due to 32 gauge wire which may be enough thin with proper suitable tension and temperature. I don't need to aaply excess pressure for cutting.

@ rastsaurabh it is 32 gauge nicrome wire and about 3 ft long and resistance of 17 ohm it need about 22volt supply and about 1.5 amp of constant dc current

What supply you are using for same?

I'm using icharger 106b+ having 1 out of 3 special mode As Foam cut where I can set voltage and current as per the requirements

Nice....

Thank you @rastsaurabh sir @ kk Iyer sir and @al ham shari

May I know how do you make/get the side profile template for the wings...

I have downloaded the profilii software on pc  where you can get perfect shape of airfoil or rib or you can draw your own rib then you can make its template on thin wooden plate. And you have to sand the edges of rib or profile to get descent cut.

Ok..

I make a cardboard piece and stick it using pins , i download MH flying wing wings for all types of wings and works pretty well on all planes.

Hello everyone.
Can anyone help me?
Is there anyway to hot wire cut elliptical wings like spitfire etc.??

I think that's not POSSIBLE

Yes you can , first cut the horizontal ellipse, the cut the vertical wing then take the two aerofoil sections , the main and the tip ones, then stick it and cut it out. You will end up having an aerofoil that looks like scale wonhs.

I am a beginner... Please will you elobarate in simple language.....
BTW  thanks for taking interest.

Sorry , I mean first cut the horizontal part then vertical. I typed the exact opposite.  So fyi and simplicity , take a rectangular block of foam and draw the elliptical outline of the wing on top and cut out the wing but you should avoid the curve at the ends. So u will end up having a parallelogram or whatever , a shape. The end tips can be cut at last.Ten,you take the two templates of the spitfire , since the spitfire wing has a broad and at the tip short rib. You should scale the template and print, then stick it onto a cardboard piece and stick it on with pins. Make sure they both are aligned at the middle of the foam core. Then hot wire it out. I recommend 2 people instead of one for cutting wings like this one , since there are different sized aerofoil. Make sure that guy knows this well. Once u cut it, don't open the core, instead cut the remaining curves. If u have done it correctly as I said , you end up having a good wing. And don't worry for minor lines in the aerofoil as it can't be avoided unless you use cnc , just sand it off.

Thank you......
I got it.... :salute: :salute: :bow:

Sure I will try and post pic of it...

What we can do is this way . Attached a top view of left wing. With R1 to R4 are ribs to be attached to foam and using hot wire to cut from A to B