Thanks to all the idea's shared by the forum members and net, I enjoyed building this one up which will bring me close to the
first scratch build Extra 300S foamy design borrowed from rcpowers.com


Just another Thermo Foam Slicer set-up:


Build time: 3.5hrs

Components:   ~Rs.500

   Plywood  2' x 3' x 1/2"         - Rs.180
   Transformer 12-6-0-6-12 2Amps    - Rs.120
   Fan Regulator          - Rs.110
   4mm Banana Jac/socket (1 pair)    - Rs. 40
   Fevikwik         - Rs.  5
   Guitar string 2 (B string)   - Rs. 10
   Old Plastic bucket handle   - priceless

Used the plywood for a decent base to support the whole contraption. The "priceless" bucket handle was used as a cantilever for providing adequate tension to the guitar string to compensate for expansion while energising the circuit. Kept one side of the bucket handle with L section and sawed of the other side. The idea was to have a hole (4mm) on the base (bottom) with a groove and the end of L-section will fall into the hole. The c-shape of the handle would curve from below, through the groove to foam working side of the plywood - Figure 1.


I did cut in a cross carefully on the flat end of the handle to hold the brass beaded end of the guitar string and is held in place with the tension of the cantilever arrangement - Figure 2. Figure 3 gives you a view that the wire is about 10cm from the cross cut end of the handle. Just have to pull down the handle and slot the string in place. The cantilever will hold the wire in place


Connected the 230V i/p phase in series with the fan regulator and soldered the 6 - 0 - 6 taps on the secondry side and extended to the banana sockets.
At no load the o/p was about 12.5 V and I could adjust it all the way from 0 - 12.5V. Connected the wire with resistance of 1.3 ohms to the banana sockets and a full 230V i/p to the primary the o/p dropped to about 9V and it
heated the wire enough to cut at about 0.5 cm/sec (very approximate).

Figure 5 is the complete setup. Tested it last night and works pretty well. Will do some testing and probably use 18V at the secondry and check it out.


PS:

a) All pictures taken with blackberry and waslazy to use my camera kit with close-up lens, tripod et al..


b) My first trip to SP road, got me a decent multi-tap 2 Amps transformer 12/18/24V, 6mm / 4mm Heat shrink sleeves, wires/connectors and a good source for adhesives (address below)
   
   Address: Zenith Industrial supplies
    174/2 SP road
    Bangalore-560 002
    email:
    web: www.zenithindustrialsupplies.com
    phone: 080-22237208,22219659, 41140454

Nice

good work iwas searching for one since ages...

Thanks R/c Vish & Naatumach...

Good one, particularly the bucket-handle idea! 

Is the slicer (foam-cutter) fixed to the base plywood?

@ Swapnil: The bucket handle is CA'd (Fervi qwik) to the plywood. But the wire/slicer is not fixed- it runs through both the sides of the ply (2mm hole with brass nuts as guides) and then to the banana socket. At the socket a nut is used to hold the loose end of the wire in place. We can easily change the wire - 5mins max.

The initial plan was actually to use the bucket handle in a removable mode so as to also double up as a hand drawn slicer for aerofoils. This could have saved space for storage, without the bucket handle sticking out. Now that its fixed, it did help arresting the play which was too much, and for Rs50-100 one can easily cannibalise another bucket handle .

Thanks :-)
Arun

great job man

Thank you...