I have a hot wire cutter where the wire sits in steady place when cutting and I want to make some cylindrical fuselage for one of my model. Wondering what is the best way to do it. What I have in my mind for now is to place the foam steady and move the wire around it to cut the shape. Any expert advise here ??

I am not an expert in hot wire cutting, I have tried it only few times. But in my opinion its better to keep the cutter in one place as its difficult to handle with the wire connected to the power supply. It will be easier to hold the foam steady if you make some support under it when you are pushing/cutting it (like 2 no pipes of same diameter).

Yes.. the wire will be steady and still rotate around it... see my idea on paper... I think it should serve the purpose

Blue thing is foam piece

Now I need to make sure that both the wire holders (round pieces) move equally and at same pace

Shouldn't a static hot wire cutter and plywood templates on either side of the foam block suffice. You need to select a block of foam thats slightly bigger than the shape you are trying to form and then align and attach the templates to the two ends then run the foam thru the wire length-wise. If the fuse has multiple shapes along its length then make separate sections and attach them together. I doubt you want a cylindrical fuse with a constant section.

Multiple shapes == multiple cross sections (not a constant cross section).

Hi Vikas

What you will generate from the above set up will be frustum. please see the attached pic to add a handlebar (instead of the hand crank)..this will solve your problem of rotating both discs at the same time.

Regards
Ankur

thanks. I was thinking the same... great minds think alike I guess

TG, yes I gave that a thought and trust me it is much easy and smooth when you have full control of both wire as well as foam. I do not like to hold anything in my hand as they shake a lot

This site is good and explains the exact same thing that you are attempting and the links (those that work) at the bottom of the page are good too -
http://rcfaq.com/ANSWERS/modelbuilding/foamcutting.htm

Thanks. I will check that.