I'm building a hot-wire foam cutter, and want to use a wooden mount/base
board of some type, about 5 feet by 2 feet.
What's the most dimensionally-stable material to use? MDF, OSB, ply,
chipboard, something else?
Thanks,
-- Peter Fairbrother
Bob Minchin - 26 Apr 2009 20:23 GMT
> I'm building a hot-wire foam cutter, and want to use a wooden mount/base
> board of some type, about 5 feet by 2 feet.
[quoted text clipped - 5 lines]
>
> -- Peter Fairbrother
I'd suggest moisture resistant MDF - the green one
Use a couple of stiffners along the 5 foot dimension.
Seal with varnish.
Bob
Dirk - 26 Apr 2009 20:37 GMT
Peter Fairbrother heeft ons zojuist aangekondigd :
> I'm building a hot-wire foam cutter, and want to use a wooden mount/base
> board of some type, about 5 feet by 2 feet.
[quoted text clipped - 5 lines]
>
> -- Peter Fairbrother
I would prefer exterior 18mm plywood. I used what I had, 18mm chipboard
as base, MDF for the stand and wood for the arm. Just make sure the
wire is, or can easily be set square in 2D. A parallel guide and some
holes for cutting circles make it work easy.
Dirk
David Billington - 26 Apr 2009 21:45 GMT
> I'm building a hot-wire foam cutter, and want to use a wooden
> mount/base board of some type, about 5 feet by 2 feet.
[quoted text clipped - 5 lines]
>
> -- Peter Fairbrother
Don't know what your budget is but I have been considering Jabroc for
the likes of metal spinning formers. I'm pissed off with maple and other
woods changing size with humidity and the Jabroc is supposed to be very
stable . I want to find something that is easier to form than metal but
is stable, a number of current spinning formers are in steel or aluminium.
UK dist for the stuff is http://www.permalideho.co.uk/hydu.html
Peter Parry - 26 Apr 2009 22:21 GMT
>I'm building a hot-wire foam cutter, and want to use a wooden mount/base
>board of some type, about 5 feet by 2 feet.
>
>What's the most dimensionally-stable material to use? MDF, OSB, ply,
>chipboard, something else?
I made a simple one for a single job about 3 weeks ago - 22mm MDF
about 16 in long with the wire 2in above the surface (to slice some
polystyrene packing pieces). It had a pretty average sort of spring
tensioner on the wire. I now have a banana shaped baseboard where the
MDF has bent.
By the way if you want some resistance wire I've got about half a
kilometre of the stuff.

Signature
Peter Parry
www.remapsherts.org.uk
bigegg - 26 Apr 2009 23:26 GMT
> I'm building a hot-wire foam cutter, and want to use a wooden mount/base
> board of some type, about 5 feet by 2 feet.
>
> What's the most dimensionally-stable material to use? MDF, OSB, ply,
> chipboard, something else?
carton making formes (for cutting cornflake boxes from sheets of
cardboard)are made from 18-24mm cabinet grade plyboard (the stuff with
13+ layers which are about 1.5mm thick each) - it is INCREDIBLY stable -
formes are usually required to a tolerance of about .2mm - which might
not sound much to an engineering group, but it's f*ing close for wood.
It's available in 8x4 sheets - might be about 60! quid+ per sheet.
If you have any carton printing companies in your area, you *might* be
able to cadge an offcut big enough.

Signature
bigegg
gunsmith - 27 Apr 2009 10:18 GMT
> If you have any carton printing companies in your area, you *might* be
> able to cadge an offcut big enough.
>
> --
> bigegg
E-mail me Peter. I may be able to help depending on location.
max@hotmail.com - 27 Apr 2009 17:17 GMT
For ecomomy, can I suggest a visit to your local IKEA. They do 'spares' of
doors and shelves, basically bits left over, usually £1 or £2 depending on
size.
Various thicknesses and finishes, usually very flat and nicely smooth finish
on one side (often holes on the other though).
MH