Hot Wire Foam Cutting By murrayec

[murrayec]

Hi

 

Here are the photos of my home spun Hot Wire Foam Cutter;-

 

The table was based on the size of the Proxxon one, great for small stuff but not for big sheet. After making and using this I recommend a table of at least 3 times the size if you have the space, and at least 400mm high- that is the length of the cutting wire.

 

 

 

 

The fence guide is shown;- 30mm aluminium angle fence clipped to the board edges. The table is marked out with lines at 10mm ctrs to aid squaring the fence to the table if required. The arm is 19mm aluminium rod with ms fixings, the upper hot wire connection to the arm can be moved back to set the wire at an angle to the table- this arm allows a max angle of 30deg.

 

A sliding fence is shown;- for trimming foam lengths square to the left edge of the board. Its two aluminium angles stuck to a 45deg set-square, one faces down to catch the edge of the table, the other facing up to push the foam into the wire. I also use an adjustable set-square to set different angles for cutting.

 

 

Note- you need some form of adjustment on the arm so that you can square up the cutting wire perpendicular to the table and perpendicular/parallel to the left edge face of the board. I always use the left edge as my datum to keep things square.

 

The last photo is of the controller;- it's a two stage heavy 6v transformer, it works 6v and 12v. The twelve volt is achieved by connecting the two stages together giving 12v at high current- that's controlled by the toggle switch.* The stat varies the voltage in both 6v and 12v modes, its just a standard household light dimmer switch.

 

 

12v at high current is used with the thicker hot wire material, it's about .8mm and holds the shape its bent into, even when glowing RED!. I tried to run the system with the 12v workbench power supply under my controller in the photo- it was fine with the thin wire but it could not heat the .8mm wire at all and began to make a loud hum! So I built my own.

 

When cutting irregular shapes I print out the part from the drawings on heavy paper, cut it out and then pin it down on the foam and use the edge of this template to cut out the foam shape. It takes a bit of practice to cut the foam like this, trying to rotate the foam on the table, move it by the wire at a constant rate and keep to the edge of the paper template- practice makes perfect.

[WRENNEIRE]

I recommend wearing rubber boots.........

[Broithe]

I recommend wearing rubber boots.........

 

Are you getting your Forums confused..?

[murrayec]

Hi WRENNIE

 

.....if your thinking of the high current all is cool, if not- the mind boggles...

 

Eoin

[Georgeconna]

Mad stuff, Just add a flux capacitor and your off!!

[burnthebox]

Scissors usually works for me,

[murrayec]

[DiveController]

Wow! That's very impressive, Eoin. Did you use the light saber for that?

[BosKonay]

Wow! That's a work of art!

[closetmodeller]

Most impressive.

[murrayec]

Hi All

 

Thanks for the great comments...

 

and here it is finished, sporting one of BK's DARTs

 

 

 

 

 

Eoin

[Broithe]

Health & Safety! Get the railings on....

 

Nicely done, though.

[Weshty]

[ATTACH=CONFIG]19150[/ATTACH]

I am liking that a lot. The unfinished one shows the construction work more clearly. Nice one Eoin:)

[murrayec]

Hi Broithe

 

Yes H&S is a problem, though as the station building is not erected yet! the bridge wont be used for some time, which will allow the etching department of the works to get things right....

 

Weshty

 

Here are a few more construction shots for you

 

 

 

Eoin

[murrayec]

Hi

 

Here are a few photos of the set-up for an N Gauge Martello Tower cut out with the hot wire cutter;-

 

This shot shows the exploded components for one tower and a second assembled. The tower is done in two sheets so that the door recess can be cut in the lower section.

 

This shot shows the components just about to be glued together

 

This shot shows the tower set up on the machine ready to slide in under the wire and cut the top parapet chamfer. The tower is held to the cardboard template by a drawing pin so the tower can be rotated under the wire when in position. The cardboard with tower is slid in under the hot wire up to the mark, taped down, and then the tower is carefully rotated

 

This shot shows the parapet cut

 

Eoin