Seeking perfect speed and temp for foam cutting

[johnono]

I've been trying for a while today with our modifyed CNC, with vertical hot wire attachment to cut some foam shapes. Most times comes out very liney as if the speed and or temperature is off. Anyone have an idea of a solid combination for this

[cnccutter]

It depends on the type of foam your using, 1lb white bead foam I use 3mm @ 26.5 volt dc, pink foam 2mm @ 24volt dc..hope this helps..and that is with a 55", SS, .015" wire...

[Sam A]

It depends on the type of foam your using, 1lb white bead foam I use 3mm @ 26.5 volt dc, pink foam 2mm @ 24volt dc..hope this helps..and that is with a 55", SS, .015" wire...

Is that mm per sec?

Sam

[cnccutter]

"It depends on the type of foam your using, 1lb white bead foam I use 3mm @ 26.5 volt dc, pink foam 2mm @ 24volt dc..hope this helps..and that is with a 55", SS, .015" wire... "


Yes, mm per second........

[Sam A]

"It depends on the type of foam your using, 1lb white bead foam I use 3mm @ 26.5 volt dc, pink foam 2mm @ 24volt dc..hope this helps..and that is with a 55", SS, .015" wire... "


Yes, mm per second........

I am new to foam cutting. On cnc router I ususally work in the 5,000 to 7000 range.

Thanks

Sam

[esawyja]

Hope this will help you a bit, I use INCONEL wire, that seems to be the best

The wire that you are using, might be hotter at the edges than in the middle, because the part of the wire sticking out from either side of the block, doesn't have anything but air to dissipate the heat.

If you're dragging in the middle you're traveling too fast. If you slow down and get bubbling on the edges but it's good in the middle you have to increase tension and lower the heat. It's a fine line between perfect results and almost good.

Stainless stell wire stretches a lot when heated. You can try adding more tension to the wire but it will likely just stretch more or snap. Inconel will stretch far less when heated and in my personal testing will handle 11 Lbs of tension before breaking. I keep mine at about 4 bar of preassure, that will give you about 4kg of pull.


It all comes down to heat produced, or Watts (Watts = Volts * Amps). As a point of reference, the INCONEL wire I use is about 2m long and at 4Kg pull, for EPS foam, the voltage is set to about 65V and I do 380mm per minute

Check my website for more http://www.poly-cor.com