[TheForge] Re:3 axis plasma cutting

Fri Nov 7 18:32:03 2003

Yup, CAD or however you use a puter to do a .dxf or whatever type of file
your cnc software uses can be a NIGHMARE!
Is this a table you built or bought? The optical trace is intersting and I
havent really seen one up close. Its got a computer in the loop somewhere??
how does it scan and find cuts within the main outline and how does it
determine, what to cut out first? or has that never been a problem, its
really only matters with small pieces that will drop to the floor through
the grate. What is the eye? do you need to illiminate the drawing? Does it
work on a scale up method, you draw at x and the machine cuts at 3x?
----- Original Message -----
From: "Ries Niemi" <[email protected]>
To: <[email protected]>
Sent: Saturday, November 08, 2003 5:19 AM
Subject: Re: [TheForge] Re:3 axis plasma cutting


>
> My plasma table, which is not cnc, but optical trace, has 3 axis
> motors, and I wouldnt think of having one without it. The third, z
> axis, is controlled by  a voltage sensing circuit that samples the
> voltage from the plasma power supply. It then adjusts the height
> accordingly, so the arc gap is always consistent. This means the torch
> is always cutting at its most efficient, but more importantly it will
> follow the warped surface of a piece of plate. Even though I built my
> water table flat, then levelled it in the shop, not every piece of
> sheet metal is flat. And then, when you start cutting it, it warps like
> crazy. Especially thinner stuff like 16ga- It can warp an inch or more
> in height as you cut parts out. If the plasma cutter doesnt have z axis
> adjustment, the torch either runs into the metal, and you lose
> registration, or it gets so high you lose contact and the torch goes
> out. Either way, bad news. So 3 axis is needed unless you want to
> manually adjust the torch height every inch of the way.
> Personally I prefer my optical trace table to a full on cnc one. I can
> do a full size drawing of the part up to 4' x 8', and it goes on the
> right side of the machine, then I lay a 4x8 sheet of metal on the water
> table on the left. It is a little slower than full cnc when you are
> cutting more than 20 or 30 parts, but I dont do that kind of quantity
> anyway very often. More often I will be cutting a full sheet in a very
> complicated pattern, once. I just finished a job where we had to make a
> 4 foot by 16 foot artwork panel out of 3/16" plate, and to troubleshoot
> the design in software on the computer would have taken twice as long
> as cutting it would have. Plus, I am an artist, and it is easy enough
> for me to draw what I want.
>
> ries
>
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