Re: plasma accuracy

> machine. "
>
> And, in reading the notes, I think Caudlet is saying overall and

Jim

> C. is saying plus or minus. That means to either half Caudlet's or
> double Jim's numbers.
>
> The question becomes one of cost. How precice can you afford to

go ?

>
> Dave

I was referring to kerf width (the smallest amount of metal you can
remove with the flame). As for accuracy to an edge that has a lot of
variables like cut speed, material thickness, direction of cut and
any tilt of the cutting tip. I plug in .065 as the diameter of my
plasma kerf in the CAM which offsets the cuts by half of that so in
theory the edge of the kerf is on the object's cut line. Plasma will
waver back and forth depending on some or all of the factors listed
above. The flame is "hungry" in that It will seek out metal to
vaporize so if you linger too long it will start to cut surrounding
metal. That is why smooth, even motion is important. while the basic
machine accuracy is part of the equation, the nature of conventional
plasma is many times less accurate. My machine with servos and
ballscrews (yes, I found them in a dumpster ...sorta) will hold
about .004 accuracy across several feet and has a repeatability
of .002. If I can hold .025 to .030 edge accuracy on a plasma cut I
go get a beer and celebrate!