Plasmacam settings: "slower on circles under (inch)"

[Jacampb2]

This question is pretty simple. Does the "slower on circles under (inch)" setting apply to all arcs or just circles? I've got my dimensional errors sorted out, but I have some radiused corners in a part and although it does very well, I have had to hand file to get them close to perfect. They are pretty small arcs, and I am wondering if I need to enter something in this setting.

That said, I did order the current video manual from plasmacam, but they will no longer sell the video manual for the 3.11 version of the software... So, much of the video manual is for design edge. I purchased it already knowing this though, I knew the mechanical sections would still be pertinent. I'm slowly going through the design edge info as well and trying to glean what is applicable to the older software version.

Thank you!
Jason

[rdj357]

Hi Jason,

I can only speak to Design Edge BUT that setting in Design Edge now reads, "slow on circles/curves under (diameter, inch). So I assume it also did that in 3.11 but the instructions were clarified. I don't have direct knowledge of this but I have a machine on 3.11 and assume that to be the case.

[Jacampb2]

Adjusting the setting seemed to do the trick. Thank you

[Joe Jones]

I have not experimented with that setting. I think it prevents the torch flame from distorting around sharp curves. When you change the direction of the flame, it bends slightly to follow the new path. The flame will take the path of least resistance, so it tends to flare out, like the spray behind someone on water skies. This would give you a bevel on the radius. By slowing down in small circles, it allows the flame to maintain a vertical cut path around the curve, giving a better, more vertical edge.

At least I believe this is the reason for slowing on curves. I could be totally wrong... There is a first time for everything .

Joe

[rdj357]

Holes with unacceptable taper are caused by flame drag. The flare is actually not out but in toward the center at the bottom of the sheet/plate. Slowing down allows the arc to straighten. It is important to disable height control when this speed is slowed because the rate the material is being fed under the torch is much slower.

https://www.hypertherm.com/en-US/suppor ... e-quality/

[Joe Jones]

Holes with unacceptable taper are caused by flame drag. The flare is actually not out but in toward the center at the bottom of the sheet/plate. Slowing down allows the arc to straighten. It is important to disable height control when this speed is slowed because the rate the material is being fed under the torch is much slower.

https://www.hypertherm.com/en-US/suppor ... e-quality/

This makes sense, since the heat IS in the center of the circle. First, the pierce, and then the torch runs around the circle. so the metal in the center of the circle would be hotter, and therefore more apt to yielding to the flame. So the hole ends up being cone shaped. Good explanation Robert! That make is clear.

Joe