Plasma arc's look faceted when cut, not sure why?

[marbles]

Hi,

I'm cutting out the letter 'a' (arial font) in 3mm as test forms with my Thermal Dynamics plasma cutter. Letter size, approx 80mm x 50mm.

I've exported a dxf from Vectric Aspire using the fit curves to selected vectors (arcs) command. I brought the dfx info Sheetcam and cut using Mach 3.

Something isn't right, with the inner curves, they appear faceted and i'm not sure if its a problem with original vector file, (attached as the exported dxf) or, for example a velocity /acceleration and CV issue in Mach3. I'm currently using a velocity of 17,500 and an acceleration of 1750 in Mach3, perhaps an issue?

In Mach3 I currently have CV feedrate override turned off. CV is on, exact stop therefore off.

Its a process of elimination and i'm guessing its a vector file issue or Mach 3 feeds and speeds.

I'm all ears for solutions,

Thanks