Jagged/Uneven cuts on Letters

[jbirge23]

In search of Help....I am cutting out a sign with letters and some but not all of the letter have a jagged edge. I am not sure if it is the table or the design in the letter itself. I am using Fusion 360 to import the font "Arial Black" in Bold. I use Sheetcam for the gcode and mach3 to cut it out. I can't see where the edges are ridged in any of the programs. I cut this at 150 ipm on 16 gauge mild steel using Hypertherm 85 but I have the amperage at 45 on a crossfire table with no height control.

[adbuch]

Maybe you could post your dxf file so we could take a look.
David

[jbirge23]

This is the DXF File I am cutting out

[adbuch]

Your file looks fine with no problems. I would assume you are having some mechanical issues with your table, or problems with settings for your plasma cutter or Mach3. Perhaps you can tell us more. Do you have these same problems with other files? I would suggest trying to cut a simple square and a circle to see how the edges look. This might give us some more to go on.
David

[djreiswig]

If you have no thc, have you verified that you are cutting at the correct cut height of 0.06"?

[acourtjester]

I suggest you attach an ink pen to your torch and run a cut operation drawing on paper, this saves metal and will also show that you most likely have a mechanical problem. here is a video showing how it works, Use rubber band to hold the pen to the torch so it can slip lightly up and down.
Here is a simple pen test of squares and circles. I use a generic post processor like Mach 3 no plasma as you do not need the pierce operation.

[adbuch]

I suggest you attach an ink pen to your torch and run a cut operation drawing on paper

This is a good suggestion! Using the pen will tell you if your problem is mechanical or some other issue with your plasma cutter or settings.
David

[acourtjester]

Another simple test is to see if there is a mechanical problem is the push and pull the X and Y directions when power is on, this should not me any movement. With power on the axis should be locked as to movements and do the same thing with the torch. If it seems to have like a backlash in either direction it is not correct, I am not saying to push it around the room just to see if there is movement. What some have found is a loose gear or pulley in the drive assemblies.