Hi,

i'am looking for an help with cutting a gcode in Mach4 where an "Artwork" from realy short lines is. (Spline that is not possible to convert in Arcs and lines).

In Mach3 works this gcode well without problems, ibcan just modify the CV Dist tolerance and the machine cuts the gcode as well.

In oposite i can not cut the same code in Mach4. The terrible toolpath (green) is seen in Mach4 and the same are thr movements of the machine.

Buyed a Mach4 license a year ago, but i mus still work with Mach3, because can not find any working solution. Please help.

Is some way to setup Mach4 general CV Dist tolerance? some parameter in .ini ?

1.as i see even in mach 3you have some problem with yours shape( final position not same as first)
2. i had a lot of problems with cv with mach4 i can suggest you: try increase the acceleration /deceleration
    but i can tell you from start this solution its problem because mach not support  jerk and its big problem with increase acceleration
    but for us this the only way we solve all that cv problems with mach4

1. .. it is not exactly the same programm, there is no problem with the shape.

2. I do not think ot is about jerk, i have the jerk supression function in the servos. The problem looks to be in interpolation trought the points. Mach4 do not support cutting trought many points ? The same problem see if i try to cut some 3D complicated sculptures. There is no othere way than using short lines from an CAM.It is not a normal behavior of an CNC controller. I neee to decrease a general tolerance of the Mach4, but can not find where to do it.

I didn't say it's because jerk ,I said because there no jerk in Mach4 you must put very very poor acceleration ,then the cv become strange behavior

need to modify this parameter in Mach4.  "Toolpath error tolerance".

It can not be true that Mach4 do not have any jerk and works with zero tolerance.

Can you show yours acceleration deceleration ,max speed parameters?

i tried to go harder or softer (higher/lower Acc, ), but the motion is still extremly jerky, unuseful for milling on this contour.


I tried to recalculate the contour in CAM for lower and higher amount of points, lower and higher tolerances, but without any good reasons.

Can you send me some curves oor dxf I'll try?

here is the Gcode


If i read the gcode in NCPlot, the toolpath is nice and smooth.

If i read that file in Mach3, also smooth, and smooth running.

If i read that file in Mach4, it looks like if there are 50 Point per profile, but there ar at least 1000 points per profile.



I'am running in mm not in inches, maybe some bug ? Wrong readed file ?  new instalation of Mach4 needed ?     ¨It happens every time i read some file with short lines. Don't seems to be a problem with CV i think.

I'll check tomaroow morningi also use only mm