Newbie- flowline 'tool down' continuity in mastercam 9

[davidsutton]

Hi I am experimenting with surface - finish - flowline toolpaths.

However when I backplot the toolpath I see that the tool is not being held down between the end of 1 pass and the start of the next. The tool is rising in Z for a few mm to clear the part, then moving across to the start of the next pass before going down in Z - before cutting the next pass. This very small 'hiccup' is causing my cnc machine to crash as it can't manage the change at the speed I am driving the rest of the normal surface flowline toolpath at.

Ideally I would like the tool to stay down on the surface of the part between passes - but can't find an option to do this.

I am cutting a 3d surface imported as iges into MCAM9.
I generate the flowline toolpath - with retract off -
The parts about 200mm by 200mm and 60mm deep.

Any advice gratefully received.

[Superman]

Start off by making the tool "Follow Surfaces" in gap settings and adjust the retract gap stepover from 300% of stepover to a value of say .15"

You may also have to use "Direction" to get a feed action onto and off the shape ( try [LH side]---45° plunge, -90° XY, 0.04", and cut direction----[RH side retract] 90° plunge, 0° XY, 0.04",cut direction )
This should rapid to a point 0.04" at 45° from the 1st contact point of your surface, feed onto the surface then do your paths, the retract part will feed vertically for 0.04" before rapiding up to the retract plane.

Do the direction changes after you get the surfacing paths correct

[davidsutton]

Hi Superman - thanks very much for the reply... using your input and re-evaluating the quality and direction of the isoparms on the surface - I realised that my iges imported surfaces were -"crap". Now using your suggested values and improved surfaces I think I have got much closer to a solution ( I
started importing iges hemispheres and then working back towards my complex surfaces).
Cheers again for your input - since joining cnczone a year ago I have been really impressed by everyones can do spirit and I look forward to knowing enough one day so that I can start helping others out as you helped me.