Please help me with Parallel Finish

[kwolf]

Hi,

I have a problem in parallel finish.

I used parallel finish for a convex semi-sphere

(with 40 radius) with a 8mm ballnose and 4mm

stepover.In the Gap Settings I set the gap size

to 10 and selected to "follow surface(s)".

What I expected to do was the tool follow the

surface in a planar motion around the

semi-sphere so that the motion would be an arc in XY plane without retracting and plunging.

After regen, I saw the tool went up and down

in a spatial arc move between each pass.

I used the "Direct" in Gap Settings but the

motion was a line in XY,but unless I checked gap

motion for gouge ,it gouged to part.

How can I get such a path ?

[Tim Scott]

Change your gap size to about 300% of the stepover. This will eliminate the retract moves. I would also change your motion to broken and have the gouge protectors all on.

[cadcam]

Have you tried Scallop instead to stay constant to the surface.

[Guest CNC Apps Guy 1]

Relying on your description of the surface, I'd have to say scallop or flowline or contour would offer you the toolpath you were looking for. Try those in that order. I thing scallop will do exactly as you want though.

JM2C

[gstephens]

The only way to get the tool to follow the edges of a surface between passes is to define a tool center boundary and then set your gap settings to "Follow boundary at gap". You still get linear motion, but it follows the boundary within your surface tolerance.