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Author Topic: Is there any way to have the pocketing ops ramp down rather than directly plunge  (Read 5806 times)

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Offline ERP

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I'm currently using my CNC Sherline mill to cut parts for another CNC conversion, and the parts involve several deep pockets.
Because the Z Axis on the Sherline is not the most robust thing in the world I have to set the plunge rate to some ridiculously low value, it's made worse because the wizard uses the plunge rate from the safe Z height, on a 0.8 inch pocket I actually spend more time watching the cutter plunge from the safe Z height than I do watching it cut.
Is there anyway in the wizard to have the cutter ramp in, or use the rapid speeds until it's closer to the material?
The circular and rectangular pockets in the NFS wizards do have a ramp in function- see the DRO labeled Ramp Angle

There is no setting to cause a fast Z to the surface, it makes the Z move from the rapid height to the cut depth at feed rate. It would be nice to add the fast plunge, its 'on my list' for someday.
I just did some testing of the pockets wizards. If the ramp angle is greater than 90 the rectangular pocket generates  crazy code, with a huge spiral. I will add a test to the number to clip it at 90.

the circular pocket seems to work Ok with big values of the ramp angle, it looks like the program just internally clips that to 90.

Offline ERP

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So the angle is relative to the cutting plane or to the axis direction?
i.e are bigger numbers more gradual or less gradual ramps?

Offline Bjorn Toulouse

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So the angle is relative to the cutting plane or to the axis direction?
i.e are bigger numbers more gradual or less gradual ramps?

I am very interested in some clarification on ramp angle, as well.


Rex
I am sorry to report that I do not understand the ramp angle. Brian wrote that code, and I really hope I never have to dig a bug out of it, because it is strange code.

I believe the ramp angle refers to the slope of the ramp the tool follows down- 90 is a straight plunge, 10 seems to take a long slow ramp, in one circle case it took more than one turn around the circle to get to full cut depth.

Best way to see it is to try a few examples, just changing the ramp angle, then use the preview button to see the code and the tool path.

Dont ask abut Ramp Dist- as far as I can tell it does nothing. Ill try to get Brian to explain it all to me someday.

Offline BR549

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The ramp angle was to allow a helix Z leadin to the start point of the cut. The angle sets the helix value per turn to equal the ramp angle. BUT as you see the math is not exactly correct as it will bust OUT and create some weird things. It works fair up to 15deg.

The circle pocket attemps the same thing with the ramp distance BUT it does not work at all from what I see. I think it got turned off(;-)

IF you would want some help to POSSIBLY correct it I have the time, Your call.

Just a thought, (;-)TP