[GregGleason]

I am trying to mill a centering ring from plywood for my hobby from Rhino 4.0 to DeskProto to Mach3.

I am still very new at milling, so I still have a lot to learn.

The outside is 2.915" and the inside is 1.640" on a 0.250" thick plank of plywood.

I have used a waterline strategy, which is mostly working.

The problem is that cut seems to go beyond the bridge points. The workpiece is coming off, so it never finishes the roughing, let alone the finishing.

I only need it to cut around the circumference.

Can someone provide some suggestions?

Greg

[ger21]

Your really using the wrong CAM software for a part like that. A 2D CAM program would cut that part about 15x faster.
Sorry, but I don't have any DP advise.

[awerby]

You need to reset your segment so that the ends of your supports are outside the segment, and set the borders to "no extra". Assuming you don't really need to remove all that material, you could use a circle instead of a rectangle for your segment (use Freeform Segment) and get done a lot faster. Just make sure you leave enough area outside your disk for the tool to get down in there.

2.5D software probably would be quicker, but few of the low-end 2.5D programs would provide the supports, or avoid them when cutting out the disk.

[GregGleason]

Andrew,

Thanks for that tip. I tried your suggestion and I think that it might work. I have attached a screen shot.

Greg

[awerby]

That looks like it should work. To save even more time, think about extending the supports inward, and putting another sub-segment circle in the middle of your doughnut that overlaps them. This will avoid spending time removing that entire area, and confine cutting operations to the area between the circles (the inner circle will be treated as an "island".) You should end up with a disk inside that hole, also held in place by the supports.

[GregGleason]

Andrew, that's another great tip. Attached is the new milling strategy.

Greg

[awerby]

Looking good, Greg. Now you're cooking with gas!