Best tool path for this one specific hole

I have figured out most of EstlCAM except this one toolpath. I have a 27mm round hole (like a pocket maybe?) with 1mm left at the bottom. I also have a 23mm hole in the center of the 27mm hole that goes all the way through the material. I setup a helical drill on the 23mm hole and a regular hole on the 27mm part leaving the 1mm lip and I was left with a very thin edge. The image shows what was left. It was easy enough to trim but what is the best way to do a toolpath for this type of milling?

  1. Define the center as a “part”

  2. Define the outer circle as a “hole” - select “Pocket” and “island”

This will pocket cut the part between the inner and outer circle.

You can then define the inner circle as a hole, and cut it out after.

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Awesome, I will give it a go later. Thanks for the help!

I’d helical drill a 27mm hole that leaves a 1mm floor, then helical drill a 23mm hole starting 2mm from the full depth.

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A word of warning. Estlcam will do some bad things if your tool diameter is greater than the distance between the 2 paths. In this case, you should just define the outer path as a hole, then cut out the inner path.

When going all the way through material, I don’t like using the helical drill because it makes a lot more chips than necessary. This fills more space in your shop vac, is harder on your cutting bit, and takes more time.

With a 1mm floor like that, I would probably arrange the machining order to cut the center out first, then do the pocket/island cut for the rim afterwards. (This is how I did it for the bearing holes in my spool holder.)

Something like this. Assuming quarter inch thick board.
test.zip (4.1 KB)

Thanks guys, with y’alls help I was able to figure it out. I ended up doing a pocket hole on the large circle leaving a 1mm floor and then cutting out the center hole through the material doing another pocket hole starting at 2mm. Worked great, and doing the pocket holes ended up being faster than the helical drill.