Advice to avoid slotting

I have a large rectangle of 6mm aluminium plate and need to cut a slightly smaller rectangle out from the center leaving me with a bezel. Adaptive clearing or pocketing would take a prohibitively long time and also turn a usefully large waste center piece into chips. I had though about using a jigsaw to rough out and then a contour cut to clean up but if I can let the Nomad do the whole lot then all the better. If I did slot then would a slot width of, say, 1.5x the cutter width help so it is actually a very narrow pocket?

Actually, you only need 10% or so of the diameter to reduce tooling engagement (and that’s mostly for the sake of the software doing the calculating).

Can you elaborate?

I thought it was mostly for the sake of preventing friction & chip buildup.
If the stepover is 50% or greater, then 10% or 50% should take the same time to calculate. It’s just 2 passes either way.

The things you can’t control, or are a lot more tedious to control, is the order of cut & tool direction.
Ideally I would want the first pass on each level to be the clearance pass, away from the ‘good’ wall.
And I would want the tool to conventional cut the clearance pass, and climb cut the finish pass.

Even 1% wider is sufficient to get enough clearance to reduce tooling engagement — but for complex geometry, the CAM program may not see that as sufficient to allow the tool to fit.

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I guess this is due to rounding errors etc (software tolerance in F360 speak).

It won’t make any difference to the FnS I can use for the clearance pass so
it doesn’t matter whether what percentage diameter I use. I guess slightly
higher could improve chip evac… so I’ll stick with 50% or so.

But thanks for validating that this is a reasonable way forward.

I added an offset to circles I was using to cut out some coasters so that I could do a pocket and then the final contour passes. With one minute left in a 58 minute job my favorite 1/8 bit broke. It is a Slim Jen from Cadence.

Earlier in the job some of the pocket clearing passes had too high DOC although still within specs for the bit, but the contour pass was .0625. I think the problem was that during the portions of the cut that were too deep I lost some steps in X and the stress of the cut during the circle was too much. I finished the job by disabling all the other paths and switching to #102.

I did a job after this with #102 and a .03 DOC for pocket clearing on some walnut and it took a long time but nothing broke.

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