Not sure how to set up roughing and finishing passes

[JetForMe]

I'm trying to make softjaws to hold a 4" round piece of aluminum. I'd like to do roughing and finishing passes on it. I created a 2D Adaptive Countour, with 0.5 mm stock to leave. Then I created another 2D adaptive contour for the same geometry, with no stock to leave.

It seems to do the exact same thing, just a little lower. Is that what I want?

The model is accessible, but I'm not sure if that gives you access to check the paths, etc.

Thanks!

[Laurens-3DTechDraw]

That is not what you want.

What you want to do is use the Adaptive to rough out the part because it is very quick.

Then use a 2D Contour to finish it.(Maybe witha horizontal to finish the bottom, or a pocket)

[JetForMe]

Thanks, Laurens.

So, do I do a contour or a pocket? 😉

The other thing I'm having trouble doing is setting the correct cut width. I'm trying to use GWizard calculator, and for my cutter (a 25.4 mm diameter 2-flute HSS, cutting Al 6061-T6551), an open pocket that's 25 mm deep, it tells me the cut width should be 12.7 mm! That's more than half the cutter. It also says 1556 rpm, 394 mm/min. That seems like way too much! (I realize that's not a Fusion360 question, but I'm trying to learn to use the two of them together).

[Laurens-3DTechDraw]

Not very familiar with GWizard.

A little more with FSWizard/HSMAdvisor.

But here some general info.

Adaptive works at it's best 40% and below width of cut.(50% and downwards is it's territory. It works with 80% as well but that's mainly used to make sure the cutter really doesn't ever get more load than the set width. But it's usually slower than a pocket at those widths)

Using adaptive clearing(or any constant engagement toolpath) you'll see speeds are possible beyond your expectation.(If your tool is max 2xD long I would recommend going even faster than that)

Keep in mind most tools nowadays can go faster than most machines, so what the tool can handle isn't necessarily what you can do on the machine.

Use coolant on aluminium cutting, when going to the edge of what is possible I strongly advise using coolant so the tool doesn't clog up.

I would use a 2D Contour with roughing passes on and select the stock contours so it doesn't cut air. Now you can set a wide step-over for the roughing passes(Floor finish) and if wanted a smaller step-over for the finishing passes if you wan to do multiple wall finishing passes.

[JetForMe]

I guess I'm just going to have to experiment a bunch. It seems like such an aggressive operation, I'm a little scared to try it. But maybe I can set up a few cuts on a large piece, each one more aggressive than the next, to get comfortable with it.