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How can I figure out the ramp angle or helix I should use for entry into a cut?

Answered Closed

The Cam software I use creates very nice constant tool engagement toolpaths. When it feeds into a pocket initially it does this in a helical motion. The tools I use are centre cutting 4 flute solid carbide. I generally use the full flute length if required so DOC could be 2D or more.

On the Helical feed, if I don’t specify a ramp angle, the tool takes one full revolution to depth, which seems a bit excessive. I can specify a ramp angle. Does anyone have any idea what sort of ramp angle or helix I should use for entry.

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Best Answer

Set up a cut like you were going to slot. Say you have a 1/2″ EM. Use GW to tell you the max full slot depth based on the material and cutter. For aluminum, let’s say a 1/2″ 2 flute HSS EM will go up to 1″.

Okay, let’s further assume you need to go deeper than that (if not, you can do it in one revolution of the helix), that depth of cut is simply how far you can go in one revolution of the helix.

Now bring up the Interpolation Mini-Calc and enter the hole diameter, say 2″. As soon as you hit enter, it tells you the ramp angle will be 23 degrees on the example given. It also gives you the geometry-adjusted feedrate. Hit the Adjust button and now you know the helix angle plus the feeds and speeds for the helix.

Beware indexable tooling which has clearance issues that lead to ramp angle limits.

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