Trying to 'face' using a trace toolpath - problem establishing lead-in point

[t.g.mandel]

I am machining several frame-like parts from a large square of aluminum plate.

I need to reduce their thickness, but rather than face a large area of the stock, I thought I would try to just follow the frame's top face. I plan to use a dual insert PCD cutter that will face the full width of the narrow frame.

I had success making the toolpath by creating a separate sketch of a rectangle that was in the centre of the frame. The problem is that the trace toolpath is not really designed for this purpose, and I am finding limited options for a lead in path to the frame.

I came up with the idea of adding a line to the sketch which starts off the stock and connects to the rectangle in the sketch - see below:

However, I can not get the lead-in to start at the line. I thought it might be that the line and rectangle were separate sketch features, so I went back and made the sketch one open chain. But no matter what I try the lead-in is always at the corner of the rectangle and not the outer point of the line.

I would appreciate any insights or alternative methods to accomplish my goal of having a facing operation follow a part feature.

[g_bergwerf · Accepted solution]

Hi t.g.mandel,

Usually in a situation like this, I'll use a 2d contour operation.

I'll then select either the inner or outer edge of the frame for my geometry.

Then I'll use negative radial stock to leave to make the cutter extend beyond the edge.

Since its a contour toolpath you'll have access to regular leads.

I've attached your file but added a 2d contour like i described.

Hope that helps you,

-Gerrit-Jan

[t.g.mandel]

Thank you for the quick and helpful reply, and for taking the time to provide the example.

This will work perfectly, and the negative radial STL feature will allow for accurate fine tuning of centre line position.

Thank you again,

Tom