Part 0012

I am going to make this part out of aluminium alloy.

The first thing is to saw out a piece of Delrin as the sub table and pocket a shape oversize, for the aluminium rectangle to fit in. I can specify to cut a sketch oversize by putting a negative value in the "material allowance" box. I am using a development version of HeeksCNC, which includes a commercial pocketing library written by Lou Lavery, that I am planning on reselling as an option for HeeksCNC when it is ready. I am trying to write a free version of pocketing, but it's not easy.

Pocketing Reorder

Now, in HeeksCNC, you don't have to worry about which direction ( clockwise or anti-clockwise ) your sketches are drawn. Simply select them all, do "Combine Sketches", then select that resultant sketch before making a pocket operation. The python script now uses the new function area.Reorder(), which checks which curves are inside which and reorders their direction ready for offsetting.

Commercial Pocketing Software

I have been asked to help someone make a commercial Windows dll to do pocketing like in HeeksCNC. Unfortunately the polygon offsetting used in HeeksCNC is derived from the "kbool" software, with its' GPL license, so it has to stay free. I have done quite a lot of work recently to adapt the "Clipper" polygon clipping library to do offsetting too.

Here are my results.
The first picture was made using kbool.

The second picture was made using my modified version of clipper.

More dialog work

I tidied up the pocket dialog.

I noticed that if the viewing units are in mm, but the NC output units are inches, then all the values in the dialog are in mm ( which is what I expected ) except for the tool description. I am reluctant to change it because the tool decription is used in the comment in the NC code comments, so maybe it should be in NC code units for that.

Pocket operation now uses a dialog

I have added a pocket operation dialog. When you select a sketch and add a new pocket operation, you get this dialog. When you OK it, the pocket operation gets added. When you double click the operation in the tree, you get the dialog again. When you select a different control, or press Tab to go to the next control, a different picture is shown.

opencamlib operations working again in HeeksCNC

The 3D operations weren't working in HeeksCNC because of some changes that had happened to the syntax in opencamlib . They work OK now. Here is an "attach operation" modifying the toolpath of a pocket operation.

zig zag option for pocket operation

I added a "use zig zag" check box to the pocket operation in HeeksCNC. It seems to work really well. It works by making a rectangle for each slice of the area. It does a boolean "intersect" of the rectangle with the area to pocket. Then it loops through the resulting spans. It starts with the straight line at the bottom of the result and adds all the spans until it gets to the top of the slice. I also added a "zig angle" value too.